XWayland is required even though wxPython programs runs under wayland

[bhepple]

Operating system: Void Linux
wxPython version & source: wxPython-4.2.1_4 from voidlinux repo
Python version & source: python3-3.12.3_1

Description of the problem:
On linux, wxPython programs can run under wayland for example in the sway WM.

However, if XWayland is not available and enabled they will not run:

Unable to access the X Display, is $DISPLAY set properly?

Any wxPython program will do eg:

import wx

class MyFrame(wx.Frame):
    def __init__(self, parent, title):
        super(MyFrame, self).__init__(parent, title=title)
        top_panel = wx.Panel(self)
        top_panel_sizer = wx.BoxSizer(wx.VERTICAL)
        top_panel.SetSizer(top_panel_sizer)
        collapsible_pane = wx.CollapsiblePane(top_panel, label="Collapsible Pane",
                                              style=wx.CP_DEFAULT_STYLE|wx.CP_NO_TLW_RESIZE)
        self.Bind(wx.EVT_COLLAPSIBLEPANE_CHANGED, self.OnPaneChanged, collapsible_pane)
        pane = collapsible_pane.GetPane()
        pane_sizer = wx.BoxSizer(wx.VERTICAL)
        pane.SetSizer(pane_sizer)
        text_box = wx.TextCtrl(pane, value = "foo")
        pane_sizer.Add(text_box, 1, wx.ALL | wx.EXPAND, 5)
        top_panel_sizer.Add(collapsible_pane, 1, wx.ALL | wx.EXPAND, 5)
        
    def OnPaneChanged(self, evt=None):
        self.Layout()
        
if __name__ == "__main__":
    app = wx.App()
    frm = MyFrame(None, title="Minimal wxPython Program")
    frm.Show()
    app.MainLoop()

[swt2c]

Confirmed. wxPython calls XOpenDisplay unconditionally here:
https://github.com/wxWidgets/Phoenix/blob/master/src/app_ex.cpp#L303

[swt2c]

You can probably hack around this problem by monkey-patching IsDisplayAvailable:

wx.PyApp.IsDisplayAvailable = lambda _: True

I wonder if the check still makes sense, but it does seem at least somewhat useful. If I remove it on a system with no display (e.g., over an SSH connection), wxPython startup will just hang there.

[bhepple]

Thanks for that - works just fine without Xwayland now.

The problem for me is that my Xwayland is rather buggy and brings down the sway session occasionally - so this should be a life changer.

[bhepple]

Up to you if you want to close this. I'm OK with the patch but I still think it's a bit janky that otherwise you must have Xwayland.

[swt2c]

No, this is definitely an issue that we need to address. I'm just not sure how exactly.