Properly enable forward/backward buttons on GTK3. (#12888)

QuLogic · timhoffm · commit 585644b53608 · 2018-11-28T23:29:30.000+01:00
diff --git a/lib/matplotlib/backends/backend_gtk3.py b/lib/matplotlib/backends/backend_gtk3.py
@@ -492,14 +492,15 @@ def _init_toolbar(self):
         self.set_style(Gtk.ToolbarStyle.ICONS)
         basedir = os.path.join(rcParams['datapath'], 'images')
 
+        self._gtk_ids = {}
         for text, tooltip_text, image_file, callback in self.toolitems:
             if text is None:
                 self.insert(Gtk.SeparatorToolItem(), -1)
                 continue
             fname = os.path.join(basedir, image_file + '.png')
             image = Gtk.Image()
             image.set_from_file(fname)
-            tbutton = Gtk.ToolButton()
+            self._gtk_ids[text] = tbutton = Gtk.ToolButton()
             tbutton.set_label(text)
             tbutton.set_icon_widget(image)
             self.insert(tbutton, -1)
@@ -572,6 +573,12 @@ def configure_subplots(self, button):
     def _get_canvas(self, fig):
         return self.canvas.__class__(fig)
 
+    def set_history_buttons(self):
+        can_backward = self._nav_stack._pos > 0
+        can_forward = self._nav_stack._pos < len(self._nav_stack._elements) - 1
+        self._gtk_ids['Back'].set_sensitive(can_backward)
+        self._gtk_ids['Forward'].set_sensitive(can_forward)
+
 
 class FileChooserDialog(Gtk.FileChooserDialog):
     """GTK+ file selector which remembers the last file/directory
