RE: Problem resizing a window and button placement
>> The configuration event
hasn't fired at the time you
include the print statement in
the handler's def block, and
therefore the print function
inside your handler hasn't
invoked. It won't be invoked
until you resize the window.
Exactly
>> There is no point (really?)
to saving the width and height
outside your
on_configure() function,
because outside that function
you can't know if they have
been changed. There could
even have been a race
condition where you use one
but the other changes before
you get around to using it.
Aside from using it to resized
the window, is there no way to
know the last value of the
change for use in the program?
I could write the value to a
label and read it back later
in the process but that sounds
to be klugy.
>> It's better just to ask tk
for the values whenever you
need them, as you do inside
your handler.
How would that be done?
SGA
-Original Message-
From: Python-list
On
Behalf Of Thomas Passin via
Python-list
Sent: Monday, February 26,
2024 8:34 AM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement
On 2/26/2024 6:02 AM, Steve GS
via Python-list wrote:
> Although your code produces
the value of Ww outside the
function, I do not see how I
can use the value of Ww unless
I close the program.
The configuration event hasn't
fired at the time you include
the print statement in the
handler's def block, and
therefore the print function
inside your handler hasn't
invoked. It won't be invoked
until you resize the window.
There is no point to saving
the width and height outside
your
on_configure() function,
because outside that function
you can't know if they have
been changed. There could
even have been a race
condition where you use one
but the other changes before
you get around to using it.
It's better just to ask tk for
the values whenever you need
them, as you do inside your
handler.
> import tkinter as tk
>
> Ww = None # What does this
do? Why not Integer?
> WwZ = None
# These could be integers,
like 0, but that would not be
the correct # window sizes at
that point. The window is
either not constructed or it #
has some definite size that is
not zero.
> def on_configure(*args):
> global Ww
> global WwZ
> Ww =
root.winfo_width()
> print("9 Ww Inside
=<"+str(Ww)+">") # works
> WwZ = Ww * 2
> print("11 WwZ
Inside =<"+str(WwZ)+">") #
works
> return(Ww) #Can I
use this?
>
> root = tk.Tk()
>
root.bind('',on_con
figure)
> print("15 Ww Inside1 =
<"+str(Ww)+">")
> #Ww2 = int(Ww) * 2 # fails
> print("17 WwZ Inside2 =
<"+str(WwZ)+">")
>
> root.mainloop()
>
> Ww2 = int(Ww) * 2 #Works
but only after the program
stops
> print("21 Ww Outside2 =
<"+str(WwZ)+">") # Can I have
concentric
> loops?
>
>
> SGA
>
> -Original Message-
> From: Alan Gauld
> Sent: Monday, February 26,
2024 4:04 AM
> To: Steve GS
;
python-list@python.org
> Subject: Re: RE: Problem
resizing a window and button
placement
>
> On 26/02/2024 07:56, Steve
GS via Python-list wrote:
>
>> Then there is that
discovery
>> element: Why is my original
>> idea not working? I still
>> cannot pass the value back
>> from the function. What is
>> different about this
function
>> that others would have
given
>> me the value?
>
> There is nothing different,
see the code below.
> print() is a function like
any other.
> In this case it is called
after you close the window, ie
after mainloop() exits.
> But any other function
called inside
> mainloop - eg any other
event handler can also access
it.
>
> For example, if you added a
button:
>
> def printW(): print("Button
Ww = ", Ww)
>
> bw = tk.Button(root,
text="Print Width",
command=printW)
> bw.pack()
>
> You would be able to print
the value on demand.
>
>>> import tkinter as tk
>>>
>>> Ww = None
>>>
>>> def on_configure(*args):
>>> global Ww
>>> Ww =
root.winfo_width()
>>> print("Ww Inside
=<"+str(Ww)+">")
>>>
>>> root = tk.Tk()
>>>
root.bind('',on_con
figure)
>>> root.mainloop()
>>>
>>> print("Ww Outside =
<"+str(Ww)+">")
>
> --
> Alan G
> Author of the Learn to
Program web site
http://www.alan-g.me.uk/
>
http://www.amazon.com/author/a
lan_gauld
> Follow my photo-blog on
Flickr at:
>
http://www.flickr.com/photos/a
langauldphotos
>
>
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Re: Problem resizing a window and button placement
On 2/26/2024 6:02 AM, Steve GS via Python-list wrote:
Although your code produces the value of Ww outside the function, I do not see
how I can use the value of Ww unless I close the program.
The configuration event hasn't fired at the time you include the print
statement in the handler's def block, and therefore the print function
inside your handler hasn't invoked. It won't be invoked until you
resize the window.
There is no point to saving the width and height outside your
on_configure() function, because outside that function you can't know if
they have been changed. There could even have been a race condition
where you use one but the other changes before you get around to using
it. It's better just to ask tk for the values whenever you need them,
as you do inside your handler.
import tkinter as tk
Ww = None # What does this do? Why not Integer?
WwZ = None
# These could be integers, like 0, but that would not be the correct
# window sizes at that point. The window is either not constructed or it
# has some definite size that is not zero.
def on_configure(*args):
global Ww
global WwZ
Ww = root.winfo_width()
print("9 Ww Inside =<"+str(Ww)+">") # works
WwZ = Ww * 2
print("11 WwZ Inside =<"+str(WwZ)+">") # works
return(Ww) #Can I use this?
root = tk.Tk()
root.bind('',on_configure)
print("15 Ww Inside1 = <"+str(Ww)+">")
#Ww2 = int(Ww) * 2 # fails
print("17 WwZ Inside2 = <"+str(WwZ)+">")
root.mainloop()
Ww2 = int(Ww) * 2 #Works but only after the program stops
print("21 Ww Outside2 = <"+str(WwZ)+">")
# Can I have concentric loops?
SGA
-Original Message-
From: Alan Gauld
Sent: Monday, February 26, 2024 4:04 AM
To: Steve GS ; python-list@python.org
Subject: Re: RE: Problem resizing a window and button placement
On 26/02/2024 07:56, Steve GS via Python-list wrote:
Then there is that discovery
element: Why is my original
idea not working? I still
cannot pass the value back
from the function. What is
different about this function
that others would have given
me the value?
There is nothing different, see the code below.
print() is a function like any other.
In this case it is called after you close the window, ie after mainloop() exits.
But any other function called inside
mainloop - eg any other event handler can also access it.
For example, if you added a button:
def printW(): print("Button Ww = ", Ww)
bw = tk.Button(root, text="Print Width", command=printW)
bw.pack()
You would be able to print the value on demand.
import tkinter as tk
Ww = None
def on_configure(*args):
global Ww
Ww = root.winfo_width()
print("Ww Inside =<"+str(Ww)+">")
root = tk.Tk()
root.bind('',on_configure)
root.mainloop()
print("Ww Outside = <"+str(Ww)+">")
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
--
https://mail.python.org/mailman/listinfo/python-list
Re: RE: RE: Problem resizing a window and button placement
On 26/02/2024 11:02, Steve GS via Python-list wrote:
> Although your code produces the value of Ww outside the function,
> I do not see how I can use the value of Ww unless I close the program.
You have to use a function that operates inside the mainloop.
Thats the nature of event driven programs, all activity happens
inside the mainloop except initialisation and cleanup.
So you need to create an event handler as I described below.
Here is the complete program including the button:
###
import tkinter as tk
Ww=None
def on_configure(*args):
global Ww
Ww = root.winfo_width()
print("Ww Inside = <" + str(Ww) + ">")
def printW(): print("Button Ww = ", Ww)
root = tk.Tk()
bw = tk.Button(root, text="Print Width", command=printW)
bw.pack()
root.bind('', on_configure)
root.mainloop()
print("Ww Outside = <" + str(Ww) + ">")
Notice that the button callback picks up the latest value of Ww.
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
--
https://mail.python.org/mailman/listinfo/python-list
RE: RE: Problem resizing a window and button placement
Although your code produces the value of Ww outside the function, I do not see
how I can use the value of Ww unless I close the program.
import tkinter as tk
Ww = None # What does this do? Why not Integer?
WwZ = None
def on_configure(*args):
global Ww
global WwZ
Ww = root.winfo_width()
print("9 Ww Inside =<"+str(Ww)+">") # works
WwZ = Ww * 2
print("11 WwZ Inside =<"+str(WwZ)+">") # works
return(Ww) #Can I use this?
root = tk.Tk()
root.bind('',on_configure)
print("15 Ww Inside1 = <"+str(Ww)+">")
#Ww2 = int(Ww) * 2 # fails
print("17 WwZ Inside2 = <"+str(WwZ)+">")
root.mainloop()
Ww2 = int(Ww) * 2 #Works but only after the program stops
print("21 Ww Outside2 = <"+str(WwZ)+">")
# Can I have concentric loops?
SGA
-Original Message-
From: Alan Gauld
Sent: Monday, February 26, 2024 4:04 AM
To: Steve GS ; python-list@python.org
Subject: Re: RE: Problem resizing a window and button placement
On 26/02/2024 07:56, Steve GS via Python-list wrote:
> Then there is that discovery
> element: Why is my original
> idea not working? I still
> cannot pass the value back
> from the function. What is
> different about this function
> that others would have given
> me the value?
There is nothing different, see the code below.
print() is a function like any other.
In this case it is called after you close the window, ie after mainloop() exits.
But any other function called inside
mainloop - eg any other event handler can also access it.
For example, if you added a button:
def printW(): print("Button Ww = ", Ww)
bw = tk.Button(root, text="Print Width", command=printW)
bw.pack()
You would be able to print the value on demand.
>> import tkinter as tk
>>
>> Ww = None
>>
>> def on_configure(*args):
>> global Ww
>> Ww = root.winfo_width()
>> print("Ww Inside =<"+str(Ww)+">")
>>
>> root = tk.Tk()
>> root.bind('',on_configure)
>> root.mainloop()
>>
>> print("Ww Outside = <"+str(Ww)+">")
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
--
https://mail.python.org/mailman/listinfo/python-list
Re: RE: Problem resizing a window and button placement
On 26/02/2024 07:56, Steve GS via Python-list wrote:
> Then there is that discovery
> element: Why is my original
> idea not working? I still
> cannot pass the value back
> from the function. What is
> different about this function
> that others would have given
> me the value?
There is nothing different, see the code below.
print() is a function like any other.
In this case it is called after you close the
window, ie after mainloop() exits.
But any other function called inside
mainloop - eg any other event handler can
also access it.
For example, if you added a button:
def printW(): print("Button Ww = ", Ww)
bw = tk.Button(root, text="Print Width", command=printW)
bw.pack()
You would be able to print the value on demand.
>> import tkinter as tk
>>
>> Ww = None
>>
>> def on_configure(*args):
>> global Ww
>> Ww = root.winfo_width()
>> print("Ww Inside =<"+str(Ww)+">")
>>
>> root = tk.Tk()
>> root.bind('',on_configure)
>> root.mainloop()
>>
>> print("Ww Outside = <"+str(Ww)+">")
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
--
https://mail.python.org/mailman/listinfo/python-list
RE: Problem resizing a window and button placement
Musta misstit
I had thought of that before I
started the discussion but
figured it would take more
code than it finally needed.
I guess I was also
variable-dependent thinking
that I would need the result
elsewhere in the code. So
far, I see that I don't need
the value.
Then there is that discovery
element: Why is my original
idea not working? I still
cannot pass the value back
from the function. What is
different about this function
that others would have given
me the value?
SGA
-Original Message-
From: Python-list
On
Behalf Of Thomas Passin via
Python-list
Sent: Sunday, February 25,
2024 5:55 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement
On 2/25/2024 4:19 PM, Steve GS
via Python-list wrote:
> SOLUTION FOUND!
>
> The fix was to write the
code that uses the width value
and to place it into the
function itself.
> Kluge? Maybe but it works.
Right, just what I wrote
earlier:
"have the function that
responds to the resize event
perform the action that you
want"
> Mischief Managed.
>
>
> As for the most recent
suggestion, it fails for me:
>
> Traceback (most recent call
last):
>File "F:/___zInsulin Code
A 08-02-23/WinPic/IOWw.pyw",
line 14, in
> print("Ww Outside = <"
+ str(Ww) > + ">")
> TypeError: bad operand type
for unary +: 'str'
>
> With the need to close the
window, it adds an extra step
and intervention to the
program to use. I am not sure
how this help[s.
>
> As a curio, it would be
interesting to see how to use
the value of a variable,
created in the function used
here, and make it available to
the code outside the function.
>
>
>
> SGA
>
> -Original Message-
> From: Alan Gauld
> Sent: Sunday, February 25,
2024 12:44 PM
> To: Steve GS
;
python-list@python.org
> Subject: Re: RE: Problem
resizing a window and button
placement
>
> On 25/02/2024 03:58, Steve
GS via Python-list wrote:
> import tkinter as tk
>
> Ww = None
>
> def on_configure(*args):
> global Ww
> Ww =
root.winfo_width()
> print("Ww Inside =
<" + str(Ww) + ">")
>
> root = tk.Tk()
> root.bind('',
on_configure)
> root.mainloop()
>
> print("Ww Outside = <" +
str(Ww) > + ">")
>
> Produces:
> Ww Inside = <200>
> Ww Inside = <200>
> Ww Inside = <205>
> Ww Inside = <205>
> Ww Inside = <206>
> Ww Inside = <206>
> Ww Outside = <206>
>
> HTH
>
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RE: Problem resizing a window and button placement
Ww Inside = <250>
Ww Inside = <249>
Ww Inside = <250>
Ww Outside =
<1770662408256on_configure>
Here is my result...
SGA
-Original Message-
From: Python-list
On
Behalf Of MRAB via Python-list
Sent: Sunday, February 25,
2024 6:40 PM
To: python-list@python.org
Subject: Re: Problem resizing
a window and button placement
On 2024-02-25 21:19, Steve GS
via Python-list wrote:
> SOLUTION FOUND!
>
> The fix was to write the
code that uses the width value
and to place it into the
function itself.
> Kluge? Maybe but it works.
>
> Mischief Managed.
>
>
> As for the most recent
suggestion, it fails for me:
>
> Traceback (most recent call
last):
>File "F:/___zInsulin Code
A 08-02-23/WinPic/IOWw.pyw",
line 14, in
> print("Ww Outside = <"
+ str(Ww) > + ">")
> TypeError: bad operand type
for unary +: 'str'
>
It fails because there's a
mistake. It should be:
print("Ww Outside = <" +
str(Ww) + ">")
> With the need to close the
window, it adds an extra step
and intervention to the
program to use. I am not sure
how this help[s.
>
> As a curio, it would be
interesting to see how to use
the value of a variable,
created in the function used
here, and make it available to
the code outside the function.
>
[snip]
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