Restore dark theme support in wx backend

jmoraleda · jmoraleda · commit 63f4c2b92288 · 2023-09-10T19:12:53.000-04:00
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -1058,8 +1058,21 @@ def _icon(name):
         *name*, including the extension and relative to Matplotlib's "images"
         data directory.
         """
-        return wx.BitmapBundle.FromSVGFile(str(cbook._get_data_path("images", name)),
-                                    wx.ArtProvider().GetDIPSizeHint(wx.ART_TOOLBAR))
+        svg = cbook._get_data_path("images", name).read_bytes()
+        try:
+            dark = wx.SystemSettings.GetAppearance().IsDark()
+        except AttributeError:  # wxpython < 4.1
+            # copied from wx's IsUsingDarkBackground / GetLuminance.
+            bg = wx.SystemSettings.GetColour(wx.SYS_COLOUR_WINDOW)
+            fg = wx.SystemSettings.GetColour(wx.SYS_COLOUR_WINDOWTEXT)
+            # See wx.Colour.GetLuminance.
+            bg_lum = (.299 * bg.red + .587 * bg.green + .114 * bg.blue) / 255
+            fg_lum = (.299 * fg.red + .587 * fg.green + .114 * fg.blue) / 255
+            dark = fg_lum - bg_lum > .2
+        if dark:
+            svg = svg.replace(b'style="fill:black;"', b'style="fill:white;"')
+        toolbarIconSize = wx.ArtProvider().GetDIPSizeHint(wx.ART_TOOLBAR)
+        return wx.BitmapBundle.FromSVG(svg, toolbarIconSize)
 
     def _update_buttons_checked(self):
         if "Pan" in self.wx_ids:
