Re: [DUG] Strange behavour - WebBrowser and ADO

[Dennis Chuah]

Folks,

Hi.  You guys may want to know the solution to this issue.  If you call 
TWebBrowser.ExecWB, after it returns, you will find that the EmptyParam 
global variable is no longer the same value.  It gets set to Unassigned. 
There is a bug logged on Quality Central:

http://qc.embarcadero.com/wc/qcmain.aspx?d=61255

This is perhaps not a VCL bug per se, but more of how Delphi calls dual 
interface methods and perhaps a bug in IE itself.  The workaround is simple, 
bypass TWebBrowser.ExecWB and call the browser's ExecWB method directly, 
passing in dummy OLEVariant variables initialised to the same value as 
EmptyParam.

Regards,
Dennis.

--
From: "Edward Huang" 
Sent: Wednesday, August 03, 2011 7:39 PM
To: "'NZ Borland Developers Group - Delphi List'" 
Subject: [DUG] Strange behavour - WebBrowser and ADO

> Hi,
>
> We have just noticed a strange behaviour recently, which I couldn't figure
> out how to resolve.  The issue could have been there all the time, just we
> didn't used the sequence before.
>
> We have an application, uses ADO to connect to SQL Server database.
> Components used include TADOQuery, TADOStoreProcedure etc.  It all works
> fine.
>
> Then we have a form which contains among other things, a TWebBrowser and a
> 'Print' button.  On click event of the Print button, we call:
>
>  WebBrowser_Help.ExecWB(OLECMDID_PRINT, 1);
>
> Which will bring up printing dialog and print the contents of the
> TWebBrowser component.
>
> The strange thing is that after the Print button clicked, subsequent 
> access
> to database via ADO components all failed with Exception.  The following 
> is
> a sample exception message:
>
> Arguments are of the wrong type, are out of acceptable range, or are in
> conflict with one another
>
> I have tried to close ADOConnection, reopen etc, the database access still
> doesn't success.
>
> Anyone knows how to fix this issue?
>
> Edward
>



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Re: [DUG] Sending notification between programs

[Dennis Chuah]

John,

Hi.  What I'd suggest is you use FILE_NOTIFY_CHANGE_FILE_NAME.  Program A 
creates the file and writes to it using a temporary filename.  When it is 
done writing, it renames the file to something that program B recognises. 
This will trigger a FILE_NOTIFY_CHANGE_FILE_NAME and B can then pick up the 
file.  Actually, creating the file will also trigger a 
FILE_NOTIFY_CHANGE_FILE_NAME, but A is using a temporary filename that B 
does recognise, B ignores it.

Regards,
Dennis.

--
From: "John Bird" 
Sent: Wednesday, August 18, 2010 6:02 PM
To: "NZ Borland Developers Group - Delphi List" 
Subject: Re: [DUG] Sending notification between programs

> The property
> FILE_NOTIFY_CHANGE_LAST_WRITE
>
> looks like a possibility, as if structured data has just been written to a
> file this event should be triggered.   The only gotcha seems to be that 
> the
> better the caching is the less likely the event will fire - according to 
> the
> help.  Tricky.
>
> John
>
>>
>> John,
>>
>> Hi.  What you want to use is WinAPI: FindFirstChangeNotification,
>> FindNextChangeNotification and FindCloseChangeNotification in program B.
>> Essentially, A writes to a file, and renames it.  This causes the handle
>> returned by FindFirstChangeNotification to be signaled.  You can test for
>> this using a loop and WaitForSingleObject / WaitForMulitipleObjects.  You
>> can even specify a timeout in the WaitXXX calls so that B wakes
>> periodically, even if there are nothing signaled.  When the WaitXXX
>> function
>> returns, you can check for the existence of the file.
>>
>> Regards,
>> Dennis.
>>
>> --
>> From: "John Bird" 
>> Sent: Wednesday, August 18, 2010 4:43 PM
>> To: "NZ Borland Developers Group - Delphi List" 
>> Subject: [DUG]  Sending notification between programs
>>
>>> Which way would you favour to do the following ?
>>>
>>> I have two Delphi programs (A and B) that I will pass data from A to B -
>>> I
>>> will probably use  a file to put the data in because its quite
>>> structured.
>>> B will sleep on a timer loop until this something is triggered.
>>>
>>> What I want to do is send a simple notification from program A to B that
>>> there is something to do - i.e. trigger an event in B to wake and do
>>> something to process this.
>>>
>>> There are various ways I could communicate this notification
>>>
>>> 1 - Has to add minimal overhead of size and processing to programs A and
>>> B
>>> 2 - A can tolerate B not responding immediately without freezing but
>>> preferably will know
>>>
>>> The ways I have considered to be candidates are
>>>
>>> a - Windows messaging
>>> b - TCP/IP Indy   (which could send the data too.  (adds complexity of
>>> needs to be done in a thread to not affect the main program A)
>>> c - make program B a DLL
>>> d - Roll my own - make a timer in B which polls for for some condition
>>> and
>>> otherwise continues to sleep
>>> e - something else.
>>>
>>> Kindly share your favoured options how you might do this.
>>>
>>> John
>>
>>
>>
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Re: [DUG] Sending notification between programs

[Dennis Chuah]

John,

Hi.  What you want to use is WinAPI: FindFirstChangeNotification, 
FindNextChangeNotification and FindCloseChangeNotification in program B. 
Essentially, A writes to a file, and renames it.  This causes the handle 
returned by FindFirstChangeNotification to be signaled.  You can test for 
this using a loop and WaitForSingleObject / WaitForMulitipleObjects.  You 
can even specify a timeout in the WaitXXX calls so that B wakes 
periodically, even if there are nothing signaled.  When the WaitXXX function 
returns, you can check for the existence of the file.

Regards,
Dennis.

--
From: "John Bird" 
Sent: Wednesday, August 18, 2010 4:43 PM
To: "NZ Borland Developers Group - Delphi List" 
Subject: [DUG]  Sending notification between programs

> Which way would you favour to do the following ?
>
> I have two Delphi programs (A and B) that I will pass data from A to B - I 
> will probably use  a file to put the data in because its quite structured. 
> B will sleep on a timer loop until this something is triggered.
>
> What I want to do is send a simple notification from program A to B that 
> there is something to do - i.e. trigger an event in B to wake and do 
> something to process this.
>
> There are various ways I could communicate this notification
>
> 1 - Has to add minimal overhead of size and processing to programs A and B
> 2 - A can tolerate B not responding immediately without freezing but 
> preferably will know
>
> The ways I have considered to be candidates are
>
> a - Windows messaging
> b - TCP/IP Indy   (which could send the data too.  (adds complexity of 
> needs to be done in a thread to not affect the main program A)
> c - make program B a DLL
> d - Roll my own - make a timer in B which polls for for some condition and 
> otherwise continues to sleep
> e - something else.
>
> Kindly share your favoured options how you might do this.
>
> John



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Re: [DUG] faster TreeView

[Dennis Chuah]

Hi.  Check out Virtual Treeview .  Very fast and 
very flexible.  The programming paradigm is different, so there is a leaning 
curve.  But once you get over that, you will find that it is the best 
treeview / grid component ever.

Regards,
Dennis.

--
From: "Rogério Martins" 
Sent: Saturday, July 24, 2010 12:42 AM
To: "NZ Borland Developers Group - Delphi List" 
Subject: [DUG] faster TreeView

> Hi all !
> Does any one know a TreeView component faster than the original borland
> TTreeView when adding, deleting nodes (many at once) and changing its text 
> ?
>
> Thanks
>



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Re: [DUG] Script Engines for use with Delphi

[Dennis Chuah]

Python for Delphi works very well.  Python is open sourced and there is 
great support.

Javascript (and vbscript) via Windows Script work fine too.  Not as 
functional as Python but there is a bigger user base.

--
From: "Alistair Ward" 
Sent: Monday, March 22, 2010 3:03 PM
To: 
Subject: [DUG] Script Engines for use with Delphi

> Hi,
>
> We're looking to integrate a scripting engine of some sort into a Delphi 
> app.
>
> Possibilities are:
> 1) DelphiScript from RemObjects
> 2) Python for Delphi
> 3) TMS Scripter Studio
> 4) JavaScript (?)
>
> Has anybody had experience with using any of these products? I am 
> particularly interested if anyone has managed to integrate JavaScript with 
> a Delphi app.
>
> Thanks,
> Alistair Ward
> Forum 8 NZ Ltd.
>



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Re: [DUG] MSSQL with D2007

[Dennis Chuah]

John,

Hi.  If you do not use data aware controls, or otherwise need TDataset, then 
I would recommend that you use ADO directly.  Fast, simple, and does not 
have the overhead of TADOConnection, etc.  I normally import the type 
library into Delphi, but you can also use the one that comes with Delphi.

Regards,
Dennis.

--
From: "John Bird" 
Sent: Tuesday, January 19, 2010 8:04 PM
To: "NZ Borland Developers Group - Delphi List" 
Subject: [DUG]  MSSQL with D2007

> Been trying to connect to MSSQL 2005 with DB Express (TSQLConnection and 
> TSQLQuery), but cannot get it to work, we are getting an access violation 
> at address 017E0913  in DBXMSS30.DLL  read of address 0182
>
> Using instead ADO (TADOConnection and TADOQuery) works fine, but is slow - 
> 7000 records takes 30-40 seconds to load.
>
> The rest of the components the same  (ie TDatasetProvider, TCLientDataSet, 
> TDatasource)  ie have been pointing the Datasetprovider at either the 
> TADOQuery or the TSQLQuery
>
> Also tried the TSimpleDataSet, has the same error as the first sentence.
> All the queries allow me at design time to set active to true 
> successfully, but still crash when the dataset is set to open
>
> Does anyone have any idea what could be going wrong?
>
> And any recommendations of best combinations you prefer for MSSQL with 
> D2007.   I am new to connecting D2007 to MSSQL so willing to do it 
> whichever way works best.
>
> John



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Re: [DUG] Just for the odd job.

[Dennis Chuah]

I don't belief it ... there are actually people still using Delphi 4.  It 
has to be the next most buggy version of Delphi apart from 8.  You can even 
get different EXEs just by compiling at different times of the day!

My advise then would be for you to upgrade, even if it is just to get a more 
stable version of Delphi!

Saying that, you will not be able to use your D4 components unless you have 
the source.  Even so, part of the VCL have changed and they may need some 
work to get going.

- Original Message - 
From: "Marshland Engineering" 
To: 
Sent: Wednesday, July 15, 2009 10:30 PM
Subject: [DUG] Just for the odd job.


I have been using Delphi 4 for the few projects I have.

Embarcadero Technologies are a offering 2 for 1 purchase.

Why is Delphi 2009 - Professional Upgrade and Delphi 2007 for Win32 R2 
Professional Upgrade both the same price.

Is it worth the upgrade.

>From what I understand  2007 and 2009 makes bigger exes and are they is 
>compatible with Ver 4 software.
I have quite a few third party ver 4 components installed on my system.

Thanks Wallace












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Re: [DUG] PDFCreator

[Dennis Chuah]

A better PDF creator is Primo - just google for Primo PDF.  Its freeware and 
produces better quality output.


- Original Message - 
From: "John" <[EMAIL PROTECTED]>

To: "'NZ Borland Developers Group - Delphi List'" 
Sent: Thursday, November 08, 2007 8:09 PM
Subject: [DUG] PDFCreator


Hi Eion

This PDFCreator is really fantastic! Thanks for the tip Eion. The only thing
I don't understand is that, after choosing the PDFCreator as output device
and printing the document, it starts installing SmartSound QuickTracks
Plug-in. Although I cancel this all works fine. Is this normal? Is there any
way to disable this "feature"?

Cheers
John

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Eion McIntosh (Christchurch)
Sent: Thursday, 8 November 2007 2:09 p.m.
To: NZ Borland Developers Group - Delphi List
Subject: RE: [DUG] Quick Reports


Hi

We generally are now using PDFCreator which is freeware and can be found at
http://www.pdfforge.org/products/pdfcreator/. If just installs as a printer
and when you want to create a PDF, just change your printer to the
PDFCreator printer and print as normal. I've used it numerous times for
various projects and it works great. Plenty of different options for setting
it up for saving, auto-saving, filename, PDF Format and DPI settings.

Regards
Eion McIntosh
PPCS Ltd








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Re: [DUG] Expression Parser/Evaluator

[Dennis Chuah]

Try Python for Delphi.  It can do all that you want below, plus a lot more. 
And besides, the price is right!


- Original Message - 
From: "David Brennan" <[EMAIL PROTECTED]>

To: "DUG" 
Sent: Wednesday, October 24, 2007 4:18 PM
Subject: [DUG] Expression Parser/Evaluator



Hi,



Another question in the popular family of "what is the best component 
suite

for X?".



Can anyone recommend a good expression parser/evaluator? Ideally a bit 
more

than just mathematical expressions, we would like it to handle logical
evaluation (ie Booleans), IF statements and ideally strings (primarily for
comparison within boolean IF conditions but if the parser/evaluator could
handle strings as results then all the better). We don't need any loop
constructs or more advanced program control constructs. We would probably
like to be able to define our own expression functions but the user 
probably

doesn't need to be able to.



Quality (ie reliability), functionality and availability of source code 
are

our main criteria here. Price isn't going to be so much of an issue unless
they are hideously expensive or there are multiple good options to choose
between.



Any recommendations? Warnings on what to avoid?



Thanks,

David.



























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Re: [DUG] Debugger - variable values

[Dennis Chuah]

The method will be eliminated by the linker if you do not reference it in 
your program.  Try Text, or SaveToFile().


- Original Message - 
From: "Wayne Roser" <[EMAIL PROTECTED]>

To: "NZ Borland Developers Group - Delphi List" 
Sent: Wednesday, August 08, 2007 9:05 AM
Subject: Re: [DUG] Debugger - variable values



Situation
Using D6. Optimization off. Frames on. Allow function calls in new watches 
on.


Problem
Still cannot see CommaText: function TStrings.GetCommaText eliminated by 
linker. What else must I

set?

Wayne

NZ Borland Developers Group - Delphi List  on 
Tuesday, 7 August 2007 at 11:22

p.m. + wrote:


To see the contents of a string list, a quick way (turn on allow function
calls):

srcTemplateInputLines.Text or
srcTemplateInputLines.CommaText

to see an individual element:

srcTemplateInputLines[0], or srcTemplateInputLines[1], ...

- Original Message - 
From: "John Bird" <[EMAIL PROTECTED]>

To: "'NZ Borland Developers Group - Delphi List'" 
Sent: Tuesday, August 07, 2007 7:16 PM
Subject: [DUG] Debugger - variable values



There is something I wanted to know about the debugger.I love the
debugger being able to examine the values of variables in code.  I have
also
got used to that it just won't show the values of some.   Loop pointers
often won't get shown, particularly as you say after the loop is 
finished.
Some others as well, I assume because of optimisation, or sometimes 
simply

because it is time to reboot the PC or restart the IDE.

The other type I had got used to never seeing the value of was a member 
of

a
stringlist, eg

   TmWorkLine1:=srcTemplateInputLines.Strings[TemplatePtr];

The debugger would just show srcTemplateInputLines | () as the value.
However one day, and it has only happened once, it did show the value of
the
string.  I got a surprise!

So.is the debugger supposed to be able to show the actual string
values
in a stringlist or not?

John


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Re: [DUG] Debugger - variable values

[Dennis Chuah]

To see the contents of a string list, a quick way (turn on allow function 
calls):


srcTemplateInputLines.Text or
srcTemplateInputLines.CommaText

to see an individual element:

srcTemplateInputLines[0], or srcTemplateInputLines[1], ...

- Original Message - 
From: "John Bird" <[EMAIL PROTECTED]>

To: "'NZ Borland Developers Group - Delphi List'" 
Sent: Tuesday, August 07, 2007 7:16 PM
Subject: [DUG] Debugger - variable values



There is something I wanted to know about the debugger.I love the
debugger being able to examine the values of variables in code.  I have 
also

got used to that it just won't show the values of some.   Loop pointers
often won't get shown, particularly as you say after the loop is finished.
Some others as well, I assume because of optimisation, or sometimes simply
because it is time to reboot the PC or restart the IDE.

The other type I had got used to never seeing the value of was a member of 
a

stringlist, eg

   TmWorkLine1:=srcTemplateInputLines.Strings[TemplatePtr];

The debugger would just show srcTemplateInputLines | () as the value.
However one day, and it has only happened once, it did show the value of 
the

string.  I got a surprise!

So.is the debugger supposed to be able to show the actual string 
values

in a stringlist or not?

John


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Re: [DUG] Pulling status bar text off another application

[Dennis Chuah]

A far easier way would be to use the HTML Dom.  Get it done in a couple of 
lines of code.


- Original Message - 
From: "Jeremy Coulter" <[EMAIL PROTECTED]>

Sent: Monday, July 30, 2007 10:44 PM


Yes you are correct, you will need either the class name OR the name of 
the

control.
So, to do that, you use something like Spy++ which comes with Visual 
Studio,

or download for free windose from Greatis software which will give yo that
information.

Trust me, this definitly works on NON Delphi apps too. The getting 
info

from controls on a non delphi app. that is.


Jeremy

-Original Message-
From: Matthew Comb [mailto:[EMAIL PROTECTED]
Sent: 30 July 2007 22:36
To: [EMAIL PROTECTED]; 'NZ Borland Developers Group - Delphi List'
Subject: RE: [DUG] Pulling status bar text off another application

Correct me if I am wrong it's been a while, but you require the windows
class name in order to use FindWindowsEx ?

Your two calls use 'TfmMain' and 'TStatusbar' which are Delphi specific.

It's worthwhile keeping this in mind when thinking about 'ANY browser and
ANY app'

Your code won't work for any browser consistently.

Only way you can achieve that is by using a common interface.

Of course if you know the application you are wanting to connect to and 
can

determine these classnames then you don't have to worry.

Matt.

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
On

Behalf Of Jeremy Coulter
Sent: Monday, 30 July 2007 7:32 p.m.
To: 'NZ Borland Developers Group - Delphi List'
Subject: RE: [DUG] Pulling status bar text off another application

Nope, not at all. If you LOOK at the code you will seeit uses 
"FindWindowEx"

to find a child control. It could be a VB textbox for all it cares.
Infact, I have uses FindWindowEx to actually access a disabled textbox ina
vb app, and change it to being enabledso I could copy the text from it
and paste it into my delphi appcost I can nearly ALWAYS find a
hack...hehhehe

Jeremyp.s Matt, you firndigtal.com email bounced back when I replied.

-Original Message-
From: Matthew Comb [mailto:[EMAIL PROTECTED]
Sent: 30 July 2007 19:06
To: [EMAIL PROTECTED]; 'NZ Borland Developers Group - Delphi List'
Subject: RE: [DUG] Pulling status bar text off another application

" It also means that Phil can support ANY browser, or ANY app. That has a
statusbar."

That was written in Delphi ? :)

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
On

Behalf Of Jeremy Coulter
Sent: Monday, 30 July 2007 7:03 p.m.
To: 'NZ Borland Developers Group - Delphi List'
Subject: RE: [DUG] Pulling status bar text off another application

Did ANYONE apart from Phil take a look at the code I supplied??
My function does it is a LOT less complex manner that some of the ideas
suggested thus far.
It also means that Phil can support ANY browser, or ANY app. That has a
statusbar.

Jeremy

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
On

Behalf Of Dennis Chuah
Sent: 30 July 2007 18:49
To: NZ Borland Developers Group - Delphi List
Subject: Re: [DUG] Pulling status bar text off another application


Why don't you use automation to get access to the browser application
object.  From there you can use the HTML Dom to get access to the status 
bar

text.

- Original Message -
From: "Phil Scadden" <[EMAIL PROTECTED]>
To: 
Sent: Monday, July 30, 2007 2:57 PM
Subject: [DUG] Pulling status bar text off another application



A webapp running in IE put text in the status bar that I would dearly
like  to snaffle into another running application. Statusbar I think is
a  wincontrol  so could be possible. Anyone with bright ideas on
discovering it?

--
Phil Scadden, GNS Science Ltd
764 Cumberland St, Private Bag 1930, Dunedin, New Zealand Ph +64 3
4799663, fax +64 3 477 5232

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No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.476 / Virus Database: 269.10.19/917 - Release Date: 
25/07/2007

01:16


No virus found in this outgoing message.
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25/07/2007

01:16



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Post: delph

Re: [DUG] Pulling status bar text off another application

[Dennis Chuah]

Why don't you use automation to get access to the browser application 
object.  From there you can use the HTML Dom to get access to the status bar 
text.


- Original Message - 
From: "Phil Scadden" <[EMAIL PROTECTED]>

To: 
Sent: Monday, July 30, 2007 2:57 PM
Subject: [DUG] Pulling status bar text off another application



A webapp running in IE put text in the status bar that I would dearly like
to snaffle into another running application. Statusbar I think is a 
wincontrol

so could be possible. Anyone with bright ideas on discovering it?

--
Phil Scadden, GNS Science Ltd
764 Cumberland St, Private Bag 1930, Dunedin, New Zealand
Ph +64 3 4799663, fax +64 3 477 5232

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Re: [DUG] basic question

[Dennis Chuah]

No, a constuctor will not return Nil.  If an exception is raised in a 
constructor, the implicit finalisation code is called (which then calls the 
Destructor), and the exception bubbles up to the next exception handler.


- Original Message - 
From: "Jeremy North" <[EMAIL PROTECTED]>

To: "NZ Borland Developers Group - Delphi List" 
Sent: Thursday, July 26, 2007 7:09 PM
Subject: Re: [DUG] basic question



Which means any constructor could return NIL. Which you didn't make
clear in your explanation. I just wanted to clear that up for others
incase they weren't aware of this.

On 7/26/07, Dennis Chuah <[EMAIL PROTECTED]> wrote:


A constructor ALWAYS creates an instance, even if it encounters an
exception.  The implicit exception handling code then finalises the
instance.

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Re: [DUG] basic question

[Dennis Chuah]

A constructor ALWAYS creates an instance, even if it encounters an 
exception.  The implicit exception handling code then finalises the 
instance.


- Original Message - 
From: "Jeremy North" <[EMAIL PROTECTED]>

To: "NZ Borland Developers Group - Delphi List" 
Sent: Thursday, July 26, 2007 9:35 AM
Subject: Re: [DUG] basic question



On 7/26/07, Dennis Chuah <[EMAIL PROTECTED]> wrote:


...  A constructor always instantiates an instance.


Unless the constructor raises an exception.
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Re: [DUG] basic question

[Dennis Chuah]

It is called a constructor ... subtle differences, but *significant*.  Eg., 
you cannot return a Nil from a constructor.  A constructor always 
instantiates an instance.


As for the use of class methods ... plenty.  Eg., use it to replace unit 
procedures and functions.  Use it to implement singleton classes and class 
factories.  Class methods can also be virtual and get overriden, etc.  The 
'self' parameter to class methods is the class reference.  Not as useless as 
Neven thinks.


- Original Message - 
From: "David Moorhouse" <[EMAIL PROTECTED]>

To: "NZ Borland Developers Group - Delphi List" 
Sent: Wednesday, July 25, 2007 10:15 PM
Subject: Re: [DUG] basic question



AnInstance := TAnObject.Create;

if that's not a class method I'm not sure what is ;)

D


On Wed, 25 Jul 2007 21:33:25 +1200, you wrote:


Sean

Thanks, I grovel corrected :-), Still little use with no data, ie Data +
Algorithms = Programs

N

Class methods have been around for years, explicitly.  As in
TMyClass.DoSomething, no nil instances required.
 have just looked it up in my "Using Delphi 3" (pub 1997) book that I 
keep

lying around for no apparent reason, so it's been at least a decade.

Class variables etc are newer


Regards

Sean
---
Sean Cross
mailto:[EMAIL PROTECTED]

Pics Print - The photo printing solution for Windows.
http://www.picsprint.com

Rental Property Manager - Rental management made easy
http://www.sourceitsoftware.com




-Original Message-
From: [EMAIL PROTECTED] [mailto:delphi-
[EMAIL PROTECTED] On Behalf Of Neven MacEwan
Sent: Wednesday, 25 July 2007 8:19 p.m.
To: NZ Borland Developers Group - Delphi List
Subject: Re: [DUG] basic question

Dennis


Class methods have been around since Delphi 2.  Where have you been
all these years?


Not explicitly, as I said, you cannot for example call them on the
class, you call them on a nil instance
which is hardly elegant php for example you would call a class method
by
TClass::Method()

To reinforce this, why did they introduce a 'class' keyword if they
were
already there?

N


Class types, consts and vars came in D2006, I think, or might be in
D2005.

- Original Message - From: "Neven MacEwan" <[EMAIL PROTECTED]>
To: "NZ Borland Developers Group - Delphi List"





Sent: Wednesday, July 25, 2007 7:25 PM
Subject: Re: [DUG] basic question




J

My point is Delphi (generic) does not have Class Methods/Vars or
are you saying that 'Delphi' only applies to D2005+

As for sarcasm, its a matter of opinion I found his response smug.

N



I'll answer for Chee Wee (not Chee - common mistake)

These articles were by Nick about changes since Delphi 7.
http://dn.codegear.com/article/34325 (VCL)
http://dn.codegear.com/article/34323 (IDE)
http://dn.codegear.com/article/34324 (Language)

I don't think his original reply was sarcastic either. Why would he
need to clarify something, you're the one that didn't do any


research


before saying something. Especially when coming from a version that


is


like 6 years old
(http://delphi.wikia.com/wiki/Borland_Compiler_Release_Dates).

Even if you don't run the latest version, it is hardly a great


effort


to subscribe to some blogs (www.delphifeeds.com).

As for when they came in, they are a by product of Delphi.NET. So
codegear doing .NET was good for something! So they came into the
win32 around D2005 and have become less buggy each release since.

cheers,
Jeremy



Chee

When did they sneak in?, Before you get all sarcastic I'd suggest


you


clarify things,
Some of us are using older versions (D6 in my case)


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Post: de

Re: [DUG] basic question

[Dennis Chuah]

Class methods have been around since Delphi 2.  Where have you been all 
these years?


Class types, consts and vars came in D2006, I think, or might be in D2005.

- Original Message - 
From: "Neven MacEwan" <[EMAIL PROTECTED]>

To: "NZ Borland Developers Group - Delphi List" 
Sent: Wednesday, July 25, 2007 7:25 PM
Subject: Re: [DUG] basic question



J

My point is Delphi (generic) does not have Class Methods/Vars or
are you saying that 'Delphi' only applies to D2005+

As for sarcasm, its a matter of opinion I found his response smug.

N


I'll answer for Chee Wee (not Chee - common mistake)

These articles were by Nick about changes since Delphi 7.
http://dn.codegear.com/article/34325 (VCL)
http://dn.codegear.com/article/34323 (IDE)
http://dn.codegear.com/article/34324 (Language)

I don't think his original reply was sarcastic either. Why would he
need to clarify something, you're the one that didn't do any research
before saying something. Especially when coming from a version that is
like 6 years old
(http://delphi.wikia.com/wiki/Borland_Compiler_Release_Dates).

Even if you don't run the latest version, it is hardly a great effort
to subscribe to some blogs (www.delphifeeds.com).

As for when they came in, they are a by product of Delphi.NET. So
codegear doing .NET was good for something! So they came into the
win32 around D2005 and have become less buggy each release since.

cheers,
Jeremy


Chee

When did they sneak in?, Before you get all sarcastic I'd suggest you
clarify things,
Some of us are using older versions (D6 in my case)

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Re: [DUG]: Freeing exceptions?

[Dennis Chuah]

Message> Is the below code a memory leak?

> procedure TSam.Samuel;
> var
>   e: Exception;
> begin
>   e := Exception.Create('Foobar');
> end;

Yes, every time the method is called.

> Is the below code okay?

> procedure TSam.TrySamuel;
> var
>   e: Exception;
> begin
>   e := Exception.Create('Foobar');
>   try
> //do some stuff
>   finally
> e.Free;
>   end;
> end;

Okay is subjective.  From a pure coding point of view, as long as "e" is not
used to raise any exceptions inside the try -- finally, the code is OK.
>From a design point of view, it is IMHO, poor practise to create an
exception object and not raise it.  A class should do only one thing and do
it well.  So an exception class should only be used to raise exceptions, and
no more.  Create it when you need to use it.

Dennis.
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Re: [DUG]: Packages problem

[Dennis Chuah]

Hmmm... strange problem.  The Clipbrd unit is quite small and simple, but
then again, you are dealing with a M$ product, so anything can happen.

As a hack, why don't you simply copy the unit and put that into your
package.  You will need to give it a new unit name as the unit name space is
global.

- Original Message -
From: Jason Coley
To: Multiple recipients of list delphi
Sent: Friday, November 14, 2003 11:25 AM
Subject: [DUG]: Packages problem


I have a com addin that works inside of Outlook, and this addin is linked to
a package which holds all of the Delphi runtime components I use and need
for all my addins, keeps my addins small.

Anyway, for some reason whenever I use the clipboard in the addin (the
ClipBrd unit is in the runtime package) Outlook crashes.

If I compile the addin without using the package it works fine.

Is there a way I can explicitly compile the ClipBrd unit into my com addin
to eliminate this problem, without taking it out of the runtime package, (I
tired to take it out of the runtime package but there are other units that
depend on the clipbrd unit which means I may have to take out a few other
units as well)

Not sure the best way to get around this problem, any help would be
appreciated.

Jason
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Re: [DUG]: Another custom component question

[Dennis Chuah]

Another custom component question
Why don't you simply create two components?

- Original Message -
From: [EMAIL PROTECTED]
To: Multiple recipients of list delphi
Sent: Friday, November 14, 2003 9:14 AM
Subject: [DUG]: Another custom component question


Hi all
I drop my custom TTable component on a form and I assign it a table name on
the object inspector. If I choose to name it, Policy, then I would like
certain methods to be exposed when I type "Policy." However, if I name my
table, Adviser, then when I type "Adviser." in code, I don't want the policy
methods to appear. At the moment all existing methods appear. Is there a way
to do this at design time, so if the user gives a table name of Policy, it
then unhides certain methods?
Thanks.
Dave Jollie
Developer, TOWER NZ IT

(: 09 368 4259
J: 09 306 6801
*: [EMAIL PROTECTED]
.: 46 Parnell Rd, Parnell, Auckland
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Re: [DUG]: How do i GET this HTML...

[Dennis Chuah]

Perhaps you need to preserve cookies?
Perhaps the cgi / servlet only expects POST?
Are you having to go through a proxy server?



- Original Message -
From: <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, November 12, 2003 2:41 PM
Subject: [DUG]: How do i GET this HTML...


> 2 Questions really.
> 1.
> I'm writting a component that will goto a defined webpage
> and download all the files from it based off the links in
> the html. This works fine with normal HTML but heres my
> problem. The page that i need it to work on is generating
> HTML via cgi or a Java servlet and when i use a GET on the
> page i am returned a 404 error. Goto the define URL in my
> browser and i get it fine. I get no html returned at all.
> What can i do?
>
> 2. Other question is, where is the DUG page these days? I
> wanted to sign up for the list at work but cant seem to
> locate the page anymore.
>
> Regards,
> Matthew Evans
> --
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Re: [DUG]: Menus.pas Delphi 5 'Attempt to free a non-existing resource'

[Dennis Chuah]

if FItems<>nil then  FItems.Free;

does nothing more than FItems.Free

There is nothing wrong in that line of code - the items list is being
freed - if you are getting an exception there, it might indicate that you
are either freeing the menu twice, or there might have been some memory
corruption.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, November 13, 2003 11:32 AM
Subject: [DUG]: Menus.pas Delphi 5 'Attempt to free a non-existing resource'


> Hi all.
> I have found a destroy resource problem which is indicated to be in
menus.pas.
>
> destructor TMenuItem.Destroy;
> begin
>   ShortCutItems.ClearItem(Self);
>   if FParent <> nil then
>   begin
> FParent.Remove(Self);
> FParent := nil;
>   end;
>   while Count > 0 do Items[0].Free;
>   if FHandle <> 0 then
>   begin
> MergeWith(nil);
> DestroyMenu(FHandle);
>   end;
> //The offending line is 'FItems.Free;' which I changed to below
>   if FItems<>nil then  FItems.Free;
>   FreeAndNil(FActionLink);
>   FreeAndNil(FImageChangeLink);
>   if FCommand <> 0 then CommandPool[FCommand] := False;
>   if Assigned(FBitmap) then FBitmap.Free;
>   inherited Destroy;
> end;
>
> but by changing the line to that creates a different problem.
> can you suggest what the correct way to free 'Fitems' would be given the
> circumstances thanks.
> Alistair+
>
>
> --
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Re: [DUG]: Capturing input focus

[Dennis Chuah]

Message
TCustomControl is already a descendent of TWinControl.

Haven't had this happen to me before, but check the ControlState property.
Also how are you setting the focus to the control.  Try using the keyboard
(TAB key), or do it in code (SetFocus, ActiveControl).  Do you handle the
WM_NCHITTEST message and are setting the focus using the mouse?

- Original Message -
From: Wes Edwards
To: Multiple recipients of list delphi
Sent: Wednesday, November 05, 2003 7:37 AM
Subject: RE: [DUG]: Capturing input focus


Derive from TWinControl (Windows only) or TWidgetControl (cross-platform) to
receive focus / keyboard input etc.

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Allan Vergara
Sent: Tuesday, 4 November 2003 2:01 p.m.
To: Multiple recipients of list delphi
Subject: [DUG]: Capturing input focus


Been trying to figure this one out for a while now but still no luck.  What
I have is a TrackBar control derived from TCustomControl.  Within this
control I'm trying to trapping the messages WM_SETFOCUS and WM_KILLFOCUS but
this little experiment fails because these messages are not being sent to
this control (I've also set TabStop to TRUE). I need to trap these messages
in order to draw/remove a focusRect  on the Thumb (a TGraphicControl
control).  Thanks in advance.

Actual contol:


__
Allan D. Vergara
Software Engineer
Niche Software Ltd.
http://www.WorkPace.com
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Re: [DUG]: Automated build tool for packages

[Dennis Chuah]

To open source, you first need to decide which open source license to use.
There are many variations, but essentially most of them boil down to
variants of either MPL or GPL.

You can create a project in SourceForge (http://sourceforge.net) - put your
code there and its effectively open source.

Not wanting to detract from your colleague's achievements, I wonder what is
the use of the software?  Doesn't Delphi automatically recompile all
dependent packages for you?

- Original Message -
From: "Allan, Samuel" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, November 04, 2003 4:34 PM
Subject: [DUG]: Automated build tool for packages


A colleague at my work has written an automated builder which uses the
command line compiler to compile packages.

Given a root directory, it finds all the packages in subfolders. You can
then choose the ones that you want to compile. It sorts out the
dependencies between the packages and recompiles dependent packages as
well. It compiles them in the right order, sorts out all the other
complications (of which there are many).

I thought that maybe there were people other than us who would find such
a tool very useful. I also thought it would be nice kudos for him. I am
approaching our boss to see if it could be released outside of us. We
don't normally give / sell our software to other people.

If released it would most likely be source code, no support, but works
for us. Would anyone actually be interested? If a small sum of money was
required (a possibility because someone in the chain of command will
ask), would anyone pay it? If no money was required how would we go
about making it open source?
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Re: [DUG]: C Conversion

[Dennis Chuah]

Use Cardinal instead of Integer - because the C code uses "unsigned int".

Your for should be 0-based:

  for currByte := 0 to dataLength-1 do

^ maps to xor

  if ((dataStore xor accum) and $8000) > 0 then
accum := (accum shl 1) xor CRCDIV;

Lastly, this does not affect your code, but for correctness:

for currBit := 0 to 7 do

Interesting polynomial:

CRCDIV = $8005;


- Original Message -
From: James Sugrue
To: Multiple recipients of list delphi
Sent: Tuesday, November 04, 2003 11:50 AM
Subject: [DUG]: C Conversion


I have the following code. I have tried to convert into Delphi but it isn't
100% correct. Could some kind soul show me where I've gone wrong?

#define CRCDIV 0x8005

unsigned int computeCRC (unsigned char *data, unsigned int dataLength)
{
  unsigned int accum;
  unsigned int currByte;
  unsigned int currBit;
  unsigned int dataStore;

  accum = 0;

  // repeat for all bytes in message from the header to the data
  for (currByte = 0;  currByte < dataLength;  currByte++) {
dataStore = ((unsigned int) data[currByte]) << 8;

for (currBit = 0;  currBit < 8;  currBit++) {
  if ((dataStore ^ accum) & 0x8000) {
accum = (accum << 1) ^ CRCDIV;
  }
  else {
accum <<= 1;
  }
  dataStore <<= 1;
}
  }

  return (accum);
}


function computeCRC (data : PChar; dataLength : Integer) : Integer;
const
CRCDIV = $8005;
var
  accum : Integer;
  currByte : Integer;
  currBit : Integer;
  dataStore : Integer;
begin
  accum := 0;

  // repeat for all bytes in message from the header to the data
  for currByte := 1 to dataLength do
  begin
dataStore := Integer(data[currByte]) shl 8;

for currBit := 1 to 8 do
begin
  if ((dataStore or accum) and $8000) > 0 then
  begin
accum := (accum shl 1) or CRCDIV;
  end
  else
  begin
accum := accum shl 1;
  end;
  dataStore := dataStore shl 1;
end;
  end;

  result := accum;
end;






James Sugrue

Software Developer
WA Systems
Timaru
Phone 03 688-1131

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Re: [DUG]: Just wondering...

[Dennis Chuah]

Ross,

Using the local boolean variable is most efficient in terms of speed and
code/data space - this is because in *MOST* cases the optimiser will use a
CPU register to hold the local variable and this is not only faster than
calling methods, it also generates less code (one extra call is generated),
and being a register variable, there is no data storage.

However, the point I was trying to make is:  It is rather pointless trying
to optimise the code as it really doesn't matter which form you use - for 6
controls, the user isn't going to see any difference.  You might be able to
save a few bytes of code if you choose one technique over another, but once
again, IMHO, that is hardly worth it.  In this instance, I think it is
better to write and comment the code so that the meaning is clearly
represented.  Sometimes optimised code isn't the easiest to read.

Often it is one is tempted to try and optimise little snippets of code, but
if you really want to tweak your program, it is better to run it inside a
profiler.  You will be amazed at the results.  Often you will find that it
is the database / file access or some inefficient routine in a loop that
executes 2000 times that is slowing down your program.

Having said that, it doesn't hurt to use good algorithms, even if the gains
are not apparent.  This way, when it *DOES* matter, at least, you know that
your code will be fast.

Dennis.

- Original Message -
From: "Ross Levis" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, October 31, 2003 1:49 PM
Subject: Re: [DUG]: Just wondering...


> Hi Dennis (and others)
>
> So I presume you are suggesting the more efficient way is to repeat the
> itemindex = 1 expression.
>
> Options is usually a radio group, but sometimes it's a checkbox and using
> the checked property instead of itemindex = 1.
>
> Often it is more than 2 components I want enabled/disabled based on the
> Options selection.  There can be 6 for example, which is why I was
> interested to know the best way of coding it.  Not that the speed
difference
> would be noticeable but if one is more efficient than the other then why
not
> use it from now on.
>
> Is it more efficient to store the value in a local boolean variable before
> applying to several components?
>
> Regards,
> Ross.
>
> - Original Message -
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Friday, October 31, 2003 1:11 PM
> Subject: Re: [DUG]: Just wondering...
>
>
> >
> > Actually, this is a misconception.  The compiler cannot fold the code
> > because Option.ItemIndex accesses a property, which translates to a
method
> > call, and therefore can have side-effects.  (Yes folks, all property
> > accesses are method calls, even if no accessor methods are defined and
the
> > property points directly at a variable.)  So, if the optimiser were to
> fold
> > the code, you would only get one method call instead of two!  The only
> time
> > when code is folder (and it is not even guaranteed), is when you
directly
> > access variables.
> >
> > - Original Message -
> > From: "Rohit Gupta" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Friday, October 31, 2003 12:07 PM
> > Subject: Re: [DUG]: Just wondering...
> >
> >
> > > First because the compiler should detect it and fodl the code.
> > >
> > > Second because it uses less cpu cycles.
> > >
> > > :-)
> > >
> > > I normally use a local variable to hold teh value with a name that
> > > tells the world what it means.  Or
> > >
> > > if Option.ItemIndex = 1
> > > then begin
> > > end
> > > else begin
> > > end
> > >
> > > >
> > > > Which of the following codeis the most efficient/fastest to execute?
> > > >
> > > > Label1.Enabled := Option.ItemIndex = 1;
> > > > Label2.Enabled := Option.ItemIndex = 1;
> > > >
> > > > or
> > > >
> > > > Label1.Enabled := Option.ItemIndex = 1;
> > > > Label2.Enabled := Label1.Enabled;
> > > >
> > > > Thanks,
> > > > Ross Levis.
>
> --
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Re: [DUG]: Just wondering...

[Dennis Chuah]

> Which of the following code is the most efficient/fastest to execute?

The following code is faster than the both of them:

var
  temp: Boolean;
begin
  temp := Option.ItemIndex = 1;
  Label1.Enabled := temp;
  Label2.Enabled := temp;

Of course, the screen is going to update asynchronously, so that regardless
of which method you use, the user will not be able to notice the difference!

- Original Message -
From: Ross Levis
To: Multiple recipients of list delphi
Sent: Thursday, October 30, 2003 9:23 PM
Subject: [DUG]: Just wondering...


Which of the following code is the most efficient/fastest to execute?

Label1.Enabled := Option.ItemIndex = 1;
Label2.Enabled := Option.ItemIndex = 1;

or


Label1.Enabled := Option.ItemIndex = 1;

Label2.Enabled := Label1.Enabled;

Thanks,
Ross Levis.
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Re: [DUG]: Just wondering...

[Dennis Chuah]

Actually, this is a misconception.  The compiler cannot fold the code
because Option.ItemIndex accesses a property, which translates to a method
call, and therefore can have side-effects.  (Yes folks, all property
accesses are method calls, even if no accessor methods are defined and the
property points directly at a variable.)  So, if the optimiser were to fold
the code, you would only get one method call instead of two!  The only time
when code is folder (and it is not even guaranteed), is when you directly
access variables.

- Original Message -
From: "Rohit Gupta" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, October 31, 2003 12:07 PM
Subject: Re: [DUG]: Just wondering...


> First because the compiler should detect it and fodl the code.
>
> Second because it uses less cpu cycles.
>
> :-)
>
> I normally use a local variable to hold teh value with a name that
> tells the world what it means.  Or
>
> if Option.ItemIndex = 1
> then begin
> end
> else begin
> end
>
> >
> > Which of the following codeis the most efficient/fastest to execute?
> >
> > Label1.Enabled := Option.ItemIndex = 1;
> > Label2.Enabled := Option.ItemIndex = 1;
> >
> > or
> >
> > Label1.Enabled := Option.ItemIndex = 1;
> > Label2.Enabled := Label1.Enabled;
> >
> > Thanks,
> > Ross Levis.
> >
> >
> >
>
> Regards
>
> Rohit
>
> ==
> CFL - Computer Fanatics Ltd.  21 Barry's Point Road, AKL, New Zealand
> PH(649) 489-2280
> FX(649) 489-2290
> email [EMAIL PROTECTED]  or  [EMAIL PROTECTED]
> ==
>
>
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Re: [DUG]: one for the MSDE people

[Dennis Chuah]

Message
SQL Server uses the same database structure as MSDE, so should be
compatible.

If you are not using any new stuff in MSDE2000, the database should be
backwards compatible.  I usually script the database and run the script
during installation.  You can also run MSDE / SQL server in backwards
compatible mode, so that way, you do not use the functions that are not
backwards compatible.

- Original Message -
From: Jeremy Coulter
To: Multiple recipients of list delphi
Sent: Thursday, October 30, 2003 8:34 AM
Subject: [DUG]: one for the MSDE people


Hi all.
With MSDE, how do you get on if the company already has SQL Server?
Also, what if they SQL Server, but tis say version 7, and you are using the
latest MSDE?

Cheers,

Jeremy Coulter



All email scanned with Nortons Antivirus 2003

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Re: [DUG]: Delphi Testing Tools

[Dennis Chuah]

Gary,

Download MemProof - its pretty good for locating memory leaks.  GpProfiler
is a another pretty good product, except it does not do packages.

Dennis.

- Original Message -
From: "GARY T BENNER" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, October 27, 2003 2:28 PM
Subject: [DUG]: Delphi Testing Tools


Hi all,

I note that the Turbopower QA Suite has not been made Open Source, and their
website indicates it is not available anymore.

What other such tools are out there, and / or has someone else taken over
the product?

Looking for Memory leak testing, stress testing etc.

regards

Gary



Gary Benner  -  e-Engineer and Software Developer  -  [EMAIL PROTECTED]
   123 Internet Ltd
Lecturer in Information Technology-   Waiariki Institute of Technology



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Re: [DUG]: IXMLDocument

[Dennis Chuah]

Download MSXML 4 from Microsoft (or get it from MSDN).  Version 4 has more
features and a few bugs fixed.  Install it and use Delphi to create a PAS
unit from the type library (msxml2_tlb).

// Include the PAS unit into your unit.
uses SysUtils, Classes, msxml2_tlb, Variants, ActiveX;

var
  dom: IXMLDomDocument2;
  root, node: ICMLDomNode;
  stm: TStream;
  istm: IStream;

begin
  dom := CoDOMDocument40.Create;
  // or if you need to access it from multiple threads then
  // dom := CoFreeThreadedDOMDocument40.Create;

  // Create the root node
  root := dom.CreateElement ('SomeTag');
  dom.documentElement := root;

  // Create other elements on the root...
  node := dom.CreateElement ('Node1');
  node.nodeValue := 'Some text'
  root.appendChild (node);

  node := dom.CreateElement ('Node2');
  node.nodeValue := 'Some other text'
  root.appendChild (node);

  // Show the XML
  ShowMessage (root.xml);

  // Save the XML
  stm := TFileStream.Create ('test.xml', fmCreate);
  istm := TStreamAdapter.Create (stm, soOwned);
  dom.save (istm);
  istm := Nil; // Close the file

- Original Message -
> Has anyone had any experience using this to create an XML document from
> scratch ?
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Re: [DUG]: Moving to MSDE

[Dennis Chuah]

You do not have to develop in SQL server, you can use MSDE.  Install the SQL
server client tools that come with Small Business Server - the client
installation is separate from the server install.

- Original Message -
From: "Robert martin" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, October 07, 2003 10:38 AM
Subject: Re: [DUG]: Moving to MSDE


> We are also looking at doing a package that uses MSDE (for small sites),
Do
> you have to develop using SQL Server 7?  We have a copy of it included
with
> Small Business Server 4.5 (believe it or not :) ), but don't want to
install
> that just to Get SQL Server 7.
>
> Rob Martin
> Software Engineer
>
> phone 03 377 0495
> fax 03 377 0496
> web www.chreos.com
> - Original Message -
> From: "Neven MacEwan" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Tuesday, October 07, 2003 10:32 AM
> Subject: Re: [DUG]: Moving to MSDE
>
>
> > J
> >
> > Develop using SQL Server 7, Then you just install the MSDE package
> > on the client site, Network performance will always be better than an
> > isam even indexed
> >
> > N
> >
> > - Original Message -
> > From: "Jeremy Coulter" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Tuesday, October 07, 2003 10:24 AM
> > Subject: RE: [DUG]: Moving to MSDE
> >
> >
> > > Whats its performance like over a network? This is one area that
DBISAM
> > > is not so flash. Well its OK, but I have a table that I have had to
put
> > > 5 or is it 6 indexes onto to speed up querys that run in an instant
> > > locally.
> > >
> > > Also, how exactly do you get started with MSDE?
> > > Do you basically do everything in SQLServer then export it?
> > > Maybe you have a site I can look at?
> > >
> > > Thanks, Jeremy
> > >
> > > -Original Message-
> > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
> > > Behalf Of Neven MacEwan
> > > Sent: Tuesday, 7 October 2003 10:21
> > > To: Multiple recipients of list delphi
> > > Subject: Re: [DUG]: Moving to MSDE
> > >
> > >
> > > J
> > >
> > > Its v simple, In my experiance MSDE is indistinguishable from SQL 7
The
> > > one caveate is that some queries will run slower, they have removed
some
> > > of the query opt stuff from MSDE, I use a kbmMemtable loaded from ADO
> > > and my own resolver
> > >
> > > Also if you want to manage an MSDE site we have an 'Enterprise
manager'
> > > like tool which you are welcome to
> > >
> > > HTH
> > >
> > > Neven
> > >
> > > - Original Message -
> > > From: "Jeremy Coulter" <[EMAIL PROTECTED]>
> > > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > > Sent: Tuesday, October 07, 2003 9:49 AM
> > > Subject: [DUG]: Moving to MSDE
> > >
> > >
> > > > HI all.
> > > > At the moment I have a project where I am using the evaluation
version
> > >
> > > > of DBISAM. It does everything I want it to do, its fast compact, and
I
> > >
> > > > REALLY like it !
> > > >
> > > > BUT, after using MSSQL for so long, I miss stored proc.s and now
have
> > > > a situation where a Stored Proc would solve a problem. I am thinking
> > > > that the move to MSDE might be an idea. Ok, its prob. a LOT of work,
> > > > but really,  I am wondering how well MSDE interacts with Delphi, and
> > > > if it IS worth it, um...hehehewhere do I start ? hehehe
> > > >
> > > >
> > > > Cheers,
> > > >
> > > > Jeremy Coulter
> > > >
> > > >
> > >
> --
> > > > --
> > > > All email scanned with Nortons Antivirus 2003
> > > >
> >
> 
> > > >
> > > >
> > >
> >
> 
> > > ---
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> >
> >
>
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>

Re: [DUG]: Fw: MSDE tool

[Dennis Chuah]

Rob,

You as a programmer decide what is a batch.  Every time you execute a query
against SQL server, it is one batch - within reason, size does not matter -
it can be one simple statement, one complex statement or multiple
statements.  The only limitations are stored procedure and function creation
/ alter statements must be the first in the batch.

If you use query analyser, anything between GO statements is a batch.
Internally, it splits the query on the GO statements into multiple queries
and issues each query in sequence to SQL server.

I cannot comment on 100 users using MSDE because you shouldn't be using it
for anything other than a few concurrent users.  With that sort of a number,
you should be using SQL server instead.

I suspect internally, the thread manager only allows 5 threads, so if you
already have 5 batches running, the other will have to wait until a thread
is free.  Its only a suspicion though - I have no concrete proof.

Regards,
Dennis.

- Original Message -
From: "Robert martin" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, October 08, 2003 2:02 PM
Subject: Re: [DUG]: Fw: MSDE tool


> Thanks Dennis
>
> Any idea how big a gap between the SQL is required for it to count as a
new
> batch?  So I can have 100 users each doing and Query every now and then
> without any performance hit?
>
>
> Rob Martin
> Software Engineer
>
> phone 03 377 0495
> fax 03 377 0496
> web www.chreos.com
> - Original Message -
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Wednesday, October 08, 2003 1:41 PM
> Subject: Re: [DUG]: Fw: MSDE tool
>
>
> >
> > A batch in SQL server is basically one or more queries executed in
series
> by
> > one database connection.
> >
> >
> > - Original Message -
> > From: "Robert martin" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Tuesday, October 07, 2003 11:49 AM
> > Subject: Re: [DUG]: Fw: MSDE tool
> >
> >
> > > I have just checked the Microsoft site for information and spotted the
> > > following.
> > >
> > > "MSDE 2000 is a local data engine that can be shared. It has a managed
> > > concurrency workload governor that limits up to five concurrent batch
> > > workloads for optimal performance. Commands and log entries are
> available
> > to
> > > monitor instances where more than five workloads are executed
> > concurrently,
> > > a situation that can cause slower performance even on well-tuned
> systems.
> > As
> > > more batch workloads are submitted beyond the five-workload limit, the
> > > concurrency governor continues to slow down the system. These
workloads
> > are
> > > not dropped or lost; they are still processed, but in an increasingly
> > > degraded performance mode. If your solution must support more than
five
> > > concurrent workloads, it is highly recommended that you migrate to SQL
> > > Server 2000 or SQL Server 2000 Enterprise Edition for optimal
> performance
> > at
> > > this higher level of scalability."
> > >
> > >
> > > I had taken 'five concurrent batch workloads' to mean users but it
might
> > be
> > > concurrent queries or maybe complex queries count as multiple batches?
> > >
> > >
> > > Rob Martin
> > > Software Engineer
> > >
> > > phone 03 377 0495
> > > fax 03 377 0496
> > > web www.chreos.com
> > > - Original Message -
> > > From: "Neven MacEwan" <[EMAIL PROTECTED]>
> > > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > > Sent: Tuesday, October 07, 2003 11:33 AM
> > > Subject: Re: [DUG]: Fw: MSDE tool
> > >
> > >
> > > > Robert
> > > >
> > > > As I said I've not experianced this (and i have
> > > > a site running 10+ users on MSDE with a financials package)
> > > > The only performance hit I've had is on joined queries
> > > >
> > > > N
> > > > - Original Message -
> > > > From: "Robert martin" <[EMAIL PROTECTED]>
> > > > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > > > Sent: Tuesday, October 07, 2003 11:12 AM
> > > > Subject: Re: [DUG]: Fw: MSDE tool
> > > >
> > > &g

Re: [DUG]: Fw: MSDE tool

[Dennis Chuah]

A batch in SQL server is basically one or more queries executed in series by
one database connection.


- Original Message -
From: "Robert martin" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, October 07, 2003 11:49 AM
Subject: Re: [DUG]: Fw: MSDE tool


> I have just checked the Microsoft site for information and spotted the
> following.
>
> "MSDE 2000 is a local data engine that can be shared. It has a managed
> concurrency workload governor that limits up to five concurrent batch
> workloads for optimal performance. Commands and log entries are available
to
> monitor instances where more than five workloads are executed
concurrently,
> a situation that can cause slower performance even on well-tuned systems.
As
> more batch workloads are submitted beyond the five-workload limit, the
> concurrency governor continues to slow down the system. These workloads
are
> not dropped or lost; they are still processed, but in an increasingly
> degraded performance mode. If your solution must support more than five
> concurrent workloads, it is highly recommended that you migrate to SQL
> Server 2000 or SQL Server 2000 Enterprise Edition for optimal performance
at
> this higher level of scalability."
>
>
> I had taken 'five concurrent batch workloads' to mean users but it might
be
> concurrent queries or maybe complex queries count as multiple batches?
>
>
> Rob Martin
> Software Engineer
>
> phone 03 377 0495
> fax 03 377 0496
> web www.chreos.com
> - Original Message -
> From: "Neven MacEwan" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Tuesday, October 07, 2003 11:33 AM
> Subject: Re: [DUG]: Fw: MSDE tool
>
>
> > Robert
> >
> > As I said I've not experianced this (and i have
> > a site running 10+ users on MSDE with a financials package)
> > The only performance hit I've had is on joined queries
> >
> > N
> > - Original Message -
> > From: "Robert martin" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Tuesday, October 07, 2003 11:12 AM
> > Subject: Re: [DUG]: Fw: MSDE tool
> >
> >
> > > I believe the deal with MSDE is that it IS throttled to give very poor
> > > performance with more than 5 connections.  I heard it was something
like
> a
> > > 50% drop for each user over 5.
> > >
> > > Rob Martin
> > > Software Engineer
> > >
> > > phone 03 377 0495
> > > fax 03 377 0496
> > > web www.chreos.com
> > > - Original Message -
> > > From: "Neven MacEwan" <[EMAIL PROTECTED]>
> > > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > > Sent: Tuesday, October 07, 2003 10:45 AM
> > > Subject: [DUG]: Fw: MSDE tool
> > >
> > >
> > > > Alan
> > > >
> > > > Yeah, i'm happy for it to go into the public domain
> > > > (We don't realy want to support it), It uses virtualtreeview
> > > > and is a warpper for the SQL-DMO Objects
> > > >
> > > > I'd prefer to keep it under subversion (so everyone
> > > > benfits from changes) so if anyone else would like access to it I'll
> set
> > > up
> > > > a public domain repository (email me off list)
> > > >
> > > > Re the licencing, I think its pretty loose (I've not
> > > > worried to much) from what I've read on ADO
> > > > newgroup M$ just want it out there as a launching pad
> > > > for full SQL, AFAIK its NOT user limitied but the only
> > > > problems I've had have been performance on relatively
> > > > simple queries over multiple tables (3 to 4) on large
> > > > databases, 1 query ran 32 seconds on SQL 7, 20+ minutes on
> > > > MSDE (same database, same memory and CPU),
> > > > Almost as if the thing was throttled (do do do do )
> > > > My theory is that M$ made it this way because when it
> > > > is backended to Access the query opt would be done by
> > > > Jet (and MSDE would act as a glorified ISAM) but it
> > > > prevents you from using it in serious DB applications
> > > >
> > > > HTH
> > > >
> > > > Neven
> > > >
> > > >
> > > >
> > > > - Original Message -
> > > > From: "Allan, Samuel" <[EMAIL PROTECTED]>
> > > > To: <[EMAIL PROTECTED]>
> > > > Sent: Tuesday, October 07, 2003 10:27 AM
> > > > Subject: MSDE tool
> > > >
> > > >
> > > > > Hi Neven,
> > > > >
> > > > > I am interested in your MSDE tool because I am also looking at
using
> > > > > MSDE. Is it free? Can I have it?
> > > > >
> > > > > On another note, I have been looking at the licensing guff on the
> > > > > Micrsoft website, and I am confused. Perhaps you know off the top
of
> > > > > your head what I have to buy to be able to re-distribute MSDE as
> part
> > of
> > > > > my software, and if I can then develop in Delphi instead of
whatever
> I
> > > > > bought?
> > > > >
> > > > > Thanks,
> > > > > Samuel Allan
> > > > >
> > > > >
> > >
> >
>
> --
> > > -
> > > > New Zealand Delphi Users group - Delphi List -
> [EMAIL PROTECTED]
> > > > 

Re: [DUG]: Frames

[Dennis Chuah]

When you create the frame at run time, set the owner of the frame to the tab
sheet.

- Original Message -
From: Paul Mckenzie
To: Multiple recipients of list delphi
Sent: Friday, October 03, 2003 8:55 AM
Subject: [DUG]: Frames


I have an Application in which I create and delete TabPages dynamically -
the Tab Pages contain a Frame which I create at Run Time.
To do this the Name of the Frame must be set to ''.
I can set the name to '' at design time (Object Inspector) - but I cannot
save it ... each time I re-open the Frame the Name is set to the class name.
How can I fix this "bug" !!!


Regards
Paul McKenzie
Analyst Programmer
SMSS Ltd.

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Re: [DUG]: ImageList images

[Dennis Chuah]

Message
Not sure if this will fix your problem, but there is a bug in the VCL - when
toolbars are loaded in a form, in some instances, the associated image list
becomes unassigned.  The workaround is to reassign the image list in the
FormShow - but only do it once per form.

- Original Message -
From: Phil Middlemiss
To: Multiple recipients of list delphi
Sent: Thursday, September 25, 2003 1:41 PM
Subject: [DUG]: ImageList images


I have a form in a DLL that has an action list and an associated image list.
When I use the actions on toolbar buttons (or anything else, I think) - the
images don't appear. The DLL form has it's own TApplication even though it's
loaded into the same memory space as the main app and I hade to take that
into account to pass on the On Idle event to the DLL so that actions could
update their status. But I can't seem to get the image list to show. Any
ideas?

Cheers,
Phil.
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Re: [DUG]: random thread crashes

[Dennis Chuah]

Using synchronize does not negate the benefits of using a thread.  It all
depends on how you are using synchronize.  For example, you might have a
lengthy process and you want that to run in the background.  When you create
the thread - in suspend mode, you can pass it parameters (eg. create
properties on the TThread subclass).  You then tell the thread to resume.
On your UI, you might have a cancel button that when clicked, sets a boolean
variable.  Periodically, the thread may check the value of this variable and
terminates if required.  You can protect access to this variable using a
simple critical section lock.  However, the thread also needs to tell the UI
when it has complete.  This can be done using synchronize - the sync. method
runs in the main thread and can safely access the VCL.

How much data does the thread need to read from your UI controls?

- Original Message -
From: "Ross Levis" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, September 24, 2003 3:40 PM
Subject: Re: [DUG]: random thread crashes


> Hi Dennis
>
> Using synchronize will negate the effect of using a thread in the first
> place.  I'm not using any methods but I am reading properties.  Should I
> copy the value of all properties into say global variables before calling
> the thread?
>
> Regards,
> Ross Levis.
>
> - Original Message -
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Wednesday, September 24, 2003 2:02 PM
> Subject: Re: [DUG]: random thread crashes
>
>
> >
> > The VCL is not thread safe and parts of it are not re-entrant.  You
might
> > need to use synchronize to sync to your main thread before you call any
> VCL
> > methods.
>
> --
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Re: [DUG]: random thread crashes

[Dennis Chuah]

The VCL is not thread safe and parts of it are not re-entrant.  You might
need to use synchronize to sync to your main thread before you call any VCL
methods.

- Original Message -
From: Ross Levis
To: Multiple recipients of list delphi
Sent: Wednesday, September 24, 2003 11:52 AM
Subject: [DUG]: random thread crashes


I moved a procedure, which updates a text file, from my main unit to a
thread so it didn't effect the operation of the program.  The thread reads
data from the main units object including some data in a listview in the
main unit, but it doesn't update any information.  I'm getting the odd rare
crash when the thread is created/run.  I'm testing that the thread is not
active before it gets run.  Do I need to move all the data I'm using from
the main unit to temporary variables before calling the thread?  It can work
50 times without a problem but then crashes out of the blue.

Any ideas?

Best regards,

Ross Levis
Tauranga.

StationPlaylist.com
http://www.stationplaylist.com
Low-cost music scheduling, live assist & automation software.
Mailing List: http://groups.yahoo.com/group/StationPlaylist

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Re: [DUG]: Email questions

[Dennis Chuah]

Ah, another virus author... :)

SMTP should be as reliable (or unreliable as the case may be) as MAPI,
because at end of the day, SMTP is the mechanism where emails are forwarded
in the internet, and SMTP does not guarantee delivery.  In fact, there is
also no guarantee that you will get a bounced email because of no delivery.
Worse still, you can get a bounced email, yet the email is delivered.  I.e.,
you don't know whether the email is ever delivered.  Some say email was
modeled after postal mail!

The one problem with using SMTP is not all exchange servers are installed
with SMTP, but this may not be a problem with you case, if you are sending
email from the lab.

If you use automation or CDO to send emails using Outlook, there is no way
to alter the from address, but you can do that with extended MAPI.

Dennis.
(Also in Parnell)

- Original Message -
From: [EMAIL PROTECTED]
To: Multiple recipients of list delphi
Sent: Thursday, September 18, 2003 1:12 PM
Subject: [DUG]: Email questions


Hi all

I recently moved an app from using MAPI with Outlook, to using SMTP. My
reasons were 2-fold. To get around the Outlook prompt - "A program is trying
to send an email on your behalf. This could be a virus. Do you want to allow
this?" My other reason, was that it's a batch app which sends 100's of
emails out to our advisers and I didn't want the "from" address to be the
developers email, where the app was run. (With SMTP I could define the from
address).

Now I have a concern. One email I read recently made me wonder if SMTP is as
reliable as MAPI - in getting bulk emails out successfully without failure.

My questions:
Is MAPI more reliable than SMTP?
Can the "from" be forced to a different address using MAPI?

Any comments appreciated.

Cheers
Dave Jollie
Developer, TOWER NZ IT
(: 09 368 4259
J: 09 306 6801
*: [EMAIL PROTECTED]
.: 46 Parnell Rd, Parnell, Auckland
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Re: [DUG]: Sending emails with Outlook

[Dennis Chuah]

Jason,

I'm afraid you'd say that.  I'll be grateful for your code snippets - they
would be most helpful.

Thanks,
Dennis.

- Original Message -
From: "Jason Coley" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, September 18, 2003 8:40 AM
Subject: RE: [DUG]: Sending emails with Outlook


Ive been writing Exchange Extensions for a few years now and the only
way that works and is guaranteed to work is using Extended MAPI, I could
maybe send you some snippets of code that may help?

Regards

Jason Coley
Manawatu Software Solutions
email: [EMAIL PROTECTED]
web: http://www.software-solutions.co.nz



-Original Message-
From: Dennis Chuah [mailto:[EMAIL PROTECTED]
Sent: Thursday, 18 September 2003 7:29 a.m.
To: Multiple recipients of list delphi
Subject: [DUG]: Sending emails with Outlook


Folks,

I am currently using automation to send emails using Outlook (no, I am
not
writing the next killer virus) and it works fine.  But with the security
upgrade and Outlook 2002, Outlook pops up a series of confirmation
dialog
boxes (presumably to allow the user to stop virii from using Outlook to
propagate).  This also happens if you try to do a mail merge from Word.

I have searched Google and some of the workarounds are:

1.  Disable the security feature in Exchange - No!
2.  Use a USD199 Active-X component that reputedly blocks the messages -
it
blocks the messages but does not seem to send the email - Duh!
3.  Use extended MAPI - complex and convoluted API, as a last resort?

I cannot use SMTP because it is an optional install on exchange servers
and
some people see it as a security hole.

Any other ideas, anyone?

TIA,
Dennis.

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Re: [DUG]: Sharing a drawing surface

[Dennis Chuah]

> 1) use a plugin DLL - works, but a bit ugly since the forms used in the
DLL
> have to StayOnTop and are producing similar errors to the other thread
where
> things like FileOpen dialogs are being hidden behind the DLL forms.

The NormaliseTopMosts and RestoreTopMosts methods should fix this problem -
see Delphi help for more info.

You can perhaps move your Active-X server into a DLL and register it.  There
should be no code change required for the client because you would be using
the ProgID to create an instance of the server, and when you do that, OLE
will load the DLL for you.  This is your in-process server!

Dennis.

- Original Message -
From: "Phil Middlemiss" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, September 18, 2003 8:48 AM
Subject: Re: [DUG]: Sharing a drawing surface


> Thanks Dennis,
>
> The situation is that a plugin wants to annotate the drawing surface. I've
> explored 2 options:
>
> 1) use a plugin DLL - works, but a bit ugly since the forms used in the
DLL
> have to StayOnTop and are producing similar errors to the other thread
where
> things like FileOpen dialogs are being hidden behind the DLL forms.
>
> 2) use a separate exe that connects to the main program via an ActiveX
> server inside the main program. This doesn't give me access to the drawing
> surface anymore.
>
> I probably should have explained that earlier. I can't make the plugin an
> in-process ActiveX server since the main program only finds out at run
time
> what plugins there are (looks for files in a directory). Is that what you
> meant?
>
> Phil.
> - Original Message -
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Thursday, September 18, 2003 7:19 AM
> Subject: Re: [DUG]: Sharing a drawing surface
>
>
> >
> > Phil,
> >
> > You cannot share a DC between different processes - because they are in
> > different address space.  However, you can try to FindWindow to look for
> the
> > window handle, and obtain a DC to paint on its surface.
> >
> > The other suggestion is to use an in-process (ie Active-X DLL) server.
> >
> > Dennis.
> >
> > - Original Message -
> > From: "Phil Middlemiss" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Wednesday, September 17, 2003 1:16 PM
> > Subject: [DUG]: Sharing a drawing surface
> >
> >
> > > Apologies if you get this twice but I think our mail server swallowed
it
> > the
> > > first time I sent it:
> > >
> > > Does anyone know how to share a device context for drawing between
> > separate
> > > programs? Is it possible at all? I have tried passing the handle to
the
> > > context using an ActiveX connection so that a separate program can
> > annotate
> > > an image but even though the correct handle value is passed, none of
the
> > > annotation code seems to have any effect (the drawing code itself
works
> > > fine - I've tested that separately).
> > >
> > >
> > > Any help would be appreciated.
> > >
> > > Cheers,
> > > Phil.
> > >
> >
>
> --
> > -
> > > New Zealand Delphi Users group - Delphi List -
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> > >
>
> --
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> >
>
>
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Re: [DUG]: Form size changing/scrolling?

[Dennis Chuah]

Sounds like you may have a font size / scaling issue.  Can you try setting
the form's Scaled property to False.  This will display the form and its
controls at the same size as when they were designed, but the controls may
clip data - because the font size may be different.

Alternatively, you may want to set the form's AutoSize property to True -
this will resize the form so that all controls are visible.  This works if
the form is designed like a dialogbox, with fixed controls.

Dennis.

- Original Message -
From: "Chris Veale" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, September 18, 2003 8:47 AM
Subject: [DUG]: Form size changing/scrolling?


> Hi all.
>
> I have created a program that runs fine on desktop computers but when it
is
> run on laptops the forms do something weird and the user now has to scroll
> them to see the full screen.
>
> the first form I display is only 400 x 200 pixels but no matter what
> resolution the laptop is set to the user has to scroll, even if its 1400 x
> 1080 resolution and the form is small in the center of the screen -
without
> having a need (technically) to scroll.
>
> Can anyone suggest a solution to this?  I've never come across this
before.
>
> Cheers
>
> Chris Veale
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.518 / Virus Database: 316 - Release Date: 11/09/03
>
>
>
>
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[DUG]: Sending emails with Outlook

[Dennis Chuah]

Folks,

I am currently using automation to send emails using Outlook (no, I am not
writing the next killer virus) and it works fine.  But with the security
upgrade and Outlook 2002, Outlook pops up a series of confirmation dialog
boxes (presumably to allow the user to stop virii from using Outlook to
propagate).  This also happens if you try to do a mail merge from Word.

I have searched Google and some of the workarounds are:

1.  Disable the security feature in Exchange - No!
2.  Use a USD199 Active-X component that reputedly blocks the messages - it
blocks the messages but does not seem to send the email - Duh!
3.  Use extended MAPI - complex and convoluted API, as a last resort?

I cannot use SMTP because it is an optional install on exchange servers and
some people see it as a security hole.

Any other ideas, anyone?

TIA,
Dennis.
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Re: [DUG]: Sharing a drawing surface

[Dennis Chuah]

Phil,

You cannot share a DC between different processes - because they are in
different address space.  However, you can try to FindWindow to look for the
window handle, and obtain a DC to paint on its surface.

The other suggestion is to use an in-process (ie Active-X DLL) server.

Dennis.

- Original Message -
From: "Phil Middlemiss" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, September 17, 2003 1:16 PM
Subject: [DUG]: Sharing a drawing surface


> Apologies if you get this twice but I think our mail server swallowed it
the
> first time I sent it:
>
> Does anyone know how to share a device context for drawing between
separate
> programs? Is it possible at all? I have tried passing the handle to the
> context using an ActiveX connection so that a separate program can
annotate
> an image but even though the correct handle value is passed, none of the
> annotation code seems to have any effect (the drawing code itself works
> fine - I've tested that separately).
>
>
> Any help would be appreciated.
>
> Cheers,
> Phil.
>
> --
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Re: [DUG]: Button Caption

[Dennis Chuah]

Not sure if this will work, but it is worth a try.  Create a sub-class of
TButton and override the CreateParams method:

procedure TButtonNew .CreateParams(var Params: TCreateParams);
begin
  inherited;

  Params.Style := Params.Style or BS_LEFTTEXT;
end;

BS_LEFTTEXT is declared in the Windows unit.

- Original Message -
From: "Ross Levis" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Sunday, August 31, 2003 8:54 PM
Subject: Re: [DUG]: Button Caption


> >Ross Levis wrote:
> >>Is there an easy way to left justify a TButton caption
>
> Rohit Gupta wrote:
> > Its possible but will take you hours to find it look  at the VCL
> > code for TBitBtn and then try to copy the relevant bits into TButton.
> > Or start with TPanel and make your own button component.
>
> TPanel in D5 must not use standard Windows controls either.  It doesn't
show
> with the new rounded edges and colors etc.  Most of the D5 components do.
>
> I'm trying to follow the VCL code but I can't find where the caption is
> updated using the Windows API.  Buttons don't appear to have a canvas.
Can
> anyone point me in the right direction?  Or is it basically impossible.
>
> Regards,
> Ross.
>
> --
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Re: [DUG]: How do I copy the state of one object to another?

[Dennis Chuah]

Yes, use RTTI - here is a simple example:

type
 TDog = class (TComponent)
 private
   FColour: TColor;
   FSize: Integer;
 published
   property Colour: TColor read FColor write FColor;
   property Size: Integer read FInteger write FInteger;
 end;
To clone this, you simply:

var
 stm: TTStream;
 dog1, dog2: TDog;
begin
 stm := TMemoryStream.Create;
 try
   stm.WriteComponent (dog1);
   stm.Seek (0, 0);
   stm.ReadComponent (dog2);
 finally
  stm.Free;
 end;
And BTW, I disagree that using RTTI breaks under different versions of 
Delphi - in fact, this code runs on *ALL* versions of Delphi!  I wonder why 
Borland didn't write a generic Assign method using this!

Dennis.

From: "Neven MacEwan" <[EMAIL PROTECTED]>
Dave
You could use RTTI, There are some good tutorials
around
google Delphi RTTI

Neven

- Original Message -
From: <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, August 27, 2003 4:50 PM
Subject: [DUG]: How do I copy the state of one object to another?
> Hi all
>
>
>
> I want to copy the state (variables) of one instance object of a class, 
to
> another instance object of the same class. Eg. Class TDog, instance Dog1
and
> Dog2. I could do the following:
>
> Dog2.Colour := Dog1.Colour;
>
> Dog2.Breed := Dog1.Breed;etc.
>
> But this seems a little silly. How do I do this in OO?
>
>
>
> If knowing more would be helpful, here's what I'm doing:
>
>
>
> I'm using ICS to connect to an smtp server and want to make multiple
> connections so that I can offload 4000 emails as quickly as possible,
> leaving the smtp server to send them out. (No I'm not a spammer, this is 
a
> report - email with pdf attachment).
>
>
>
> I've just run a test and I can paste multiple ICS components on my form
i.e.
> SmtpCli1, SmtpCli2, SmtpCli3, etc. And I can assign my email details 
into
> SmtpCli1 as my "holder' object. When I go to send, I see if SmptCli2 is 
in
a
> ready state - if so, I copy all of the details from SmtpCli1 to SmtpCli2
and
> send via Cli2. Else, I try SmtpCli3, etc. Using this method, and keeping 
5
> sessions active, I found it sped up my job 5 fold - so seems worth it.
>
>
>
> So this all works but it's very manual with lots of code. How do I do 
this
> with OO elegance?
>
>
>
> Cheers
>
> Dave Jollie
> Developer, TOWER NZ IT
>
> *: 09 368 4259
> *: 09 306 6801
> *: [EMAIL PROTECTED]

> *: 46 Parnell Rd, Parnell, Auckland
>
>
>
>

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Re: [DUG]: GetMenuBarInfo

[Dennis Chuah]

Pass the form's handle, not the menu bar's.

- Original Message - 
From: "Vaughan, Benjamin Carl" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, August 25, 2003 1:11 PM
Subject: [DUG]: GetMenuBarInfo


Hi,

I am currently attempting to get the size of a Menu using the windows
API method GetMenuBarInfo.

My code is as follows

var
  menuInfo: tagMENUBARINFO;
  res : longbool;
begin
  //tbMenu is the TToolbar that TMainMenu is hooked up to
  res := GetMenuBarInfo(tbMenu.Handle,OBJID_MENU,0,menuInfo)
end;

The method is failing and GetLastError is only giving me the extremely
useful message of "The parameter is incorrect." ,
ERROR_INVALID_PARAMETER.

Does anybody have any idea what would be wrong with this piece of code,
or has anyone used this method before?

Regards
Ben
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Re: [DUG]: Best methods for representing a 3 dimensional array

[Dennis Chuah]

There is probably no generic best method - it all depends on what you want
to do with the data.  A few examples are:

1.  Use dynamic arrays like you suggested.  This is simple and does not
violate any OO programming methodologies.  Ie., it is OK to use dynamic
arrays with OO.

2.  Use TStringList.  The first string list would hold Q1, Q2, etc.  For
each Q1, Q2, etc, you attach another string list to hold X1, X2, etc.  Eg.

var
  MainList, SubList, SubSubList: TStringList;

begin
  MainList := TStringList.Create;

  SubList := TStringList.Create;
  MainList.AddObject ('Q1', SubList);

  SubSubList := TStringList.Create;
  SubList.AddObject ('X1', SubSubList);

  SubSubList.Add ('F1');
  SubSubList.Add ('F2');

  SubList := TStringList.Create;
  MainList.AddObject ('Q2', SubList);

Remember to free the sublists when you free the main list.

3.  Use the composite pattern.

type
  TItem = class (TObject);

  TContainer = class (TItem)
  private
FChildren: TList;
  end;

  TData = class (TContiner)
  private
FData: string;
  end;

4.  Use TCollection

type
  TDataItem = class (TColletionItem)
  private
FChildren: TCollection;
FData: string;

  public
constructor Create (ACollection: TCollection);
property Children: TCollection read FChildren;
property Data: string read FData write FData;
  end;

constructor TDataItem.Create (ACollection: TCollection);
begin
  inherited;

  FChildren := TCollection.Create (TDataItem);
end;

to add items...

var
  Root: TCollection;

begin
  Root := TCollection.Create (TDataItem);
  with TDataItem (Root.Add) do begin
Data := 'Q1';
with TDataItem (Children.Add) do begin
  Data := 'X1';
  TDataItem (Children.Add).Data := 'F1';
  TDataItem (Children.Add).Data := 'F2';
end;
  end;

- Original Message -
From: [EMAIL PROTECTED]
To: Multiple recipients of list delphi
Sent: Wednesday, August 06, 2003 7:29 AM
Subject: [DUG]: Best methods for representing a 3 dimensional array


Morning all,

I need to code a structure that looks like this:

Q1 --- X1 --- F1
  --- F2
  --- F3
 --- X2  F1

Q2 -- X2 --- F1

i.e. For every Q (highest level), there can be multiple X's. For every X,
there can be multiple F's (lowest level). I want to create this structure
and then be able to traverse it. E.g. Q1, X1, F1, then Q1, X1, F2, etc.
right through the whole structure. Each Q, X, and F, are purely a string.

I thought about using a multidimensional dynamic array and using Delphi help
could probably get this working. However, I'm new to Windows programming (1+
yrs) and want to learn OO. I've written a couple of objects recently, so
thought I might try to tackle this as a Q object which has multiple X
objects inside it, and then multiple F objects inside the X objects.

I've started reading about collections and trying some sample code, but
don't know enough to "create a collection within a collection", or even if
that's a correct concept.

Any comments or suggestions? Would a TObjectList be better? Should I just
stick to an array?

TIA
Dave Jollie
Developer, TOWER NZ IT
(: 09 368 4259
J: 09 306 6801
*: [EMAIL PROTECTED]
.: 46 Parnell Rd, Parnell, Auckland
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Re: [DUG]: Best methods for representing a 3 dimensional array

[Dennis Chuah]

It could also be a Graph structure - the child may need to know about its
parent.  It all depends on how the data is going to be used, but lets not
confuse Dave too much :).

- Original Message -
From: Leigh Wanstead
To: Multiple recipients of list delphi
Sent: Wednesday, August 06, 2003 9:37 AM
Subject: RE: [DUG]: Best methods for representing a 3 dimensional array


Hi Dave,

I still want to make a suggestion even you decided which way to go.

I thought that is a tree structure. There are lots of options around tree,
i.e. Microsoft DOM tree.

Regards
Leigh
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of [EMAIL PROTECTED]
Sent: Wednesday, August 06, 2003 9:00 AM
To: Multiple recipients of list delphi
Subject: RE: [DUG]: Best methods for representing a 3 dimensional array


Thanks Dennis and Phil. Your replies were very helpful - now to decide which
way to go...

Cheers
Dave Jollie
Developer, TOWER NZ IT
(: 09 368 4259
J: 09 306 6801
*: [EMAIL PROTECTED]
.: 46 Parnell Rd, Parnell, Auckland
-Original Message-
From: Phil Middlemiss [mailto:[EMAIL PROTECTED]
Sent: Wednesday, 6 August 2003 8:44AM
To: Multiple recipients of list delphi
Subject: Re: [DUG]: Best methods for representing a 3 dimensional array

It really depends upon the architecture it is fitting into, and whether you
are likely to want to reuse such a structure in other projects, or elsewhere
in the same project. It would probably be worthwhile you doing as OO anyway
just to get a bit of practice in.

I would use a base class that had all of the parent-child behaviour already
implemented. For example:

// forward declare this so that we can declare the TParentChildClass;
TParentChild = class;
TParentChildClass = class of TParentChild;

// finish declaring this
TParentChild = class
private
  FOwner : TParentChild;
  FChildClass : TParentChildClass;
  FChildList : TList;
protected
  function GetChild(Index : Integer): TParentChild;
  Property ChildClass : TParentChildClass read FChildClass write
FChildClass;
public
  function AddChild : TParentChild;
  procedure RemoveChild(Index : Integer; FreeChild : Boolean);
  function ChildCount : Integer;
  property Child[Index : Integer] : TParentChild read GetChild;
end;

This is just a rough outline really, you will want to add or change the
functionality depending on what you want to acheive.

Phil.
- Original Message -
From: [EMAIL PROTECTED]
To: Multiple recipients of list delphi
Sent: Wednesday, August 06, 2003 7:29 AM
Subject: [DUG]: Best methods for representing a 3 dimensional array

Morning all,

I need to code a structure that looks like this:

Q1 --- X1 --- F1
  --- F2
  --- F3
 --- X2  F1

Q2 -- X2 --- F1

i.e. For every Q (highest level), there can be multiple X's. For every X,
there can be multiple F's (lowest level). I want to create this structure
and then be able to traverse it. E.g. Q1, X1, F1, then Q1, X1, F2, etc.
right through the whole structure. Each Q, X, and F, are purely a string.

I thought about using a multidimensional dynamic array and using Delphi help
could probably get this working. However, I'm new to Windows programming (1+
yrs) and want to learn OO. I've written a couple of objects recently, so
thought I might try to tackle this as a Q object which has multiple X
objects inside it, and then multiple F objects inside the X objects.

I've started reading about collections and trying some sample code, but
don't know enough to "create a collection within a collection", or even if
that's a correct concept.

Any comments or suggestions? Would a TObjectList be better? Should I just
stick to an array?

TIA
Dave Jollie
Developer, TOWER NZ IT
(: 09 368 4259
J: 09 306 6801
*: [EMAIL PROTECTED]
.: 46 Parnell Rd, Parnell, Auckland
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Re: [DUG]: What is the best way

[Dennis Chuah]

Jeremy,

OK then, is it even simpler.

> Design:  Use interfaces or an abstract base class.  Define the methods
> that do the data conversion in the interface / abstract base class.
> For each dat conversion method, create a concrete class that either
> implements the interface or sub-classes the abstract base class.

Then,

Create a factory method that reads an INI file and creates the appropriate
class for the device that you are trying to read.

Dennis.
- Original Message -
From: "vss" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, August 06, 2003 9:26 AM
Subject: Re: [DUG]: What is the best way


> But Dennis, I might as well write a DLL for each type of device which as
> I have mentioned is NOT ideal and NOT practical. The same woudl apply to
> writting a package for each device.
>
> I think I will just uses classes and if there is a device not catered
> for, I will just have to release a new EXE.
>
> BUT I still have one or 2 other ideas to look at too as well tho.
>
> Jeremy
>
> -Original Message-
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: Multiple recipients of list delphi <[EMAIL PROTECTED]>
> Date: Wed, 6 Aug 2003 08:06:38 +1200
> Subject: Re: [DUG]:  What is the best way
>
> > Message
> > Design:  Use interfaces or an abstract base class.  Define the methods
> > that
> > do the data conversion in the interface / abstract base class.
> > For each dat conversion method, create a concrete class that either
> > implements the interface or sub-classes the abstract base class.
> >
> > Implementation:  Use packages.  Each class can be in its own package.
> > Use
> > an INI file setting to determine which package to load.  You can export
> > a
> > method in the package that creates an instance of the class and either
> > returns the interface or the abstract base class reference.
> >
> > - Original Message -
> > From: Jeremy Coulter
> > To: Multiple recipients of list delphi
> > Sent: Tuesday, August 05, 2003 10:54 PM
> > Subject: [DUG]: What is the best way
> >
> >
> > Hi All.
> > I have got an app. that gets data from devices via the comport.
> > 60% if not more of the data from these devices is similar or easy  to
> > deal
> > with, like dates and times, but other info can be specific to a device,
> > and
> > i have to normalize it into a format that I want.
> >
> > In times gone by, about 6-7 years ago, if not more, when I first wrote
> > this
> > app., I used DLL's and depending onn teh devide you specified in an INI
> > file
> > it used that DLL, which I think from memory was done via the setup, so
> > there
> > was only one DLL.
> > BUT this was really not a good idea, as it was hard to debug and just
> > overall never practical.
> >
> > I have thought that I could use classes this time round, once again
> > specifying the device type in an INI file, and then based onthat it
> > would
> > know hat class to use.
> > But is this the best way either? I mean, if I find a device that has
> > not got
> > a class for it already, then its a new EXE release.
> >
> > I guess what woud be idea would be if I could load some specific
> > functions
> > up at runtime, and then access them then it would only ever be a txt
> > file or
> > whatever that I would need to distribute.
> > I thought something like Delphi WebScript, but I need to get results
> > back to
> > go into a DB.
> >
> > Has anyone got any Ideas? Would Classes be the best? or is there
> > something
> > else I can look at?
> >
> > Cheers,
> >
> > Jeremy Coulter
> >
> >
> > ---
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>
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Re: [DUG]: What is the best way

[Dennis Chuah]

Message
Design:  Use interfaces or an abstract base class.  Define the methods that
do the data conversion in the interface / abstract base class.
For each dat conversion method, create a concrete class that either
implements the interface or sub-classes the abstract base class.

Implementation:  Use packages.  Each class can be in its own package.  Use
an INI file setting to determine which package to load.  You can export a
method in the package that creates an instance of the class and either
returns the interface or the abstract base class reference.

- Original Message -
From: Jeremy Coulter
To: Multiple recipients of list delphi
Sent: Tuesday, August 05, 2003 10:54 PM
Subject: [DUG]: What is the best way


Hi All.
I have got an app. that gets data from devices via the comport.
60% if not more of the data from these devices is similar or easy  to deal
with, like dates and times, but other info can be specific to a device, and
i have to normalize it into a format that I want.

In times gone by, about 6-7 years ago, if not more, when I first wrote this
app., I used DLL's and depending onn teh devide you specified in an INI file
it used that DLL, which I think from memory was done via the setup, so there
was only one DLL.
BUT this was really not a good idea, as it was hard to debug and just
overall never practical.

I have thought that I could use classes this time round, once again
specifying the device type in an INI file, and then based onthat it would
know hat class to use.
But is this the best way either? I mean, if I find a device that has not got
a class for it already, then its a new EXE release.

I guess what woud be idea would be if I could load some specific functions
up at runtime, and then access them then it would only ever be a txt file or
whatever that I would need to distribute.
I thought something like Delphi WebScript, but I need to get results back to
go into a DB.

Has anyone got any Ideas? Would Classes be the best? or is there something
else I can look at?

Cheers,

Jeremy Coulter



All email scanned with Nortons Antivirus 2003

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Re: Re[2]: [DUG]: Textfile display on web page

[Dennis Chuah]

Not 100% sure what you are after, but you can always warp any text file with
the following - will display in most browsers!





--- the contents of the text file 





You need to make sure you escape these characters in the contents: < becomes
<  > becomes >  & becomes &
There is a whole list of other escapes you can use, but with most browsers
the above 3 seem to be all that is needed.

Dennis.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, July 24, 2003 9:09 AM
Subject: Re[2]: [DUG]: Textfile display on web page


> Hello James(Jim),
> Sorry - but what would the html code be for getting this to display??
>
>
>
> Thursday, July 24, 2003, 8:37:26 AM, you wrote:
> JJS> On my local IIS http://localhost/version.txt seems to work
>
> JJS> -Original Message-
> JJS> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
> JJS> Behalf Of Alistair George
> JJS> Sent: Thursday, 24 July 2003 8:03 a.m.
> JJS> To: Multiple recipients of list delphi
> JJS> Subject: [DUG]: Textfile display on web page
>
> JJS> You can display a graphics file easily enough in html on a web page,
but
> JJS> how do
> JJS> you display a textfile on a web page?
> JJS> I want to display each new version and date of my software which is
in a
> JJS> textfile
> JJS> on a web site (version.txt). Myprogram links to it for update
> JJS> information, so it
> JJS> makes sense to use that info as well on the programs web page.
> JJS> Anyone know how? html code please.
> JJS> Al+
>
>
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Re: [DUG]: tregistry...

[Dennis Chuah]

I tend to avoid the registry like plague.  It is slow, has all sorts of 
permissions issues and is not suitable for storing larger amounts of data 
(you can run out of registry storage space).  Also I find too many programs 
stuff keys in the registry, bloating it up and making it unmanageable.  That 
is why there is so many "registry clean-up" programs out there.

I prefer to use Delphi class streaming (as used by Delphi to stream dfm 
files) to store data.  Keep your configuration info in a TPersistent class, 
and make sure all properties you want to store are in the published section. 
 I prefer to save as text (use ObjectBinaryToText and ObjectTextToBinary) 
because you can load the text file into a simple text editor and modify it - 
useful if you need to support clients.

Secure data can be encrypted - see TurboPower Lockbox in SourceForge for an 
open-sourced data encryption library.

Dennis.

From: "Chris Veale" <[EMAIL PROTECTED]>
Hi.
I just thought that if I am going to be having to process these regularly,
would it be better to store information in the system registry?  there is
going to be lots of data, but I know tregistry replaces the old 16 bit
tinifile.
would this be an option if I have about 5000 lines of variables I want to
retain?
plus the same number for approximately 20 other files I need to reference,
or is this complete overkill?
I have never played around with the registry before and Im not sure of the
load or proper procedure for doing something like this.
essentially the files I'm referencing are lookup files that, when the user
selects a certain combination of variables in the program, we graph the 
vars
read in from the file.

Hope that makes sence.

Chris

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Re: [DUG]: Casting

[Dennis Chuah]

No, you cannot do it with a simple cast.

var
  Newfile:string;
  temp: TStringList;

begin
  temp := TStringList.Create;
  try
temp.Text := Newfile;
success := Burnfiles (temp);
  finally
temp.Free;
  end;


- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, July 21, 2003 7:32 PM
Subject: [DUG]: Casting


> Hi all.
> Is there a way to cast a string to a single item stringlist eg
> function BurnFiles(Fileslist: tstringlist): boolean;
>
> var Newfile:string;
>
> if Burnfiles(Newfile ?? as Tstringlist.text) then success:=true;
>
> --
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Re: [DUG]: [Q] Stream.ReadComponent, Stream.WriteComponent problem....

[Dennis Chuah]

May be asking the obvious but is the Boo property of TNamMessageForComms
published and not read-only?  Which version of Delphi are you using?  Also,
is TNamMessageForComms a TComponent?

- Original Message -
From: "Donovan J. Edye" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, July 10, 2003 6:59 PM
Subject: [DUG]: [Q] Stream.ReadComponent, Stream.WriteComponent problem


> G'Day,
>
> See below for the class declarations and the encode and decode methods
that
> I am using. I am not compressing anything so this should be a plain write
> component to a stream and read it back again. However when I read the
> component again from the stream I can only see properties that are from
> TNamMessageForComms so for instance I can see Boo2, Payload, Header. But
all
> the properties for these subcomponents are not there. So for instance
> Payload.Boo is always an empty string. What am I missing here that is not
> making the sub components of TNamMessageForComms stream correctly.
>
> Any pointers etc. greatly appreciated.
>
> TIA
>
>
> function TNamMessageForCommsEncDec.Encode(const ACompression :
> TCompressionRange;
>   const ASourceStream : TMemoryStream; var AOutputStream : TMemoryStream)
:
> TEncodeDecodeError;
>

> 
> // PURPOSE: Encodes the supplied data into a stream for transmission. This
> // method is called by all the other overloaded methods of the same name.
It
> // makes use of the TNamMessageForComms
> // HISTORY:
> //   DJE 10/07/2003 #   Initial Creation
> begin
>   //Default behaviour
>   result := MSG_DECODE_ERR_UNKNOWN;
>   AOutputStream.Clear;
>
>   //Header
>   FMessage.Header.MessageType := MSG_REGULAR;
>
>   //Payload
>   //Clear
>   FMessage.Payload.Data_Clear;
>   //Compression
>   FMessage.Payload.Compressed := ACompression;
>   //Assign
>   FMessage.Payload.Data_Set(ASourceStream);
>
>   //Now place on the output stream
>   AOutputStream.WriteComponent(FMessage);
>
>   //Show success
>   result := MSG_DECODE_ERR_NONE;
> end;
>
> function TNamMessageForCommsEncDec.Decode(ASourceStream : TMemoryStream;
>   var AOutputStream : TMemoryStream) : TEncodeDecodeError;
>

> 
> // PURPOSE: Decodes a byte stream that was placed into the source stream
> // originally by Encode.
> // HISTORY:
> //   DJE 10/07/2003 #   Initial Creation
> begin
>   //Default behaviour
>   result := MSG_DECODE_ERR_UNKNOWN;
>   AOutputStream.Clear;
>
>   //First get the component in its entirey
>   ASourceStream.Position := 0;
>   FMessage := TNamMessageForComms(ASourceStream.ReadComponent(nil));
>
>   //Decompress it if required
>   //The class is optomised to deal with this assignment so there is no
> performance
>   //penalty
>   FMessage.Payload.Compressed := COMPRESSION_NONE;
>
>   //Now return the payload ontothe stream supplied
>   AOutputStream.Write(FMessage.Payload.Data,
SizeOf(FMessage.Payload.Data));
>
>   //Show success
>   result := MSG_DECODE_ERR_NONE;
> end;
>
>
> initialization
>   RegisterClass(TNamMessageForComms);
>   RegisterClass(TNamMessageForCommsHeader);
>   RegisterClass(TNamMessageForCommsPayload);
> finalization
>   UnRegisterClass(TNamMessageForComms);
>   UnRegisterClass(TNamMessageForCommsHeader);
>   UnRegisterClass(TNamMessageForCommsPayload);
> end.
>
>
>   ENamMessageForCommsHeader = class(Exception);
>   TNamMessageForCommsHeader = class(TComponent)
>
>

> //
> // This class contains all the META or header information for a
> particular
> // message. See TNamMessageForComms for more detail on why we are
using
> a
> // TComponent descendant. Keep this as small as possible as it will be
> prepended
> // to each message sent.
>   private
> FMessageType : TMessageType;//Indicates the type of message
> property MessageType : TMessageType read FMessageType write
> FMessageType;
>   published
>   end;
>
>   //Byte stream containing the data
>   TPlayloadData = array of byte;
>
>   ENamMessageForCommsPayload = class(Exception);
>   TNamMessageForCommsPayload = class(TComponent)
>
>

> //
> // This class contains all the data payload for a message. See
> TNamMessageForComms
> // for more detail on why we are using a TComponent descendant
>   private
> FBoo : string;
> FCompressed : TCompressionRange;
> FData : TPlayloadData;
> FZipper : TVCLZip;
> FZipTmpFileName : TFileName;
> procedure Set_Compressed(const Value : TCompressionRange);
> function Stream_Compress(ACompressionLevel : TCompressionRange; const
> AOriginalStream : TMemoryStream;
>   var ACompressedStream : TMemoryStream) : boolean;
> function Stream_DeCompress(const AOriginalStream : TMemorySt

Re: [DUG]: format function

[Dennis Chuah]

var
  A: array of TVarRec;

Just beware - it is not as simple as it seems.  For one, you will need to
make sure strings referred to by TVarRec remains active until after the call
to Format.

- Original Message -
From: "Neven MacEwan" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, June 26, 2003 4:24 PM
Subject: [DUG]: format function


> Hi all
>
> I want to use the format function and pass it a dynamic array of values,
Can
> this be done
>
> S := 'Name is %s %s';
> Result := format(S,A)
>
> but how do I declare A?
>
> TIA
>
>  Regards Neven
>  N.K. MacEwan B.E. E&E
>  Ph 649 621 0001
>  Fax 649 621 0400
>  [EMAIL PROTECTED]
>
> --
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>
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Re: [DUG]: I want to be subscriber of delphi.org.nz but without the messages flooding email

[Dennis Chuah]

I don't normally reply to non-technical messages like this to the list, but
I make an exception for this one because I think it might be of benefit to
others.  If you object, please delete this message.

Ben,

Why don't you simply set your mail filtering rules to move all messages to
your "Deleted items" or similar folder.  That way, your inbox will not be
cluttered.  Better still, create a NZDUG folder and redirect the mail
messages there.  This list is quite easy to filter because the subject
contains "[DUG]".

Regards,
Dennis.

- Original Message -
From: "Ben none" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, June 26, 2003 3:07 PM
Subject: [DUG]: I want to be subscriber of delphi.org.nz but without the
messages flooding email


> Hi
>
> I want to be able to post messages to [EMAIL PROTECTED] and still read
> the
> message archive http://www.mail-archive.com/delphi%40delphi.org.nz/
> but I don't want to receive the messages through my email cos there is
just
> to much to read or delete.
>
> Is there anyway I can still be apart of the group without having my email
> chocka block.
>
> Please reply.
>
> Ben Iti
>
> _
> Check out the Xtra gaming servers at  http://xtramsn.co.nz/gaming !
>
> --
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Re: [DUG]: Conversion

[Dennis Chuah]

popen is a function in Visual C's library.  Basically, it creates a pipe,
executes the process, "cdrecord -atip", and redirect its output to the pipe.

Unfortunately Delphi does not have a popen in the VCL, but you can achieve
the same using a few lines of code that makes WinAPI calls.  The following
algorithm uses a temporary file instead of a pipe, but the result is the
same - you get the output of the spawned process.

1.  Call GetTempFileName to get the name of a temporary file

2.  Declare TSecurityAttributes like so:

var
  SecAtrrs: TSecurityAttributes;
begin
  SecAtrrs.nLength := SizeOf(SecAtrrs);
  SecAtrrs.lpSecurityDescriptor := nil;
  SecAtrrs.bInheritHandle := True;  // Must be set to True!!!

3.  Create the file using a call to CreateFile, passing in SecAtrrs.  It is
important to use SecAtrrs - otherwise it will not work.  Save the returned
handle in a variable.   See example:

var
  hOutput: THandle;
begin
  hOutput := CreateFile (PChar(TempFileFilename),
GENERIC_READ or GENERIC_WRITE,
FILE_SHARE_READ or FILE_SHARE_WRITE, @SecAtrrs, CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL or FILE_ATTRIBUTE_TEMPORARY, 0);

4.  Declare TStartupInfo like so:

var
  StartupInfo: TStartupInfo;
begin
  FillChar (StartupInfo, Sizeof(StartupInfo), 0);
  StartupInfo.cb := SizeOf (StartupInfo);
  StartupInfo.wShowWindow := SW_HIDE; // Or you may choose to display it
  StartupInfo.dwFlags := STARTF_USESHOWWINDOW or
STARTF_FORCEOFFFEEDBACK or
STARTF_USESTDHANDLES;
  StartupInfo.hStdOutput := hOutput;  // Reassign stdout and stderr
  StartupInfo.hStdError := hOutput;

5.  Declare TProcessInformation like so:

var
  ProcessInformation: TProcessInformation;
begin
  FillChar (ProcessInformation, Sizeof(ProcessInformation), 0);
  FillChar (SecAtrrs, SizeOf(SecAtrrs), 0);

6.  Then call CreateProcess like so:

  CreateProcess (Nil, "cdrecord -atip", Nil, Nil, True,
CREATE_NEW_CONSOLE or NORMAL_PRIORITY_CLASS, Nil,
PChar(WorkingDir), StartupInfo, ProcessInformation);

where WorkingDir is the working directory for "cdrecord".

7.  Retrieve the handles:

var
  ProcessHandle, ThreadHandle: THandle;
begin
  ProcessHandle := ProcessInformation.hProcess;
  ThreadHandle := ProcessInformation.hThread;

8.  Wait for it complete.

  if WaitForSingleObject (ProcessHandle, INFINITE) = WAIT_OBJECT_0 then

9.  Close the output file and other handles.  It is important to close the
process and thread handles because Windows will not do that automatically
for you.

  CloseHandle (hOutput); // To make sure all data is flushed to disk
  CloseHandle (ProcessHandle);
  CloseHandle (ThreadHandle);

10.  You can now read the contents of the temporary file (eg. open it using
a TFileStream), and delete it once you are done.

HTH,
Dennis.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, June 26, 2003 3:32 PM
Subject: [DUG]: Conversion


> Hi all.
> Can anyone translate this to pascal for me?
>
> FILE *fp
> fp=popen ("cdrecord -atip", "r")
> fread (fp) //gets the output
>
> --
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Re: [DUG]: Need component to imitate Windows Explorer

[Dennis Chuah]

Take a look at open sourced VirtualExplorerTree at
http://groups.yahoo.com/group/VirtualExplorerTree/.

or TurboPower Shell Shock (now open source) at
http://sourceforge.net/projects/tpshellshock/

- Original Message -
From: [EMAIL PROTECTED]
To: Multiple recipients of list delphi
Sent: Wednesday, June 25, 2003 3:07 PM
Subject: [DUG]: Need component to imitate Windows Explorer


I need a component which will allow me to imitate Windows Explorer, to allow
users access to a certain part of the file system. I need to be able to tie
it down security wise as much as I want e.g. stop deletes, stop copies, stop
renames, or allow all these things if appropriate. I've used an open dialog
which seemed by the properties provided, to suggest I could restrict these
things, but it didn't work. (With the particular scenario we have, it's not
possible to just use windows security, otherwise I'd do it that way).

Any suggestions? TIA
Dave Jollie
Developer, TOWER NZ IT
(: 09 368 4259
J: 09 306 6801
*: [EMAIL PROTECTED]
.: 46 Parnell Rd, Parnell, Auckland
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Re: [DUG]: Those const again

[Dennis Chuah]

Delphi handles typed constants just like any variables.  The only difference
is typed constants can have an initial value, which you can then safely
change.  Don't worry about overwriting string memory because internally,
string variables are pointers to the string data.  So, changing the string
merely changes the pointer value.  String data is reference counted and the
string memory manager will know to free these data blocks when the reference
count drops to 0.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, June 19, 2003 8:57 AM
Subject: [DUG]: Those const again


> Hi all.
> Thanks for enlightening me on use of const.
> But.if a const is initialised like so:
> const FirstDir: string = '';
> Say another const is initialised eg NextConst then FirstDir:='I am now a
rather large
> string, whereas before i was length 0';
> There is no possibility of collision with NextConst is there? I would
> imagine not, but not knowing the way the assembler places it into memory
it
> could be a valid consideration.
> Thanks,
> Al+
>
> --
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Re: [DUG]: Delphi optimizer

[Dennis Chuah]

One danger with hand optimising ASM code is illustrated by your example.  In
the generated code:

> mov byte ptr [eax+$304], $0

writes 0 to BYTE location [eax+$304], whereas you

mov [eax+$304], edx

writing a DWORD into location [eax+$304], possibly overwriting memory.

This sort of bugs can be vary hard to track down.  The software would seem
to work for some time, then a bug would appear in a complete unrelated area.

You should therefore write your code like:

xor edx, edx
mov [eax+$2fc], edx
mov [eax+$300], edx
mov byte ptr [eax+$304], $0

which is only a saving of one instruction!

On a Pentium CPU (and the AMD CPU's as well), basic instructions execute in
1 CPU clock cycle.  This means your hand optimised assembler only runs 1
nano second faster than that generated by Delphi.  I won't bother if I were
you.

Dennis.

- Original Message -
From: "Leigh Wanstead" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, June 17, 2003 11:43 AM
Subject: [DUG]: Delphi optimizer


> Hello everyone,
>
> I was surprised that Delphi 7 generate following asmbler code for this
> pascal code. I have turned on Code generation/Optimization.
>
>   fMyRecord.fLength := 0;
>   fMyRecord.fCount := 0;
>   fMyRecord.fReadOnly := False;
>
> xor edx, edx
> mov [eax+$2fc], edx
>
> xor edx, edx
> mov [eax+$300], edx
>
> mov byte ptr [eax+$304], $0
>
> I think the optimized asm code will look like this.
>
> xor edx, edx
> mov [eax+$2fc], edx
> mov [eax+$300], edx
> mov [eax+$304], edx
>
> I tested the hand written asm code, it is 5 cpu clock cycle faster. I hate
> to put asm in my source code. So the question is how to write delphi code
to
> generate optimize asm code like this one.
>
> I know this slow down may not sound that much, just for research purpose.
>
> I have enclosed delphi sample code for your reference. I look forward to
> hearing from you.
>
> TIA
>
> Best Regards
> Leigh
>
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Re: [DUG]: Interface Inheritance

[Dennis Chuah]

Let me simplify your example:

type
  TNewClass = class(TInterfacedObject,ISecondDescendant);

var
  First: IFirstDescendant;
  Second: ISecondDescendant;

Second := TNewClass.Create;  // Line 1
First := Second;  // Line 2

The above compiles and works fine.  Line 1 actually performs 2 operations:

1.  o := TNewClass.Create, where o is a temp var of type TNewClass
2.  Second := o

Contrary to popular belief, the second operation does not call
QueryInterface.  Instead, at compile time, the interface reference is bound
to the object reference.  This is because at compile time, the interface
reference is always a known offset from the object reference (see my last
long post).

To see this you can either look at the compiled code, or remove the GUID
from your interface declaration.  Without a GUID, the second operation still
works, whereas, if the second operation was:

Second := o as ISecondDescendent,

without a GUID will raise a compile time error.

Line 2 also works because ISecondDescendent implements all methods of
IFirstDescendents and are therefore assignment compatible.  The important
point here is they are assignment compatible, but they are different.

However, if you do:

First := Second as IFirstDescendent

you will get an exception EIntfCastError.  This is because the "as" operator
calls QueryInterface on Second, and TNewClass does not support
IFirstInterface.

Regards,
Dennis.

- Original Message -
From: "Todd Martin" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, June 16, 2003 1:46 PM
Subject: Re: [DUG]: Interface Inheritance


> Hi Guys.
>
> Thanks for all the feedback. I didn't realise it would get so much
response.
> In the end I decided to go with the following :
> IFirstDescendant = interface(IInterface);
> ISecondDescendant = interface(IFirstDescendant);
>
> TNewClass = class(TInterfacedObject,IFirstDescendant ,ISecondDescendant);
>
> However I noticed one very peculiar aspect of interfaces along the way
when
> compiling.
>
> If I define a procedure
> DoSomething(AObject : IFirstDescendant);
> and
> TNewClass = class(TInterfacedObject,ISecondDescendant);
>
> and then the following code compiles okay
>
> procedure Test;
> var
> MyObject : ISecondDescendant;
> begin
>   MyObject := TNewClass.Create;
>   DoSomething(MyObject);
> end;
>
> I haven't checked yet, but I'm assuming the MyObject passed through to
> procedure DoSomething() is then "nil", since TNewClass doesn't support
> IFirstDescendant. Would that be your guess too? So why does it compile? On
> the otherhand, does the ISecondDescendant pointer get sucessfully
converted
> to a IFirstDescendant pointer, in which case, why does
> MyObject.QueryInterface(IFirstDescendant,FirstObject) return a "nil"
pointer
> to FirstObject?
>
> However, if I define
> IFirstDescendant = interface(IInterface);
> ISecondDescendant = interface(IInterface);
>
> ie. no interface inheritance - (or whatever you want to call it)
> and
>
> TNewClass = class(TInterfacedObject,IFirstDescendant,ISecondDescendant);
>
> the Test() procedure does not compile. Any comments?
>
> Thanks.
>
> - Original Message -
> From: "Conor Boyd" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Monday, June 16, 2003 10:31 AM
> Subject: RE: [DUG]: Interface Inheritance
>
>
> > There are a lot of people (including me) who never use the term
'interface
> > inheritance'.  You're right, it's not inheritance.
> >
> > As an aside, having had the 'chance' recently to go some VB6 coding
:-( I
> > found the Microsoft documentation utterly misleading when it talks about
> > interface inheritance, when IMO it should be talking about 'interface
> > implementation', which is probably a phrase which is also appropriate to
> > what we're talking about here.
> >
> > Cheers,
> >
> > Conor
> >
> > -Original Message-
> > From: Karl Reynolds [mailto:[EMAIL PROTECTED]
> >
> > > So this is one simple case where you have IStream inheriting
> > > from ISequentialStream (see ActiveX.pas) but you are not required
> > > to implement ISequentialStream is you are implementing IStream.
> >
> > Utterly bizarre.  I get your point - that interface "inheritance" has to
> be
> > implemented the way it is in Delphi in order to support such
strangeness.
> > But it's not really inheritance any more, is it.
>
> --
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> >
>
>
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Re: [DUG]: Non-global Constants in a function

[Dennis Chuah]

> FYI, maybe this is what you meant, but AFAIK you can safely remove the
> Delphi generated form vars from every form unit except your apps main
form.

Yes, that is kinda what I meant.  Its a real pain the only way to assign a
form as the main form is to use Application.CreateForm.  Actually, you can
safely remove the form vars from ALL units, including the main form.  All
you need is the following in your .DPR file:

var
  frmMain: TfrmMain;  // Only unit level var!

begin
  Application.Initialize;
  Application.Title := 'Main application';
  Application.CreateForm(TfrmMain, frmMain);
  Application.Run;
end.

Now all I ask from Borland is another option in the IDE not to generate the
form vars.

Dennis.

- Original Message -
From: "Conor Boyd" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, June 16, 2003 11:21 AM
Subject: RE: [DUG]: Non-global Constants in a function


> FYI, maybe this is what you meant, but AFAIK you can safely remove the
> Delphi generated form vars from every form unit except your apps main
form.
>
> [Comprehensive answer on the interface stuff, BTW!]
>
> Cheers,
>
> C.
>
> -Original Message-
> From: Dennis Chuah [mailto:[EMAIL PROTECTED]
>
> What you read only applies to const parameters.  I would continue to use
> method level consts and not move them to the unit level.  In fact, I
*never*
> use unit level vars, except for the Delphi generated main form code.
Using
> method level is safer than unit level vars.
>
> [snip]
> --
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Re: [DUG]: Non-global Constants in a function

[Dennis Chuah]

What you read only applies to const parameters.  I would continue to use
method level consts and not move them to the unit level.  In fact, I *never*
use unit level vars, except for the Delphi generated main form code.  Using
method level is safer than unit level vars.

Eg. in multi-threading apps, the method can contain synchronisation code to
serialise access to the variable.

You can implement singleton classes like this:

TSingleton = class
  function GetInstance: TSingleton;
end;


function TSingleton.GetInstance: TSingleton;
const
  FInstance: TSingleton = Nil;
begin
  if not Assigned (FInstance) then begin
// Put thread sync code here
FInstance := TSingleton.Create;
  end;

  Result := FInstance;
end;

Dennis.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, June 13, 2003 3:49 PM
Subject: [DUG]: Non-global Constants in a function


> In the past I have used const in a proc or func to allow re-entering the
routine
> later  to use the same variable value. But reading the following help it
seems I
> am doing the wrong thing. Should I be using a global variable instead?
>
> QUOTE
> A  constant  (const)  parameter  is like a local constant or read-only
variable.
> Constant  parameters  are  similar  to  value  parameters, except that you
cant
> assign  a  value  to  a  constant  parameter  within  the body of a
procedure or
> function,  nor can you pass one as a var parameter to another routine.
(But when
> you  pass  an object reference as a constant parameter, you can still
modify the
> objects properties.)
>
> eg
> function Tmainform.ParseAddFiles(FName: string; Recurse: boolean): string;
> const PrevDIR: string = '
';
> begin
>   result := '';
>   if pos('*.*', fname) > 0 then
>   begin
> PrevDIR := extractfiledir(fname);  //This remains until redefined??
> result := Fname;
> exit;
>   end;
>   if extractfiledir(fname) = prevdir then //this file is already in *.* so
omit
>   begin
> result := '';
> exit;
>   end;
> end;
>
> --
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Re: [DUG]: Interface Inheritance (long)

[Dennis Chuah]

Simple answer is no.  Your class *DOES NOT* support IFirstDescendant.  You
must explicitly tell the compiler that your class supports IFirstDescendant:

TNewClass = class(TInterfacedObject,IFirstDescendant,ISecondDescendant)

Interface inheritance is *DIFFERENT* from class inheritance.  The idea of
interfaces is each interface is a complete and is independent of
implementation, whereas a class declaration can be incomplete (eg. abstract
base classes).  When you implement an interface, you must implement it
completely  (you can still make any non-implemented methods abstract).

Your example is a good one:

Though ISecondDescendant inherits from IFirstDescendant, it is a different
interface from IFirstDescendant and the only thing get from the inheritance
is the short form of not having to redeclare IFirstDescendant methods in
ISecondDescendant.

So why doesn't Delphi treat

TNewClass = class(TInterfacedObject,ISecondDescendant)

as

TNewClass = class(TInterfacedObject,IFirstDescendant,ISecondDescendant)?

The answer is because a class may implement its interfaces independently and
differently - eg.

IFirstDescendent = interface (IInterface)
  procedure A;
end;

ISecondDescendent = interface (IFirstDescendent)
  procedure X;
end;

TNewClass = class(TInterfacedObject,IFirstDescendant,ISecondDescendant)
  procedure A;
  procedure B;
  procedure X;

  procedure IFirstDescendant.A = A;
  procedure ISecondDescendant.A = B;
end;

TNewClass implements IFirstDescendent using procedure A, and
ISecondDescendant using procedures B and X.  ie.

p := TNewClass.Create;
a := p;
b := p;

a.A performs a different operation than b.A.

and even if you;

a := b;
a.A -> actually calls TNewClass.B!


At compile time:

TInterfacedObject implements IInterface
TNewClass implements *ONLY* ISecondDescendant (its base class,
TInterfacedObject, implements IInterface).

Internally, Delphi creates a separate v-table for each interface a class
implements, but only one v-table for the class members.

So:

TObject ==> has one v-table

TInterfacedObject = class (TObject, IInterface) ==> has two v-tables:
  1.  v-table for TInterfacedObject, which is made up of the v-table for
TObject, plus any new or overriden method members of TInteracedObject.
  2.  v-table for IInterface

TNewClass = class (TInterfacedObject,ISecondDescendant) ==> has 3 v-tables:
  1.  v-table for TNewClass, which is made up of the v-table for TObject,
plus any new or overriden method members of TInteracedObject., plus new or
overriden method members of TNewClass.
  2.  v-table for IInterface
  3.  v-table for ISecondDescendant
There is no v-table created for IFirstDescendant.

However, the v-table for ISecondDescendant is made up of the v-table for
IInterface, plus all new methods from IFirstDescendant, plus all new methods
from ISecondDescendant.

Then at run time:

Each instance of the object you create will contain:
1.  A reference to the object's v-table
2.  The object's data members
3.  One reference to the v-table for each directly supported interface.

Using your example, an instance of TNewClass that is stored at location p
will look like:

p -> reference to TNewClass's v-table
p+4 .. p+n+3 -> TInterfacedObject data members (n - total number of bytes)
p+n+4 -> reference to IInterface
p+n+8 .. p+n+m+7 -> data members added by TNewClass (m - total number of
bytes)
p+n+m+8 -> reference to ISecondDescendant

TNewClass.Create returns p
Casting p as IInterface returns p+n+4
Casting p as ISecondDescendant returns p+n+m+8

Optimation:

The compiler will optimise v-tables for interface declarations at compile
time so that linear sequences of inheritance without method overrides use
the same v-table.  Using your example, both IFirstDescendant and
ISecondDescendant will point to the same v-table.  If you declared TNewClass
as:

TNewClass = class(TInterfacedObject, IFirstDescendent,ISecondDescendant)

then your instance will look like

p -> reference to TNewClass's v-table
p+4 .. p+n+3 -> TInterfacedObject data members (n - total number of bytes)
p+n+4 -> reference to IInterface
p+n+8 .. p+n+m+7 -> data members added by TNewClass (m - total number of
bytes)
p+n+m+8 -> reference to ISecondDescendant (also used for IFirstDescendent)

TNewClass.Create returns p
Casting p as IInterface returns p+n+4
Casting p as IFirstDescendent returns p+n+m+8
Casting p as ISecondDescendant returns p+n+m+8

If however, your interface declarations are non-linear:

IOtherDescendent = interface (IFirstDescendent)
TNewClass = class(TInterfacedObject,
IFirstDescendent,ISecondDescendant,IOtherDescendent)

then the instance will look like:

p -> reference to TNewClass's v-table
p+4 .. p+n+3 -> TInterfacedObject data members (n - total number of bytes)
p+n+4 -> reference to IInterface
p+n+8 .. p+n+m+7 -> data members added by TNewClass (m - total number of
bytes)
p+n+m+8 -> reference to ISecondDescendant
p+n+m+12 -> reference to IOtherDescendent

TNewClass.Create returns p
Casting p as IInterface return

[DUG]: Re: Setting Windows Scheme Colours from Delphi - how?

[Dennis Chuah]

Moretti,

Windows stores the colour information in the registry on a per user basis.
The user information registry key starts with HKEY_USERS.  Under HKEY_USERS,
there should be at least 3 sub keys, .DEFAULT and for each user in the
system, a pair of keys made up of the internal GUID userID of the user.  I
am assuming Win2K + here, but Win98 is similar.  For the process' user, this
information is also reflected in HKEY_CURRENT_USER.  To change the current
user's settings, go to the key HKEY_CURRENT_USER\Control Panel\Colors, and
modify any of the named values inside that key.  Eg. the "WindowText" value
specifies the default foreground colour.  Data is stored as a
space-separated value string.  The first value is the red component,
followed by green then blue.  Valid values are from 0 to 255.

Modifications to HKEY_USERS\.DEFAULT\Control Panel\Colors only affect new
users, or existing users who create a new profile for themselves on the
machine.

After changing the registry setting(s), you must send the WM_SETTINGCHANGE
message.  This informs all top level windows to refresh themselves.  If you
forget to send this message, it is possible for some windows to remain in
the old colour while others (especially new windows) display in the new
colours.

Regards,
Dennis.

- Original Message -
From: "Moretti, Giovanni" <[EMAIL PROTECTED]>
To: "Dennis Chuah" <[EMAIL PROTECTED]>
Sent: Tuesday, June 10, 2003 10:44 AM
Subject: Setting Windows Scheme Colours from Delphi - how?


Hi Dennis

> Firstly, you need to ask yourself where it is desirable to alter the
> Windows default colours from your app.  The usual way, as you say,
> is via the control panel.  Users could be confused and irritated if
> your app changes those colours without their knowledge.
> ...  Unless of course, the purpose of the software is to allow users
> change those Windows settings.

> If you can convince me why you would want to add this "feature"
> to your software, I'll tell you the Windows API calls to make.

Yes, I know it's probably not a good idea in production software,
however this is part of my PhD research on the feasibility of generating
harmonious colour schemes, semi-automatically. Part of this is to make
the colour of windows "agree" with surrounding object including the
background, window borders ...

I'm not sure that changing the overall colour scheme is desirable, but
I'd like to be able to have tried it and then be able to state "for the
record" that users found it disturbing (or not), rather than just
assuming they will.

Reason enough ...

Thanks
Giovanni

Giovanni Moretti  |  Institute of Information Sciences and Technology
Senior Lecturer   |  Massey University, Palmerston North, New Zealand
Computer Science  |  Ph 64-6-3505799x2474 == Fax 64-6-3502259 == ZL2BOI

http://www-ist.massey.ac.nz/moretti  mailto:[EMAIL PROTECTED]
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Re: [DUG]: Setting Windows Scheme Colours from Delphi - how?

[Dennis Chuah]

Moretti,

Firstly, you need to ask yourself where it is desirable to alter the Windows
default colours from your app.  The usual way, as you say, is via the
control panel.  Users could be confused and irritated if your app changes
those colours without their knowledge.  I for one, would promptly uninstall
such a program and send a couple of rude emails to the author.  Unless of
course, the purpose of the software is to allow users change those Windows
settings.

If you can convince me why you would want to add this "feature" to your
software, I'll tell you the Windows API calls to make.

Regards,
Dennis.


- Original Message -
From: "Moretti, Giovanni" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, June 09, 2003 3:52 PM
Subject: [DUG]: Setting Windows Scheme Colours from Delphi - how?


Hi

Undoubtably it's possible to change the colours Windows uses for the
desktop background, (in)active window header ... from delphi.  I want to
be able the SET these colours, not just access their current values, but
from Delphi, not the usual Control Panel/Display property applet.

Anyone know how?

Thanks
Giovanni
===
Giovanni Moretti  |  Institute of Information Sciences and Technology
Senior Lecturer   |  Massey University, Palmerston North, New Zealand
Computer Science  |  Ph 64-6-3505799x2474 == Fax 64-6-3502259 == ZL2BOI
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Re: [DUG]: Graphics problems

[Dennis Chuah]

A JPEG file usually uses a compression algorithm that is not losses,
meaning, when you reconstruct the bitmap from a JPEG file it is different
from the original bitmap from which the JPEG was created.  This is done so
as to achieve compression rates that are higher than  loss-less compression
algorithms.  The reconstructed image is only visually similar to the
original.  Because of this, is not possible for you to convert a JPEF to
bitmap and them back to a JPEG without any loss of quality.  The JPEG format
should be used as the final storage / transmission (eg. for web sites)
format.  If you intend to do any processing on the image, then a loss-less
format, such as LZW compressed tiff should be used instead.

Dennis.


- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, March 20, 2003 12:02 PM
Subject: [DUG]: Graphics problems


> Hi All.
> I have a JPEG image, which if I convert to bitmap, then back to JPEG
again, it
> is not the same. The problem occurs in the stretchdraw function.
> Can anyone advise how I can replicate exactly the JPEG original without
copying
> the JPEG original to another JPEG?
>
> What happens is most graphics programs can load the new image, but there
is a
> difference I cannot ascertain which stuffs up some other graphics
programs.
> Thanks,
> al+
>
> procedure TForm1.btnWriteClick(Sender: TObject);
> var Orig,Smaller:tjpegimage;
> buffer:tbitmap;
> smallFname:string;
> begin
>   smallFname := copy(ImgData.Filename,1,length(ImgData.Filename)-4)
> +'_smaller.jpg';
>   JpegOut.FileName := smallFName;
>   if not JpegOut.Execute then
> exit;
>   SmallFName := JPegOut.FileName;
>   Buffer := tbitmap.Create;
>   Orig := tjpegImage.Create;
>   Smaller := tjpegimage.create;
>   try
> Orig.LoadFromFile(ImgData.Filename);
> Orig.DIBNeeded;
> Buffer.PixelFormat := pf24bit;
> Buffer.Width := orig.Width div 2;
> Buffer.Height := orig.Height div 2;
> // Even if the width & height are the same the following does not
return a
> //copy of the original JPEG (disregard compression etc)
> Buffer.Canvas.stretchdraw(rect(0,0,Buffer.width,buffer.height),Orig);
> Smaller.PixelFormat:=orig.PixelFormat;
> Smaller.Assign(Buffer);
>
> --
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Re: [DUG]: PostMessage

[Dennis Chuah]

You passed!  Been working too much in python lately:

for f in range (0, 10):  #Python
for f := 0 to 9 do // Delphi

Dennis.

- Original Message -
From: "Neven MacEwan" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, March 19, 2003 3:39 PM
Subject: Re: [DUG]: PostMessage


> Denis
>
> Thanks, that would prob work
>
> mind you shouldn't that be "for f := 0 to Screen.FormCount-1 do"
> our were you just testing me :-)
>
> Neven
>
>
> - Original Message -
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Wednesday, March 19, 2003 3:21 PM
> Subject: Re: [DUG]: PostMessage
>
>
> >
> > HWND_BROADCAST only works with SendMessage.
> >
> > Try this code instead:
> >
> > var
> >   f: Integer;
> > begin
> >   for f := 0 to Screen.FormCount do
> > Screen.Forms[f].Perform (WM_APPDATACHANGE, 0, 0);
> >
> > Dennis.
> >
> > - Original Message -
> > From: "Neven MacEwan" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Tuesday, March 18, 2003 10:28 PM
> > Subject: [DUG]: PostMessage
> >
> >
> > > Hi all
> > >
> > > In my app I have a whole lot of forms which are embedded in a page
> control
> > > of the 'Main Form'
> > > If one one these forms wants to notify all other forms in the app of a
> > > change, what is the best way to do it?
> > >
> > > Iv'e tried
> > >
> > >   PostMessage(HWND_BROADCAST, WM_APPDATACHANGE, 0, 0);
> > >
> > > but none of the other forms seem to get this message, is this because
I
> > > really only have 1 form in my app?
> > >
> > > TIA
> > >
> > >
> > >  Regards Neven
> > >  N.K. MacEwan B.E. E&E
> > >  Ph 649 621 0001
> > >  Fax 649 621 0400
> > >  [EMAIL PROTECTED]
> > >
> >
>
> --
> > -
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> >
> >
>
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Re: [DUG]: PostMessage

[Dennis Chuah]

HWND_BROADCAST only works with SendMessage.

Try this code instead:

var
  f: Integer;
begin
  for f := 0 to Screen.FormCount do
Screen.Forms[f].Perform (WM_APPDATACHANGE, 0, 0);

Dennis.

- Original Message -
From: "Neven MacEwan" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, March 18, 2003 10:28 PM
Subject: [DUG]: PostMessage


> Hi all
>
> In my app I have a whole lot of forms which are embedded in a page control
> of the 'Main Form'
> If one one these forms wants to notify all other forms in the app of a
> change, what is the best way to do it?
>
> Iv'e tried
>
>   PostMessage(HWND_BROADCAST, WM_APPDATACHANGE, 0, 0);
>
> but none of the other forms seem to get this message, is this because I
> really only have 1 form in my app?
>
> TIA
>
>
>  Regards Neven
>  N.K. MacEwan B.E. E&E
>  Ph 649 621 0001
>  Fax 649 621 0400
>  [EMAIL PROTECTED]
>
> --
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Re: [DUG]: Free TWebBrowser component for use with D7 Personal?

[Dennis Chuah]

Throw away the TWebBrowser implementation that comes with Delphi and take a
look at this alternative:

http://www.euromind.com/iedelphi/

Dennis.

- Original Message -
From: "Moretti, Giovanni" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, March 18, 2003 3:43 PM
Subject: [DUG]: Free TWebBrowser component for use with D7 Personal?


Hi

All the internet components are missing with D7 Personal. Anyone know of
an equivalent to the TwebBrowser component - looks like a memopad but is
actually a web browser window.

Just something simple - a component you can resize at design time with a
method that does a "Load this URL into it" would suffice ...

Thanks
Giovanni

Giovanni Moretti  |  Institute of Information Sciences and Technology
Senior Lecturer   |  Massey University, Palmerston North, New Zealand
Computer Science  |  Ph 64-6-3505799x2474 == Fax 64-6-3502259 == ZL2BOI

http://www-ist.massey.ac.nz/morettimailto:[EMAIL PROTECTED]
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Re: [DUG]: [Q] A design issue...

[Dennis Chuah]

You will need a second thread to solve your problem.  In a nutshell:

1.  Display a modal dialogbox with a cancel button - this provides your
"block".
2.  Run the lengthy process on a separate thread, but at regular intervals,
check that the thread is terminated, and if it is, exit out of the execute
method.
3.  The cancel button terminates the thread
4.  The thread closes the dialogbox just before it exists from the execute
method.
5.  Optionally, you can have the thread periodically update dialog, eg.
display progress.

HTH,
Dennis.

- Original Message -
From: Donovan J. Edye
To: Multiple recipients of list delphi
Sent: Friday, February 14, 2003 12:12 PM
Subject: [DUG]: [Q] A design issue...


G'Day,

I have been trying to come up with an elegant solution to something but have
not had any success. Some suggestions and comments would be most welcome.
This is the scenario:

1. Application is single threaded
2. Makes call to a procedure that is very intensive (say a recursive scan of
a directory tree)

Now I dont want the 2. call to return until it has completed what it is
doing. However as it utilises 100% CPU the main application suffers. So how
do I work around this?

Possible Solutions

a) Provide a callback in the 2. procedure so that the application can do
something about things. Say call Application.ProcessMessages

This is OK, but it would be nice if the caller of 2. did not have to do
anything.

So I guess my question is. How do I change 2 so that it:

- Co-Operates nicely with its caller in terms of resource usage
- Blocks until it finishes

Is it somehow possible to kick off a thread in 2. but still have it block
until it finishes what it has to do?

I hope this is clear. Any comments, suggestions welcome.


-- Donovan
--
Donovan J. Edye [www.edye.wattle.id.au]
Namadgi Systems [www.namsys.com.au]
Voice: +61 2 6285-3460
Fax: +61 2 6285-3459
TVisualBasic = Class(None);
Heard just before the 'Big Bang': "...Uh Oh"
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Re: [DUG]: [Q] "Library Units" --> Run Time Package?

[Dennis Chuah]

If a package only has components and does not contain any property editors
or code to register the components, then you OUGHT TO make it runtime only,
but you DONT HAVE TO.  However, if a package refers to Delphi's design time
packages, then it MUST BE made a design-time only package.  Does this make
sense?

I have a general rule that all my component packages are runtime only and I
create design-time only packages for the property editors and registration
code.  The only exception to this rule is if I need to use an object
inspector type interface at runtime, eg. using Dream Controls. I do this so
that I do not have to redistribute code that is only used at design time but
not at run time.

Dennis.

- Original Message -
From: Donovan J. Edye
To: Multiple recipients of list delphi
Sent: Thursday, February 13, 2003 1:51 PM
Subject: Re: [DUG]: [Q] "Library Units" --> Run Time Package?


D,

If a component does not have any property editors is it just a runtime
package?

At 07:34 13/02/2003 +1300, you wrote:


I would create 3 packages, a runtime only package for the common units,
another runtime only package for the components and a design-time only
package for the property editor stuff.

- Original Message -
From: Donovan J. Edye
To: Multiple recipients of list delphi
Sent: Wednesday, February 12, 2003 3:19 PM
Subject: [DUG]: [Q] "Library Units" --> Run Time Package?


G'Day,

We have some common units for things like string handling etc. At present
these are just seperate units in the file system. We also have our own
components package which has runtime and design time flags set which uses
these units. The unfortunate side effect is that if someone creates a new
package that uses one of these common units then our main package is
required. So to avoid this I was considering placing all our common units
into a package that is a run-time package. Is this the best solution or is
there another way?


-- Donovan
--
Donovan J. Edye [www.edye.wattle.id.au]
Namadgi Systems [www.namsys.com.au]
Voice: +61 2 6285-3460
Fax: +61 2 6285-3459
TVisualBasic = Class(None);
Heard just before the 'Big Bang': "...Uh Oh"
--
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Donovan J. Edye [www.edye.wattle.id.au]
Namadgi Systems [www.namsys.com.au]
Voice: +61 2 6285-3460
Fax: +61 2 6285-3459
TVisualBasic = Class(None);
Heard just before the 'Big Bang': "...Uh Oh"
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Re: [DUG]: [Q] "Library Units" --> Run Time Package?

[Dennis Chuah]

I would create 3 packages, a runtime only package for the common units,
another runtime only package for the components and a design-time only
package for the property editor stuff.

- Original Message -
From: Donovan J. Edye
To: Multiple recipients of list delphi
Sent: Wednesday, February 12, 2003 3:19 PM
Subject: [DUG]: [Q] "Library Units" --> Run Time Package?


G'Day,

We have some common units for things like string handling etc. At present
these are just seperate units in the file system. We also have our own
components package which has runtime and design time flags set which uses
these units. The unfortunate side effect is that if someone creates a new
package that uses one of these common units then our main package is
required. So to avoid this I was considering placing all our common units
into a package that is a run-time package. Is this the best solution or is
there another way?


-- Donovan
--
Donovan J. Edye [www.edye.wattle.id.au]
Namadgi Systems [www.namsys.com.au]
Voice: +61 2 6285-3460
Fax: +61 2 6285-3459
TVisualBasic = Class(None);
Heard just before the 'Big Bang': "...Uh Oh"
--
GXExplorer [http://www.gxexplorer.org] Freeware Windows Explorer
replacement. Also includes freeware delphi windows explorer components.
--
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Re: [DUG]: Interfaces without reference counting

[Dennis Chuah]

You get an AV because after the call to ReleaseObject, the interface
reference goes out of scope.  Delphi then automatically calls _Release on
the interface, but because the implementation object is already freed, you
get an AV.

A better way of doing this is for ReleaseObject to set a flag, and when
_Release is called, it checks the flag to determine whether to free the
object.  But this too is dangerous because there may be other references to
the interface and when they go out of scope, _Release will be called.

Why do you want to bypass the reference counting anyway?

Dennis.

- Original Message -
From: "Todd Martin" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, January 29, 2003 11:11 AM
Subject: [DUG]: Interfaces without reference counting


> Hi. I'm trying to use interfaces in Delphi, but I want to disable
> reference counting. So I created a new class (shown below) with a
> method to free the object, but when I call ReleaseObject() I get an
> access violation after "Free".
> Anyone got any ideas about how I can free the interfaced object when I
> only have a reference to the interface?
>
> Todd
>
>   IamUnknown = interface(IUnknown)
>   ['{171F7C01-2C89-11D7-815B-2C9E07C1}']
> procedure ReleaseObject;
>   end;
>
>   TamInterfacedObject = class(TObject,IamUnknown)
>   protected
> function QueryInterface(const IID: TGUID; out Obj): HResult;
> stdcall;
> function _AddRef: Integer; stdcall;
> function _Release: Integer; stdcall;
> procedure ReleaseObject;
>   end;
>
> procedure TamInterfacedObject.ReleaseObject;
> begin
>Free;
> end;
>
> function TamInterfacedObject._AddRef: Integer;
> begin
>   //do nothing - ignore reference counting
>   Result := 0;
> end;
>
> function TamInterfacedObject._Release: Integer;
> begin
>   //do nothing - ignore reference counting
>   Result := 0;
> end;
>
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Re: [DUG]: Ellipsis truncation

[Dennis Chuah]

Call the WinAPI function DrawText (or it might have been DrawTextEx), and
one of the options is to shorten the string with an ellipsis.  You can also
get DrawText to return the shortened string, rather than draw it on the
canvas.

Dennis.

- Original Message -
From: "Nahum Wild" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, January 22, 2003 11:49 AM
Subject: RE: [DUG]: Ellipsis truncation


> We are currently still using Delphi 4 and don't seem to have it. :o(
>
>
> Nahum.
>
> > [EMAIL PROTECTED] 
> > wrote on
> >
> > MinimiseName in FileCtrl unit...
> >
> > Why it's not in the D5 help, I dunno...
> >
> > HTH,
> >
> > C.
> >
> > -Original Message-
> > From: Nahum Wild [mailto:[EMAIL PROTECTED]]
> > Sent: Wednesday, 22 January 2003 11:32 a.m.
> > To: Multiple recipients of list delphi
> > Subject: [DUG]: Ellipsis truncation
> >
> >
> > Does anybody know of a good way of shortening a capition shown on
> > screen to X pixels and putting an '...' at the end?  I seem to recall
> > that there might be an API call that'll do it, but I can't remember
> > it's name.
> >
> >
> > Cheers,
> > Nahum.
> >
> > --
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> > [EMAIL PROTECTED]
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>
>
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Re: [DUG]: Repaint/Refresh/Invalidate ???

[Dennis Chuah]

DrawMenuBar (Form.Handle);

- Original Message - 
From: Paul Mckenzie 
To: Multiple recipients of list delphi 
Sent: Wednesday, January 15, 2003 1:30 PM
Subject: [DUG]: Repaint/Refresh/Invalidate ???


Does anyone know how to force a menu to repaint itself ?


Regards
Paul McKenzie
Analyst Programmer
SMSS ltd.
 
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Re: [DUG]: TPagecontrol

[Dennis Chuah]

The font property of the tab is used as the default font for its child
controls if the ParentFont property is True.  To display each tab
differently, you will need to handle the page control's OnTabDraw event and
draw the tab yourself (set OwnerDraw := True first).

Dennis.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Sunday, January 12, 2003 7:18 PM
Subject: [DUG]: TPagecontrol


> Hi all.
> In tabsheet there is a font property. But how does one actually change the
font
> on the tab itself??
> AL+
>
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Re: [DUG]: Adding Icons to the Menu bar....

[Dennis Chuah]

Why don't you use owner drawn menu items?  When you draw the last item, make
it large enough to accomodate the bitmaps, but draw the border so that the
menu looks like it stops at the last item.

- Original Message -
From: Paul Mckenzie
To: Multiple recipients of list delphi
Sent: Friday, January 10, 2003 2:29 PM
Subject: [DUG]: Adding Icons to the Menu bar


G'day

Does anyone know if icons can be added (preferably easily) to the menu bar -
but not as a menu item...
What i need to do is add 4 icons to the menu bar, just after the last menu
item.
I acn sort-of do this by adding blank menu items and setting a BMP for each
item.
The problem is that  they are still clickable or loook clickable even if
disabled - when the mouse goes over
the bevel edge appears to indicate they are menu items.

I could live with just turning off the bevel edge thing - but the menu is
inherited and it is only the last 4 items I want to turn it off for.

Any help, ideas, suggestions much appreciated.

Regards
Paul McKenzie
Analyst Programmer
SMSS ltd.

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Re: [DUG]: Automating Internet Explorer from Delphi

[Dennis Chuah]

Dave,

Hi.

Firstly, I suggest that you go the this web site:
http://www.euromind.com/iedelphi/index.htm and read about the updates
shdocvw and mshtml_tlb files.  The ones shipped by Borland are incorrect and
out of date.

Secondly, use the CoInternetExplorer.Create method in shdocvw to create the
automation object.  This returns the IWebBrowser2 interface, from which you
can get access to IHTMLDocument2 via its document property.

Depending on which version of IE you want to automate, you have a choice of
IHTMLDocument2 .. IHTMLDocument5.  The later version support more methods
and functions.  You can search MSDN (http://msdn.microsoft.com) for more
info on the methods and properties.  The higher versions support a more
direct method of accessing HTML elements.

Regards,
Dennis.

- Original Message -
From: <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, November 28, 2002 7:58 AM
Subject: RE: [DUG]: Automating Internet Explorer from Delphi


> Hi Dennis
>
> I found the uses clause I was looking for - it seems to be MSHTML. So just
> using this uses clause, with no Internet components on my form, I wrote
the
> following code. I'm a bit lost. Can you help, especially with the error
> message:
>
> procedure TMainForm.BitBtn1Click(Sender: TObject);
> var
>   doc: IHTMLdocument2;
>   elem: IHTMLElement;
>   IE:Variant;
> begin
>   IE := CreateOleObject('internetexplorer.application');
>   IE.Visible := True;
>
IE.navigate('http://www.somesite.com/information/register/download.asp');
>
>   doc := IE.document as IHTMLdocument2;
>   // the above line falls over with: [Error] MainUnit.pas(44): Operator
not
> applicable to this operand type
>   // have I defined IE correctly as a variant?
>
>   elem := doc.all.item('id',0) as IHTMLElement;
>   elem.value := 'MyUserName';
>
>   // how do I "send" the user name to IE? e.g. elem.click???
>
>   elem := doc.all.item('pwd',0) as IHTMLElement;
>   elem.value := 'MyPassword';
>
>   // now must focus to the "login" button and click it
>   elem := doc.all.item('LoginBtn',0) as IHTMLElement;
>   elem.click;
>
>   // click on "download file" hot link
>   // ??? wonder how this is done??? - same idea as above I guess
>
>   // all finished, so quit IE
>   IE.Quit;
>   IE:= UnAssigned;
> end;
>
> Any ideas appreciated. I'm using Delphi 6.
>
> Cheers
> Dave
>
>
>
> -Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, 28 November 2002 07:07
> To: Multiple recipients of list delphi
> Subject: RE: [DUG]: Automating Internet Explorer from Delphi
>
>
> Hi Dennis
>
> This looks good, however what components are IHTMLdocument2 and
IHTMLElement
> referring to? Or else what uses clauses do I need? (I had a look under my
> Internet tab, but couldn't find components with these names).
>
> Thanks for your help.
>
> Dave
>
> -Original Message-
> From: Dennis Chuah [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, 27 November 2002 15:47
> To: Multiple recipients of list delphi
> Subject: Re: [DUG]: Automating Internet Explorer from Delphi
>
>
>
> procedure SetData;
> var
>   doc: IHTMLdocument2;
>   elem: IHTMLElement;
> begin
> doc := IE.document as IHTMLdocument2;
> elem := doc.all.item('mycontrol',0) as IHTMLElement;
> elem.value := 'SomeValue';
> end;
>
> In the HTML document:
>
> 
>   
>
>
> HTH
> Dennis.
>
>
> - Original Message -
> From: <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Wednesday, November 27, 2002 2:44 PM
> Subject: [DUG]: Automating Internet Explorer from Delphi
>
>
> > I want to use IE as an OLE Automation server. I've found the events,
> methods
> > and properties for the IE Object on MSDN. However, I'm having trouble
> > finding what I need. I want to go to a particular URL (no problems) and
> then
> > enter a user name and password, which that page prompts for. Can I get
> this
> > level of interaction, where I can effectively fill in forms and click
> > buttons in IE, on behalf of the user? If so, which events / methods /
> > properties should I use and how?
> >
> > Anyone done this? Any sites recommended?
> >
> > Cheers
> >
> > Dave Jollie
> > Software Developer BOA IT
> > 09 368 4259 ext 6231
> >
> > The information contained in this mail message is confidential and may
> also
> > be legall

Re: [DUG]: Automating Internet Explorer from Delphi

[Dennis Chuah]

procedure SetData;
var
  doc: IHTMLdocument2;
  elem: IHTMLElement;
begin
doc := IE.document as IHTMLdocument2;
elem := doc.all.item('mycontrol',0) as IHTMLElement;
elem.value := 'SomeValue';
end;

In the HTML document:


  


HTH
Dennis.


- Original Message -
From: <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, November 27, 2002 2:44 PM
Subject: [DUG]: Automating Internet Explorer from Delphi


> I want to use IE as an OLE Automation server. I've found the events,
methods
> and properties for the IE Object on MSDN. However, I'm having trouble
> finding what I need. I want to go to a particular URL (no problems) and
then
> enter a user name and password, which that page prompts for. Can I get
this
> level of interaction, where I can effectively fill in forms and click
> buttons in IE, on behalf of the user? If so, which events / methods /
> properties should I use and how?
>
> Anyone done this? Any sites recommended?
>
> Cheers
>
> Dave Jollie
> Software Developer BOA IT
> 09 368 4259 ext 6231
>
> The information contained in this mail message is confidential and may
also
> be legally privileged. If you are not the intended recipient, please note
> that any use, dissemination, further distribution, or reproduction of this
> message in any form what so ever, is strictly prohibited.  If the mail is
in
> error, please notify me by return E-mail, delete your copy of the message,
> and accept my apologies for any inconvenience caused.
>
> --
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Re: [DUG]: Friday Challange

[Dennis Chuah]

I think you can safely assume that an SQL query will have less than 100 or
so joins, so no need for string buffers.  Perhaps the *REAL* Friday
challenge is to come with an SQL statement with > 100 joins!

Dennis.

- Original Message -
From: "Neven MacEwan" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, November 01, 2002 10:03 AM
Subject: Re: [DUG]: Friday Challange


> Dennis
>
> Therein lies the challange, to come up with an efficient 'Join' procedure
> that
> require no preknowlege of iteration count or item length
>
> would the format be sominthing like
>
> TJoinItemFunction = function(Index: integer): string;
> TJoinOption = (joRemoveBlanks, joUnique, joCaseSensitive);
> TJoinOptions = set of TJoinOption;
>
> function Join(GetItem: TJoinItemFunction ; count: integer; const Sep:
> string, Options TJoinOptions): string;
>
> N
>
>
> - Original Message -
> From: "Dennis Chuah" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Friday, November 01, 2002 9:36 AM
> Subject: Re: [DUG]: Friday Challange
>
>
> >
> > It depends on the size of your loop.  If you are going to be appeding a
> > great number of strings, then I would suggest a string buffer approach -
> > where each iteration of the loop writes one string into the string
buffer,
> > while an int variable is incremented with the length of the string.
Then
> > create a string with the length of the int.  In another loop, take the
> > strings from the buffer and write to the allocated string.
> >
> > I have done tests with loops in sizes ranging from 10, 100, 1000,
through
> to
> > 1mil.  The time savings for the 1mil loop is several oders of magnitude.
> I
> > won't bother for anything less than 100.
> >
> > Dennis.
> >
> > - Original Message -
> > From: Neven MacEwan
> > To: Multiple recipients of list delphi
> > Sent: Friday, November 01, 2002 12:27 AM
> > Subject: [DUG]: Friday Challange
> >
> >
> > Hi all,
> >
> > Further to my enpty string question, I'm writing a lot of
> > functions that return a set of strings joined by a separator
> > ie 'col1, col2,...' or 'col1 = 'a' and colb = 'b'' (as you may guess
> > these are all parts of SQL Statements)
> >
> > given a function 'Itemcount' that returns the number of items
> > and item(i) that returns the item string, and function sep what is the
> > best form of such a function
> >
> > to seed the duscussion I'll give you one of my variants
> >
> > function statement: string;
> > var
> >   I: integer;
> > begin
> >   Result := '';
> >   for I := 0 to pred(ItemCount) do
> > if I = 0 then Result := Item(I)
> > else Result := format('%s%s%s',[Result,Sep,Item(I)])
> > end;
> >
> > Variants and explainations pls
> >
> > Neven
>
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> >
>
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Re: [DUG]: Friday Challange

[Dennis Chuah]

It depends on the size of your loop.  If you are going to be appeding a
great number of strings, then I would suggest a string buffer approach -
where each iteration of the loop writes one string into the string buffer,
while an int variable is incremented with the length of the string.  Then
create a string with the length of the int.  In another loop, take the
strings from the buffer and write to the allocated string.

I have done tests with loops in sizes ranging from 10, 100, 1000, through to
1mil.  The time savings for the 1mil loop is several oders of magnitude.  I
won't bother for anything less than 100.

Dennis.

- Original Message -
From: Neven MacEwan
To: Multiple recipients of list delphi
Sent: Friday, November 01, 2002 12:27 AM
Subject: [DUG]: Friday Challange


Hi all,

Further to my enpty string question, I'm writing a lot of
functions that return a set of strings joined by a separator
ie 'col1, col2,...' or 'col1 = 'a' and colb = 'b'' (as you may guess
these are all parts of SQL Statements)

given a function 'Itemcount' that returns the number of items
and item(i) that returns the item string, and function sep what is the
best form of such a function

to seed the duscussion I'll give you one of my variants

function statement: string;
var
  I: integer;
begin
  Result := '';
  for I := 0 to pred(ItemCount) do
if I = 0 then Result := Item(I)
else Result := format('%s%s%s',[Result,Sep,Item(I)])
end;

Variants and explainations pls

Neven
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Re: [DUG]: Needs some help please

[Dennis Chuah]

Message
Is the MSB (Most significant byte) to the left or to the right?  If it is to
the left,

  ieventclass := (eventpack[3] and $F0) shr 4;
  ieventflags := (eventpack[3] and $0C) shr 2;
  iTmpSession1  := eventpack[3] and $03;

If its to the right


  ieventclass := (eventpack[0] and $F0) shr 4;
  ieventflags := (eventpack[0] and $0C) shr 2;
  iTmpSession1  := eventpack[0] and $03;

Dennis.

- Original Message -
From: Jeremy Coulter
To: Multiple recipients of list delphi
Sent: Sunday, October 27, 2002 9:47 PM
Subject: [DUG]: Needs some help please


Hi all.
I need some help with something.
I am trying to get some info out of a file that was created by someone else,
and there IS some doumentation, BUT, I am not sure if I have got the below
right.
Here is info from the document :-

4 byte EventPack structure:
    - event class   (4 bits)
xx00    - event flags   (2 bits)
00xx xx00   - event session (4 bits)
 00xx   - event type(6 bits)
   xx00 - event size(10 bits)
   00xx - event owner   (6 bits)

I have figured it out like this :-

//declaration :-
var eventpack : arry[0..3] of byte;

//read it eventpack from a memory stream
oMemStream.ReadBuffer(EventPack, sizeof(EventPack));

This is the bit I am not sure I have right :-

  ieventclass := eventpack[0] and $F0;
  ieventflags := eventpack[0] and $0C;
  iTmpSession1  := (eventpack[0] and $03 ) shl 2;
  iTmpSession2  := (eventpack[1] and $C0) shr 6;
  ieventsession := iTmpSession1+ iTmpSession2;
  ieventtype  := eventpack[1] and $3F;
  ieventsize  :=(eventpack[2] * 4)+ ((eventpack[3] and $C0) shr 6);
  ieventowner :=(eventpack[3] and $3F);

Am I right? if not, can someone please guide me here?

Thanks,

Jeremy Coulter

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Re: [DUG]: Polymorphic assignment to Color - How? (sometime it's a Property, sometimes not)

[Dennis Chuah]

> You said the first bit is a hack. Well I don't see that you
> used any blunt instruments in getting access to protected properties.
> Just a little cheating.

It is a hack because it assumes that a base class can be safely cast into a
descendent.  This is OK due to the nature of Delphi's code generation, but
code like this will not work on say the .NET framework.

>   B/ you failed to mention that in this case you would then also have to
> create adaptors for every other case available which wasn't a
> control.

In my post, there was...

  TColourableGraphicsObject = class (TInterfacedObject, IColourable)
  ... similar to TColourableControlAdapter

>   C/ when creating the adaptors in the first place to put in the list,
> you would then also have to have a big if statement testing which class
> you are creating an adaptor for.

No you don't - because you know the type of the objects at the time when you
add the objects to the list, you simply choose the appropriate
implementation, i.e., instead of writing

var
  tl: Tlist;
  MyFont: TFont;
  MyForm: TForm;

begin
  tl.Add (MyFont);
  tl.Add (MyForm);

you write:

var
  list: IInterfaceList;
  MyFont: TFont;
  MyForm: TForm;

begin
  list.Add (TColourableFontAdapter.Create (MyFont));
  list.Add (TColourableControlAdapter.Create (MyForm));

I don't see the need of if's, etc.

The very idea of using adapters is to avoid the use If's to test the class
type.  The adapters abstract out the different interfaces for the color
property into one common interface.

> The question was a simple one. Given an object of unknown class, how do
> you change the color property?

I think you also need to read the original post *CAREFULLY*.  I belief the
question was:

> Polymorphic assignment to Color - How? (sometime it's a Property,
sometimes not)

> I'm building a list of objects that can be coloured and want to be able to
get/set their colour.
>
> The object properties are all going to be stored in a Tlist so the types
will probably need to be stored along with them. I'm happy to store the
Object type (eg Tform ...) along with the reference to the object but I
can't see a general way to do this and get/set the color.

As far as I can see all the different proposed solutions satisfy the
problem:  "I can't see a general way to do this and get/set the color.".  I
don't think any one of them is right / wrong, good / bad.  They are
different approaches to solving one problem and have different pros and
cons.  The interface / adapter solution abstracts out the color property
into a common interface (polymorphic behaviour), is extensible but at the
expense of more code. The typinfo method uses RTTI and less code but assumes
that all object has a published property named "Color", is slower and is not
extensible.

Hopefully, Giovanni will have plenty to think about and choose the solution
appropriate to his problem.

This kinda reminds me of a German joke, "Our solution is your problem" - a
broken English version of "We have the solution to your problems".

Dennis.

- Original Message -
From: "Kyley Harris" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, October 24, 2002 10:36 AM
Subject: RE: [DUG]: Polymorphic assignment to Color - How? (sometime it's a
Property, sometimes not)


> Now that I've woken up (yawn)
>
> I have to reply to two posts in one.
>
> 1/ Neven. Your solution is a good one. I do agree. I disagree that it
> was a good answer only :) based on the question asked. From the samples
> given etc of source, I would think that your solution did not solve the
> question appropriately based on the coding style and requirements of the
> query.
>
> 2/ Dennis. You said the first bit is a hack. Well I don't see that you
> used any blunt instruments in getting access to protected properties.
> Just a little cheating. The control adaptor is also a good solution to a
> problem. But in this case it also is not a good answer because:
>   A/ who said anything about it coming from Tcontrol? Only that it would
> have a color property.
>   B/ you failed to mention that in this case you would then also have to
> create adaptors for every other case available which wasn't a
> control.
>   C/ when creating the adaptors in the first place to put in the list,
> you would then also have to have a big if statement testing which class
> you are creating an adaptor for. (no better than the original if
> statement), or you would need a dymamic generation of classes against
> class adaptors, Which would need to be implemented somewhere.
>
> The question was a simple one. Given an object of unknown class, how do
> you change the color property?
>
> While interfaces are cool, and adapters are neat. None of them actually
> answered the question within the standard potential of a delphi object.
>
> Hopefully they give everyone who didn't know of these options more
> insight. As I say, cats can be skinned nine times, then you get an

Re: [DUG]: Polymorphic assignment to Color - How? (sometime it's a Property, sometimes not)

[Dennis Chuah]

This is a hack but...
 
type
  TInternalControl = class 
(TControl);
  TInternalGraphicsObject = class 
(TGraphicsObject);
 
procedure setObjectColour (obj: 
TObject; newColour: TColor);
begin
  if obj is TControl then
    TInternalControl 
(obj).Color := newColour
  else if obj is TGraphicsObject 
then
    TInternalGraphicsObject 
(obj).Color := newColour;
end;
The other ways are the interface / typinfo ways as 
suggested in previous emails.  I would however, implement the 
interfaces using the adapter pattern instead of using inheritance:
 
type
  IColourable = interface
  // Interface GUID
    procedure SetColour 
(Value: TColor);
    function GetColour: 
TColor;
    property Colour: TColor 
read GetColour write SetColour;
  end;
 
  TColourableControlAdapter = class 
(TInterfacedObject, IColourable)
  private
    FControl: 
TControl;

    procedure SetColour 
(Value: TColor);
    function GetColour: 
TColor;    

  public
    constructor Create 
(AControl: TControl);
  end;
 
  TColourableGraphicsObject = class 
(TInterfacedObject, IColourable)
  ... similar to 
TColourableControlAdapter
 
constructor 
TColourableControlAdapter.Create (AControl: TControl);
begin
  inherited Create;
  FControl := AControl;
end;
 
procedure 
TColourableControlAdapter.SetColour (Value: TColor);
begin
  // using the hack 
above...
  TInternalControl (FControl).Color := 
Value;
end;
 
Then instead of a TList, you use 
TInterfaceList:
 
var
  list: IInterfaceList;
 
begin
  list := 
TInterfaceList.Create;
 
To add objects to the list:
 
list.Add (TColourableControlAdapter.Create 
(MyForm));

list.Add (TColourableGraphicsObject.Create 
(MyFont));
 
To set the colour:
 
  (list.Items[Index] as 
IColourable).Colour := newColour;
 
You don't need to free the list or any of the 
interfaces in the list because as the list goes out of scope it will 
automatically be freed via reference counting.
 
Dennis.
 
- Original Message - 
From: "Moretti, Giovanni" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" 
<[EMAIL PROTECTED]>
Sent: Wednesday, October 23, 2002 6:23 
PM
Subject: [DUG]: Polymorphic assignment to Color - 
How? (sometime it's a Property, sometimes not)
> Hi> > I'm building a list of objects that can be 
coloured and want to be able to get/set their colour.> > The 
object properties are all going to be stored in a Tlist so the types will 
probably need to be stored along with them. I'm happy to store the Object type 
(eg Tform ...) along with the reference to the object but I can't see a general 
way to do this and get/set the color.> > = ATTEMPT #1 
===>  > In the olden 
days, before properties, I'd have just passed a pointer to the Tcolor 
value:> >    procedure setObjectColour 
(Color : ^TColor ; > 
  
newColour : TColor);>  begin> 
   Color^ := newColour;> 
 end;> >   
setObjectColour(@Label3.Color, clRed);> > I tried this, but it's 
unpredictable as sometimes an object's color is just a TColor (a glorified 
integer) but other times it's a property with get/set methods.> > 
= ATTEMPT #2 ===> 
> Figuring the run-time type information should be able to handle this, I 
tried:> >   Type  TControlClass = Class of 
Tcontrol;> >   procedure setObjectColour ( 
obj   : TObject; > 
  
whatClass : TControlClass;> 
  
newColour : TColor);>   begin>     (obj as 
whatClass).color := newColour;> 
   
^-- ERROR - COLOR not declared > // OR> > 
    whatClass(object).color  := newColour;   
> 
  
^Missing Operator or ; >   end;> 
>   setObjectColour(Label3, Tlabel, clRed);  // To Recolour 
something  > > But neither will compile without 
errors.> > = FINALLY 
===> > It's not elegant 
but has the great virtue that it actually works:> >   
procedure setObjectColour ( obj   : TObject; 
> 
  
newColour : TColor);>   begin>     
if  (obj is TForm)  then (obj as TForm) .color 
:= newColour>     else if (obj is TLabel) then (obj as 
TLabel).color := newColour>     else if (obj is TFont ) 
then (obj as TFont) .color := newColour>     else if (obj 
is TBrush) then (obj as TBrush).color := newColour>     
else if (obj is TPen)   then (obj as TPen)  .color := 
newColour>     else showMessage('setObjectColour: Don''t 
know how');>   end;> >   setObjectColour(Form1, 
clRed);> > Except this means that adding new types of things will 
require adding of extra "if .." statements which with polymorphism should be 
necessary. Unfortunately you can't do the more general:> > 
   (obj as Tcontrol).color := newColour;> > As 
Tcontrol's "color" is protected (and can't be seen this won't compile). Only 
Tcontrol's descendents expose some way of getting/setting color.> 
> I want to be ab

Re: [DUG]: COM Object error

[Dennis Chuah]

>From memory, VB only supports apartment threading model.  Depending on the
type of load your server is going to experience, you could try:  Have a
worker thread that communicated with the VB COM object.  The client
connection threads will need to place the data somewhere, then wait for the
worker thread to send the data away.

Anyway, apartment threading doesn't really support heavy loads.

Dennis.

- Original Message -
From: "Phil Middlemiss" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, October 22, 2002 5:00 PM
Subject: [DUG]: COM Object error


> Hi all,
>
> I have an app that uses the Indy components to act as a TCP server. When
it
> get's a connection and receives the required data, the application uses a
> third party COM object to communicate the data to second server running on
a
> remote location.
>
> If I run a test routine and just send some dummy data to the second server
> then everything is fine. If I try exactly the same test code but this time
> call it when I have received some data from a connection to my TCP server,
> then I get an access violation from 'MSVBVM60.DLL' (the COM object was
> written in VB).
>
> I'm guessing its a threading issue since the TCP server is hanging on to a
> TIDPeerThread from it's Execute event. I've tried placing
> EnterCriticalSection etc around the code but it makes no difference.
>
> Does anyone have any ideas?
>
> Regards,
> Phil.
>
>
> --
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Re: Re[2]: [DUG]: Treelist with checkbox

[Dennis Chuah]

Alistair,

Hi.  You can download theme manager from the same place as you download
virtual tree view.  All I do is to put both of them in the same directory,
build and register the tree's design time package.  You will need to add the
dir to your project's search path.  The tree view requires the theme manager
because it is theme aware but will turn off all theme functions when not
running under XP.

I would fully recommend the virtual tree view, having used it and found that
it is very fast and reliable, with very few bugs.  There are lots of
properties and events to allow customisation to a wide degree.  Full source
is available - it makes it really easy to identify problems and to add new
features.

If you go to http://www.delphi-gems.com/VirtualTreeview/VTGallery.php, you
can download a file manager type app built using the tree - which includes
source code.  There is also another project that displays the structure and
contents of an XML document.  This project also uses the tree to display a
directory list.  Unfortunately, to download this you will need to join the
German discussion list in Yahoo.  I used the translator at altavista.com to
help me navigate through the German web site.

In anycase, I would suggest you download the advanced demo.  This displays
most of what you can do with the tree and there is certainly a page that
shows the directory / file structure with checkboxes.

HTH,
Dennis.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, October 22, 2002 3:58 PM
Subject: Re[2]: [DUG]: Treelist with checkbox


> Hello Dennis,
> Thanks for info - I had played around with VirtualTree before but compiler
asks for
> ThemeManager5 which I do not have nor can find on the delphi disk.
>
> I really wanted to know how to propagate a treeview with a directory list.
> Cheers,
> Al+
>
>
>
> Tuesday, October 22, 2002, 3:11:58 PM, you wrote:
>
> DC> Virtual Tree from Mike Lischke
> DC> (http://www.delphi-gems.com/VirtualTreeview/VT.php) has built in
support for
> DC> checkboxes.  I think there is a derivative that shows the contents of
> DC> directories as well - take a look at
> DC> http://www.delphi-gems.com/VirtualTreeview/VTGallery.php.
>
> DC> Dennis.
>
> DC> - Original Message -
> DC> From: "Alistair George" <[EMAIL PROTECTED]>
> DC> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> DC> Sent: Tuesday, October 22, 2002 2:58 PM
> DC> Subject: [DUG]: Treelist with checkbox
>
>
> >> Hi all.
> >> I have treelists galore and have searched, but cannot find, how to
> DC> propagate
> >> them with for example directories and check boxes.
> >> Anyone point me to the resource for this info please?
> >> Thanks,
> >> Alistair+
> >>
>
>> -
-
> DC> -
> >> New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED]
> >>   Website: http://www.delphi.org.nz
> >> To UnSub, send email to: [EMAIL PROTECTED]
> >> with body of "unsubscribe delphi"
> >> Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
> >>
>
DC> 
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>
>
> --
> Regards,
>  Alistair+
>
> --
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Re: [DUG]: Treelist with checkbox

[Dennis Chuah]

Virtual Tree from Mike Lischke
(http://www.delphi-gems.com/VirtualTreeview/VT.php) has built in support for
checkboxes.  I think there is a derivative that shows the contents of
directories as well - take a look at
http://www.delphi-gems.com/VirtualTreeview/VTGallery.php.

Dennis.

- Original Message -
From: "Alistair George" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Tuesday, October 22, 2002 2:58 PM
Subject: [DUG]: Treelist with checkbox


> Hi all.
> I have treelists galore and have searched, but cannot find, how to
propagate
> them with for example directories and check boxes.
> Anyone point me to the resource for this info please?
> Thanks,
> Alistair+
>
> --
-
> New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED]
>   Website: http://www.delphi.org.nz
> To UnSub, send email to: [EMAIL PROTECTED]
> with body of "unsubscribe delphi"
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>
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Re: [DUG]: polymorphism problem

[Dennis Chuah]

TGraphicClass provides you with the same scope as TGraphic, from which it is
derived.  In your code, that is outside graphics.pas, the variable, gCls,
cannot see TGraphic.Create, but it can see TObject.Create.  This visibility
is determined at compile time and the code is bound to TObject.Create.

Inside graphics.pas however, TGraphicClass *CAN* see TGraphic.Create -
because inside the same unit member visibility is public.  Therefore, the
line of code:

>   NewGraphic := TGraphicClass(Value.ClassType).Create;

Actually calls TGraphic.Create instead of TObject.Create.  Because
TGraphic.Create is virtual and TMyGraphic.Create overrides it, by applying
the rule that inherited members cannot lower the visibility of their
ancestors, TMyGraphic.Create is "visible" to the line of code in
graphics.pas.  In actual fact, the visibility isn't checked here because at
compile time, Delphi binds the call to TGraphic.Create and at run time, the
v-table is used to figure out the address of  TMyGraphic.Create.

Dennis.

- Original Message -
From: "Jianming Lin (ASL)" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, October 18, 2002 11:49 AM
Subject: RE: [DUG]: polymorphism problem


> Dear Dennis,
>
> I read the help of Delphi, it says :
> A protected member is visible anywhere in the module where its class is
> declared
> and from any descendant class, regardless of the module where the
descendant
> class appears.
>
> Now I purposely make my constructor to be Protected member, then step into
> myPic.Graphic := nGra;
> in the unit of graphics.pas,
> the call
>   NewGraphic := TGraphicClass(Value.ClassType).Create;
> of Tpicture class still call my protected construstor correctly.
> But nGra := gCls.Create won't. Why?
>
> //
> Type TMyGraphic = class(TGraphic)
> Protected
> constructor Create;  override;
> public
> procedure Assign(Source: TPersistent); override;
> end;
>
> procedure TMyGraphic.Assign(Source: TPersistent);
> begin
>  //
> end;
>
> constructor TMyGraphic.Create;
> begin
>   inherited;
>   CallNo := CallNo + 1;
> end;
>
>
>
> var CallNo : Integer;
> //
> procedure TryIt;
> var gCls : TGraphicClass;
> nGra : TGraphic;
> myPic : TPicture;
> begin
> CallNo := 0;
> gCls := TGraphicClass(TMyGraphic);
> nGra := gCls.Create;
> ShowMessage(IntToStr(CallNo));   // 0
>
> myPic := TPicture.Create;
> myPic.Graphic := nGra;
> ShowMessage(IntToStr(CallNo));   // 1
> end;
>
>
>
> -Original Message-
> From: Jianming Lin (ASL) [mailto:JianmingL@;aslnz.co.nz]
> Sent: Friday, 18 October 2002 11:20 a.m.
> To: Multiple recipients of list delphi
> Subject: RE: [DUG]: polymorphism problem
>
>
> Dear Dennis,
>
> YOU are right, TGraphic's constructor in D5 IS INDEED protected.
>
> Thanks everyone who has replied to this thread
>
> Jianming
>
> -Original Message-
> From: Dennis Chuah [mailto:dennis_cs_chuah@;hotmail.com]
> Sent: Friday, 18 October 2002 11:02 a.m.
> To: Multiple recipients of list delphi
> Subject: Re: [DUG]: polymorphism problem
>
>
>
> I stepped through your code in D6 (don't have D5 installed on this
> machine) - but perhaps there is something wrong in D5?  I am wondering in
D5
> whether TGraphic's constructor is protected?
>
> Dennis.
>
> - Original Message -
> From: "Jianming Lin (ASL)" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Friday, October 18, 2002 9:10 AM
> Subject: RE: [DUG]: polymorphism problem
>
>
> >
> >
> > -Original Message-
> > From: Dennis Chuah [mailto:dennis_cs_chuah@;hotmail.com]
> > Sent: Friday, 18 October 2002 7:14 a.m.
> > To: Multiple recipients of list delphi
> > Subject: Re: [DUG]: polymorphism problem
> >
> >
> >
> > I stepped through your code and it *DEFINITELY* calls TMetadata.Create.
> > What you have done looks correct and this is certainly not a
polymorphism
> > pproblem.  Few suggestions:
> >
> > 1.  Check that you do not have $(DELPHI)\Lib in your project path - it
> > should only be in the global library path.
> >
> > Checked
> >
> > 2.  What if you replaced your code with:
> >   NGraphic := TMetadata.Create;
> >
> > Step through the code - does it call TMetadata.Create?
> >
> > Yes it does
> >
> > 3.  Check the class type of NGraphic and compare
>

Re: [DUG]: Strange RECORD behaviour

[Dennis Chuah]

I guess you are using VB3 or a 16-bit version of VB.  If that is the case,
then the variable sizes are:

boolean - 2 bytes (-1 = true, 0 = false)
integer - 2 bytes
string * n - fixed length strings of n bytes

total = 45 bytes

In BP7:

Boolean - not quite sure about the size in BP7, but in D1 I think it is 1
byte (0 - false, 1 = true)
Integer - 2 bytes
sring[n] - 1 byte for string length, plus fixes n-bytes for string data

total = 46 bytes.

Use array of Char instead of string and you might need to use integer
instead of boolean.

HTH,
Dennis.

- Original Message -
From: <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, October 18, 2002 10:08 AM
Subject: [DUG]: Strange RECORD behaviour


> I have been playing around with writing a random file in VisualBasic which
> works OK, then thought I would use BP 7 to access this random file and so
> created a record which I thought would be identical.
>
> I was getting garbage with the Pascal program so...
>
> When I look at the size of each, the BASIC version is 45 bytes and the
> Pascal Version is 46 !!??
>
> VB ... size is 45
> Type People
>   InUse as Boolean
>   RecPos as Integer
>   Tag as Integer
>   Total as Integer
>   ID as Integer
>   FirstName as String * 15
>   LastName as String * 20
> end Type
>
> Pascal  ... size is 46
> Person = Record
>   InUse: Boolean;
>   RecPos : Integer;
>   Tag   : Integer;
>   Total : Integer;
>   ID : Integer;
>   FirstName : String[15];
>   LastName : String[20];
> end;
>
> where is the problem? What is the solution?
>
>
> Laurie..
>
>
>
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Re: [DUG]: polymorphism problem

[Dennis Chuah]

I stepped through your code in D6 (don't have D5 installed on this
machine) - but perhaps there is something wrong in D5?  I am wondering in D5
whether TGraphic's constructor is protected?

Dennis.

- Original Message -
From: "Jianming Lin (ASL)" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, October 18, 2002 9:10 AM
Subject: RE: [DUG]: polymorphism problem


>
>
> -Original Message-
> From: Dennis Chuah [mailto:dennis_cs_chuah@;hotmail.com]
> Sent: Friday, 18 October 2002 7:14 a.m.
> To: Multiple recipients of list delphi
> Subject: Re: [DUG]: polymorphism problem
>
>
>
> I stepped through your code and it *DEFINITELY* calls TMetadata.Create.
> What you have done looks correct and this is certainly not a polymorphism
> pproblem.  Few suggestions:
>
> 1.  Check that you do not have $(DELPHI)\Lib in your project path - it
> should only be in the global library path.
>
> Checked
>
> 2.  What if you replaced your code with:
>   NGraphic := TMetadata.Create;
>
> Step through the code - does it call TMetadata.Create?
>
> Yes it does
>
> 3.  Check the class type of NGraphic and compare
Pointer(NGraphic.ClassType)
> against Pointer(TMetadata).  Are they the same pointer values?
>
> Checked. still not get called.
>
> What version of Delphi are you using?
>
> D5 Ent
>
>
> Dennis.
>
> - Original Message -
> From: Jianming Lin (ASL)
> To: Multiple recipients of list delphi
> Sent: Thursday, October 17, 2002 4:35 PM
> Subject: [DUG]: polymorphism problem
>
>
>
>
> G'Day, guys,
>
> procedure TryMetadata(ImgType : Integer);
> var NGraphic: TGraphic;
> GraphicClass: TGraphicClass;
> begin
>   ImgType := 1;
>   case ImgType of
> 1 :  GraphicClass := TMetaFile;
> 2 :  GraphicClass := TBitmap;
>   end;
>   NGraphic := GraphicClass.Create;
> end;
>
>
> Why constructor  of TMetafile.Create is not called instead only
> TObject.Create is called?
>
>
>
>
>
> [Jianming Lin (ASL)]
>
>
>
>
>
> This e-mail message has been scanned for Viruses and Content and cleared
by
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>

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Re: [DUG]: polymorphism problem

[Dennis Chuah]

The is operator calls a class method to check that the object's class is
either the same as the compared to class or one of its children.  Using the
class type is the only way to test if an object is the same *BUT NOT* one of
its children.

Dennis.

- Original Message -
From: "Andreas Toth" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Friday, October 18, 2002 9:17 AM
Subject: RE: [DUG]: polymorphism problem


> Have I missed something, or, is the third point suggesting a rather odd
> technique of testing if an instance is of a specific class when the
> is-operator would have done a much tidier job?
>
>
> -Andreas
>
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:owner-delphi@;delphi.org.nz]On
> Behalf Of Dennis Chuah
> Sent: Friday, 18 October 2002 07:14
> To: Multiple recipients of list delphi
> Subject: Re: [DUG]: polymorphism problem
>
>
>
> I stepped through your code and it *DEFINITELY* calls TMetadata.Create.
> What you have done looks correct and this is certainly not a polymorphism
> pproblem.  Few suggestions:
>
> 1.  Check that you do not have $(DELPHI)\Lib in your project path - it
> should only be in the global library path.
> 2.  What if you replaced your code with:
>   NGraphic := TMetadata.Create;
>
> Step through the code - does it call TMetadata.Create?
>
> 3.  Check the class type of NGraphic and compare
Pointer(NGraphic.ClassType)
> against Pointer(TMetadata).  Are they the same pointer values?
>
> What version of Delphi are you using?
>
> Dennis.
>
> - Original Message -
> From: Jianming Lin (ASL)
> To: Multiple recipients of list delphi
> Sent: Thursday, October 17, 2002 4:35 PM
> Subject: [DUG]: polymorphism problem
>
>
>
>
> G'Day, guys,
>
> procedure TryMetadata(ImgType : Integer);
> var NGraphic: TGraphic;
> GraphicClass: TGraphicClass;
> begin
>   ImgType := 1;
>   case ImgType of
> 1 :  GraphicClass := TMetaFile;
> 2 :  GraphicClass := TBitmap;
>   end;
>   NGraphic := GraphicClass.Create;
> end;
>
>
> Why constructor  of TMetafile.Create is not called instead only
> TObject.Create is called?
>
>
>
>
>
> [Jianming Lin (ASL)]
>
>
>
>
>
> This e-mail message has been scanned for Viruses and Content and cleared
by
> MailMarshal - For more information please visit www.marshalsoftware.com
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Re: [DUG]: polymorphism problem

[Dennis Chuah]

I stepped through your code and it *DEFINITELY* calls TMetadata.Create.
What you have done looks correct and this is certainly not a polymorphism
pproblem.  Few suggestions:

1.  Check that you do not have $(DELPHI)\Lib in your project path - it
should only be in the global library path.
2.  What if you replaced your code with:
  NGraphic := TMetadata.Create;

Step through the code - does it call TMetadata.Create?

3.  Check the class type of NGraphic and compare Pointer(NGraphic.ClassType)
against Pointer(TMetadata).  Are they the same pointer values?

What version of Delphi are you using?

Dennis.

- Original Message -
From: Jianming Lin (ASL)
To: Multiple recipients of list delphi
Sent: Thursday, October 17, 2002 4:35 PM
Subject: [DUG]: polymorphism problem




G'Day, guys,

procedure TryMetadata(ImgType : Integer);
var NGraphic: TGraphic;
GraphicClass: TGraphicClass;
begin
  ImgType := 1;
  case ImgType of
1 :  GraphicClass := TMetaFile;
2 :  GraphicClass := TBitmap;
  end;
  NGraphic := GraphicClass.Create;
end;


Why constructor  of TMetafile.Create is not called instead only
TObject.Create is called?





[Jianming Lin (ASL)]





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Re: [DUG]: Toolbutton tbsCheck not working

[Dennis Chuah]

You probably need a newer version of Comctl32.dll for the Win98 machine.

Dennis.

- Original Message -
From: "Ross Levis" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Wednesday, October 16, 2002 3:16 PM
Subject: [DUG]: Toolbutton tbsCheck not working


> D5 Pro/Win98.  Clicking a toolbutton with tbsCheck is not toggling the
> Down property.  In fact, the button is acting as if it is a standard
> tbsButton.  I tried it on WinXP and it works.  Is there anyway around it?
>
> Cheers,
> Ross.
>
>
>
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Re: [DUG]: Cannot focus a disabled or invisible window

[Dennis Chuah]

tblCompany.Edit;
tblCompany.FieldByName('name').Value := txtNewValue.Text;
tblCompany.Post;
txtNewValue.Text := '';
txtHoneyPot.SetFocus;
btnSaveEdit.Visible := false;
txtNewValue.Visible := false;

The line that is causing you grief is "btnSaveEdit.Visible := false;".  When
the user clicks on the button, the focus shifts to the button and making it
invisible when it receives the focus will cause the problem.  Note: the
button only gets the focus AFTER the OnClick event is fired.

When it comes to UI design I am not a big fan of making things appear and
disappear based on a program state, but if you must hide your button, I
would suggest using actions.  In the OnUpdate event of the action determine
whether to hide the button - check first to see if the button has focus.  if
it has, set the focus to the next control, then hide the button (by setting
the action's Visible property to False).

- Original Message -
From: Tracey Maule
To: Multiple recipients of list delphi
Sent: Tuesday, October 15, 2002 9:39 AM
Subject: [DUG]: Cannot focus a disabled or invisible window


Hi there...

I have a form with a DBGrid showing values from one table (tblCompany)
I am currently trying to provide new record/edit functionality with code,
rather than use one of those ugly DBNavigators.

My problem is with the edit.  I have an edit button displayed always, when
the user selects edit, an invisible edit box is made visible, along with a
"save changes" button.
(someone told me once not to allow users to edit/add within a grid...)
my problem is that when i click save changes i receive two error messages
(the original focus message (subject line) plus a "dataset not in edit mode"
one)

i suspect the focus problem is because i am making the edit box invisible
while focus is still set to it, however i tried setting focus to another
edit box and the error did not change.

heres the few lines of code i have
tblCompany.Edit;
tblCompany.FieldByName('name').Value := txtNewValue.Text;
tblCompany.Post;
txtNewValue.Text := '';
txtHoneyPot.SetFocus;
btnSaveEdit.Visible := false;
txtNewValue.Visible := false;

please lend me the benifit of your decades of experience and knowledge here

Tracey
Software Developer / Web Master
Logis
[EMAIL PROTECTED]
(025) 213-1065
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Re: [DUG]: Resume Next in Delphi

[Dennis Chuah]

There is no direct resume next support in Delphi, but Delphi does support
goto's.  Having said that, in my many years of programming in Delphi and
before that in Turbo Pascal, I have never had to use the goto statement.

VB does not support structured exception handling (SEH), so you end up
having to write code that looks like this:

On Error GoTo SomeLabel
  DoSomething1
  If CheckForError1 then DoHandleError1
  DoSomething2
  If CheckForError2 then DoHandleError2

  GoTo EndLabel

SomeLabel:
  SomeErrorHandlingCode
  Resume Next

EndLabel:


In Delphi, you ought to use SEH:

try
  DoSomething1;
  DoSomething2;

except
  HandleError;
end;

or if you need to be more specific about which errors to handle:

try
  DoSomething1;
  DoSomething2;

except
  on Exception1 do HandleError1;
  on Exception2 do HandleError1;
end;

The SEH code tends to be easier to read - all code logic is presented in one
block and all error logic in another.  SEH is also more reliable.  Any
unhandled errors propagate to the higher level and get handled there,
whereas with VB the On Error statement only applies for the sub or function.
If you forget one, you immediately get a run time error.

SEH also has many other uses - far too many to list in an email.

Hope this helps.
Dennis.

- Original Message -
From: "Traci Sumpter" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, October 14, 2002 10:59 AM
Subject: [DUG]: Resume Next in Delphi


>
> Newbee at Delphi, Have done VB before and is wondering if Delphi has the
> same sort of function as resume next or resume LABEL:
>
> I know the try except and try finally, but am wondering how to continue or
> retry in Delphi... Hope my question is clear>>
>
>
> --
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Re: [DUG]: 64 bit ints

[Dennis Chuah]

Because IntToStr(Value: Integer) is faster (and smaller) than
IntToStr(Value: Int64) - Delphi (apart from Delphi.NET) generates code for
32-bit processors, and thus any 64-bit code will require more CPU cycles.
The linker is also able to optimise out the functions that are not
referenced, thus if IntToStr(Value: Int64) is not referenced, there is no
need for the function to live in the EXE.

Furthermore, by declaring two overloaded functions, code completion shows
both implementations - which more clearly identifies the purpose of
IntToStr.  Showing IntToStr as taking an Int64 parameter only can
potentially be confusing to someone who is new to Delphi.

Dennis.

- Original Message -
From: "Trevor Jones" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Monday, August 19, 2002 12:29 PM
Subject: Re: [DUG]: 64 bit ints


> Steve:
>   surely if you have just the one function
>
>   function IntToStr(Value: Int64): string;
>
> and it's not overloaded, then the compiler still won't complain.
>
> That's why I was wondering what I had missed
>
> Trevor
>
> - Original Message -
> From: "Steve Peacocke" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Saturday, August 17, 2002 4:58 PM
> Subject: Re: [DUG]: 64 bit ints
>
>
> > No, you are missing nothing. One converts and Int64, the other an
Integer.
> >
> > Stops the compiler complaining that you are using the wrong variable
type.
> >
> > Steve
> >
> > At 04:26 pm 17/08/02, you wrote:
> > >I use quite a lot of these in my code, and from time to time need to
> convert
> > >them to striings, so I use IntToStr in SysUtils.
> > >
> > >I've noticed that there are two versions (overloaded) in sysUtils:
> > >
> > >{ IntToStr converts the given value to its decimal string
> representation. }
> > >
> > >function IntToStr(Value: Integer): string; overload;
> > >function IntToStr(Value: Int64): string; overload;
> > >
> > >
> > >and their implementation is
> > >
> > >function IntToStr(Value: Integer): string;
> > >begin
> > >   FmtStr(Result, '%d', [Value]);
> > >end;
> > >
> > >function IntToStr(Value: Int64): string;
> > >begin
> > >   FmtStr(Result, '%d', [Value]);
> > >end;
> > >
> > >Am I missing something here?, they seem to be identical.
> > >
> > >Confused Trevor
> > >
> > >
> > >
> >
>
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> >
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Re: [DUG]: Interfaces (and classes that support them)

[Dennis Chuah]

Factory methods is the way to go.  Personally, I prefer to use factory
classes (actually factory interfaces).  You certainly don't want to limit
your design to inherit all implementation classes from the same base class,
though, sometimes, it can be helpful to have an abstract base class that
implements some of the common methods of the interface.

As for your form, you can use an adapter class that inherits from
TInterfacedObject.  Take a look at TStreamAdapter for an example.

Dennis.

- Original Message -
From: "Trevor Jones" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, August 08, 2002 1:11 PM
Subject: Re: [DUG]: Interfaces (and classes that support them)


> Phil,
>   Thanks for the idea, but it kinda breaks the idea of an Interface being
> supported by *ANY* class type.  In some cases the objects that support the
> interfaces I'm using are subclassed from TInterfacedObject, other times
they
> may be components or even forms. As luck would have it, a TForm does not
> subclass TInterfacedObject, so this stops me using this approach.
>
>
>   For the moment, I've opted to register factory functions rather than the
> classes themselves and this seems to cover most issues.
>
> Trevor
>
> - Original Message -
> From: "Phil Middlemiss" <[EMAIL PROTECTED]>
> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> Sent: Thursday, August 08, 2002 8:34 AM
> Subject: Re: [DUG]: Interfaces (and classes that support them)
>
>
> > Trevor,
> >
> > I usually create a simple base class with a virtual constructor that I
> then
> > descend from where appropriate.
> >
> > eg.
> > TMyObject = class(TInterfacedObject)
> > public
> > constructor Create; virtual;
> > end;
> >
> > TMyObjectClass = class of TMyObject;
> >
> > Now everything that needs to can descend from TMyObject, and the
> > MyInterfaceClass function uses the variables
> >
> > AClass: TMyObjectClass;
> > AObject: TMyObject;
> >
> > This assumes, of course, that you have control over which classes are
> used.
> >
> > Kind regards,
> >
> > Phil.
> >
> > - Original Message -
> > From: "Trevor Jones" <[EMAIL PROTECTED]>
> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
> > Sent: Wednesday, August 07, 2002 5:03 PM
> > Subject: [DUG]: Interfaces (and classes that support them)
> >
> >
> > > Hi all,
> > >   One of the things that I like about using Interfaces is that the
> classes
> > > supporting them can be of any type - Yeeha!
> > >
> > > However it can be tricky deciding how to construct an object from just
a
> > > class reference that supports an interface because the TObject
> constructor
> > > is not virtual.
> > >
> > > My solutions so far amount to stuff like this (where the last
registered
> > > class is the one to be created):
> > >
> > > var
> > >   List : TList;
> > >
> > > procedure RegisterMyInterfacedClass(aClass : TClass);
> > > begin
> > >   if supports(aClass,IMyInterface) then
> > > List.Add(aClass);
> > > end;
> > >
> > > procedure UnRegisterMyInterfacedClass(aClass : TClass);
> > > var
> > >   i : integer;
> > > begin
> > >   i := List.IndexOf(aClass);
> > >   if i >= 0 then
> > >   List.Delete(i);
> > > end;
> > >
> > > function MyInterfacedClass : IMyInterface;
> > > var
> > >   aClass : TClass;
> > >   aObject :  TObject;
> > > begin
> > >   result := nil;
> > >   if List.Count > 0 then
> > > begin
> > > aClass := List[List.count-1];
> > > if aClass.inheritsFrom(TComponent) then
> > >   aObject := TComponentClass(aClass).create(application)
> > > else
> > >   aObject := TClass.create;
> > > // Supports should always be true here, its just an easy way to
get
> > the
> > > interface
> > > if not Supports(aObject, IMyInterface,result) then
> > >   aObject.free;
> > > end;
> > > end;
> > >
> > >
> > > All of this nonsense seems to work very well at the moment, but I'm
> unsure
> > > how safe it is.
> > >
> > > The gotchas seem to be:
> > >   If the class inherits only from TInterfacedObject, its specific
> > > constructor is not called, the class must override AfterConstruction
to
> > > create any needed bits (like stringlists etc.).
> > >
> > >   If the class uses some fancy constructor that requires something
other
> > > than an owner, then I'm stuck.
> > >
> > > Does anyone have a more elegant way of going about this that they are
> > > willing to share?
> > >
> > > Trevor
> > >
> > >
> > >
> > >
> >
>
> --
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Re: [DUG]: [Q] Simple Streams Question in IDE

[Dennis Chuah]

If you are using D6, then it is a known debugger bug.  If you watched any
Int64 variable, you always end up with 0.

Dennis.

- Original Message -
From: "Donovan J. Edye" <[EMAIL PROTECTED]>
To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]>
Sent: Thursday, August 08, 2002 3:18 PM
Subject: [DUG]: [Q] Simple Streams Question in IDE


> G'Day,
>
> If I code the TMemoryStream example from the help "SaveToStream,
> LoadFromStream example" and then step through the code why do my watches
> for TempStream.Position and TempStream.Size always show 0? (However the
> example does work)
>
> TIA
>
>
> -- Donovan
> --
> Donovan J. Edye [www.edye.wattle.id.au]
> Namadgi Systems [www.namsys.com.au]
> Voice: +61 2 6285-3460
> Fax: +61 2 6285-3459
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