Merge pull request #12450 from anntzer/defaultcanvas

tacaswell · web-flow · commit 8fd45c0eb161 · 2018-11-10T23:35:37.000-05:00
ENH: Attach a FigureCanvasBase by default to Figures.
diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py
@@ -449,9 +449,7 @@ def pickable(self):
         --------
         set_picker, get_picker, pick
         """
-        return (self.figure is not None and
-                self.figure.canvas is not None and
-                self._picker is not None)
+        return self.figure is not None and self._picker is not None
 
     def pick(self, mouseevent):
         """
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -3245,8 +3245,7 @@ def set_xlim(self, left=None, right=None, emit=True, auto=False,
                 if other is not self:
                     other.set_xlim(self.viewLim.intervalx,
                                    emit=False, auto=auto)
-                    if (other.figure != self.figure and
-                            other.figure.canvas is not None):
+                    if other.figure != self.figure:
                         other.figure.canvas.draw_idle()
         self.stale = True
         return left, right
@@ -3634,8 +3633,7 @@ def set_ylim(self, bottom=None, top=None, emit=True, auto=False,
                 if other is not self:
                     other.set_ylim(self.viewLim.intervaly,
                                    emit=False, auto=auto)
-                    if (other.figure != self.figure and
-                            other.figure.canvas is not None):
+                    if other.figure != self.figure:
                         other.figure.canvas.draw_idle()
         self.stale = True
         return bottom, top
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -23,6 +23,7 @@
 
 import matplotlib.artist as martist
 from matplotlib.artist import Artist, allow_rasterization
+from matplotlib.backend_bases import FigureCanvasBase
 import matplotlib.cbook as cbook
 import matplotlib.colorbar as cbar
 import matplotlib.image as mimage
@@ -364,7 +365,7 @@ def __init__(self,
         self._set_artist_props(self.patch)
         self.patch.set_antialiased(False)
 
-        self.canvas = None
+        FigureCanvasBase(self)  # Set self.canvas.
         self._suptitle = None
 
         if subplotpars is None:
@@ -398,8 +399,7 @@ def __init__(self,
     def _repr_html_(self):
         # We can't use "isinstance" here, because then we'd end up importing
         # webagg unconditiionally.
-        if (self.canvas is not None and
-                'WebAgg' in self.canvas.__class__.__name__):
+        if 'WebAgg' in type(self.canvas).__name__:
             from matplotlib.backends import backend_webagg
             return backend_webagg.ipython_inline_display(self)
 
diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -652,8 +652,7 @@ def set_xlim3d(self, left=None, right=None, emit=True, auto=False,
                 if other is not self:
                     other.set_xlim(self.xy_viewLim.intervalx,
                                             emit=False, auto=auto)
-                    if (other.figure != self.figure and
-                        other.figure.canvas is not None):
+                    if other.figure != self.figure:
                         other.figure.canvas.draw_idle()
         self.stale = True
         return left, right
@@ -711,8 +710,7 @@ def set_ylim3d(self, bottom=None, top=None, emit=True, auto=False,
                 if other is not self:
                     other.set_ylim(self.xy_viewLim.intervaly,
                                             emit=False, auto=auto)
-                    if (other.figure != self.figure and
-                        other.figure.canvas is not None):
+                    if other.figure != self.figure:
                         other.figure.canvas.draw_idle()
         self.stale = True
         return bottom, top
@@ -770,8 +768,7 @@ def set_zlim3d(self, bottom=None, top=None, emit=True, auto=False,
                 if other is not self:
                     other.set_zlim(self.zz_viewLim.intervalx,
                                             emit=False, auto=auto)
-                    if (other.figure != self.figure and
-                        other.figure.canvas is not None):
+                    if other.figure != self.figure:
                         other.figure.canvas.draw_idle()
         self.stale = True
         return bottom, top
@@ -1070,17 +1067,14 @@ def mouse_init(self, rotate_btn=1, zoom_btn=3):
 
         """
         self.button_pressed = None
-        canv = self.figure.canvas
-        if canv is not None:
-            c1 = canv.mpl_connect('motion_notify_event', self._on_move)
-            c2 = canv.mpl_connect('button_press_event', self._button_press)
-            c3 = canv.mpl_connect('button_release_event', self._button_release)
-            self._cids = [c1, c2, c3]
-        else:
-            cbook._warn_external("Axes3D.figure.canvas is 'None', mouse "
-                                 "rotation disabled. Set canvas then call "
-                                 "Axes3D.mouse_init().")
-
+        self._cids = [
+            self.figure.canvas.mpl_connect(
+                'motion_notify_event', self._on_move),
+            self.figure.canvas.mpl_connect(
+                'button_press_event', self._button_press),
+            self.figure.canvas.mpl_connect(
+                'button_release_event', self._button_release),
+        ]
         # coerce scalars into array-like, then convert into
         # a regular list to avoid comparisons against None
         # which breaks in recent versions of numpy.
