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 ui

[dhollowa, 2012/06/26 18:16:27]

nit: Typically the trailing "// namespace ui" is omitted for forward
declarations.

[kuan, 2012/06/26 23:25:49]

Done.

+
+namespace chrome {
+namespace search {
+
+class SearchModel;
+class ToolbarSearchAnimatorObserver;
+
+// Animate fade in of new background.

[sky, 2012/06/26 17:11:27]

Remove this sentence. Also, how about a description something like:
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.

[kuan, 2012/06/26 23:25:49]

Done.

+// This class is used in Search Integration, where backgrounds of toolbar and
+// tab change 100ms after search model mode changes from NTP to SEARCH.
+// This class runs the animation sequence and fires notification to
+// |ToolbarSearchAnimatorObserver|s on every tick as the animation progresses.
+class ToolbarSearchAnimator : public SearchModelObserver,
+                              public ui::AnimationDelegate {
+ public:
+  // State of background to paint by observers, only applicable when mode is
+  // SEARCH.
+  enum BackgroundState {
+    // Background state is not applicable.
+    BACKGROUND_STATE_SHOW_NON_APPLICABLE = 0,

[sky, 2012/06/26 17:11:27]

Should this be BACKGROUND_STATE_SHOW_DEFAULT? Also, why the show in all of
these, eg BACKGROUND_STATE_DEFAULT, BACKGROUND_STATE_NTP are just as descriptive
and shorter:)

[kuan, 2012/06/26 23:25:49]

Done.

+    // Show background for NTP mode.
+    BACKGROUND_STATE_SHOW_NTP = 0x01,
+    // Show background for SEARCH mode.
+    BACKGROUND_STATE_SHOW_SEARCH = 0x02,
+    // Show backgrounds for both NTP and SEARCH modes.
+    BACKGROUND_STATE_SHOW_NTP_SEARCH = BACKGROUND_STATE_SHOW_NTP |
+                                       BACKGROUND_STATE_SHOW_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

[sky, 2012/06/26 17:11:27]

Should the opacity always be 1 when not default?

[kuan, 2012/06/26 23:25:49]

the opacity is for the new background, so it shouldn't be 1 when background
state is not DEFAULT until the last animation iteration - this value wld be 0-1
as the animation progresses.

+  // background needs to be shown i.e. |background_state| is
+  // BACKGROUND_STATE_SHOW_NEW or BACKGROUND_STATE_SHOW_BOTH.

[sky, 2012/06/26 17:11:27]

This comment isn't right, it can also by NON_APPLICABLE.

[kuan, 2012/06/26 23:25:49]

Done.  i assume u mean the names of the states are wrong, which i corrected.

+  // Note "background animation not running" doesn't mean we're not waiting to
+  // run the background animation.  Because background animation runs after a
+  // delay of 100ms, IsWaitingToAnimate provides state about "waiting to run"
+  // and hence should be called before this method - DCHECK happens if this
+  // method is called when waiting to run background animation.
+  void GetCurrentBackgroundState(BackgroundState* background_state,
+                                 int* new_background_opacity) const;

[sky, 2012/06/26 17:11:27]

I think it makes more sense to have opacity from 0-1 rather than 0-255.

[kuan, 2012/06/26 23:25:49]

Done.

+
+  // Called from SearchDelegate::StopObservingTab when a tab is deactivated or

[sky, 2012/06/26 17:11:27]

nit: use () after method in comments.

[kuan, 2012/06/26 23:25:49]

Done.

+  // 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);
+
+  // Caches the search model from browser.

[dhollowa, 2012/06/26 18:16:27]

// Weak.  Owned by Browser.  Non-null.

[kuan, 2012/06/26 23:25:49]

Done.

+  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 NTP to

[dhollowa, 2012/06/26 18:16:27]

...from |MODE_NTP| to |MODE_SEARCH|.

[kuan, 2012/06/26 23:25:49]

Done.  also changed for all comments in this file.

+  // 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_