Makes the tray not paint a background if the launcher is painting a

background. I refactored the animation class to allow both launcher
and tray to share it.

BUG=118357
TEST=visual test, see bug.
R=sadrul@chromium.org

Review URL: https://chromiumcodereview.appspot.com/9820002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@128052 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 146 insertions, 46 deletions

diff --git a/ash/launcher/background_animator.cc b/ash/launcher/background_animator.cc
new file mode 100644
index 0000000..db1d8aa
--- /dev/null
+++ b/ash/launcher/background_animator.cc
@@ -0,0 +1,57 @@
+// 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/launcher/background_animator.h"
+
+
+namespace ash {
+namespace internal {
+
+namespace {
+
+// Duration of the background animation.
+const int kBackgroundDurationMS = 1000;
+
+}
+
+BackgroundAnimator::BackgroundAnimator(BackgroundAnimatorDelegate* delegate,
+                                       int min_alpha,
+                                       int max_alpha)
+    : delegate_(delegate),
+      min_alpha_(min_alpha),
+      max_alpha_(max_alpha),
+      ALLOW_THIS_IN_INITIALIZER_LIST(animation_(this)),
+      paints_background_(false),
+      alpha_(min_alpha) {
+  animation_.SetSlideDuration(kBackgroundDurationMS);
+}
+
+BackgroundAnimator::~BackgroundAnimator() {
+}
+
+void BackgroundAnimator::SetPaintsBackground(bool value, ChangeType type) {
+  if (paints_background_ == value)
+    return;
+  paints_background_ = value;
+  if (type == CHANGE_IMMEDIATE && !animation_.is_animating()) {
+    animation_.Reset(value ? 1.0f : 0.0f);
+    AnimationProgressed(&animation_);
+    return;
+  }
+  if (paints_background_)
+    animation_.Show();
+  else
+    animation_.Hide();
+}
+
+void BackgroundAnimator::AnimationProgressed(const ui::Animation* animation) {
+  int alpha = animation->CurrentValueBetween(min_alpha_, max_alpha_);
+  if (alpha_ == alpha)
+    return;
+  alpha_ = alpha;
+  delegate_->UpdateBackground(alpha_);
+}
+
+}  // namespace internal
+}  // namespace ash
diff --git a/ash/launcher/background_animator.h b/ash/launcher/background_animator.h
new file mode 100644
index 0000000..602c2aa
--- /dev/null
+++ b/ash/launcher/background_animator.h
@@ -0,0 +1,72 @@
+// 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.
+
+#ifndef ASH_LAUNCHER_BACKGROUND_ANIMATOR_H_
+#define ASH_LAUNCHER_BACKGROUND_ANIMATOR_H_
+#pragma once
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/base/animation/slide_animation.h"
+
+namespace ash {
+namespace internal {
+
+// Delegate is notified any time the background changes.
+class ASH_EXPORT BackgroundAnimatorDelegate {
+ public:
+  virtual void UpdateBackground(int alpha) = 0;
+
+ protected:
+  virtual ~BackgroundAnimatorDelegate() {}
+};
+
+// BackgroundAnimator is used by the launcher and system tray to animate the
+// background (alpha).
+class ASH_EXPORT BackgroundAnimator : public ui::AnimationDelegate {
+ public:
+  // How the background can be changed.
+  enum ChangeType {
+    CHANGE_ANIMATE,
+    CHANGE_IMMEDIATE
+  };
+
+  BackgroundAnimator(BackgroundAnimatorDelegate* delegate,
+                     int min_alpha,
+                     int max_alpha);
+  virtual ~BackgroundAnimator();
+
+  // Sets whether a background is rendered. Initial value is false. If |type|
+  // is |CHANGE_IMMEDIATE| and an animation is not in progress this notifies
+  // the delegate immediately (synchronously from this method).
+  void SetPaintsBackground(bool value, ChangeType type);
+
+  // Current alpha.
+  int alpha() const { return alpha_; }
+
+  // ui::AnimationDelegate overrides:
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+
+ private:
+  BackgroundAnimatorDelegate* delegate_;
+
+  const int min_alpha_;
+  const int max_alpha_;
+
+  ui::SlideAnimation animation_;
+
+  // Whether the background is painted.
+  bool paints_background_;
+
+  // Current alpha value of the background.
+  int alpha_;
+
+  DISALLOW_COPY_AND_ASSIGN(BackgroundAnimator);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_LAUNCHER_BACKGROUND_ANIMATOR_H_
diff --git a/ash/launcher/launcher.cc b/ash/launcher/launcher.cc
index 6264bc3..2094fc5 100644
--- a/ash/launcher/launcher.cc
+++ b/ash/launcher/launcher.cc
@@ -26,9 +26,6 @@ namespace ash {
 
 namespace {
 
-// Duration of the background animation.
-const int kBackgroundDurationMS = 1000;
-
 // Delay before showing the launcher after the mouse enters the view.
 const int kShowDelayMS = 300;
 
@@ -147,9 +144,8 @@ Launcher::Launcher(aura::Window* window_container)
       window_container_(window_container),
       delegate_view_(NULL),
       launcher_view_(NULL),
-      ALLOW_THIS_IN_INITIALIZER_LIST(background_animation_(this)),
-      renders_background_(false),
-      background_alpha_(0) {
+      ALLOW_THIS_IN_INITIALIZER_LIST(
+          background_animator_(this, 0, kBackgroundAlpha)) {
   model_.reset(new LauncherModel);
   if (Shell::GetInstance()->delegate()) {
     delegate_.reset(
@@ -179,7 +175,6 @@ Launcher::Launcher(aura::Window* window_container)
   widget_->SetContentsView(delegate_view_);
   widget_->Show();
   widget_->GetNativeView()->SetName("LauncherView");
-  background_animation_.SetSlideDuration(kBackgroundDurationMS);
 }
 
 Launcher::~Launcher() {
@@ -190,19 +185,10 @@ void Launcher::SetFocusCycler(internal::FocusCycler* focus_cycler) {
   focus_cycler->AddWidget(widget_.get());
 }
 
-void Launcher::SetRendersBackground(bool value, BackgroundChangeSpeed speed) {
-  if (renders_background_ == value)
-    return;
-  renders_background_ = value;
-  if (speed == CHANGE_IMMEDIATE && !background_animation_.is_animating()) {
-    background_animation_.Reset(value ? 1.0f : 0.0f);
-    AnimationProgressed(&background_animation_);
-    return;
-  }
-  if (renders_background_)
-    background_animation_.Show();
-  else
-    background_animation_.Hide();
+void Launcher::SetPaintsBackground(
+      bool value,
+      internal::BackgroundAnimator::ChangeType change_type) {
+  background_animator_.SetPaintsBackground(value, change_type);
 }
 
 void Launcher::SetStatusWidth(int width) {
@@ -235,11 +221,7 @@ internal::LauncherView* Launcher::GetLauncherViewForTest() {
       widget_->GetContentsView()->child_at(0));
 }
 
-void Launcher::AnimationProgressed(const ui::Animation* animation) {
-  int alpha = animation->CurrentValueBetween(0, kBackgroundAlpha);
-  if (background_alpha_ == alpha)
-    return;
-  background_alpha_ = alpha;
+void Launcher::UpdateBackground(int alpha) {
   if (alpha == 0) {
     delegate_view_->set_background(NULL);
   } else {
diff --git a/ash/launcher/launcher.h b/ash/launcher/launcher.h
index 1c5dad6..12a1790 100644
--- a/ash/launcher/launcher.h
+++ b/ash/launcher/launcher.h
@@ -6,11 +6,10 @@
 #define ASH_LAUNCHER_LAUNCHER_H_
 #pragma once
 
+#include "ash/launcher/background_animator.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "ash/ash_export.h"
-#include "ui/base/animation/animation_delegate.h"
-#include "ui/base/animation/slide_animation.h"
 
 namespace aura {
 class Window;
@@ -34,23 +33,19 @@ class LauncherView;
 class LauncherDelegate;
 class LauncherModel;
 
-class ASH_EXPORT Launcher : public ui::AnimationDelegate {
+class ASH_EXPORT Launcher : public internal::BackgroundAnimatorDelegate {
  public:
-  // How the background can be changed.
-  enum BackgroundChangeSpeed {
-    CHANGE_ANIMATE,
-    CHANGE_IMMEDIATE
-  };
-
   explicit Launcher(aura::Window* window_container);
   virtual ~Launcher();
 
   // Sets the focus cycler.  Also adds the launcher to the cycle.
   void SetFocusCycler(internal::FocusCycler* focus_cycler);
 
-  // Sets whether the launcher renders a background. Default is false, but is
-  // set to true if a window overlaps the shelf.
-  void SetRendersBackground(bool value, BackgroundChangeSpeed speed);
+  // Sets whether the launcher paints a background. Default is false, but is set
+  // to true if a window overlaps the shelf.
+  void SetPaintsBackground(
+      bool value,
+      internal::BackgroundAnimator::ChangeType change_type);
 
   // Sets the width of the status area.
   void SetStatusWidth(int width);
@@ -69,8 +64,8 @@ class ASH_EXPORT Launcher : public ui::AnimationDelegate {
 
   aura::Window* window_container() { return window_container_; }
 
-  // ui::AnimationDelegate overrides:
-  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+  // BackgroundAnimatorDelegate overrides:
+  virtual void UpdateBackground(int alpha) OVERRIDE;
 
  private:
   class DelegateView;
@@ -91,13 +86,7 @@ class ASH_EXPORT Launcher : public ui::AnimationDelegate {
   scoped_ptr<LauncherDelegate> delegate_;
 
   // Used to animate the background.
-  ui::SlideAnimation background_animation_;
-
-  // Whether we render a background.
-  bool renders_background_;
-
-  // Current alpha value of the background.
-  int background_alpha_;
+  internal::BackgroundAnimator background_animator_;
 
   DISALLOW_COPY_AND_ASSIGN(Launcher);
 };