Merge pull request matplotlib#1578 from spinnau/fix_1575

Fixed blitting in Gtk3Agg backend

lib/matplotlib/backends/backend_gtk3agg.py

@@ -59,8 +59,20 @@ def on_draw_event(self, widget, ctx):
         return False
 
     def blit(self, bbox=None):
+        # If bbox is None, blit the entire canvas to gtk. Otherwise
+        # blit only the area defined by the bbox.
+        if bbox is None:
+            bbox = self.figure.bbox
+
+        allocation = self.get_allocation()
+        w, h = allocation.width, allocation.height
+        x = int(bbox.x0)
+        y = h - int(bbox.y1)
+        width = int(bbox.x1) - int(bbox.x0)
+        height = int(bbox.y1) - int(bbox.y0)
+
         self._bbox_queue.append(bbox)
-        self.queue_draw()
+        self.queue_draw_area(x, y, width, height)
 
     def print_png(self, filename, *args, **kwargs):
         # Do this so we can save the resolution of figure in the PNG file