matplotlib
diff --git a/‎doc/api/next_api_changes/deprecations/20466-AL.rst
Lines changed: 3 additions & 0 deletions b/‎doc/api/next_api_changes/deprecations/20466-AL.rst
Lines changed: 3 additions & 0 deletions
diff --git a/‎lib/matplotlib/backends/backend_pgf.py
Lines changed: 31 additions & 44 deletions b/‎lib/matplotlib/backends/backend_pgf.py
Lines changed: 31 additions & 44 deletions
@@ -0,0 +1,3 @@
+``backend_pgf.LatexManager.str_cache``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+... is deprecated.
@@ -122,8 +122,11 @@ def writeln(fh, line):
     fh.write("%\n")
 
 
-def _font_properties_str(prop):
-    # translate font properties to latex commands, return as string
+def _escape_and_apply_props(s, prop):
+    """
+    Generate a TeX string that renders string *s* with font properties *prop*,
+    also applying any required escapes to *s*.
+    """
     commands = []
 
     families = {"serif": r"\rmfamily", "sans": r"\sffamily",
@@ -149,7 +152,7 @@ def _font_properties_str(prop):
         commands.append(r"\bfseries")
 
     commands.append(r"\selectfont")
-    return "".join(commands)
+    return "".join(commands) + " " + common_texification(s)
 
 
 def _metadata_to_str(key, value):
@@ -296,7 +299,10 @@ def __init__(self):
                              "or error in preamble.", stdout)
 
         self.latex = None  # Will be set up on first use.
-        self.str_cache = {}  # cache for strings already processed
+        # Per-instance cache.
+        self._get_box_metrics = functools.lru_cache()(self._get_box_metrics)
+
+    str_cache = _api.deprecated("3.5")(property(lambda self: {}))
 
     def _setup_latex_process(self):
         # Open LaTeX process for real work; register it for deletion.  On
@@ -322,46 +328,33 @@ def finalize_latex(latex):
 
     def get_width_height_descent(self, text, prop):
         """
-        Get the width, total height and descent for a text typeset by the
-        current LaTeX environment.
+        Get the width, total height, and descent (in TeX points) for a text
+        typeset by the current LaTeX environment.
         """
+        return self._get_box_metrics(_escape_and_apply_props(text, prop))
 
-        # apply font properties and define textbox
-        prop_cmds = _font_properties_str(prop)
-        textbox = "\\sbox0{%s %s}" % (prop_cmds, text)
-
-        # check cache
-        if textbox in self.str_cache:
-            return self.str_cache[textbox]
-
-        # send textbox to LaTeX and wait for prompt
-        self._stdin_writeln(textbox)
-        try:
-            self._expect_prompt()
-        except LatexError as e:
-            raise ValueError("Error processing '{}'\nLaTeX Output:\n{}"
-                             .format(text, e.latex_output)) from e
-
-        # typeout width, height and text offset of the last textbox
-        self._stdin_writeln(r"\typeout{\the\wd0,\the\ht0,\the\dp0}")
-        # read answer from latex and advance to the next prompt
+    def _get_box_metrics(self, tex):
+        """
+        Get the width, total height and descent (in TeX points) for a TeX
+        command's output in the current LaTeX environment.
+        """
+        self._stdin_writeln(  # Send textbox to TeX & request metrics typeout.
+            r"\sbox0{%s}\typeout{\the\wd0,\the\ht0,\the\dp0}" % tex)
         try:
             answer = self._expect_prompt()
-        except LatexError as e:
-            raise ValueError("Error processing '{}'\nLaTeX Output:\n{}"
-                             .format(text, e.latex_output)) from e
-
-        # parse metrics from the answer string
+        except LatexError as err:
+            raise ValueError("Error measuring {!r}\nLaTeX Output:\n{}"
+                             .format(tex, err.latex_output)) from err
         try:
-            width, height, offset = answer.splitlines()[0].split(",")
+            # Parse metrics from the answer string.  Last line is prompt, and
+            # next-to-last-line is blank line from \typeout.
+            width, height, offset = answer.splitlines()[-3].split(",")
         except Exception as err:
-            raise ValueError("Error processing '{}'\nLaTeX Output:\n{}"
-                             .format(text, answer)) from err
+            raise ValueError("Error measuring {!r}\nLaTeX Output:\n{}"
+                             .format(tex, answer)) from err
         w, h, o = float(width[:-2]), float(height[:-2]), float(offset[:-2])
-
-        # the height returned from LaTeX goes from base to top.
-        # the height matplotlib expects goes from bottom to top.
-        self.str_cache[textbox] = (w, h + o, o)
+        # The height returned from LaTeX goes from base to top;
+        # the height Matplotlib expects goes from bottom to top.
         return w, h + o, o
 
 
@@ -671,9 +664,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         # docstring inherited
 
         # prepare string for tex
-        s = common_texification(s)
-        prop_cmds = _font_properties_str(prop)
-        s = r"%s %s" % (prop_cmds, s)
+        s = _escape_and_apply_props(s, prop)
 
         writeln(self.fh, r"\begin{pgfscope}")
 
@@ -718,10 +709,6 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
 
     def get_text_width_height_descent(self, s, prop, ismath):
         # docstring inherited
-
-        # check if the math is supposed to be displaystyled
-        s = common_texification(s)
-
         # get text metrics in units of latex pt, convert to display units
         w, h, d = (LatexManager._get_cached_or_new()
                    .get_width_height_descent(s, prop))
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+``backend_pgf.LatexManager.str_cache``
	`2`	`+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
	`3`	`+... is deprecated.`