Handles mouse clicks between apps in apps grid, preventing app_list close

Bug: 894328
Change-Id: Ia12904740ef4f57643233d26710c704908cca1c8
Reviewed-on: https://chromium-review.googlesource.com/c/1309420Reviewed-by: Weidong Guo <weidongg@chromium.org>
Commit-Queue: Kevin Strohbehn <ginko@google.com>
Cr-Commit-Position: refs/heads/master@{#604435}

ash/app_list/views/apps_grid_view.cc

@@ -1032,9 +1032,7 @@ void AppsGridView::OnGestureEvent(ui::GestureEvent* event) {
   if (!contents_view_->app_list_view()->IsHomeLauncherEnabledInTabletMode() &&
       (event->type() == ui::ET_GESTURE_TAP ||
        event->type() == ui::ET_GESTURE_LONG_PRESS)) {
-    GridIndex nearest_tile_index =
-        GetNearestTileIndexForPoint(event->location());
-    if (IsValidIndex(nearest_tile_index))
+    if (EventIsBetweenOccupiedTiles(event))
       event->SetHandled();
     return;
   }
@@ -1063,6 +1061,16 @@ void AppsGridView::OnGestureEvent(ui::GestureEvent* event) {
   }
 }
 
+bool AppsGridView::OnMousePressed(const ui::MouseEvent& event) {
+  return !contents_view_->app_list_view()
+              ->IsHomeLauncherEnabledInTabletMode() &&
+         event.IsLeftMouseButton() && EventIsBetweenOccupiedTiles(&event);
+}
+
+bool AppsGridView::EventIsBetweenOccupiedTiles(const ui::LocatedEvent* event) {
+  return IsValidIndex(GetNearestTileIndexForPoint(event->location()));
+}
+
 void AppsGridView::Update() {
   DCHECK(!selected_view_ && !drag_view_);
   view_model_.Clear();

ash/app_list/views/apps_grid_view.h

@@ -195,6 +195,10 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
 
   // Overridden from ui::EventHandler:
   void OnGestureEvent(ui::GestureEvent* event) override;
+  bool OnMousePressed(const ui::MouseEvent& event) override;
+
+  // Returns true if a touch or click lies between two occupied tiles.
+  bool EventIsBetweenOccupiedTiles(const ui::LocatedEvent* event);
 
   // Stops the timer that triggers a page flip during a drag.
   void StopPageFlipTimer();