BUGFIX: naked plot directive naively "responsive"

lib/matplotlib/sphinxext/__init__.py

@@ -0,0 +1,3 @@
+from pathlib import Path
+
+_static_path = Path(__file__).resolve().parent / Path('static')

lib/matplotlib/sphinxext/plot_directive.py

@@ -156,7 +156,7 @@
 import matplotlib
 from matplotlib.backend_bases import FigureManagerBase
 import matplotlib.pyplot as plt
-from matplotlib import _pylab_helpers, cbook
+from matplotlib import _pylab_helpers, cbook, sphinxext
 
 matplotlib.use("agg")
 align = cbook.deprecated(
@@ -254,6 +254,13 @@ def run(self):
             raise self.error(str(e))
 
 
+def _copy_css_file(app, exc):
+    if exc is None and app.builder.format == 'html':
+        src = sphinxext._static_path / Path('plot_directive.css')
+        dst = app.outdir / Path('_static')
+        shutil.copy(src, dst)
+
+
 def setup(app):
     setup.app = app
     setup.config = app.config
@@ -269,9 +276,9 @@ def setup(app):
     app.add_config_value('plot_apply_rcparams', False, True)
     app.add_config_value('plot_working_directory', None, True)
     app.add_config_value('plot_template', None, True)
-
     app.connect('doctree-read', mark_plot_labels)
-
+    app.add_css_file('plot_directive.css')
+    app.connect('build-finished', _copy_css_file)
     metadata = {'parallel_read_safe': True, 'parallel_write_safe': True,
                 'version': matplotlib.__version__}
     return metadata
@@ -521,7 +528,7 @@ def render_figures(code, code_path, output_dir, output_base, context,
     """
     formats = get_plot_formats(config)
 
-    # -- Try to determine if all images already exist
+    # Try to determine if all images already exist
 
     code_pieces = split_code_at_show(code)
 
@@ -624,6 +631,10 @@ def run(arguments, content, options, state_machine, state, lineno):
     default_fmt = formats[0][0]
 
     options.setdefault('include-source', config.plot_include_source)
+    if 'class' in options:
+        options['class'] = options['class'] + ' plot-directive'
+    else:
+        options.setdefault('class', 'plot-directive')
     keep_context = 'context' in options
     context_opt = None if not keep_context else options['context']
 

lib/matplotlib/sphinxext/static/plot_directive.css

@@ -0,0 +1,13 @@
+/*
+ * plot_directive.css
+ * ~~~~~~~~~~~~
+ *
+ * Stylesheet controlling images created using the `plot` directive within
+ * Sphinx.
+ *
+ */
+
+img.plot-directive {
+    border: 0;
+    max-width: 100%;
+}