matplotlib · tacaswell · Jul 9, 2018 · Apr 18, 2018 · Apr 18, 2018 · Apr 19, 2018
diff --git a/lib/matplotlib/backend_tools.py b/lib/matplotlib/backend_tools.py
@@ -1039,25 +1039,25 @@ def _format_tool_keymap(self, name):
         keymaps = self.toolmanager.get_tool_keymap(name)
         return ", ".join(self.format_shortcut(keymap) for keymap in keymaps)
 
-    def _get_help_text(self):
+    def _get_help_entries(self):
         entries = []
         for name, tool in sorted(self.toolmanager.tools.items()):
             if not tool.description:
                 continue
-            entries.append(
-                "{}: {}\n\t{}".format(
-                    name, self._format_tool_keymap(name), tool.description))
+            entries.append((name, self._format_tool_keymap(name),
+                            tool.description))
+        return entries
+
+    def _get_help_text(self):
+        entries = self._get_help_entries()
+        entries = ["{}: {}\n\t{}".format(*entry) for entry in entries]
         return "\n".join(entries)
 
     def _get_help_html(self):
         fmt = "<tr><td>{}</td><td>{}</td><td>{}</td></tr>"
         rows = [fmt.format(
             "<b>Action</b>", "<b>Shortcuts</b>", "<b>Description</b>")]
-        for name, tool in sorted(self.toolmanager.tools.items()):
-            if not tool.description:
-                continue
-            rows.append(fmt.format(
-                name, self._format_tool_keymap(name), tool.description))
+        rows += [fmt.format(*row) for row in self._get_help_entries()]
         return ("<style>td {padding: 0px 4px}</style>"
                 "<table><thead>" + rows[0] + "</thead>"
                 "<tbody>".join(rows[1:]) + "</tbody></table>")

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -1824,6 +1824,57 @@ def remove_rubberband(self, dc=None):
             self._rect = None
 
 
+class _HelpDialog(wx.Dialog):
+    _instance = None  # a reference to an open dialog singleton
+    headers = [("Action", "Shortcuts", "Description")]
+    widths = [100, 140, 300]
+
+    def __init__(self, parent, help_entries):
+        wx.Dialog.__init__(self, parent, title="Help",
+                           style=wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER)
+
+        sizer = wx.BoxSizer(wx.VERTICAL)
+        grid_sizer = wx.FlexGridSizer(0, 3, 8, 6)
+        # create and add the entries
+        bold = self.GetFont().MakeBold()
+        for r, row in enumerate(self.headers + help_entries):
+            for (col, width) in zip(row, self.widths):
+                label = wx.StaticText(self, label=col)
+                if r == 0:
+                    label.SetFont(bold)
+                label.Wrap(width)
+                grid_sizer.Add(label, 0, 0, 0)
+        # finalize layout, create button
+        sizer.Add(grid_sizer, 0, wx.ALL, 6)
+        OK = wx.Button(self, wx.ID_OK)
+        sizer.Add(OK, 0, wx.ALIGN_CENTER_HORIZONTAL | wx.ALL, 8)
+        self.SetSizer(sizer)
+        sizer.Fit(self)
+        self.Layout()
+        self.Bind(wx.EVT_CLOSE, self.OnClose)
+        OK.Bind(wx.EVT_BUTTON, self.OnClose)
+
+    def OnClose(self, evt):
+        _HelpDialog._instance = None  # remove global reference
+        self.DestroyLater()
+        evt.Skip()
+
+    @classmethod
+    def show(cls, parent, help_entries):
+        # if no dialog is shown, create one; otherwise just re-raise it
+        if cls._instance:
+            cls._instance.Raise()
+            return
+        cls._instance = cls(parent, help_entries)
+        cls._instance.Show()
+
+
+class HelpWx(backend_tools.ToolHelpBase):
+    def trigger(self, *args):
+        _HelpDialog.show(self.figure.canvas.GetTopLevelParent(),
+                         self._get_help_entries())
+
+
 class ToolCopyToClipboardWx(backend_tools.ToolCopyToClipboardBase):
     def trigger(self, *args, **kwargs):
         if not self.canvas._isDrawn:
@@ -1839,6 +1890,7 @@ def trigger(self, *args, **kwargs):
 backend_tools.ToolSaveFigure = SaveFigureWx
 backend_tools.ToolSetCursor = SetCursorWx
 backend_tools.ToolRubberband = RubberbandWx
+backend_tools.ToolHelp = HelpWx
 backend_tools.ToolCopyToClipboard = ToolCopyToClipboardWx