New backend - Qt

[Ksengine]

On linux toga uses GTK+
but some platforms like KDE already has Qt.
some users are familiar with Qt.

so its better if toga can develop a Qt port

Threre are few Qt impliments

• PyQt5
• PyQt4
• Pyside2
• Pyside
  They all has nearly same API.

I like to work on this issue myself

[freakboy3742]

If you want to contribute a Qt implementation of Toga, then go right ahead! A placeholder implementation already exists in the nursery. Submit pull requests against that location; once the implementation starts to show signs of viability, we can move it to the supported list.

[Ksengine]

ok I will start creating basics on toga_qt/libs folser

[johnzhou721]

What does HANDLES_COMMAND_LINE mean in an App class?

EDIT: Thanks.

[johnzhou721]

PyQt{4,5,6} are NOT usable. They're GPL'd.

@freakboy3742 Is LGPL okay?

[johnzhou721]

On the other hand, PySide6 is LGPL (EDITED), and that is what I'm using.

EDIT just realized PyQt isn't official... another reason to use PySide*.

[johnzhou721]

@freakboy3742 FYI: I've started to work on this, currently almost everything is stubbed out, it runs without errors though, but somehow no window is displayed... probably messed up somewhere.

https://github.com/johnzhou721/togax_qt

[freakboy3742]

GPL won't be acceptable in Toga's core. LGPL would be fine. PySide6 is the most recent version of the official Qt Python bindings, so it makes sense that's the one to be used.

As for "no window being displayed"... well, that's the problem to solve, isn't it :-) I can't profess any expertise with Qt, so I can't really offer any help there.