Speed up canvas redraw for GTK3Agg backend.

akhilman · akhilman · commit b18a576477e7 · 2018-09-06T01:04:48.000Z
Move `_render_figure()` call out of `on_draw_event` handler in `FigureCanvasGTK3Agg` class and call it from overloaded `draw()` method. Fixes #12010 Gtk triggers `draw` event not only when actual plot redraw required but also when any another widget drawn over canvas. This makes application with embided plot unresponsive in cases when popover or popup menu are drawn over plot. You may try example provided in #12010. Moving actual plot redraw out of `on_draw_event()` makes GUI much more responsive. This changes tested with: * animation from examples/ directory * interacive pan and zoom * cursor widget with bliting * calling draw_idle() to update interactive chart
diff --git a/lib/matplotlib/backends/backend_gtk3agg.py b/lib/matplotlib/backends/backend_gtk3agg.py
@@ -26,7 +26,6 @@ def on_draw_event(self, widget, ctx):
         w, h = allocation.width, allocation.height
 
         if not len(self._bbox_queue):
-            self._render_figure(w, h)
             Gtk.render_background(
                 self.get_style_context(), ctx,
                 allocation.x, allocation.y,
@@ -71,6 +70,12 @@ def blit(self, bbox=None):
         self._bbox_queue.append(bbox)
         self.queue_draw_area(x, y, width, height)
 
+    def draw(self):
+        if self.get_visible() and self.get_mapped():
+            allocation = self.get_allocation()
+            self._render_figure(allocation.width, allocation.height)
+        super(FigureCanvasGTK3Agg).draw()
+
     def print_png(self, filename, *args, **kwargs):
         # Do this so we can save the resolution of figure in the PNG file
         agg = self.switch_backends(backend_agg.FigureCanvasAgg)
