GTK3 still alpha

[regs]

It appears that TMemo.OnChange doesn't fire with GTK3

[Thaddy]

I am quite sure you are not using the trunk version.
The improvements have not been back-ported.

[zeljko]

He is using trunk , I've implemented TMemo.OnChange few hours ago

[Thaddy]

Tnx. As usual 

[dbannon]

zeljko, as I have said before, thanks so much for this progress !

I note that the GTK3 ListView.OwnerData mode is not working. Attached is a small demo of how it works in GTK3, GTK2 and Qt5,Qt6. Easily adapted to Win and Cocoa but I am currently traveling, don't have the hardware and am at the end of a length of wet string in a network  sense.

The OwnerData mode is very useful when you have a large and possibly complicated data set to display, in theory saving some time and memory.

The Qt versions also, incidentally, seem to have a problems with mouse over triggering data reads. And the GTK2 version reads the whole data set initially but then is well behaved.

Want a bug report ?  (IMHO gtk2 is near its use by date)

I am also chasing a mysterious GTK3 window startup bug specific to my project, will take some drill down time.... 

Davo

[zeljko]

Yes please, open issue and attach example project. I know about gtk3 listview problem, it is on my todo list.

[Zoran]

I have got two questions about what is planned for gtk3 in the future Lazarus versions. Please tell us:

1. Lazarus 4 (which is already in pre-release status and separated from main branch) - is the stable gtk3 included (backported) there?

2. Lazarus 5 (current main branch) - will gtk3 be the default widgetset on Linux? Will gtk2 be deprecated?

[zeljko]

1. No, recent gtk3 changes are trunk only. It is very complex to merge gtk3 stuff since it contains new features like GetCanvasScaleFactor and SetCanvasScaleFactor and I'm not willing to do that.
2. If gtk3 will be enough stable why not, but while I'm one man band on gtk3 it is hard to say.

[Zoran]

1. No, recent gtk3 changes are trunk only. It is very complex to merge gtk3 stuff since it contains new features like GetCanvasScaleFactor and SetCanvasScaleFactor and I'm not willing to do that.
2. If gtk3 will be enough stable why not, but while I'm one man band on gtk3 it is hard to say.

I understand, thank you.

[regs]

There are also issues with scaling. Forms created at PPI over 96 do not look well. Same problem as with Qt6. They rely on internal GTK3 and Qt6 raster scaling, which is bad, and always presume that they were created at 96 PPI. LCL scaling fixes it adjusting and downscaling back, but not everything goes well with this upscale/downscale process. Ideally it's better to rely only on LCL. And with Qt6 to use PassThrough with QT_ENABLE_HIGHDPI_SCALING=0 (they removed a function to make it worse).

Like TLazVirtualStringTree.

Qt6 does some proper scaling with own components. But everything custom drawn is blurry. With GTK3 it's not as bad because of integer scaling, at least not blurry.

GTK4 made it far worse with "fractional scaling", which is entirely blurry disaster.

[regs]

LCLQt5 also has same problem now

[zeljko]

Is it lazarus trunk ?