TitleEntry - save title on activate (Enter)

Learners have to use tab to finish editing, followed by clicking the
activity icon to dismiss the dialog.  A slow work flow and inconsistent
with journal list view.  The enter key is ignored.

Add an activate signal handler to save the title.  Force the focus to
move by calling hide and show.

Signed-off-by: James Cameron <quozl@laptop.org>

src/sugar3/activity/widgets.py

@@ -177,6 +177,7 @@ class TitleEntry(Gtk.ToolItem):
         self.entry.set_text(activity.metadata['title'])
         self.entry.connect(
             'focus-out-event', self.__title_changed_cb, activity)
+        self.entry.connect('activate', self.__on_activate, activity)
         self.entry.connect('button-press-event', self.__button_press_event_cb)
         self.entry.show()
         self.add(self.entry)
@@ -184,6 +185,12 @@ class TitleEntry(Gtk.ToolItem):
         activity.metadata.connect('updated', self.__jobject_updated_cb)
         activity.connect('_closing', self.__closing_cb)
 
+    def __on_activate(self, widget, activity):
+        self.save_title(activity)
+        self.entry.hide()
+        self.entry.show()
+        return False
+
     def modify_bg(self, state, color):
         Gtk.ToolItem.modify_bg(self, state, color)
         self.entry.modify_bg(state, color)