Update search behavior

* Show all tasks for empty query
* Revert filter when closing search

app/src/main/java/com/todoroo/astrid/activity/TaskListFragment.java

@@ -259,17 +259,33 @@ public class TaskListFragment extends InjectingFragment
 
   private void setupSearchView(Menu menu) {
     final MenuItem item = menu.findItem(R.id.menu_search);
+    item.setOnActionExpandListener(
+        new MenuItem.OnActionExpandListener() {
+          @Override
+          public boolean onMenuItemActionExpand(MenuItem item) {
+            searchByQuery("");
+            return true;
+          }
+
+          @Override
+          public boolean onMenuItemActionCollapse(MenuItem item) {
+            taskListViewModel.searchByFilter(filter);
+            return true;
+          }
+        });
     final SearchView actionView = (SearchView) MenuItemCompat.getActionView(item);
     searchSubject = PublishSubject.create();
-    searchDisposable = searchSubject
+    searchDisposable =
+        searchSubject
             .debounce(SEARCH_DEBOUNCE_TIMEOUT, TimeUnit.MILLISECONDS)
             .subscribe(this::searchByQuery);
-
     actionView.setOnQueryTextListener(
         new SearchView.OnQueryTextListener() {
           @Override
           public boolean onQueryTextSubmit(String query) {
-                    return false;
+            ((MainActivity) getActivity()).onFilterItemClicked(createSearchFilter(query.trim()));
+            MenuItemCompat.collapseActionView(item);
+            return true;
           }
 
           @Override
@@ -286,21 +302,21 @@ public class TaskListFragment extends InjectingFragment
       Filter savedFilter = createSearchFilter(query);
       taskListViewModel.searchByFilter(savedFilter);
     } else {
-        MainActivity activity = (MainActivity) getActivity();
+      taskListViewModel.searchByFilter(
-        taskListViewModel.searchByFilter(activity.defaultFilterProvider.getDefaultFilter());
+          BuiltInFilterExposer.getMyTasksFilter(context.getResources()));
     }
   }
 
-  private Filter createSearchFilter(String query){
+  private Filter createSearchFilter(String query) {
     String title = getString(R.string.FLA_search_filter, query);
     return new Filter(
-    title, new QueryTemplate()
+        title,
+        new QueryTemplate()
             .where(
                 Criterion.and(
                     Task.DELETION_DATE.eq(0),
                     Criterion.or(
-                                    Task.NOTES.like("%" + query + "%"),
+                        Task.NOTES.like("%" + query + "%"), Task.TITLE.like("%" + query + "%")))));
-                                    Task.TITLE.like("%" + query + "%")))));
   }
 
   @Override