[ScrollableShelf] Enable gestures to trigger context menu

This CL enables the scrollable shelf to show context menu for proper
gestures (like long-time tapping). It helps to keep the UI consistency
with the shelf view.

Bug: 1003584
Change-Id: I74b69ffea84fedc6c780cacc01b6eea680b6875b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1801320Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Andrew Xu <andrewxu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697036}

ash/shelf/scrollable_shelf_view.cc

@@ -257,6 +257,8 @@ void ScrollableShelfView::Init() {
   focus_search_ = std::make_unique<ScrollableShelfFocusSearch>(this);
 
   GetShelf()->tooltip()->set_shelf_tooltip_delegate(this);
+
+  set_context_menu_controller(this);
 }
 
 void ScrollableShelfView::OnFocusRingActivationChanged(bool activated) {
@@ -580,6 +582,14 @@ void ScrollableShelfView::OnShelfButtonAboutToRequestFocusFromTabTraversal(
     ShelfButton* button,
     bool reverse) {}
 
+void ScrollableShelfView::ShowContextMenuForViewImpl(
+    views::View* source,
+    const gfx::Point& point,
+    ui::MenuSourceType source_type) {
+  // |point| is in screen coordinates. So it does not need to transform.
+  shelf_view_->ShowContextMenuForViewImpl(shelf_view_, point, source_type);
+}
+
 void ScrollableShelfView::ButtonPressed(views::Button* sender,
                                         const ui::Event& event,
                                         views::InkDrop* ink_drop) {

ash/shelf/scrollable_shelf_view.h

@@ -14,6 +14,7 @@
 #include "ash/shelf/shelf_tooltip_delegate.h"
 #include "ash/shelf/shelf_view.h"
 #include "ui/views/animation/ink_drop_host_view.h"
+#include "ui/views/context_menu_controller.h"
 #include "ui/views/controls/button/button.h"
 
 namespace views {
@@ -25,7 +26,8 @@ namespace ash {
 class ASH_EXPORT ScrollableShelfView : public views::AccessiblePaneView,
                                        public ShellObserver,
                                        public ShelfButtonDelegate,
-                                       public ShelfTooltipDelegate {
+                                       public ShelfTooltipDelegate,
+                                       public views::ContextMenuController {
  public:
   enum LayoutStrategy {
     // The arrow buttons are not shown. It means that there is enough space to
@@ -131,6 +133,12 @@ class ASH_EXPORT ScrollableShelfView : public views::AccessiblePaneView,
   // ShelfButtonDelegate:
   void OnShelfButtonAboutToRequestFocusFromTabTraversal(ShelfButton* button,
                                                         bool reverse) override;
+
+  // ContextMenuController:
+  void ShowContextMenuForViewImpl(views::View* source,
+                                  const gfx::Point& point,
+                                  ui::MenuSourceType source_type) override;
+
   void ButtonPressed(views::Button* sender,
                      const ui::Event& event,
                      views::InkDrop* ink_drop) override;

ash/shelf/shelf_view.cc

@@ -822,6 +822,32 @@ void ShelfView::CreateDragIconProxy(
   drag_image_->SetWidgetVisible(true);
 }
 
+void ShelfView::ShowContextMenuForViewImpl(views::View* source,
+                                           const gfx::Point& point,
+                                           ui::MenuSourceType source_type) {
+  // Prevent concurrent requests that may show application or context menus.
+  const ShelfItem* item = ShelfItemForView(source);
+  if (!item_awaiting_response_.IsNull()) {
+    if (item && item->id != item_awaiting_response_) {
+      static_cast<views::Button*>(source)->AnimateInkDrop(
+          views::InkDropState::DEACTIVATED, nullptr);
+    }
+    return;
+  }
+  last_pressed_index_ = -1;
+  if (!item || !model_->GetShelfItemDelegate(item->id)) {
+    ShowShelfContextMenu(ShelfID(), point, source, source_type, nullptr);
+    return;
+  }
+
+  item_awaiting_response_ = item->id;
+  const int64_t display_id = GetDisplayIdForView(this);
+  model_->GetShelfItemDelegate(item->id)->GetContextMenu(
+      display_id, base::BindOnce(&ShelfView::ShowShelfContextMenu,
+                                 weak_factory_.GetWeakPtr(), item->id, point,
+                                 source, source_type));
+}
+
 void ShelfView::OnTabletModeStarted() {
   // Close all menus when tablet mode starts to ensure that the clamshell only
   // context menu options are not available in tablet mode.
@@ -2311,32 +2337,6 @@ void ShelfView::ShowShelfContextMenu(
   ShowMenu(std::move(model), source, point, /*context_menu=*/true, source_type);
 }
 
-void ShelfView::ShowContextMenuForViewImpl(views::View* source,
-                                           const gfx::Point& point,
-                                           ui::MenuSourceType source_type) {
-  // Prevent concurrent requests that may show application or context menus.
-  const ShelfItem* item = ShelfItemForView(source);
-  if (!item_awaiting_response_.IsNull()) {
-    if (item && item->id != item_awaiting_response_) {
-      static_cast<views::Button*>(source)->AnimateInkDrop(
-          views::InkDropState::DEACTIVATED, nullptr);
-    }
-    return;
-  }
-  last_pressed_index_ = -1;
-  if (!item || !model_->GetShelfItemDelegate(item->id)) {
-    ShowShelfContextMenu(ShelfID(), point, source, source_type, nullptr);
-    return;
-  }
-
-  item_awaiting_response_ = item->id;
-  const int64_t display_id = GetDisplayIdForView(this);
-  model_->GetShelfItemDelegate(item->id)->GetContextMenu(
-      display_id, base::BindOnce(&ShelfView::ShowShelfContextMenu,
-                                 weak_factory_.GetWeakPtr(), item->id, point,
-                                 source, source_type));
-}
-
 void ShelfView::ShowMenu(std::unique_ptr<ui::SimpleMenuModel> menu_model,
                          views::View* source,
                          const gfx::Point& click_point,

ash/shelf/shelf_view.h

@@ -207,6 +207,11 @@ class ASH_EXPORT ShelfView : public views::AccessiblePaneView,
                            const gfx::Vector2d& cursor_offset_from_center,
                            float scale_factor) override;
 
+  // Overridden from views::ContextMenuController:
+  void ShowContextMenuForViewImpl(views::View* source,
+                                  const gfx::Point& point,
+                                  ui::MenuSourceType source_type) override;
+
   // ash::TabletModeObserver:
   void OnTabletModeStarted() override;
   void OnTabletModeEnded() override;
@@ -510,11 +515,6 @@ class ASH_EXPORT ShelfView : public views::AccessiblePaneView,
                          ShelfAction action,
                          ShelfItemDelegate::AppMenuItems menu_items);
 
-  // Overridden from views::ContextMenuController:
-  void ShowContextMenuForViewImpl(views::View* source,
-                                  const gfx::Point& point,
-                                  ui::MenuSourceType source_type) override;
-
   // Show either a context or normal click menu of given |menu_model|.
   // If |context_menu| is set, the displayed menu is a context menu and not
   // a menu listing one or more running applications.