defer to ipython for html whenever possible

tdpetrou · tdpetrou · commit b09de9c9bb0c · 2020-03-18T10:09:17.000-04:00
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1596,71 +1596,43 @@ def __init__(self, figure):
         self._is_idle_drawing = False
 
     def _repr_html_(self):
-        if not self.figure.axes and not self.figure.lines:
-            return
-
-        dpi = self.figure.dpi
-        is_retina = False
-
-        import IPython
-        ip = IPython.get_ipython()
-        ib_list = [c for c in ip.configurables 
-                    if 'InlineBackend' in type(c).__name__]
-
-        # having an 'inline' backend doesn't mean '%matplotlib inline' has been run
-        # Running %matplotlib inline runs pylabtools.configure_inline_support
-        # which appends the InlineBackend to the list of configurables
-        if get_backend() == 'module://ipykernel.pylab.backend_inline' and ib_list:
-            ib = ib_list[0]
-            bbox_inches = ib.print_figure_kwargs['bbox_inches']
-            fmt = next(iter(ib.figure_formats))
-            if fmt == 'retina':
-                is_retina = True
-                dpi = dpi * 2
-                fmt = self.get_default_filetype()
-        else:
-            bbox_inches = 'tight' # how to let user choose self.figure.bbox_inches?
-            fmt = self.get_default_filetype()
-
-        if fmt not in {'png', 'svg', 'jpg', 'pdf'}:
-            fmt = 'png' 
+        # Defer to IPython to handle html output if possible
+        if 'IPython' in sys.modules:
+            import IPython
+            ip = IPython.get_ipython()
+            # Check whether %matplotlib was run. Is there a better way?
+            ib_list = [c for c in ip.configurables 
+                       if 'InlineBackend' in type(c).__name__]
+            if ib_list:
+                return
+            
+        fmt = self.get_default_filetype()
 
         kw = {
             "format":fmt,
             "facecolor":self.figure.get_facecolor(),
             "edgecolor":self.figure.get_edgecolor(),
-            "dpi":dpi,
-            "bbox_inches":bbox_inches,
+            "dpi":self.figure.dpi,
+            "bbox_inches":self.figure.bbox_inches
         }
 
         bytes_io = io.BytesIO()
         self.print_figure(bytes_io, **kw)
         raw_bytes = bytes_io.getvalue()
 
-        from IPython.core.display import _pngxy, _jpegxy
-        
+        from base64 import b64encode
+        data = b64encode(raw_bytes).decode()
+
         if fmt == 'svg':
             return raw_bytes.decode()
         elif fmt == 'png':
-            w, h = _pngxy(raw_bytes)
-        elif fmt == 'jpg':
-            w, h = _jpegxy(raw_bytes)
+            return f'<img src="data:image/png;base64, {data}" />'
         elif fmt == 'pdf':
             w, h = self.figure.get_size_inches()
-            w, h = w * dpi, h * dpi
-
-        if is_retina:
-            w, h = w // 2, h // 2
-
-        from base64 import b64encode
-        data = b64encode(raw_bytes).decode()
-
-        if fmt == 'png':
-            return f'<img width="{w}" height="{h}"  src="data:image/png;base64, {data}" />'
-        elif fmt == 'pdf':
+            w, h = w * self.figure.dpi, h * self.figure.dpi
             return f'<embed width="{w}" height="{h}" src="data:application/pdf;base64, {data}">'
         elif fmt == 'jpg':
-            return f'<img width="{w}" height="{h}" src="data:image/jpeg;base64, {data}" />'
+            return f'<img src="data:image/jpeg;base64, {data}" />'
 
     @classmethod
     @functools.lru_cache()
