Merge pull request #13644 from meeseeksmachine/auto-backport-of-pr-13612-on-v3.1.x

jklymak · web-flow · commit 20f9c2761d45 · 2019-03-10T12:55:01.000-07:00
Backport PR #13612 on branch v3.1.x (Improve Demo Text Rotation Mode)
diff --git a/examples/text_labels_and_annotations/demo_text_rotation_mode.py b/examples/text_labels_and_annotations/demo_text_rotation_mode.py
@@ -1,64 +1,80 @@
-"""=======================
+r"""
+=======================
 Demo Text Rotation Mode
 =======================
 
-The axes' method `~.axes.Axes.text` takes an argument ``rotation_mode`` that
-controls the alignment and rotation of the text. If ``rotation_mode`` is
-``None`` or ``default`` the text will first be rotated and then aligned
-according to the horizontal and vertical alignments (``ha`` and ``va`` in the
-example). If ``rotation_mode`` is ``anchor`` the text is aligned before
-rotation.
+This example illustrates the effect of ``rotation_mode`` on the positioning
+of rotated text.
+
+Rotated `.Text`\s are created by passing the parameter ``rotation`` to
+the constructor or the axes' method `~.axes.Axes.text`.
+
+The actual positioning depends on the additional parameters
+``horizontalalignment``, ``verticalalignment`` and ``rotation_mode``.
+``rotation_mode`` determines the order of rotation and alignment:
+
+- ``roation_mode='default'`` (or None) first rotates the text and then aligns
+  the bounding box of the rotated text.
+- ``roation_mode='anchor'`` aligns the unrotated text and then rotates the
+  text around the point of alignment.
 
 """
+import matplotlib.pyplot as plt
 from mpl_toolkits.axes_grid1.axes_grid import ImageGrid
 
 
 def test_rotation_mode(fig, mode, subplot_location):
-    ha_list = "left center right".split()
-    va_list = "top center baseline bottom".split()
+    ha_list = ["left", "center", "right"]
+    va_list = ["top", "center", "baseline", "bottom"]
     grid = ImageGrid(fig, subplot_location,
                      nrows_ncols=(len(va_list), len(ha_list)),
-                     share_all=True, aspect=True,
-                     # label_mode='1',
-                     cbar_mode=None)
+                     share_all=True, aspect=True, cbar_mode=None)
 
+    # labels and title
     for ha, ax in zip(ha_list, grid.axes_row[-1]):
         ax.axis["bottom"].label.set_text(ha)
-
-    # create a grid of axes to display text on.
-    grid.axes_row[0][1].set_title(mode, size="large")
-
     for va, ax in zip(va_list, grid.axes_column[0]):
         ax.axis["left"].label.set_text(va)
+    grid.axes_row[0][1].set_title(f"rotation_mode='{mode}'", size="large")
+
+    if mode == "default":
+        kw = dict()
+    else:
+        kw = dict(
+            bbox=dict(boxstyle="square,pad=0.", ec="none", fc="C1", alpha=0.3))
+
+    # use a different text alignment in each axes
+    texts = []
+    for (va, ha), ax in zip([(x, y) for x in va_list for y in ha_list], grid):
+        # prepare axes layout
+        for axis in ax.axis.values():
+            axis.toggle(ticks=False, ticklabels=False)
+        ax.axis([0, 1, 0, 1])
+        ax.axvline(0.5, color="skyblue", zorder=0)
+        ax.axhline(0.5, color="skyblue", zorder=0)
+        ax.plot(0.5, 0.5, color="C0", marker="o", zorder=1)
+
+        # add text with rotation and alignment settings
+        tx = ax.text(0.5, 0.5, "Tpg",
+                     size="x-large", rotation=40,
+                     horizontalalignment=ha, verticalalignment=va,
+                     rotation_mode=mode, **kw)
+        texts.append(tx)
+
+    if mode == "default":
+        # highlight bbox
+        fig.canvas.draw()
+        for ax, tx in zip(grid, texts):
+            bb = tx.get_window_extent().inverse_transformed(ax.transData)
+            rect = plt.Rectangle((bb.x0, bb.y0), bb.width, bb.height,
+                                 facecolor="C1", alpha=0.3, zorder=2)
+            ax.add_patch(rect)
+
 
-    # use a different horizontal and vertical alignment for the text in each
-    # axes.
-    i = 0
-    for va in va_list:
-        for ha in ha_list:
-            ax = grid[i]
-            for axis in ax.axis.values():
-                axis.toggle(ticks=False, ticklabels=False)
-
-            # add text to the axes. Set the rotation_mode, horizontal
-            # alignment (ha) and vertical alignment (va).
-            ax.text(0.5, 0.5, "Tpg",
-                    size="large", rotation=40,
-                    bbox=dict(boxstyle="square,pad=0.",
-                              ec="none", fc="0.5", alpha=0.5),
-                    ha=ha, va=va,
-                    rotation_mode=mode)
-            ax.axvline(0.5)
-            ax.axhline(0.5)
-            i += 1
-
-
-if __name__ == "__main__":
-    import matplotlib.pyplot as plt
-    fig = plt.figure(figsize=(5.5, 4))
-    test_rotation_mode(fig, "default", 121)
-    test_rotation_mode(fig, "anchor", 122)
-    plt.show()
+fig = plt.figure(figsize=(8, 6))
+test_rotation_mode(fig, "default", 121)
+test_rotation_mode(fig, "anchor", 122)
+plt.show()
 
 
 #############################################################################
