part 5 of the scrollableshelf view

Add focus traversal to ScrollableShelfView

Bug: 973481
Change-Id: I3beeea53aff1ed32ccb588f2033ab67851590574
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1767484
Commit-Queue: Andrew Xu <andrewxu@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691759}

ash/shelf/hotseat_widget.cc

@@ -96,8 +96,12 @@ void HotseatWidget::OnGestureEvent(ui::GestureEvent* event) {
 bool HotseatWidget::OnNativeWidgetActivationChanged(bool active) {
   if (!Widget::OnNativeWidgetActivationChanged(active))
     return false;
-  if (active)
+
+  if (IsScrollableShelfEnabled())
+    scrollable_shelf_view_->OnFocusRingActivationChanged(active);
+  else if (active)
     GetShelfView()->SetPaneFocusAndFocusDefault();
+
   return true;
 }
 

ash/shelf/hotseat_widget.h

@@ -43,6 +43,10 @@ class ASH_EXPORT HotseatWidget : public views::Widget {
   ShelfView* GetShelfView();
   const ShelfView* GetShelfView() const;
 
+  ScrollableShelfView* scrollable_shelf_view() {
+    return scrollable_shelf_view_;
+  }
+
  private:
   class DelegateView;
 

ash/shelf/scrollable_shelf_view.h

@@ -15,9 +15,13 @@
 #include "ui/views/animation/ink_drop_host_view.h"
 #include "ui/views/controls/button/button.h"
 
+namespace views {
+class FocusSearch;
+}
+
 namespace ash {
 
-class ASH_EXPORT ScrollableShelfView : public views::View,
+class ASH_EXPORT ScrollableShelfView : public views::AccessiblePaneView,
                                        public ShellObserver,
                                        public ShelfButtonDelegate {
  public:
@@ -41,6 +45,20 @@ class ASH_EXPORT ScrollableShelfView : public views::View,
 
   void Init();
 
+  // Called when the focus ring for ScrollableShelfView is enabled/disabled.
+  // |activated| is true when enabling the focus ring.
+  void OnFocusRingActivationChanged(bool activated);
+
+  // Scrolls to a new page of shelf icons. |forward| indicates whether the next
+  // page or previous page is shown.
+  void ScrollToNewPage(bool forward);
+
+  // AccessiblePaneView:
+  views::FocusSearch* GetFocusSearch() override;
+  views::FocusTraversable* GetFocusTraversableParent() override;
+  views::View* GetFocusTraversableParentView() override;
+  views::View* GetDefaultFocusableChild() override;
+
   views::View* GetShelfContainerViewForTest();
 
   ShelfView* shelf_view() { return shelf_view_; }
@@ -48,6 +66,13 @@ class ASH_EXPORT ScrollableShelfView : public views::View,
   LayoutStrategy layout_strategy_for_test() const { return layout_strategy_; }
   gfx::Vector2dF scroll_offset_for_test() const { return scroll_offset_; }
 
+  int first_tappable_app_index() { return first_tappable_app_index_; }
+  int last_tappable_app_index() { return last_tappable_app_index_; }
+
+  void set_default_last_focusable_child(bool default_last_focusable_child) {
+    default_last_focusable_child_ = default_last_focusable_child;
+  }
+
   // Size of the arrow button.
   static int GetArrowButtonSize();
 
@@ -143,6 +168,18 @@ class ASH_EXPORT ScrollableShelfView : public views::View,
   // Updates the gradient zone.
   void UpdateGradientZone();
 
+  // Returns the actual scroll offset on the view's main axis. When the left
+  // arrow button shows, |shelf_view_| is translated due to the change in
+  // |shelf_container_view_|'s bounds. That translation offset is not included
+  // in |scroll_offset_|.
+  int GetActualScrollOffset() const;
+
+  // Updates |first_tappable_app_index_| and |last_tappable_app_index_|.
+  void UpdateTappableIconIndices();
+
+  views::View* FindFirstFocusableChild();
+  views::View* FindLastFocusableChild();
+
   LayoutStrategy layout_strategy_ = kNotShowArrowButtons;
 
   // Child views Owned by views hierarchy.
@@ -169,6 +206,20 @@ class ASH_EXPORT ScrollableShelfView : public views::View,
 
   std::unique_ptr<GradientLayerDelegate> gradient_layer_delegate_;
 
+  std::unique_ptr<views::FocusSearch> focus_search_;
+
+  // The index of the first/last tappable app index.
+  int first_tappable_app_index_ = -1;
+  int last_tappable_app_index_ = -1;
+
+  // Whether this view should focus its last focusable child (instead of its
+  // first) when focused.
+  bool default_last_focusable_child_ = false;
+
+  // Indicates whether the focus ring on shelf items contained by
+  // ScrollableShelfView is enabled.
+  bool focus_ring_activated_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(ScrollableShelfView);
 };
 

ash/shelf/shelf_focus_cycler.cc

@@ -6,6 +6,7 @@
 
 #include "ash/focus_cycler.h"
 #include "ash/shelf/login_shelf_view.h"
+#include "ash/shelf/scrollable_shelf_view.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_navigation_widget.h"
 #include "ash/shelf/shelf_view.h"
@@ -14,6 +15,7 @@
 #include "ash/system/status_area_widget.h"
 #include "ash/system/status_area_widget_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
+#include "chromeos/constants/chromeos_switches.h"
 
 namespace ash {
 
@@ -83,8 +85,13 @@ void ShelfFocusCycler::FocusShelf(bool last_element) {
     Shell::Get()->focus_cycler()->FocusWidget(shelf_widget);
   } else {
     HotseatWidget* hotseat_widget = shelf_->shelf_widget()->hotseat_widget();
+    if (chromeos::switches::ShouldShowScrollableShelf()) {
+      hotseat_widget->scrollable_shelf_view()->set_default_last_focusable_child(
+          last_element);
+    } else {
       hotseat_widget->GetShelfView()->set_default_last_focusable_child(
           last_element);
+    }
     Shell::Get()->focus_cycler()->FocusWidget(hotseat_widget);
   }
 }

ash/shelf/shelf_view.cc

@@ -576,6 +576,11 @@ void ShelfView::OnMouseEvent(ui::MouseEvent* event) {
 }
 
 views::FocusTraversable* ShelfView::GetPaneFocusTraversable() {
+  // ScrollableShelfView should handles the focus traversal if the flag
+  // is enabled.
+  if (chromeos::switches::ShouldShowScrollableShelf())
+    return nullptr;
+
   return this;
 }