ash: Extract animator from PowerButtonController

ash/wm/session_state_animator.h

Index: ash/wm/session_state_animator.h
diff --git a/ash/wm/session_state_animator.h b/ash/wm/session_state_animator.h
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index 0000000000000000000000000000000000000000..894875c5737bf8d4484ee550ca2f0eff12394f47
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+++ b/ash/wm/session_state_animator.h
@@ -0,0 +1,125 @@
+// 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_WM_SESSION_STATE_ANIMATOR_H_
+#define ASH_WM_SESSION_STATE_ANIMATOR_H_
+
+#include "ash/ash_export.h"
+#include "ash/shell_observer.h"
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time.h"
+#include "base/timer.h"
+#include "ui/aura/root_window_observer.h"
+#include "ui/aura/window.h"
+
+namespace gfx {
+class Rect;
+class Size;
+}
+
+namespace ui {
+class Layer;
+}
+
+namespace ash {
+
+// Animations that can be applied to groups of containers.
+// Exposed here for TestApi::ContainerGroupIsAnimated().
+enum SessionStateAnimationType {
+  ANIMATION_SLOW_CLOSE = 0,
+  ANIMATION_UNDO_SLOW_CLOSE,
+  ANIMATION_FAST_CLOSE,
+  ANIMATION_FADE_IN,
+  ANIMATION_HIDE,
+  ANIMATION_RESTORE,
+};
+
+
+// Groups of containers that can be animated.
+// Exposed here for TestApi::ContainerGroupIsAnimated().
+enum AnimationContainerGroup {

[Daniel Erat, 2012/08/30 18:05:24]

This is too generally-named to go in the toplevel ash namespace.  Can these
enums be moved inside of SessionStateAnimator, or do lines wrap when you do
that?

[Denis Kuznetsov (DE-MUC), 2012/08/30 18:17:48]

Yes, they seem to be too long.
Would StateAnimationContainerGroup be a good replacement?

[Daniel Erat, 2012/08/30 18:28:17]

I think that it's really best to keep these enums within the class.  Maybe the
enum names can be shortened.

[Daniel Erat, 2012/08/30 21:10:10]

Alternately, I'd be fine moving the enums inside the class and keeping the
longer names but adding "using" directives in power_button_controller.cc so you
don't need to specify the class name over and over there.  My main concern is
not seeing generic names creep into the ash namespace in headers, which then get
included by other headers, and so on.

[Denis Kuznetsov (DE-MUC), 2012/08/31 16:02:37]

Done.

+  ALL_CONTAINERS = 0,
+  SCREEN_LOCKER_CONTAINERS,
+  SCREEN_LOCKER_AND_RELATED_CONTAINERS,
+  ALL_BUT_SCREEN_LOCKER_AND_RELATED_CONTAINERS,
+};
+
+// Displays onscreen animations for session state changes (lock/unlock,sign out,
+// shut down).
+class ASH_EXPORT SessionStateAnimator : public aura::RootWindowObserver {
+ public:
+
+
+  // Helper class used by tests to access internal state.
+  class ASH_EXPORT TestApi {
+   public:
+    explicit TestApi(SessionStateAnimator* animator)
+        : animator_(animator) {}
+
+    bool hide_background_layer_timer_is_running() const {
+      return animator_->hide_background_layer_timer_.IsRunning();
+    }
+
+    void trigger_hide_background_layer_timeout() {
+      animator_->HideBackgroundLayer();
+      animator_->hide_background_layer_timer_.Stop();
+    }
+
+
+    bool ContainerGroupIsAnimated(AnimationContainerGroup group,
+                                  SessionStateAnimationType type) const;
+
+    // Returns true if |background_layer_| is non-NULL and visible.
+    bool BackgroundLayerIsVisible() const;
+
+    // Returns |background_layer_|'s bounds, or an empty rect if the layer is
+    // NULL.
+    gfx::Rect GetBackgroundLayerBounds() const;
+
+   private:
+    SessionStateAnimator* animator_;  // not owned
+
+    DISALLOW_COPY_AND_ASSIGN(TestApi);
+  };
+
+  SessionStateAnimator();
+  virtual ~SessionStateAnimator();
+
+  // aura::RootWindowObserver overrides:
+  virtual void OnRootWindowResized(const aura::RootWindow* root,
+                                   const gfx::Size& old_size) OVERRIDE;
+  // Shows or hides |background_layer_|.  The show method creates and
+  // initializes the layer if it doesn't already exist.
+  void ShowBackgroundLayer();
+  void HideBackgroundLayer();
+  void DropBackgroundLayer();
+
+  // Apply animation |type| to all containers described by |group|.
+  void StartAnimation(AnimationContainerGroup group,
+                      SessionStateAnimationType type);
+  // Fills |containers| with the containers described by |group|.
+  void GetContainers(AnimationContainerGroup group,
+                     aura::Window::Windows* containers);
+ private:
+
+
+  // Layer that's stacked under all of the root window's children to provide a
+  // black background when we're scaling all of the other windows down.
+  // TODO(derat): Remove this in favor of having the compositor only clear the
+  // viewport when there are regions not covered by a layer:
+  // http://crbug.com/113445
+  scoped_ptr<ui::Layer> background_layer_;
+
+  // Started when we abort the pre-lock state.  When it fires, we hide
+  // |background_layer_|, as the desktop background is now covering the whole
+  // screen.
+  base::OneShotTimer<SessionStateAnimator> hide_background_layer_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SessionStateAnimator);
+};
+
+}  // namespace ash
+
+#endif  // ASH_WM_SESSION_STATE_ANIMATOR_H_