Merge pull request matplotlib#3970 from blink1073/add-figure-event-webagg

ENH : Add Figure Enter/Leave Events to Webagg

Author: tacaswell

lib/matplotlib/backends/backend_webagg_core.py

@@ -191,7 +191,8 @@ def handle_event(self, event):
             pass
         elif e_type == 'draw':
             self.draw()
-        elif e_type in ('button_press', 'button_release', 'motion_notify'):
+        elif e_type in ('button_press', 'button_release', 'motion_notify',
+                        'figure_enter', 'figure_leave'):
             x = event['x']
             y = event['y']
             y = self.get_renderer().height - y
@@ -213,6 +214,10 @@ def handle_event(self, event):
                 self.button_release_event(x, y, button)
             elif e_type == 'motion_notify':
                 self.motion_notify_event(x, y)
+            elif e_type == 'figure_enter':
+                self.enter_notify_event(xy=(x, y))
+            elif e_type == 'figure_leave':
+                self.leave_notify_event()
         elif e_type in ('key_press', 'key_release'):
             key = event['key']
 

lib/matplotlib/backends/web_backend/mpl.js

@@ -125,6 +125,9 @@ mpl.figure.prototype._init_canvas = function() {
     // Throttle sequential mouse events to 1 every 20ms.
     rubberband.mousemove('motion_notify', mouse_event_fn);
 
+    rubberband.mouseenter('figure_enter', mouse_event_fn);
+    rubberband.mouseleave('figure_leave', mouse_event_fn);
+
     canvas_div.append(canvas);
     canvas_div.append(rubberband);