Deprecate DraggableBase.on_motion_blit.

anntzer · anntzer · commit 3f6a3b116c57 · 2020-03-09T14:23:47.000+01:00
It was mostly duplicated with DraggableBase.on_motion.  Make on_motion
handle both the blitting and nonblitting cases.
diff --git a/doc/api/next_api_changes/deprecations.rst b/doc/api/next_api_changes/deprecations.rst
@@ -259,3 +259,8 @@ Not passing the *renderer* parameter to `.Axes.draw` is deprecated.  Use
 These changes make the signature of the ``draw`` (``artist.draw(renderer)``)
 method consistent across all artists; thus, additional parameters to
 `.Artist.draw` are deprecated.
+
+``DraggableBase.on_motion_blit``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+This method is deprecated.  `.DraggableBase.on_motion` now handles both the
+blitting and the non-blitting cases.
diff --git a/lib/matplotlib/offsetbox.py b/lib/matplotlib/offsetbox.py
@@ -1734,8 +1734,14 @@ def on_motion(self, evt):
             dx = evt.x - self.mouse_x
             dy = evt.y - self.mouse_y
             self.update_offset(dx, dy)
-            self.canvas.draw()
+            if self._use_blit:
+                self.canvas.restore_region(self.background)
+                self.ref_artist.draw(self.ref_artist.figure._cachedRenderer)
+                self.canvas.blit()
+            else:
+                self.canvas.draw()
 
+    @cbook.deprecated("3.3", alternative="self.on_motion")
     def on_motion_blit(self, evt):
         if self._check_still_parented() and self.got_artist:
             dx = evt.x - self.mouse_x
@@ -1747,23 +1753,18 @@ def on_motion_blit(self, evt):
 
     def on_pick(self, evt):
         if self._check_still_parented() and evt.artist == self.ref_artist:
-
             self.mouse_x = evt.mouseevent.x
             self.mouse_y = evt.mouseevent.y
             self.got_artist = True
-
             if self._use_blit:
                 self.ref_artist.set_animated(True)
                 self.canvas.draw()
-                self.background = self.canvas.copy_from_bbox(
-                                    self.ref_artist.figure.bbox)
+                self.background = \
+                    self.canvas.copy_from_bbox(self.ref_artist.figure.bbox)
                 self.ref_artist.draw(self.ref_artist.figure._cachedRenderer)
                 self.canvas.blit()
-                self._c1 = self.canvas.mpl_connect('motion_notify_event',
-                                                   self.on_motion_blit)
-            else:
-                self._c1 = self.canvas.mpl_connect('motion_notify_event',
-                                                   self.on_motion)
+            self._c1 = self.canvas.mpl_connect(
+                "motion_notify_event", self.on_motion)
             self.save_offset()
 
     def on_release(self, event):
