Revise the shelf alignment locking mechanism.

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/root_window_controller.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf_layout_manager.h"
+#include "ash/shelf/shelf_util.h"
 #include "ash/shelf/shelf_widget.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/system_tray.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_event_filter.h"
 #include "ash/wm/window_animations.h"
 #include "base/command_line.h"
@@ skipping 165 matching lines @@
 
 void TrayBackgroundView::TrayContainer::ViewHierarchyChanged(
     const ViewHierarchyChangedDetails& details) {
   if (details.parent == this)
     PreferredSizeChanged();
 }
 
 void TrayBackgroundView::TrayContainer::UpdateLayout() {
   // Adjust the size of status tray dark background by adding additional
   // empty border.
-  if (alignment_ == SHELF_ALIGNMENT_BOTTOM) {
+  if (IsHorizontalAlignment(alignment_)) {
     SetBorder(views::Border::CreateEmptyBorder(
         kPaddingFromEdgeOfShelf,
         kPaddingFromEdgeOfShelf,
         kPaddingFromEdgeOfShelf,
         kPaddingFromEdgeOfShelf));
 
     views::BoxLayout* layout =
         new views::BoxLayout(views::BoxLayout::kHorizontal, 0, 0, 0);
     layout->SetDefaultFlex(1);
     views::View::SetLayoutManager(layout);
@@ skipping 190 matching lines @@
   shelf_alignment_ = alignment;
   SetTrayBorder();
   tray_container_->SetAlignment(alignment);
 }
 
 void TrayBackgroundView::SetTrayBorder() {
   views::View* parent = status_area_widget_->status_area_widget_delegate();
   // Tray views are laid out right-to-left or bottom-to-top
   bool on_edge = (this == parent->child_at(0));
   int left_edge, top_edge, right_edge, bottom_edge;
-  if (shelf_alignment() == SHELF_ALIGNMENT_BOTTOM) {
+  if (IsHorizontalAlignment(shelf_alignment())) {
     top_edge = ShelfLayoutManager::kShelfItemInset;
     left_edge = 0;
     bottom_edge = kShelfSize -
         ShelfLayoutManager::kShelfItemInset - kShelfItemHeight;
     right_edge = on_edge ? kPaddingFromEdgeOfShelf : 0;
   } else if (shelf_alignment() == SHELF_ALIGNMENT_LEFT) {
     top_edge = 0;
     left_edge = kShelfSize -
         ShelfLayoutManager::kShelfItemInset - kShelfItemHeight;
     bottom_edge = on_edge ? kPaddingFromEdgeOfShelf : 0;
@@ skipping 26 matching lines @@
   // This is needed so that OnImplicitAnimationsCompleted() is called even upon
   // destruction of the animator. This can occure when parallel animations
   // caused by ScreenRotationAnimator end before the animations of
   // TrayBackgroundView. This allows for a proper update to the visual state of
   // the view. (crbug.com/476667)
   return true;
 }
 
 void TrayBackgroundView::HideTransformation() {
   gfx::Transform transform;
-  if (shelf_alignment_ == SHELF_ALIGNMENT_BOTTOM)
+  if (IsHorizontalAlignment(shelf_alignment_))
     transform.Translate(width(), 0.0f);
   else
     transform.Translate(0.0f, height());
   layer()->SetTransform(transform);
 }
 
 void TrayBackgroundView::InitializeBubbleAnimations(
     views::Widget* bubble_widget) {
   wm::SetWindowVisibilityAnimationType(
       bubble_widget->GetNativeWindow(),
@@ skipping 88 matching lines @@
           kPaddingFromRightEdgeOfScreenBottomAlignment :
           rect.width() - kPaddingFromRightEdgeOfScreenBottomAlignment,
           rect.height() - kPaddingFromBottomOfScreenBottomAlignment,
           0, 0);
     }
   }
   return rect;
 }
 
 TrayBubbleView::AnchorAlignment TrayBackgroundView::GetAnchorAlignment() const {
-  switch (shelf_alignment_) {
-    case SHELF_ALIGNMENT_BOTTOM:
-      return TrayBubbleView::ANCHOR_ALIGNMENT_BOTTOM;
-    case SHELF_ALIGNMENT_LEFT:
-      return TrayBubbleView::ANCHOR_ALIGNMENT_LEFT;
-    case SHELF_ALIGNMENT_RIGHT:
-      return TrayBubbleView::ANCHOR_ALIGNMENT_RIGHT;
-  }
-  NOTREACHED();
+  if (shelf_alignment_ == SHELF_ALIGNMENT_LEFT)
+    return TrayBubbleView::ANCHOR_ALIGNMENT_LEFT;
+  if (shelf_alignment_ == SHELF_ALIGNMENT_RIGHT)
+    return TrayBubbleView::ANCHOR_ALIGNMENT_RIGHT;
   return TrayBubbleView::ANCHOR_ALIGNMENT_BOTTOM;
 }
 
 void TrayBackgroundView::SetDrawBackgroundAsActive(bool visible) {
   if (draw_background_as_active_ == visible)
     return;
   draw_background_as_active_ = visible;
   if (!background_)
     return;
 
   // Do not change gradually, changing color between grey and blue is weird.
   if (draw_background_as_active_)
     background_->set_color(kTrayBackgroundPressedColor);
   else if (hovered_)
     background_->set_alpha(kTrayBackgroundHoverAlpha);
   else
     background_->set_alpha(kTrayBackgroundAlpha);
   SchedulePaint();
 }
 
 void TrayBackgroundView::UpdateBubbleViewArrow(
     views::TrayBubbleView* bubble_view) {
   // Nothing to do here.
 }
 
 }  // namespace ash