Disable draw_foo methods on renderer used to estimate tight extents.

anntzer · anntzer · commit e7fac8e47f52 · 2020-03-11T19:17:32.000+01:00
For the pgf backend, in particular draw_image() cannot succeed because
that needs actual filesystem access (to set up \includegraphics).
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1510,6 +1510,17 @@ def _draw(renderer): raise Done(renderer)
             return figure._cachedRenderer
 
 
+def _disable_renderer_draw_methods(renderer):
+    """
+    Replace draw_foo methods on *renderer* by no-ops.  This is used by the
+    tight-bbox-saving renderer, which needs to walk through the artist tree to
+    compute the tight-bbox, but for which the output file may be closed early.
+    """
+    for meth_name in dir(RendererBase):
+        if meth_name.startswith("draw_"):
+            setattr(renderer, meth_name, lambda *args, **kwargs: None)
+
+
 def _is_non_interactive_terminal_ipython(ip):
     """
     Return whether we are in a a terminal IPython, but non interactive.
@@ -2059,6 +2070,7 @@ def print_figure(self, filename, dpi=None, facecolor=None, edgecolor=None,
                         self.figure,
                         functools.partial(
                             print_method, dpi=dpi, orientation=orientation))
+                    _disable_renderer_draw_methods(renderer)
                     self.figure.draw(renderer)
                     bbox_artists = kwargs.pop("bbox_extra_artists", None)
                     bbox_inches = self.figure.get_tightbbox(
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
@@ -291,3 +291,11 @@ def test_tex_restart_after_error():
     fig = plt.figure()  # start from scratch
     fig.suptitle(r"this is ok")
     fig.savefig(BytesIO(), format="pgf")
+
+
+@needs_xelatex
+def test_bbox_inches_tight(tmpdir):
+    fig, ax = plt.subplots()
+    ax.imshow([[0, 1], [2, 3]])
+    fig.savefig(os.path.join(tmpdir, "test.pdf"), backend="pgf",
+                bbox_inches="tight")
