Merge pull request matplotlib#25989 from saranti/offset_fontsize

test annotate(textcoords=offset fontsize)

Author: rcomer

lib/matplotlib/tests/test_text.py

@@ -886,3 +886,19 @@ def call(*args, **kwargs):
     # Every string gets a miss for the first layouting (extents), then a hit
     # when drawing, but "foo\nbar" gets two hits as it's drawn twice.
     assert info.hits > info.misses
+
+
+def test_annotate_offset_fontsize():
+    # Test that offset_fontsize parameter works and uses accurate values
+    fig, ax = plt.subplots()
+    text_coords = ['offset points', 'offset fontsize']
+    # 10 points should be equal to 1 fontsize unit at fontsize=10
+    xy_text = [(10, 10), (1, 1)]
+    anns = [ax.annotate('test', xy=(0.5, 0.5),
+                        xytext=xy_text[i],
+                        fontsize='10',
+                        xycoords='data',
+                        textcoords=text_coords[i]) for i in range(2)]
+    points_coords, fontsize_coords = [ann.get_window_extent() for ann in anns]
+    fig.canvas.draw()
+    assert str(points_coords) == str(fontsize_coords)