Port to gedit 3.12

GEdit version 3.12 changed the API for plugins; in particular, this patch
interfaces correctly with the side panel, which is now a GtkStack.

Author: toobaz

sourcecodebrowser/plugin.py

@@ -330,7 +330,7 @@ def do_activate(self):
         self._sourcetree.expand_rows = self.expand_rows
         self._sourcetree.sort_list = self.sort_list
         panel = self.window.get_side_panel()
-        panel.add_item(self._sourcetree, "SymbolBrowserPlugin", "Source Code", self.icon)
+        panel.add_titled(self._sourcetree, "SymbolBrowserPlugin", "Source Code")
         self._handlers = []
         hid = self._sourcetree.connect("focus", self.on_sourcetree_focus)
         self._handlers.append((self._sourcetree, hid))
@@ -353,7 +353,7 @@ def do_deactivate(self):
             obj.disconnect(hid)
         self._handlers = None
         pane = self.window.get_side_panel()
-        pane.remove_item(self._sourcetree)
+        pane.remove(self._sourcetree)
         self._sourcetree = None
 
     def _has_settings_schema(self):
@@ -393,7 +393,7 @@ def _load_active_document_symbols(self):
         self._is_loaded = False
         # do not load if not the active tab in the panel
         panel = self.window.get_side_panel()
-        if not panel.item_is_active(self._sourcetree):
+        if panel.get_visible_child() != self._sourcetree:
             return
 
         document = self.window.get_active_document()