Remove Patch visibility tracking by Legend & OffsetBox.

anntzer · anntzer · commit 00892637dd33 · 2020-04-23T23:41:44.000+02:00
Instead of having a separate _drawFrame attribute on Legend/OffsetBox,
just set the visibility attribute on the underlying Patch.
diff --git a/doc/api/api_changes_3.3/behaviour.rst b/doc/api/api_changes_3.3/behaviour.rst
@@ -186,3 +186,9 @@ anymore.
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 This ensures that they go above gridlines by default.  The old ``zorder`` can
 be kept by passing it as a keyword argument to `.Axes.hist`.
+
+`.Legend` and `.OffsetBox` visibility
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+`.Legend` and `.OffsetBox` subclasses (`.PaddedBox`, `.AnchoredOffsetbox`, and
+`.AnnotationBbox`) no longer directly keep track of the visibility of their
+underlying `.Patch` artist, but instead pass that flag down to the `.Patch`.
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -499,12 +499,11 @@ def __init__(self, parent, handles, labels,
                       else "square,pad=0"),
             mutation_scale=self._fontsize,
             snap=True,
+            visible=(frameon if frameon is not None
+                     else mpl.rcParams["legend.frameon"])
         )
         self._set_artist_props(self.legendPatch)
 
-        self._drawFrame = (frameon if frameon is not None
-                           else mpl.rcParams["legend.frameon"])
-
         # init with null renderer
         self._init_legend_box(handles, labels, markerfirst)
 
@@ -580,17 +579,13 @@ def draw(self, renderer):
         # update the location and size of the legend. This needs to
         # be done in any case to clip the figure right.
         bbox = self._legend_box.get_window_extent(renderer)
-        self.legendPatch.set_bounds(bbox.x0, bbox.y0,
-                                    bbox.width, bbox.height)
+        self.legendPatch.set_bounds(bbox.x0, bbox.y0, bbox.width, bbox.height)
         self.legendPatch.set_mutation_scale(fontsize)
 
-        if self._drawFrame:
-            if self.shadow:
-                shadow = Shadow(self.legendPatch, 2, -2)
-                shadow.draw(renderer)
-
-            self.legendPatch.draw(renderer)
+        if self.shadow:
+            Shadow(self.legendPatch, 2, -2).draw(renderer)
 
+        self.legendPatch.draw(renderer)
         self._legend_box.draw(renderer)
 
         renderer.close_group('legend')
@@ -895,7 +890,7 @@ def get_tightbbox(self, renderer):
 
     def get_frame_on(self):
         """Get whether the legend box patch is drawn."""
-        return self._drawFrame
+        return self.legendPatch.get_visible()
 
     def set_frame_on(self, b):
         """
@@ -905,7 +900,7 @@ def set_frame_on(self, b):
         ----------
         b : bool
         """
-        self._drawFrame = b
+        self.legendPatch.set_visible(b)
         self.stale = True
 
     draw_frame = set_frame_on  # Backcompat alias.
diff --git a/lib/matplotlib/offsetbox.py b/lib/matplotlib/offsetbox.py
@@ -592,24 +592,19 @@ def __init__(self, child, pad=None, draw_frame=False, patch_attrs=None):
             Additional parameters passed to the contained `.FancyBboxPatch`.
         """
         super().__init__()
-
         self.pad = pad
         self._children = [child]
-
         self.patch = FancyBboxPatch(
             xy=(0.0, 0.0), width=1., height=1.,
             facecolor='w', edgecolor='k',
             mutation_scale=1,  # self.prop.get_size_in_points(),
-            snap=True
-            )
-
-        self.patch.set_boxstyle("square", pad=0)
-
+            snap=True,
+            visible=draw_frame,
+            boxstyle="square,pad=0",
+        )
         if patch_attrs is not None:
             self.patch.update(patch_attrs)
 
-        self._drawFrame = draw_frame
-
     def get_extent_offsets(self, renderer):
         # docstring inherited.
         dpicor = renderer.points_to_pixels(1.)
@@ -637,20 +632,15 @@ def draw(self, renderer):
         self.stale = False
 
     def update_frame(self, bbox, fontsize=None):
-        self.patch.set_bounds(bbox.x0, bbox.y0,
-                              bbox.width, bbox.height)
-
+        self.patch.set_bounds(bbox.x0, bbox.y0, bbox.width, bbox.height)
         if fontsize:
             self.patch.set_mutation_scale(fontsize)
         self.stale = True
 
     def draw_frame(self, renderer):
         # update the location and size of the legend
-        bbox = self.get_window_extent(renderer)
-        self.update_frame(bbox)
-
-        if self._drawFrame:
-            self.patch.draw(renderer)
+        self.update_frame(self.get_window_extent(renderer))
+        self.patch.draw(renderer)
 
 
 class DrawingArea(OffsetBox):
@@ -1110,10 +1100,10 @@ def __init__(self, loc,
             xy=(0.0, 0.0), width=1., height=1.,
             facecolor='w', edgecolor='k',
             mutation_scale=self.prop.get_size_in_points(),
-            snap=True
-            )
-        self.patch.set_boxstyle("square", pad=0)
-        self._drawFrame = frameon
+            snap=True,
+            visible=frameon,
+            boxstyle="square,pad=0",
+        )
 
     def set_child(self, child):
         """Set the child to be anchored."""
@@ -1210,26 +1200,22 @@ def _offset(w, h, xd, yd, renderer, fontsize=fontsize, self=self):
         self.set_offset(_offset)
 
     def update_frame(self, bbox, fontsize=None):
-        self.patch.set_bounds(bbox.x0, bbox.y0,
-                              bbox.width, bbox.height)
-
+        self.patch.set_bounds(bbox.x0, bbox.y0, bbox.width, bbox.height)
         if fontsize:
             self.patch.set_mutation_scale(fontsize)
 
     def draw(self, renderer):
         # docstring inherited
-
         if not self.get_visible():
             return
 
         fontsize = renderer.points_to_pixels(self.prop.get_size_in_points())
         self._update_offset_func(renderer, fontsize)
 
-        if self._drawFrame:
-            # update the location and size of the legend
-            bbox = self.get_window_extent(renderer)
-            self.update_frame(bbox, fontsize)
-            self.patch.draw(renderer)
+        # update the location and size of the legend
+        bbox = self.get_window_extent(renderer)
+        self.update_frame(bbox, fontsize)
+        self.patch.draw(renderer)
 
         width, height, xdescent, ydescent = self.get_extent(renderer)
 
@@ -1512,12 +1498,12 @@ def __init__(self, offsetbox, xy,
             xy=(0.0, 0.0), width=1., height=1.,
             facecolor='w', edgecolor='k',
             mutation_scale=self.prop.get_size_in_points(),
-            snap=True
-            )
+            snap=True,
+            visible=frameon,
+        )
         self.patch.set_boxstyle("square", pad=pad)
         if bboxprops:
             self.patch.set(**bboxprops)
-        self._drawFrame = frameon
 
     @property
     def xyann(self):
@@ -1670,9 +1656,7 @@ def draw(self, renderer):
                 self.arrow_patch.figure = self.figure
             self.arrow_patch.draw(renderer)
 
-        if self._drawFrame:
-            self.patch.draw(renderer)
-
+        self.patch.draw(renderer)
         self.offsetbox.draw(renderer)
         self.stale = False
 
