Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 30/6/22 a les 14:47, Luca Olivetti via lazarus ha escrit:
El 30/6/22 a les 13:45, Luca Olivetti via lazarus ha escrit:
I'm puzzled: now I removed the vampyre lib from the ide, in a form I
need ImagingComponent and ImagingClassed.
I drop a TPicture with a png image and it is blank at runtime.
This time it is streamed as TPortableNetworkGraphic *but*
FindClassName cannot find it.
How is that possible?
AAAGH Because the Vampyre library explicitly deletes it
{$IFDEF COMPONENT_SET_LCL}
// Unregister Lazarus´ default PNG loader which crashes on some PNG
files
TPicture.UnregisterGraphicClass(TPortableNetworkGraphic);
{$ENDIF}
Two years later I forgot about this issue and I found it again with
lazarus 3.2 and a freshly downloade vampyre imaging library (which is
still at version 0.80 in the online package manager, though I see that
the line is still there in the github repository).
Probably my fault for not reporting the issue to Vampyre, I just hope
my memory serves me better next time.
Bye
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Luca Olivetti
Wetron Automation Technology https://wetron.es/
Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007
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Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On 30.06.2022 18:20, Werner Pamler via lazarus wrote:
Am 30.06.2022 um 17:03 schrieb Ondrej Pokorny via lazarus:
On 30.06.2022 16:54, Werner Pamler via lazarus wrote:
Am 30.06.2022 um 15:11 schrieb Mattias Gaertner via lazarus:
Maybe instead of the GraphicClass.ClassName the first extension can be
written.
That means, that an old IDE cannot read the graphic.
This will break Delphi compatibility, i.e. forms with an image in
which the Picture has been loaded by Delphi will not be readable by
Lazarus any more, and vice versa. Just checked again the signature
that Delphi writes to the begin of the Picture.Data: it's the class
name, not the extension.
And what about writing the extension to the data end?
Picture.Data = {
0B 54 49 6D 61 67 69 6E 67 50 4E 47 89 50 4E 47 0D 0A 1A 0A 00
00 00 0D 49 48 44 52 00 00 01 C6
11 T I m a g i n g P N G // 11 is the
length byte
03 p n g
That should be both Delphi and legacy Lazarus compatible if the
reader reads only the defined count of bytes for the classname?
But isn't this the same problem? When Vampyre is not installed, and
the streamer sees the TImageingPNG classname there is no way how to
find the end of the Picture.Data block.
Oh yes, you are right. The ClassName is written in the beginning of the
stream. From the sample I assumed it is written in the end but that
doesn't make sense. My bad.
---
Well there is an easier solution. I just remembered that I added an
image handler resolver TFPCustomImage.FindHandlerFromStream() to FPC
three years ago: https://gitlab.com/freepascal.org/fpc/source/-/issues/33955
So if the ClassName is not found, the FP image handler can be found from
the actual image stream. Every image format can be detected directly
from the stream, so the ClassName is actually redundant. When we have
the TIHData for the stream, then we have everything - the extension and
the FP reader/writer. From this information we can find the LCL image
handler from the registered list - of course only if at least /some/
handler is registered for the extension.
Of course, we are limited to the FPC version - I don't know if the
feature is already in a released version. But we can add the support for
the FPC versions with this feature.
Ondrej
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Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 30/6/22 a les 18:20, Werner Pamler via lazarus ha escrit: But isn't this the same problem? When Vampyre is not installed, and the streamer sees the TImageingPNG classname there is no way how to find the end of the Picture.Data block. Wouldn't it be better (if at all possible) to add a dependency on the unit that registered the class for streaming? Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Am 30.06.2022 um 17:03 schrieb Ondrej Pokorny via lazarus:
On 30.06.2022 16:54, Werner Pamler via lazarus wrote:
Am 30.06.2022 um 15:11 schrieb Mattias Gaertner via lazarus:
Maybe instead of the GraphicClass.ClassName the first extension can be
written.
That means, that an old IDE cannot read the graphic.
This will break Delphi compatibility, i.e. forms with an image in
which the Picture has been loaded by Delphi will not be readable by
Lazarus any more, and vice versa. Just checked again the signature
that Delphi writes to the begin of the Picture.Data: it's the class
name, not the extension.
And what about writing the extension to the data end?
Picture.Data = {
0B 54 49 6D 61 67 69 6E 67 50 4E 47 89 50 4E 47 0D 0A 1A 0A 00
00 00 0D 49 48 44 52 00 00 01 C6
11 T I m a g i n g P N G // 11 is the
length byte
03 p n g
That should be both Delphi and legacy Lazarus compatible if the reader
reads only the defined count of bytes for the classname?
But isn't this the same problem? When Vampyre is not installed, and the
streamer sees the TImageingPNG classname there is no way how to find the
end of the Picture.Data block.
Newer Lazarus versions would first search the extension and if not
found they search for the classname.
Where's that? AFAICS, TPicture only looks for the classname. From Laz/main:
procedure TPicture.ReadData(Stream: TStream);
var
GraphicClassName: Shortstring;
NewGraphic: TGraphic;
GraphicClass: TGraphicClass;
ok: boolean;
begin
* Stream.Read(GraphicClassName[0], 1);**
** Stream.Read(GraphicClassName[1], length(GraphicClassName));*
GraphicClass := GetPicFileFormats.FindClassName(GraphicClassName);
NewGraphic := nil;
if GraphicClass <> nil then begin
NewGraphic := GraphicClass.Create;
ok:=false;
try
NewGraphic.ReadData(Stream);
ok:=true;
finally
if not ok then NewGraphic.Free;
end;
end;
FGraphic.Free;
FGraphic := NewGraphic;
if NewGraphic <> nil then begin
NewGraphic.OnChange := @Changed;
NewGraphic.OnProgress := @Progress;
end;
Changed(Self);
end;
procedure TPicture.WriteData(Stream: TStream);
var
GraphicClassName: ShortString;
begin
with Stream do
begin
if Graphic <> nil then
GraphicClassName := Graphic.ClassName
else
GraphicClassName := '';
* Write(GraphicClassName, Length(GraphicClassName) + 1);*
if Graphic <> nil then
Graphic.WriteData(Stream);
end;
end;
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Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On 30.06.2022 16:54, Werner Pamler via lazarus wrote:
Am 30.06.2022 um 15:11 schrieb Mattias Gaertner via lazarus:
Maybe instead of the GraphicClass.ClassName the first extension can be
written.
That means, that an old IDE cannot read the graphic.
This will break Delphi compatibility, i.e. forms with an image in
which the Picture has been loaded by Delphi will not be readable by
Lazarus any more, and vice versa. Just checked again the signature
that Delphi writes to the begin of the Picture.Data: it's the class
name, not the extension.
And what about writing the extension to the data end?
Picture.Data = {
0B 54 49 6D 61 67 69 6E 67 50 4E 47 89 50 4E 47 0D 0A 1A 0A 00 00
00 0D 49 48 44 52 00 00 01 C6
11 T I m a g i n g P N G // 11 is the
length byte
03 p n g
That should be both Delphi and legacy Lazarus compatible if the reader
reads only the defined count of bytes for the classname?
Newer Lazarus versions would first search the extension and if not found
they search for the classname.
Ondrej
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Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Am 30.06.2022 um 15:11 schrieb Mattias Gaertner via lazarus: Maybe instead of the GraphicClass.ClassName the first extension can be written. That means, that an old IDE cannot read the graphic. This will break Delphi compatibility, i.e. forms with an image in which the Picture has been loaded by Delphi will not be readable by Lazarus any more, and vice versa. Just checked again the signature that Delphi writes to the begin of the Picture.Data: it's the class name, not the extension. Or the vampyrlib defines type TPortableNetworkGraphic = class(TImagingPNG); and registers that in TPicture. Yes, that might be a solution at first sight. But I don't know what happens when a project requires Vampyre (i.e. registers this new TPortableNetworkgraphic), but a unit has only the ordinary graphics unit in its uses clause, i.e. accesses the old TPortableNetworkGraphic. -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On 30.06.2022 15:11, Mattias Gaertner via lazarus wrote: On Fri, 24 Jun 2022 17:27:13 +0200 Werner Pamler via lazarus wrote: [...] But still the situation is not very satisfying. Maybe instead of the GraphicClass.ClassName the first extension can be written. That means, that an old IDE cannot read the graphic. I did this already before: the next stable release should write the ClassName but support reading the extension and then the second stable release should write the extension. With it we make sure that always the last 2 released version can read the LFM. That is enough. Ondrej -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On Fri, 24 Jun 2022 17:27:13 +0200 Werner Pamler via lazarus wrote: >[...] > But still the situation is not very satisfying. Maybe instead of the GraphicClass.ClassName the first extension can be written. That means, that an old IDE cannot read the graphic. Or the vampyrlib defines type TPortableNetworkGraphic = class(TImagingPNG); and registers that in TPicture. Mattias -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 30/6/22 a les 13:45, Luca Olivetti via lazarus ha escrit:
I'm puzzled: now I removed the vampyre lib from the ide, in a form I
need ImagingComponent and ImagingClassed.
I drop a TPicture with a png image and it is blank at runtime.
This time it is streamed as TPortableNetworkGraphic *but* FindClassName
cannot find it.
How is that possible?
AAAGH Because the Vampyre library explicitly deletes it
{$IFDEF COMPONENT_SET_LCL}
// Unregister Lazarus´ default PNG loader which crashes on some PNG
files
TPicture.UnregisterGraphicClass(TPortableNetworkGraphic);
{$ENDIF}
Bye
--
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Wetron Automation Technology http://www.wetron.es/
Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007
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Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 24/6/22 a les 9:48, Luca Olivetti via lazarus ha escrit: El 24/6/22 a les 0:19, Mattias Gaertner via lazarus ha escrit: but why did it find the class for writing and not for reading it back? Also, once solved that, if it streams it using a class provided by a package, shouldn't the project have a dependency automatically added on that package? Both should read+write valid png files, otherwise there is a bug. I was stepping though the method TPicture.ReadData(Stream: TStream) and I saw that GraphicClassName was "TImagingPNG" but the line GraphicClass := GetPicFileFormats.FindClassName(GraphicClassName) returned nil I'm puzzled: now I removed the vampyre lib from the ide, in a form I need ImagingComponent and ImagingClassed. I drop a TPicture with a png image and it is blank at runtime. This time it is streamed as TPortableNetworkGraphic *but* FindClassName cannot find it. How is that possible? Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 26/6/22 a les 13:44, Werner Pamler via lazarus ha escrit: Am 26.06.2022 um 13:20 schrieb Luca Olivetti via lazarus: El 26/6/22 a les 11:36, Werner Pamler via lazarus ha escrit: Am 26.06.2022 um 10:54 schrieb Luca Olivetti via lazarus: VampyreImaginPackage 0.80 Mine is v0.82 which is the current version in OPM. According to their release notes there are changes related to PNG saving. My online package manager only has 0.80, the repository is http://packages.lazarus-ide.org Ah, I had installed the git version, and then OPM displays the installed version number... You can find the author's github version (v0.82) at https://github.com/galfar/imaginglib (if you don't use git, you can download also a zip from there). Even if version 0.82 solves the stream read error, the underlying problem is still there: it hijacks the format used for streaming TPicture but there is no dependency added to the projects when you add a TPicture. I don't know if that's even possible, but it is a problem nevertheless. Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Am 26.06.2022 um 13:20 schrieb Luca Olivetti via lazarus: El 26/6/22 a les 11:36, Werner Pamler via lazarus ha escrit: Am 26.06.2022 um 10:54 schrieb Luca Olivetti via lazarus: VampyreImaginPackage 0.80 Mine is v0.82 which is the current version in OPM. According to their release notes there are changes related to PNG saving. My online package manager only has 0.80, the repository is http://packages.lazarus-ide.org Ah, I had installed the git version, and then OPM displays the installed version number... You can find the author's github version (v0.82) at https://github.com/galfar/imaginglib (if you don't use git, you can download also a zip from there). -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 26/6/22 a les 11:36, Werner Pamler via lazarus ha escrit: Am 26.06.2022 um 10:54 schrieb Luca Olivetti via lazarus: VampyreImaginPackage 0.80 Mine is v0.82 which is the current version in OPM. According to their release notes there are changes related to PNG saving. My online package manager only has 0.80, the repository is http://packages.lazarus-ide.org Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Am 26.06.2022 um 10:54 schrieb Luca Olivetti via lazarus: VampyreImaginPackage 0.80 Mine is v0.82 which is the current version in OPM. According to their release notes there are changes related to PNG saving. -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 26/6/22 a les 1:08, Werner Pamler via lazarus ha escrit: It doesn't even work at designtime (see above). Try attached demo project. The "paw" image was inserted into a TImage after installation of Vampyre. All I had to do to get it working is to add Vampyre to the project requirements and to add ImagingComponents to the uses clause (or check the box "Add package unit to uses section" in the package options, then the formats will be registered for runtime automatically). With the VampyreImaginPackage 0.80 not installed in the ide, I can open the project, see a blank image and when I try to run it: "Project project1 raised exception class 'EReadError' with message: Stream read error" With the package installed I get the error as soon as I try to open the project (as well as when I try to run it). I cannot install the VampyreImagingPackageExt Warning: linker: /usr/bin/ld: /home/luca/Datos/laz_2_2/onlinepackagemanager/packages/VampyreImaging/Packages/lib/VampyreImagingPackageExt/3.2.2/x86_64-linux/default/ZLibDelphi.o: undefined reference to symbol 'deflateInit_' (in fact, I never installed it, yet it streamed the pictures as TImagingPMG) Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Am 26.06.2022 um 00:14 schrieb Luca Olivetti via lazarus: First observation after installing VampyreImagingPackageExt (the other package, VampyreImagingPackage, has no registration unit): I add TImage to a form and load the Lazarus "paw" to it. Works fine at designtime, but at runtime the image is empty. As the OP already noted Vampyre's TImagingPNG class is not found. This is because the Vampyre formats are registered only at designtime, but not at runtime of a project. It doesn't even work at designtime (see above). Try attached demo project. The "paw" image was inserted into a TImage after installation of Vampyre. All I had to do to get it working is to add Vampyre to the project requirements and to add ImagingComponents to the uses clause (or check the box "Add package unit to uses section" in the package options, then the formats will be registered for runtime automatically). Please note: I am not talking about the clipboard here, in fact I did not even investigate this because this is a different issue. <> -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 24/6/22 a les 17:27, Werner Pamler via lazarus ha escrit: Ah, of course. (I thought I had searched for "Register" in unit graphics...). Now I saw that Vampyre also uses these TPicture class methods to finally register their formats for TPicture. Thus, everything should be fine. No, it isn't: it doesn't find the class when reading. When you copy and paste a TImage you'll have a stream read error, as well as when reopening the project. But still the situation is not very satisfying. Yes, I find it suboptimal that the picture format can be hijacked without adding a dependency on the needed package to correctly read it back. Of course it's my fault since I installed it in the ide without a real need, but I still think there's something wrong. First observation after installing VampyreImagingPackageExt (the other package, VampyreImagingPackage, has no registration unit): I add TImage to a form and load the Lazarus "paw" to it. Works fine at designtime, but at runtime the image is empty. As the OP already noted Vampyre's TImagingPNG class is not found. This is because the Vampyre formats are registered only at designtime, but not at runtime of a project. It doesn't even work at designtime (see above). Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Am 24.06.2022 um 11:30 schrieb Mattias Gaertner via lazarus:
On Fri, 24 Jun 2022 11:09:17 +0200
Werner Pamler via lazarus wrote:
[...] It is
my impression there is no way to register a new format in any way
without modifying the sources of TPicture.
TPicture:
class function SupportsClipboardFormat(FormatID: TClipboardFormat):
Boolean;
class procedure RegisterFileFormat(const AnExtension, ADescription: string;
AGraphicClass: TGraphicClass);
class procedure RegisterClipboardFormat(FormatID: TClipboardFormat;
AGraphicClass: TGraphicClass);
class procedure UnregisterGraphicClass(AClass: TGraphicClass);
class function FindGraphicClassWithFileExt(const Ext: string;
ExceptionOnNotFound: boolean = true): TGraphicClass;
Ah, of course. (I thought I had searched for "Register" in unit
graphics...). Now I saw that Vampyre also uses these TPicture class
methods to finally register their formats for TPicture. Thus, everything
should be fine.
But still the situation is not very satisfying.
First observation after installing VampyreImagingPackageExt (the other
package, VampyreImagingPackage, has no registration unit): I add TImage
to a form and load the Lazarus "paw" to it. Works fine at designtime,
but at runtime the image is empty. As the OP already noted Vampyre's
TImagingPNG class is not found. This is because the Vampyre formats are
registered only at designtime, but not at runtime of a project. But this
can be fixed easily: After adding unit *ImagingComponents *to the uses
clause, the "paw" is displayed at runtime, too.
Next complication comes into play if the user decides to uninstall
Vampyre. The problem is that every graphic type writes its class name to
the lfm file in front of the image data (Picture.Data). So, when a
picture was loaded into TImage while Vampyre was installed all the
images are brand-marked by the Vampyre classes, e.g. TImagingPNG rather
than TPortableNetworkGraphic:
This is the part of the lfm written when Vampyre is installed (I am
adding spaces to the hex data to see the digits:
object Image1: TImage
Left = 8
Height = 344
Top = 8
Width = 456
Picture.Data = {
0B 54 49 6D 61 67 69 6E 67 50 4E 47 89 50 4E 47 0D 0A 1A 0A 00 00
00 0D 49 48 44 52 00 00 01 C6
11 T I m a g i n g P N G // 11 is the
length byte
An image written by the LCL without Vampyre contains this:
object Image1: TImage
Left = 24
Height = 284
Top = 20
Width = 376
Picture.Data = {
17 54 50 6F 72 74 61 62 6C 65 4E 65 74 77 6F 72 6B 47 72 61 70 68
69 63 9A 3D 00 00 89 50 4E 47
23 T P o r t a b l e N e t w o r k G r a p h
i c
When such a project is loaded into a Lazarus without Vampyre at first
the VampyreImagingPackage and/or VampyreImagingPackageExt requirements
must be removed from the project. But, of course, the Vampyre image
class signatures are still in the lfm file, and the IDE refuses to load
the form with this error:
Unable to find the component class "TForm1".
It is not registered via RegisterClass and no lfm was found.
It is needed by unit:
D:\Prog_Lazarus\tests\_images\vampyre\format_registration\vampyre_stripped\unit1.lfm
I think this is the most confusing part of that issue. If it would say
"Unable to find class "TImagingPNG"" it would be much clearer.
However, I don't think that much can be done against that. There is
always a risk when using third-party components that irreversible
changes could occur. Hmm, well, somebody could write a tool the fix the
image classname header in the lfm's Picture.Data.
Werner
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Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
[sorry for the top post, I'm answering from my phone] I think it does, otherwise the TPicture in the TImage wouldn't be streamed as TImagingPNG. OTOH, if I read the TPicture code correctly, there's only one registration so I don't understand how it is possible that it finds the class for writing but not for reading. 24 jun. 2022 11:09:36 Werner Pamler via lazarus : > Vampyre does not take care of the FPC image type registration. But that's not > the problem.. -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On Fri, 24 Jun 2022 11:09:17 +0200 Werner Pamler via lazarus wrote: >[...] It is > my impression there is no way to register a new format in any way > without modifying the sources of TPicture. TPicture: class function SupportsClipboardFormat(FormatID: TClipboardFormat): Boolean; class procedure RegisterFileFormat(const AnExtension, ADescription: string; AGraphicClass: TGraphicClass); class procedure RegisterClipboardFormat(FormatID: TClipboardFormat; AGraphicClass: TGraphicClass); class procedure UnregisterGraphicClass(AClass: TGraphicClass); class function FindGraphicClassWithFileExt(const Ext: string; ExceptionOnNotFound: boolean = true): TGraphicClass; Mattias -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
Vampyre has its own file format registration system. There is a class TImageFileFormat, and there is a list ImageFileFormats which stores the parameters for all known file formats. Each file format has a reader/writer unit, and these units add the file format to the ImageFileFormatsList if such a unit exists in a uses clause. FPC has a similar registration system, it registeres its own reader/writers in a similar list, ImageHandlers. Vampyre does not take care of the FPC image type registration. But that's not the problem... To make things worse, LCL has another registration system for the image types known to TPicture. There is a list TPicFileFormatsList which stores pointers to TPicFileFormat records. The instance of this list, PicFileFormats, is accessible only via a factory function GetPicFileformats which is not accessible from the outside. The formats known to the TPicture are added in the constructor of TPicFileFormatsList, again fully hidden inside the picture.inc. It is my impression there is no way to register a new format in any way without modifying the sources of TPicture. This is bad... In my opinion, the TPicture file format registration should be moved into the interface part of the graphics unit so that the user can add his own image formats. Then Vampyre could call GetPicFileFormats.Add and provide the information for its own readers/writers; if there are duplicate formats the old ones should be removed in the Add call. Werner -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 24/6/22 a les 0:19, Mattias Gaertner via lazarus ha escrit: but why did it find the class for writing and not for reading it back? Also, once solved that, if it streams it using a class provided by a package, shouldn't the project have a dependency automatically added on that package? Both should read+write valid png files, otherwise there is a bug. I was stepping though the method TPicture.ReadData(Stream: TStream) and I saw that GraphicClassName was "TImagingPNG" but the line GraphicClass := GetPicFileFormats.FindClassName(GraphicClassName) returned nil Are you sure, that the VampyreImaging lib is supposed to be installed in the IDE and to replace the default png TPicture? Actually I'm not, since it works fine for what I need without installing it, but in its options IDE Integration is marked as "Designtime and runtime". Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On Fri, 24 Jun 2022 00:05:02 +0200 Luca Olivetti via lazarus wrote: > El 23/6/22 a les 21:40, Mattias Gaertner via lazarus ha escrit: > > On Thu, 23 Jun 2022 20:38:59 +0200 > > Luca Olivetti via lazarus wrote: > > > >> [...] > >> I don't understand why the ide prefers one class over the other, I > >> guess they are all treated the same and the one registered last > >> wins? > > > > Correct. See TPicture.RegisterFileFormat > > Not that it's going to matter now that I uninstalled the package, > but why did it find the class for writing and not for reading it back? > Also, once solved that, if it streams it using a class provided by a > package, shouldn't the project have a dependency automatically added > on that package? Both should read+write valid png files, otherwise there is a bug. Are you sure, that the VampyreImaging lib is supposed to be installed in the IDE and to replace the default png TPicture? Mattias -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 23/6/22 a les 21:40, Mattias Gaertner via lazarus ha escrit: On Thu, 23 Jun 2022 20:38:59 +0200 Luca Olivetti via lazarus wrote: [...] I don't understand why the ide prefers one class over the other, I guess they are all treated the same and the one registered last wins? Correct. See TPicture.RegisterFileFormat Not that it's going to matter now that I uninstalled the package, but why did it find the class for writing and not for reading it back? Also, once solved that, if it streams it using a class provided by a package, shouldn't the project have a dependency automatically added on that package? Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
On Thu, 23 Jun 2022 20:38:59 +0200 Luca Olivetti via lazarus wrote: >[...] > I don't understand why the ide prefers one class over the other, I > guess they are all treated the same and the one registered last wins? Correct. See TPicture.RegisterFileFormat Mattias -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 23/6/22 a les 13:29, Luca Olivetti via lazarus ha escrit: I self build lazarus from the git sources, so maybe it is something in my environment. I found the cause: it's the VampyreImaging library. If I install it in the ide, it will stream png as "TImagingPNG" instead of "TPortableNetworkGraphic" but then it cannot read that format back (the method TPicture.ReadData doesn't find the corresponding class). I suppose it does the same for all other image type that the VampyreImaging library supports. I just uninstalled it from the ide and left it as a dependency for the projects where I need it (that's what I did with the previous version of lazarus, maybe I encountered the same problem and forgot about it). I don't understand why the ide prefers one class over the other, I guess they are all treated the same and the one registered last wins? Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
Re: [Lazarus] Strange issue with TImage and lazarus 2.2.2
El 23/6/22 a les 13:29, Luca Olivetti via lazarus ha escrit: I tested under both linux(qt5) and windows and the behavior is the same (the only difference is that under windows I use fpc 3.2.0 with lazarus 2.0.12 and 3.2.2 with 2.2.2, while under windows I use fpc 3.2.2 for both). Windows 32 bits and Linux 64 bits. That doesn't make sense: under *linux* I use the same fpc for both lazarus versions. Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
[Lazarus] Strange issue with TImage and lazarus 2.2.2
Before reporting an issue, I wanted to ask. I have a strange issue with TImage and lazarus 2.2.2: if (at designtime) I load a png or a jpg image in a TImage but at runtime it is blank. Worse, if I copy paste it, I get a streaming read error on Data (either when pasting or when running the program, the latter not always). Only .ico seems to work with lazarus 2.2.2. Now, if I open the same project in lazarus 2.0.12, the image is blank, I load a picture and it works. Then I open the modified project with lazarus 2.2.2, at designtime the image is blank, but when the program is run I can see the image I loaded with lazarus 2.0.12. I self build lazarus from the git sources, so maybe it is something in my environment. I tested under both linux(qt5) and windows and the behavior is the same (the only difference is that under windows I use fpc 3.2.0 with lazarus 2.0.12 and 3.2.2 with 2.2.2, while under windows I use fpc 3.2.2 for both). Windows 32 bits and Linux 64 bits. Bye -- Luca Olivetti Wetron Automation Technology http://www.wetron.es/ Tel. +34 93 5883004 (Ext.3010) Fax +34 93 5883007 -- ___ lazarus mailing list lazarus@lists.lazarus-ide.org https://lists.lazarus-ide.org/listinfo/lazarus
