app_list: Handle event in assistant_page_view

This patch will set the click or tap event in assistant_page_view to be
handled to prevent app_list_view changing state.

Bug: 924624
Test: manual
Change-Id: I5bcdca18a7980f85803556b282227eeeb87c46c1
Reviewed-on: https://chromium-review.googlesource.com/c/1455271
Commit-Queue: Tao Wu <wutao@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630125}

ash/app_list/views/assistant/assistant_page_view.cc

@@ -60,6 +60,32 @@ void AssistantPageView::RequestFocus() {
   assistant_main_view_->RequestFocus();
 }
 
+void AssistantPageView::OnMouseEvent(ui::MouseEvent* event) {
+  switch (event->type()) {
+    case ui::ET_MOUSE_PRESSED:
+      // Prevents closing the AppListView when a click event is not handled.
+      event->StopPropagation();
+      break;
+    default:
+      break;
+  }
+}
+
+void AssistantPageView::OnGestureEvent(ui::GestureEvent* event) {
+  switch (event->type()) {
+    case ui::ET_GESTURE_TAP:
+    case ui::ET_GESTURE_DOUBLE_TAP:
+    case ui::ET_GESTURE_LONG_PRESS:
+    case ui::ET_GESTURE_LONG_TAP:
+    case ui::ET_GESTURE_TWO_FINGER_TAP:
+      // Prevents closing the AppListView when a tap event is not handled.
+      event->StopPropagation();
+      break;
+    default:
+      break;
+  }
+}
+
 gfx::Rect AssistantPageView::GetPageBoundsForState(
     ash::AppListState state) const {
   gfx::Rect onscreen_bounds;

ash/app_list/views/assistant/assistant_page_view.h

@@ -32,6 +32,10 @@ class APP_LIST_EXPORT AssistantPageView : public AppListPage {
   gfx::Size CalculatePreferredSize() const override;
   void RequestFocus() override;
 
+  // ui::EventHandler:
+  void OnMouseEvent(ui::MouseEvent* event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
+
   // AppListPage:
   gfx::Rect GetPageBoundsForState(ash::AppListState state) const override;
   gfx::Rect GetSearchBoxBounds() const override;