Reland of "Apply Shelf/Dock opacity animations for the Material Design style."

ash/common/shelf/app_list_button.cc

 // Copyright 2014 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/common/shelf/app_list_button.h"
 
 #include "ash/common/ash_constants.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/ink_drop_button_listener.h"
 #include "ash/common/shelf/shelf_constants.h"
@@ skipping 17 matching lines @@
 #include "ui/views/animation/square_ink_drop_ripple.h"
 #include "ui/views/painter.h"
 
 namespace ash {
 
 AppListButton::AppListButton(InkDropButtonListener* listener,
                              ShelfView* shelf_view,
                              WmShelf* wm_shelf)
     : views::ImageButton(nullptr),
       draw_background_as_active_(false),
+      background_alpha_(0),
       listener_(listener),
       shelf_view_(shelf_view),
       wm_shelf_(wm_shelf) {
   DCHECK(listener_);
   DCHECK(shelf_view_);
   DCHECK(wm_shelf_);
   if (ash::MaterialDesignController::IsShelfMaterial()) {
     SetInkDropMode(InkDropMode::ON_NO_GESTURE_HANDLER);
     set_ink_drop_base_color(kShelfInkDropBaseColor);
     set_ink_drop_visible_opacity(kShelfInkDropVisibleOpacity);
@@ skipping 18 matching lines @@
     SchedulePaint();
 }
 
 void AppListButton::OnAppListDismissed() {
   if (ash::MaterialDesignController::IsShelfMaterial())
     AnimateInkDrop(views::InkDropState::DEACTIVATED, nullptr);
   else
     SchedulePaint();
 }
 
+void AppListButton::SetBackgroundAlpha(int alpha) {
+  background_alpha_ = alpha;
+  SchedulePaint();
+}
+
 bool AppListButton::OnMousePressed(const ui::MouseEvent& event) {
   ImageButton::OnMousePressed(event);
   shelf_view_->PointerPressedOnButton(this, ShelfView::MOUSE, event);
   return true;
 }
 
 void AppListButton::OnMouseReleased(const ui::MouseEvent& event) {
   ImageButton::OnMouseReleased(event);
   shelf_view_->PointerReleasedOnButton(this, ShelfView::MOUSE, false);
 }
@@ skipping 64 matching lines @@
     PaintBackgroundMD(canvas);
     PaintForegroundMD(canvas, foreground_image);
   } else {
     PaintAppListButton(canvas, foreground_image);
   }
 
   views::Painter::PaintFocusPainter(this, canvas, focus_painter());
 }
 
 void AppListButton::PaintBackgroundMD(gfx::Canvas* canvas) {
-  SkPaint background_paint;
-  background_paint.setColor(SK_ColorTRANSPARENT);
-  background_paint.setFlags(SkPaint::kAntiAlias_Flag);
-  background_paint.setStyle(SkPaint::kFill_Style);
-
-  if (wm_shelf_->GetBackgroundType() ==
-      ShelfBackgroundType::SHELF_BACKGROUND_DEFAULT) {
-    background_paint.setColor(
-        SkColorSetA(kShelfBaseColor, GetShelfConstant(SHELF_BACKGROUND_ALPHA)));
-  }
-
   // Paint the circular background of AppList button.
   gfx::Point circle_center = GetContentsBounds().CenterPoint();
   if (!IsHorizontalAlignment(wm_shelf_->GetAlignment()))
     circle_center = gfx::Point(circle_center.y(), circle_center.x());
 
+  SkPaint background_paint;
+  background_paint.setColor(SkColorSetA(kShelfBaseColor, background_alpha_));
+  background_paint.setFlags(SkPaint::kAntiAlias_Flag);
+  background_paint.setStyle(SkPaint::kFill_Style);
+
   canvas->DrawCircle(circle_center, kAppListButtonRadius, background_paint);
 }
 
 void AppListButton::PaintForegroundMD(gfx::Canvas* canvas,
                                       const gfx::ImageSkia& foreground_image) {
   gfx::Rect foreground_bounds(foreground_image.size());
   gfx::Rect contents_bounds = GetContentsBounds();
 
   if (IsHorizontalAlignment(wm_shelf_->GetAlignment())) {
     foreground_bounds.set_x(
@@ skipping 101 matching lines @@
 }
 
 void AppListButton::SetDrawBackgroundAsActive(bool draw_background_as_active) {
   if (draw_background_as_active_ == draw_background_as_active)
     return;
   draw_background_as_active_ = draw_background_as_active;
   SchedulePaint();
 }
 
 }  // namespace ash