Replace ClabelText by set_transform_rotates_text.

anntzer · anntzer · commit 7473396f586c · 2022-10-11T11:30:12.000+02:00
ContourLabeler previously optionally used a custom Text subclass to
ensure that text rotation took place in data space, not in screen space,
but this is now available for all Text instances via the
transform_rotates_text property, so directly use that.  This means that
_get_label_text, _add_label, and set_label_props can also directly get
inlined into their now only callsite (add_label).
diff --git a/doc/api/next_api_changes/deprecations/XXXXX-AL.rst b/doc/api/next_api_changes/deprecations/XXXXX-AL.rst
@@ -0,0 +1,6 @@
+``contour.ClabelText`` and ``ContourLabeler.set_label_props``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+... are deprecated.
+
+Use `.Text.set_transform_rotates_text` as a replacement for the former and
+`.Artist.set` as a replacement for the latter.
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -31,6 +31,7 @@
 # per level.
 
 
+@_api.deprecated("3.7", alternative="Text.set_transform_rotates_text")
 class ClabelText(text.Text):
     """
     Unlike the ordinary text, the get_rotation returns an updated
@@ -150,10 +151,8 @@ def clabel(self, levels=None, *,
             or minus 90 degrees from level.
 
         use_clabeltext : bool, default: False
-            If ``True``, `.ClabelText` class (instead of `.Text`) is used to
-            create labels. `ClabelText` recalculates rotation angles
-            of texts during the drawing time, therefore this can be used if
-            aspect of the axes changes.
+            If ``True``, use `.Text.set_transform_rotates_text` to ensure that
+            label rotation is updated whenever the axes aspect changes.
 
         zorder : float or None, default: ``(2 + contour.get_zorder())``
             zorder of the contour labels.
@@ -273,6 +272,7 @@ def get_label_width(self, lev, fmt, fsize):
         width *= 72 / fig.dpi
         return width
 
+    @_api.deprecated("3.7", alternative="Artist.set")
     def set_label_props(self, label, text, color):
         """Set the label properties - color, fontsize, text."""
         label.set_text(text)
@@ -417,57 +417,32 @@ def calc_label_rot_and_inline(self, slc, ind, lw, lc=None, spacing=5):
 
         return rotation, nlc
 
-    def _get_label_text(self, x, y, rotation):
-        dx, dy = self.axes.transData.inverted().transform((x, y))
-        t = text.Text(dx, dy, rotation=rotation,
-                      horizontalalignment='center',
-                      verticalalignment='center', zorder=self._clabel_zorder)
-        return t
-
-    def _get_label_clabeltext(self, x, y, rotation):
-        # x, y, rotation is given in pixel coordinate. Convert them to
-        # the data coordinate and create a label using ClabelText
-        # class. This way, the rotation of the clabel is along the
-        # contour line always.
-        transDataInv = self.axes.transData.inverted()
-        dx, dy = transDataInv.transform((x, y))
-        drotation = transDataInv.transform_angles(np.array([rotation]),
-                                                  np.array([[x, y]]))
-        t = ClabelText(dx, dy, rotation=drotation[0],
-                       horizontalalignment='center',
-                       verticalalignment='center', zorder=self._clabel_zorder)
-
-        return t
-
-    def _add_label(self, t, x, y, lev, cvalue):
-        color = self.labelMappable.to_rgba(cvalue, alpha=self.alpha)
-
-        _text = self.get_text(lev, self.labelFmt)
-        self.set_label_props(t, _text, color)
+    def add_label(self, x, y, rotation, lev, cvalue):
+        """Add contour label without `.Text.set_transform_rotates_text`."""
+        data_x, data_y = self.axes.transData.inverted().transform((x, y))
+        t = text.Text(
+            data_x, data_y,
+            text=self.get_text(lev, self.labelFmt),
+            rotation=rotation,
+            horizontalalignment='center', verticalalignment='center',
+            zorder=self._clabel_zorder,
+            color=self.labelMappable.to_rgba(cvalue, alpha=self.alpha),
+            fontproperties=self.labelFontProps,
+            clip_box=self.axes.bbox)
         self.labelTexts.append(t)
         self.labelCValues.append(cvalue)
         self.labelXYs.append((x, y))
-
         # Add label to plot here - useful for manual mode label selection
         self.axes.add_artist(t)
 
-    def add_label(self, x, y, rotation, lev, cvalue):
-        """
-        Add contour label using :class:`~matplotlib.text.Text` class.
-        """
-        t = self._get_label_text(x, y, rotation)
-        self._add_label(t, x, y, lev, cvalue)
-
     def add_label_clabeltext(self, x, y, rotation, lev, cvalue):
-        """
-        Add contour label using :class:`ClabelText` class.
-        """
-        # x, y, rotation is given in pixel coordinate. Convert them to
-        # the data coordinate and create a label using ClabelText
-        # class. This way, the rotation of the clabel is along the
-        # contour line always.
-        t = self._get_label_clabeltext(x, y, rotation)
-        self._add_label(t, x, y, lev, cvalue)
+        """Add contour label with `.Text.set_transform_rotates_text`."""
+        self.add_label(x, y, rotation, lev, cvalue)
+        # Grab the last added text, and reconfigure its rotation.
+        t = self.labelTexts[-1]
+        data_rotation, = self.axes.transData.inverted().transform_angles(
+            [rotation], [[x, y]])
+        t.set(rotation=data_rotation, transform_rotates_text=True)
 
     def add_label_near(self, x, y, inline=True, inline_spacing=5,
                        transform=None):
