Merge pull request matplotlib#22175 from greglucas/macosx-animations

FIX: Update macosx animation handling

Author: dstansby

lib/matplotlib/animation.py

@@ -1185,9 +1185,16 @@ def _setup_blit(self):
         # Setting up the blit requires: a cache of the background for the Axes
         self._blit_cache = dict()
         self._drawn_artists = []
+        # _post_draw needs to be called first to initialize the renderer
+        self._post_draw(None, self._blit)
+        # Then we need to clear the Frame for the initial draw
+        # This is typically handled in _on_resize because QT and Tk
+        # emit a resize event on launch, but the macosx backend does not,
+        # thus we force it here for everyone for consistency
+        self._init_draw()
+        # Connect to future resize events
         self._resize_id = self._fig.canvas.mpl_connect('resize_event',
                                                        self._on_resize)
-        self._post_draw(None, self._blit)
 
     def _on_resize(self, event):
         # On resize, we need to disable the resize event handling so we don't

src/_macosx.m

@@ -1294,6 +1294,8 @@ - (void)updateDevicePixelRatio:(double)scale
         goto exit;
     }
     if (PyObject_IsTrue(change)) {
+        // Notify that there was a resize_event that took place
+        gil_call_method(canvas, "resize_event");
         [self setNeedsDisplay: YES];
     }