Fix status area accessability issues.

ash/system/tray/tray_background_view.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/system/tray/tray_background_view.h"
 
 #include "ash/launcher/background_animator.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/status_area_widget_delegate.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ui/aura/window.h"
+#include "ui/base/accessibility/accessible_view_state.h"
+#include "ui/compositor/layer_animation_observer.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/views/background.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace {
 
 const SkColor kTrayBackgroundAlpha = 100;
 const SkColor kTrayBackgroundHoverAlpha = 150;
 
 // Adjust the size of TrayContainer with additional padding.
 const int kTrayContainerVerticalPaddingBottomAlignment  = 1;
 const int kTrayContainerHorizontalPaddingBottomAlignment  = 1;
 const int kTrayContainerVerticalPaddingVerticalAlignment  = 1;
 const int kTrayContainerHorizontalPaddingVerticalAlignment = 1;
 
 }  // namespace
 
 namespace ash {
 namespace internal {
 
+// Observe the tray layer animation and update the anchor when it changes.
+// TODO(stevenjb): Observe or mirror the actual animation, not just the start
+// and end points.
+class TrayLayerAnimationObserver : public ui::LayerAnimationObserver {
+ public:
+  explicit TrayLayerAnimationObserver(TrayBackgroundView* host)
+      : host_(host) {
+  }
+
+  virtual void OnLayerAnimationEnded(ui::LayerAnimationSequence* sequence) {
+    host_->AnchorUpdated();
+  }
+
+  virtual void OnLayerAnimationAborted(ui::LayerAnimationSequence* sequence) {
+    host_->AnchorUpdated();
+  }
+
+  virtual void OnLayerAnimationScheduled(ui::LayerAnimationSequence* sequence) {
+    host_->AnchorUpdated();
+  }
+
+ private:
+  TrayBackgroundView* host_;
+
+  DISALLOW_COPY_AND_ASSIGN(TrayLayerAnimationObserver);
+};
+
 class TrayBackground : public views::Background {
  public:
   TrayBackground() : alpha_(kTrayBackgroundAlpha) {}
   virtual ~TrayBackground() {}
 
   void set_alpha(int alpha) { alpha_ = alpha; }
 
  private:
   // Overridden from views::Background.
   virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE {
@@ skipping 94 matching lines @@
   hover_background_animator_.SetPaintsBackground(false,
       internal::BackgroundAnimator::CHANGE_IMMEDIATE);
 
   tray_container_ = new TrayContainer(shelf_alignment_);
   SetContents(tray_container_);
 }
 
 TrayBackgroundView::~TrayBackgroundView() {
 }
 
+void TrayBackgroundView::Initialize() {
+  layer_animation_observer_.reset(new TrayLayerAnimationObserver(this));
+  GetWidget()->GetNativeView()->layer()->GetAnimator()->AddObserver(
+      layer_animation_observer_.get());
+  SetBorder();
+}
+
 void TrayBackgroundView::OnMouseEntered(const views::MouseEvent& event) {
   hover_background_animator_.SetPaintsBackground(true,
       internal::BackgroundAnimator::CHANGE_ANIMATE);
+  UpdateShouldShowLauncher();
 }
 
 void TrayBackgroundView::OnMouseExited(const views::MouseEvent& event) {
   hover_background_animator_.SetPaintsBackground(false,
       internal::BackgroundAnimator::CHANGE_ANIMATE);
+  UpdateShouldShowLauncher();
 }
 
 void TrayBackgroundView::ChildPreferredSizeChanged(views::View* child) {
   PreferredSizeChanged();
 }
 
+void TrayBackgroundView::OnPaintFocusBorder(gfx::Canvas* canvas) {
+  // The tray itself expands to the right and bottom edge of the screen to make
+  // sure clicking on the edges brings up the popup. However, the focus border
+  // should be only around the container.
+  if (HasFocus() && (focusable() || IsAccessibilityFocusable()))
+    DrawBorder(canvas, GetContentsBounds());
+}
+
+void TrayBackgroundView::GetAccessibleState(ui::AccessibleViewState* state) {
+  state->role = ui::AccessibilityTypes::ROLE_PUSHBUTTON;
+  state->name = GetAccessibleName();
+}
+
+void TrayBackgroundView::AboutToRequestFocusFromTabTraversal(bool reverse) {
+  // Return focus to the login view. See crbug.com/120500.
+  views::View* v = GetNextFocusableView();
+  if (v)
+    v->AboutToRequestFocusFromTabTraversal(reverse);
+}
+
 bool TrayBackgroundView::PerformAction(const ui::Event& event) {
   return false;
 }
 
 void TrayBackgroundView::UpdateBackground(int alpha) {
   if (background_) {
     background_->set_alpha(hide_background_animator_.alpha() +
                            hover_background_animator_.alpha());
   }
   SchedulePaint();
@@ skipping 14 matching lines @@
 }
 
 void TrayBackgroundView::SetShelfAlignment(ShelfAlignment alignment) {
   shelf_alignment_ = alignment;
   SetBorder();
   tray_container_->SetAlignment(alignment);
 }
 
 void TrayBackgroundView::SetBorder() {
   views::View* parent = status_area_widget_->status_area_widget_delegate();
-  int child_count = parent->child_count();
-  DCHECK(child_count > 0);
-  int on_edge = (this == parent->child_at(child_count-1));
+  // Tray views are laid out right-to-left or bottom-to-top
+  int on_edge = (this == parent->child_at(0));
   // Change the border padding for different shelf alignment.
   if (shelf_alignment() == SHELF_ALIGNMENT_BOTTOM) {
     set_border(views::Border::CreateEmptyBorder(
         0, 0, kPaddingFromBottomOfScreenBottomAlignment,
         on_edge ? kPaddingFromRightEdgeOfScreenBottomAlignment : 0));
   } else if (shelf_alignment() == SHELF_ALIGNMENT_LEFT) {
     set_border(views::Border::CreateEmptyBorder(
         0, kPaddingFromOuterEdgeOfLauncherVerticalAlignment,
         on_edge ? kPaddingFromBottomOfScreenVerticalAlignment : 0,
         kPaddingFromInnerEdgeOfLauncherVerticalAlignment));
   } else {
     set_border(views::Border::CreateEmptyBorder(
         0, kPaddingFromInnerEdgeOfLauncherVerticalAlignment,
         on_edge ? kPaddingFromBottomOfScreenVerticalAlignment : 0,
         kPaddingFromOuterEdgeOfLauncherVerticalAlignment));
   }
 }
 
+void TrayBackgroundView::UpdateShouldShowLauncher() {
+  status_area_widget()->UpdateShouldShowLauncher();
+}
+
 }  // namespace internal
 }  // namespace ash