alternate ntp (cros/partial-win): add tab-related stuff and toolbar/tab background change

chrome/browser/ui/search/toolbar_search_animator.h

+// 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 CHROME_BROWSER_UI_SEARCH_TOOLBAR_SEARCH_ANIMATOR_H_
+#define CHROME_BROWSER_UI_SEARCH_TOOLBAR_SEARCH_ANIMATOR_H_
+#pragma once
+
+#include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
+#include "base/timer.h"
+#include "chrome/browser/ui/search/search_model_observer.h"
+#include "ui/base/animation/animation_delegate.h"
+
+class TabContents;
+
+namespace ui {
+class SlideAnimation;
+}
+
+namespace chrome {
+namespace search {
+
+class SearchModel;
+class ToolbarSearchAnimatorObserver;
+
+// ToolbarSearchAnimator is used to track the background state of the toolbar
+// and related classes.  To use ToolbarSearchAnimator, add a
+// ToolbarSearchAnimatorObserver.  The ToolbarSearchAnimatorObserver is then
+// notified appropriately.
+class ToolbarSearchAnimator : public SearchModelObserver,
+                              public ui::AnimationDelegate {
+ public:
+  // State of background to paint by observers, only applicable for
+  // |MODE_SEARCH|.
+  enum BackgroundState {
+    // Background state is not applicable.
+    BACKGROUND_STATE_DEFAULT = 0,
+    // Show background for |MODE_NTP|.
+    BACKGROUND_STATE_NTP = 0x01,
+    // Show background for |MODE_SEARCH|.
+    BACKGROUND_STATE_SEARCH = 0x02,
+    // Show backgrounds for both |MODE_NTP| and |MODE_SEARCH|.
+    BACKGROUND_STATE_NTP_SEARCH = BACKGROUND_STATE_NTP |
+                                  BACKGROUND_STATE_SEARCH,
+  };
+
+  explicit ToolbarSearchAnimator(SearchModel* search_model);
+  virtual ~ToolbarSearchAnimator();
+
+  // Get the current background state to paint.
+  // |new_background_opacity| contains a valid opacity value only if new
+  // background needs to be shown i.e. |background_state| is
+  // BACKGROUND_STATE_SEARCH or BACKGROUND_STATE_NTP_SEARCH.
+  // Only call this for |MODE_SEARCH|.
+  void GetCurrentBackgroundState(BackgroundState* background_state,
+                                 double* new_background_opacity) const;
+
+  // Called from SearchDelegate::StopObservingTab() when a tab is deactivated or
+  // closing or detached, to jump to the end state of the animation.
+  // This allows a reactivated tab to show the end state of the animation,
+  // rather than the transient state.
+  void FinishAnimation(TabContents* tab_contents);
+
+  // Add and remove observers.
+  void AddObserver(ToolbarSearchAnimatorObserver* observer);
+  void RemoveObserver(ToolbarSearchAnimatorObserver* observer);
+
+  // Overridden from SearchModelObserver:
+  virtual void ModeChanged(const Mode& mode) OVERRIDE;
+
+  // Overridden from ui::AnimationDelegate:
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+  virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;
+
+ private:
+  // State of animation.
+  enum AnimateState {
+    ANIMATE_STATE_NONE,     // Doing nothing.
+    ANIMATE_STATE_WAITING,  // Waiting to run background animation.
+    ANIMATE_STATE_RUNNING,  // Running background animation.
+  };
+
+  // Callback for |background_change_timer_| to actually start the background
+  // change animation.
+  void StartBackgroundChange();
+
+  // Reset state of animator: reset animate_state_, stop timer or animation,
+  // Set |notify_observers| to true to notify observers via
+  // ToolbarSearchAnimatorObserver::BackgroundChangeCanceled.
+  // Pass in |tab_contents| if animation is canceled because of deactivating or
+  // detaching or closing a tab.
+  void Reset(bool notify_observers, TabContents* tab_contents);
+
+  // Weak.  Owned by Browser.  Non-NULL.
+  SearchModel* search_model_;
+
+  // State of animation.
+  AnimateState animate_state_;
+
+  // The background fade animation.
+  scoped_ptr<ui::SlideAnimation> background_animation_;
+
+  // The timer to delay start of animation after mode changes from |MODE_NTP| to
+  // |MODE_SEARCH|.
+  base::OneShotTimer<ToolbarSearchAnimator> background_change_timer_;
+
+  // Observers.
+  ObserverList<ToolbarSearchAnimatorObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ToolbarSearchAnimator);
+};
+
+}  // namespace chrome
+}  // namespace search
+
+#endif  // CHROME_BROWSER_UI_SEARCH_TOOLBAR_SEARCH_ANIMATOR_H_