Force X Window repaint upon resize

repaint-upon-resize.py

# This is a hacky workaround for the XQuartz repaint bug reported in
# https://github.com/XQuartz/XQuartz/issues/438.
# This requires python-xlib.
#
# FIXME:
#  - I don't know how to get rid of BadMatch errors.
#  - Sometimes you need to explicitly set DISPLAY as:
#    DISPLAY=:0 python repaint-upon-resize.py
#  - Ctrl-C does not work even though I catch KeyboardInterrupt.

import sys
from Xlib import X, display, error

def redraw_window_recursively(window, d):
    try:
        attrs = window.get_attributes()
        if attrs.map_state == X.IsViewable:
#            print("Repaint window", window)
            window.clear_area(x=0, y=0, width=0, height=0, exposures=True)
            
        tree = window.query_tree()
        for child in tree.children:
            redraw_window_recursively(child, d)

    except error.XError:
        pass

def detect_window_resize():
    try:
        d = display.Display()
    except error.DisplayError:
        print("Cannot connect to the X server.", file=sys.stderr)
        sys.exit(1)

    root = d.screen().root

    event_mask = X.SubstructureNotifyMask | X.StructureNotifyMask
    root.change_attributes(event_mask=event_mask)

    while True:
        try:
            event = d.next_event()
            
            if event.type == X.ConfigureNotify:
                window_id = event.window.id
                window = d.create_resource_object('window', window_id)
                redraw_window_recursively(window, d)
        except KeyboardInterrupt:
            break
        except:
            continue

if __name__ == "__main__":
    detect_window_resize()

adding

    if attrs.win_class != 1:
        return

before line 17 fixes BadMatch error (don't ask)

Confirm. Adding these two lines does seem to address the BadMatch errors.

oops. let me retract the confirmation. If I add the lines to return early then I don't see my debug message saying it is repainting the window at new line 22 so it's skipping everything.