Add blitting support to the CheckButtons widget

QuLogic · QuLogic · commit 664520d1f9f1 · 2022-11-29T03:23:42.000-05:00
diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
@@ -977,6 +977,7 @@ class CheckButtons(AxesWidget):
     ----------
     ax : `~matplotlib.axes.Axes`
         The parent Axes for the widget.
+
     labels : list of `.Text`
 
     rectangles : list of `.Rectangle`
@@ -986,21 +987,22 @@ class CheckButtons(AxesWidget):
         each box, but have ``set_visible(False)`` when its box is not checked.
     """
 
-    def __init__(self, ax, labels, actives=None):
+    def __init__(self, ax, labels, actives=None, useblit=False):
         """
         Add check buttons to `matplotlib.axes.Axes` instance *ax*.
 
         Parameters
         ----------
         ax : `~matplotlib.axes.Axes`
             The parent Axes for the widget.
-
         labels : list of str
             The labels of the check buttons.
-
         actives : list of bool, optional
             The initial check states of the buttons. The list must have the
             same length as *labels*. If not given, all buttons are unchecked.
+        useblit : bool, default: False
+            Use blitting for faster drawing if supported by the backend.
+            See the tutorial :doc:`/tutorials/advanced/blitting` for details.
         """
         super().__init__(ax)
 
@@ -1024,8 +1026,13 @@ def __init__(self, ax, labels, actives=None):
         self.lines = []
         self.rectangles = []
 
+        self._useblit = useblit and self.canvas.supports_blit
+        self._background = None
+
         lineparams = {'color': 'k', 'linewidth': 1.25,
                       'transform': ax.transAxes, 'solid_capstyle': 'butt'}
+        if self._useblit:
+            lineparams['animated'] = True
         for y, label, active in zip(ys, labels, actives):
             t = ax.text(0.25, y, label, transform=ax.transAxes,
                         horizontalalignment='left',
@@ -1050,9 +1057,20 @@ def __init__(self, ax, labels, actives=None):
             ax.add_line(l2)
 
         self.connect_event('button_press_event', self._clicked)
+        if self._useblit:
+            self.connect_event('draw_event', self._clear)
 
         self._observers = cbook.CallbackRegistry(signals=["clicked"])
 
+    def _clear(self, event):
+        """Internal event handler to clear the buttons."""
+        if self.ignore(event):
+            return
+        self._background = self.canvas.copy_from_bbox(self.ax.bbox)
+        for l1, l2 in self.lines:
+            self.ax.draw_artist(l1)
+            self.ax.draw_artist(l2)
+
     def _clicked(self, event):
         if self.ignore(event) or event.button != 1 or event.inaxes != self.ax:
             return
@@ -1086,7 +1104,15 @@ def set_active(self, index):
         l2.set_visible(not l2.get_visible())
 
         if self.drawon:
-            self.ax.figure.canvas.draw()
+            if self._useblit:
+                if self._background is not None:
+                    self.canvas.restore_region(self._background)
+                for l1, l2 in self.lines:
+                    self.ax.draw_artist(l1)
+                    self.ax.draw_artist(l2)
+                self.canvas.blit(self.ax.bbox)
+            else:
+                self.canvas.draw()
 
         if self.eventson:
             self._observers.process('clicked', self.labels[index].get_text())
