replace GTK glue wherever possible

[totaam]

When we drop support for Python2 / GTK2, it will be easier to replace some of the GTK X11 glue code with pure Cython code. (see #1977 for GTK4 problems)

For example, composite and damage classes should handle raw X11 windows using their xid, the add_event_receiver / remove_event_receiver functions can just use the xid directly.

[totaam]

May become more pressing due to issues such as #3822 and the fact that we can't use GTK4.

[totaam]

A lot of progress has been made and #3822 is mostly resolved, at least in git master.

New issues:

• the size in motif wm hints should probably be used as default size
• "group-leader" and "transient-for" and window "parent", are tracking and forwarding these properly? even for OR windows?
• X11Window.get_server_time needs implementing - XIfEvent in Cython is going to be a pain
• event receivers: dictionary size should match the number of managed windows - dump to verify no leaks?
• GDKX11Window is still used in 3 places: clipboard, tray and wm - should we get rid of it completely now?
• is the X11 event mask set correctly on all window models

[totaam]

@borneoa had reported this in #3822:

Plus clipboard looks not working, probably by the same errors (two are in clipboard.py)

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/clipboard.py", line 160, in do_xpra_selection_request
    proxy.do_selection_request_event(event)
  File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/clipboard.py", line 373, in do_selection_request_event
    wininfo = self.get_wininfo(requestor.get_xid())
                               ^^^^^^^^^^^^^^^^^
AttributeError: 'int' object has no attribute 'get_xid'
Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/clipboard.py", line 200, in do_xpra_property_notify_event
    proxy.do_property_notify(event)
  File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/clipboard.py", line 659, in do_property_notify
    data = X11Window.XGetWindowProperty(self.xid, event.atom, dtype, None, MAX_DATA_SIZE, True)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "xpra/x11/bindings/window_bindings.pyx", line 995, in xpra.x11.bindings.window_bindings.X11WindowBindingsInstance.XGetWindowProperty
TypeError: an integer is required

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/xpra/server/server_base.py", line 974, in call_handler
    handler(proto, packet)
  File "/usr/lib/python3.11/site-packages/xpra/x11/server.py", line 1028, in _process_configure_window
    self._tray.move_resize(window, x, y, w, h)
  File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/tray.py", line 274, in move_resize
    window.move_resize(x, y, w, h)
  File "/usr/lib/python3.11/site-packages/xpra/x11/models/systray.py", line 48, in move_resize
    if not X11Window.XMoveResizeWindow(self.xid, x, y, width, height):
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'xpra.x11.bindings.window_bindings.X11WindowBinding' object has no attribute 'XMoveResizeWindow'. Did you mean: 'MoveResizeWindow'?

Then again, later:

On current master 370947e, still not fixed one point. The fix looks like:
sed -i '474s/.get_xid()//' xpra/x11/gtk_x11/clipboard.py

Then, menus doesn't work, and each attempt to open one causes the log

2023-05-23 22:47:22,952 Error: unmanaged X11 context
2023-05-23 22:47:22,952  MoveResizeWindow
(..)
2023-05-23 22:47:22,954    File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/tray.py", line 274, in move_resize
2023-05-23 22:47:22,954      window.move_resize(x, y, w, h)
2023-05-23 22:47:22,954    File "/usr/lib/python3.11/site-packages/xpra/x11/models/systray.py", line 48, in move_resize
2023-05-23 22:47:22,954      if not X11Window.MoveResizeWindow(self.xid, x, y, width, height):
Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/xpra/server/server_base.py", line 974, in call_handler
    handler(proto, packet)
  File "/usr/lib/python3.11/site-packages/xpra/x11/server.py", line 1028, in _process_configure_window
    self._tray.move_resize(window, x, y, w, h)
  File "/usr/lib/python3.11/site-packages/xpra/x11/gtk_x11/tray.py", line 275, in move_resize
    embedded_window = self.window_trays[window.xid]
                      ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
KeyError: 2097501

Should be fixed in 08cf69d

[totaam]

That's enough for V5, will follow up in #3871