Manual invocation of trust search (#738)

Addresses slowness in search due to compounding search events by
changing the search bar behavior to only begin filtering when `Enter`
key is pressed instead of upon any key press.

The root cause of the slowness was multiple compounding search events
generated by the 150 millisecond keystroke delay. That is now eliminated
at the cost of having to press enter to initiate search.

Closes #684

fapolicy_analyzer/glade/searchable_list.glade

@@ -36,7 +36,7 @@
             <property name="primary_icon_name">edit-find-symbolic</property>
             <property name="primary_icon_activatable">False</property>
             <property name="primary_icon_sensitive">False</property>
-            <signal name="search-changed" handler="on_search_changed" swapped="no"/>
+            <signal name="activate" handler="on_search_activate" swapped="no"/>
           </object>
           <packing>
             <property name="expand">True</property>

fapolicy_analyzer/tests/test_searchable_list.py

@@ -97,6 +97,7 @@ def test_filtering(widget):
     view = widget.get_object("treeView")
     viewFilter = widget.get_object("search")
     viewFilter.set_text("foo")
+    widget.on_search_activate()
     refresh_gui(delay=0.3)
     paths = [x[0] for x in view.get_model()]
     assert "foo" in paths

fapolicy_analyzer/ui/searchable_list.py

@@ -184,6 +184,6 @@ def on_view_selection_changed(self, selection):
         data = [model[i] for i in treeiter] if model and treeiter else []
         self.selection_changed(data)
 
-    def on_search_changed(self, search):
+    def on_search_activate(self, *args):
         self._store.refilter()
         self._update_list_status(self._get_tree_count())