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

chrome/browser/ui/search/toolbar_search_animator.cc

+// 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 "chrome/browser/ui/search/toolbar_search_animator.h"
+
+#include "chrome/browser/ui/search/search_model.h"
+#include "chrome/browser/ui/search/search_types.h"
+#include "chrome/browser/ui/search/toolbar_search_animator_observer.h"
+#include "chrome/browser/ui/tab_contents/tab_contents.h"
+#include "ui/base/animation/slide_animation.h"
+
+namespace {
+
+const int kBackgroundChangeDelayMs = 100;
+const int kBackgroundChangeDurationMs = 200;
+
+const double kMinOpacity = 0.0f;
+const double kMaxOpacity = 1.0f;
+
+}  // namespace
+
+namespace chrome {
+namespace search {
+
+ToolbarSearchAnimator::ToolbarSearchAnimator(SearchModel* search_model)
+    : search_model_(search_model),
+      animate_state_(ANIMATE_STATE_NONE) {
+  search_model_->AddObserver(this);
+}
+
+ToolbarSearchAnimator::~ToolbarSearchAnimator() {
+  search_model_->RemoveObserver(this);
+}
+
+void ToolbarSearchAnimator::GetCurrentBackgroundState(
+    BackgroundState* background_state,
+    double* search_background_opacity) const {
+  // Should only be called for SEARCH mode.
+  DCHECK(search_model_->mode().is_search());
+  *background_state = BACKGROUND_STATE_DEFAULT;
+  *search_background_opacity = -1.0f;
+  switch (animate_state_) {
+    case ANIMATE_STATE_WAITING:
+      *background_state = BACKGROUND_STATE_NTP;
+      break;
+    case ANIMATE_STATE_RUNNING:
+      *background_state = BACKGROUND_STATE_NTP_SEARCH;
+      *search_background_opacity = background_animation_->CurrentValueBetween(
+          kMinOpacity, kMaxOpacity);
+      break;
+    case ANIMATE_STATE_NONE:
+      break;
+  }
+}
+
+void ToolbarSearchAnimator::FinishAnimation(TabContents* tab_contents) {
+  Reset(tab_contents);
+}
+
+void ToolbarSearchAnimator::AddObserver(
+    ToolbarSearchAnimatorObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ToolbarSearchAnimator::RemoveObserver(
+    ToolbarSearchAnimatorObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void ToolbarSearchAnimator::ModeChanged(const Mode& mode) {
+  if (mode.is_search() && mode.animate &&
+      animate_state_ == ANIMATE_STATE_NONE) {
+    background_change_timer_.Start(
+        FROM_HERE,
+        base::TimeDelta::FromMilliseconds(kBackgroundChangeDelayMs),
+        this,
+        &ToolbarSearchAnimator::StartBackgroundChange);
+    animate_state_ = ANIMATE_STATE_WAITING;
+    return;
+  }
+  // For all other cases, reset |animate_state_| and stop timer or animation.
+  // Stopping animation will jump to the end of it.
+  Reset(NULL);
+}
+
+void ToolbarSearchAnimator::AnimationProgressed(
+    const ui::Animation* animation) {
+  DCHECK_EQ(animation, background_animation_.get());
+  animate_state_ = ANIMATE_STATE_RUNNING;
+  FOR_EACH_OBSERVER(ToolbarSearchAnimatorObserver, observers_,
+                    OnToolbarBackgroundAnimatorProgressed());
+}
+
+void ToolbarSearchAnimator::AnimationEnded(const ui::Animation* animation) {
+  DCHECK_EQ(animation, background_animation_.get());
+  // Only notify observers via OnToolbarBackgroundAnimatorProgressed if the
+  // animation has runs its full course i.e |animate_state_| is still
+  // ANIMATE_STATE_RUNNING.
+  // Animation that is canceled, i.e. |animate_state_| has been set to
+  // ANIMATE_STATE_NONE in Reset, should notify observers via
+  // OnToolbarBackgroundAnimatorCanceled.
+  if (animate_state_ == ANIMATE_STATE_RUNNING) {
+    animate_state_ = ANIMATE_STATE_NONE;
+    FOR_EACH_OBSERVER(ToolbarSearchAnimatorObserver, observers_,
+                      OnToolbarBackgroundAnimatorProgressed());
+  }
+}
+
+void ToolbarSearchAnimator::StartBackgroundChange() {
+  if (!background_animation_.get()) {
+    background_animation_.reset(new ui::SlideAnimation(this));
+    background_animation_->SetTweenType(ui::Tween::LINEAR);
+    background_animation_->SetSlideDuration(kBackgroundChangeDurationMs);
+  }
+  background_animation_->Reset(0.0);
+  background_animation_->Show();
+}
+
+void ToolbarSearchAnimator::Reset(TabContents* tab_contents) {
+  bool notify_observers = animate_state_ != ANIMATE_STATE_NONE;
+  animate_state_ = ANIMATE_STATE_NONE;
+  background_change_timer_.Stop();
+  // If animation is still running, stopping it will trigger AnimationEnded
+  // where we've prevented from notifying observers via BackgroundChanged;
+  // see comments in AnimationEnded.
+  if (background_animation_.get())
+    background_animation_->Stop();
+  if (notify_observers) {
+    FOR_EACH_OBSERVER(ToolbarSearchAnimatorObserver, observers_,
+                      OnToolbarBackgroundAnimatorCanceled(tab_contents));
+  }
+}
+
+}  // namespace search
+}  // namespace chrome