matplotlib · timhoffm · Apr 5, 2025 · Copilot · Apr 5, 2025 · timhoffm
diff --git a/lib/matplotlib/testing/decorators.py b/lib/matplotlib/testing/decorators.py
@@ -15,6 +15,7 @@
 import matplotlib.units
 import matplotlib.testing
 from matplotlib import _pylab_helpers, cbook, ft2font, pyplot as plt, ticker
+import matplotlib.text as mtext
 from .compare import comparable_formats, compare_images, make_test_filename
 from .exceptions import ImageComparisonFailure
 
@@ -117,11 +118,12 @@ class _ImageComparisonBase:
     any code that would be specific to any testing framework.
     """
 
-    def __init__(self, func, tol, remove_text, savefig_kwargs):
+    def __init__(self, func, tol, remove_text, replace_text, savefig_kwargs):
         self.func = func
         self.baseline_dir, self.result_dir = _image_directories(func)
         self.tol = tol
         self.remove_text = remove_text
+        self.replace_text = replace_text
         self.savefig_kwargs = savefig_kwargs
 
     def copy_baseline(self, baseline, extension):
@@ -164,19 +166,23 @@ def compare(self, fig, baseline, extension, *, _lock=False):
         lock = (cbook._lock_path(actual_path)
                 if _lock else contextlib.nullcontext())
         with lock:
+            if self.replace_text:
+                mtext.Text._draw_bbox_only = True
             try:
                 fig.savefig(actual_path, **kwargs)
             finally:
                 # Matplotlib has an autouse fixture to close figures, but this
                 # makes things more convenient for third-party users.
                 plt.close(fig)
+            if self.replace_text:
+                mtext.Text._draw_bbox_only = False
             expected_path = self.copy_baseline(baseline, extension)
             _raise_on_image_difference(expected_path, actual_path, self.tol)
 
 
 def _pytest_image_comparison(baseline_images, extensions, tol,
-                             freetype_version, remove_text, savefig_kwargs,
-                             style):
+                             freetype_version, remove_text, replace_text,
+                             savefig_kwargs, style):
     """
     Decorate function with image comparison for pytest.
 
@@ -212,6 +218,7 @@ def wrapper(*args, extension, request, **kwargs):
                 pytest.skip(f"Cannot compare {extension} files {reason}")
 
             img = _ImageComparisonBase(func, tol=tol, remove_text=remove_text,
+                                       replace_text=replace_text,
                                        savefig_kwargs=savefig_kwargs)
             matplotlib.testing.set_font_settings_for_testing()
 
@@ -259,6 +266,7 @@ def wrapper(*args, extension, request, **kwargs):
 
 def image_comparison(baseline_images, extensions=None, tol=0,
                      freetype_version=None, remove_text=False,
+                     replace_text=False,
                      savefig_kwarg=None,
                      # Default of mpl_test_settings fixture and cleanup too.
                      style=("classic", "_classic_test_patch")):
@@ -344,6 +352,7 @@ def image_comparison(baseline_images, extensions=None, tol=0,
     return _pytest_image_comparison(
         baseline_images=baseline_images, extensions=extensions, tol=tol,
         freetype_version=freetype_version, remove_text=remove_text,
+        replace_text=replace_text,
         savefig_kwargs=savefig_kwarg, style=style)
 
 

diff --git a/lib/matplotlib/tests/baseline_images/test_text/replace_text.png b/lib/matplotlib/tests/baseline_images/test_text/replace_text.png
diff --git a/lib/matplotlib/tests/test_text.py b/lib/matplotlib/tests/test_text.py
@@ -1190,3 +1190,15 @@ def test_ytick_rotation_mode():
         tick.set_rotation(angle)
 
     plt.subplots_adjust(left=0.4, right=0.6, top=.99, bottom=.01)
+
+
+@image_comparison(baseline_images=['replace_text'],
+                  replace_text=True, extensions=['png'], style='mpl20')
+def test_replace_text():
+    fig, ax = plt.subplots()
+    ax.plot([2, 1], label='line 1')
+    ax.plot([3, 2], label='line 2')
+    ax.legend(title='mylegend')
+    ax.set_title('testing text replacement')
+    ax.set_xlabel('xlabel')
+    ax.set_ylabel('ylabel')
diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
@@ -97,6 +97,13 @@ class Text(Artist):
 
     zorder = 3
     _charsize_cache = dict()
+    _draw_bbox_only = False
+    """
+    A helper flag to replace texts by a bounding box. This is primarily
+    intended for use in figure comparison tests.
+    For sipmlicity, the flag is evaluated at draw time and thus applies
-    For sipmlicity, the flag is evaluated at draw time and thus applies
+    For simplicity, the flag is evaluated at draw time and thus applies
-    For sipmlicity, the flag is evaluated at draw time and thus applies
+    For simplicity, the flag is evaluated at draw time and thus applies
+    to all drawn text.
+    """
 
     def __repr__(self):
         return f"Text({self._x}, {self._y}, {self._text!r})"
@@ -778,6 +785,9 @@ def draw(self, renderer):
 
             # Update the location and size of the bbox
             # (`.patches.FancyBboxPatch`), and draw it.
+            if self._draw_bbox_only:
+                self.set_bbox(dict(facecolor='none', edgecolor='red', pad=0))
+
             if self._bbox_patch:
                 self.update_bbox_position_size(renderer)
                 self._bbox_patch.draw(renderer)
@@ -793,6 +803,9 @@ def draw(self, renderer):
 
             for line, wh, x, y in info:
 
+                if self._draw_bbox_only:
+                    break
+
                 mtext = self if len(info) == 1 else None
                 x = x + posx
                 y = y + posy