gtk: Fix draw on unmapped windows.

QuLogic · QuLogic · commit 2f725a68a9f9 · 2020-07-20T17:17:38.000-04:00
Most other backends do not skip drawing on unmapped windows; this skip
causes explicit draws to do nothing and breaks things that expect it to
work.

For example, the `TextBox` example broke since the widget was changed to
set text before showing the window. This required drawing to work in
order to measure text size and place the caret.
diff --git a/lib/matplotlib/backends/backend_gtk3.py b/lib/matplotlib/backends/backend_gtk3.py
@@ -539,8 +539,10 @@ def set_message(self, s):
         self.message.set_label(s)
 
     def set_cursor(self, cursor):
-        self.canvas.get_property("window").set_cursor(cursord[cursor])
-        Gtk.main_iteration()
+        window = self.canvas.get_property("window")
+        if window is not None:
+            window.set_cursor(cursord[cursor])
+            Gtk.main_iteration()
 
     def draw_rubberband(self, event, x0, y0, x1, y1):
         height = self.canvas.figure.bbox.height
diff --git a/lib/matplotlib/backends/backend_gtk3agg.py b/lib/matplotlib/backends/backend_gtk3agg.py
@@ -67,8 +67,7 @@ def blit(self, bbox=None):
         self.queue_draw_area(x, y, width, height)
 
     def draw(self):
-        if self.get_visible() and self.get_mapped():
-            backend_agg.FigureCanvasAgg.draw(self)
+        backend_agg.FigureCanvasAgg.draw(self)
         super().draw()
 
     def print_png(self, filename, *args, **kwargs):
