Refactor GestureNavigation to eliminate code redundancy

content/browser/web_contents/aura/window_slider.cc

Index: content/browser/web_contents/aura/window_slider.cc
diff --git a/content/browser/web_contents/aura/window_slider.cc b/content/browser/web_contents/aura/window_slider.cc
deleted file mode 100644
index f7ffa7e38392c0607513efa7219946bd47d34ba5..0000000000000000000000000000000000000000
--- a/content/browser/web_contents/aura/window_slider.cc
+++ /dev/null
@@ -1,309 +0,0 @@
-// Copyright (c) 2013 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 "content/browser/web_contents/aura/window_slider.h"
-
-#include <algorithm>
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "content/browser/web_contents/aura/shadow_layer_delegate.h"
-#include "content/public/browser/overscroll_configuration.h"
-#include "ui/aura/window.h"
-#include "ui/compositor/layer_animation_observer.h"
-#include "ui/compositor/scoped_layer_animation_settings.h"
-#include "ui/events/event.h"
-
-namespace content {
-
-namespace {
-
-// An animation observer that runs a callback at the end of the animation, and
-// destroys itself.
-class CallbackAnimationObserver : public ui::ImplicitAnimationObserver {
- public:
-  CallbackAnimationObserver(const base::Closure& closure)
-      : closure_(closure) {
-  }
-
-  ~CallbackAnimationObserver() override {}
-
- private:
-  // Overridden from ui::ImplicitAnimationObserver:
-  void OnImplicitAnimationsCompleted() override {
-    if (!closure_.is_null())
-      closure_.Run();
-    base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
-  }
-
-  const base::Closure closure_;
-
-  DISALLOW_COPY_AND_ASSIGN(CallbackAnimationObserver);
-};
-
-}  // namespace
-
-WindowSlider::WindowSlider(Delegate* delegate,
-                           aura::Window* event_window,
-                           aura::Window* owner)
-    : delegate_(delegate),
-      event_window_(event_window),
-      owner_(owner),
-      active_animator_(NULL),
-      delta_x_(0.f),
-      active_start_threshold_(0.f),
-      start_threshold_touchscreen_(content::GetOverscrollConfig(
-          content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHSCREEN)),
-      start_threshold_touchpad_(content::GetOverscrollConfig(
-          content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHPAD)),
-      complete_threshold_(content::GetOverscrollConfig(
-          content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_COMPLETE)),
-      weak_factory_(this) {
-  event_window_->AddPreTargetHandler(this);
-
-  event_window_->AddObserver(this);
-  owner_->AddObserver(this);
-}
-
-WindowSlider::~WindowSlider() {
-  if (event_window_) {
-    event_window_->RemovePreTargetHandler(this);
-    event_window_->RemoveObserver(this);
-  }
-  if (owner_)
-    owner_->RemoveObserver(this);
-  delegate_->OnWindowSliderDestroyed();
-}
-
-void WindowSlider::ChangeOwner(aura::Window* new_owner) {
-  if (owner_)
-    owner_->RemoveObserver(this);
-  owner_ = new_owner;
-  if (owner_) {
-    owner_->AddObserver(this);
-    UpdateForScroll(0.f, 0.f);
-  }
-}
-
-bool WindowSlider::IsSlideInProgress() const {
-  // if active_start_threshold_ is 0, it means that sliding hasn't been started
-  return active_start_threshold_ != 0 && (slider_.get() || active_animator_);
-}
-
-void WindowSlider::SetupSliderLayer() {
-  ui::Layer* parent = owner_->layer()->parent();
-  parent->Add(slider_.get());
-  if (delta_x_ < 0)
-    parent->StackAbove(slider_.get(), owner_->layer());
-  else
-    parent->StackBelow(slider_.get(), owner_->layer());
-  slider_->SetBounds(owner_->layer()->bounds());
-  slider_->SetVisible(true);
-}
-
-void WindowSlider::UpdateForScroll(float x_offset, float y_offset) {
-  if (active_animator_) {
-    // If there is an active animation, complete it before processing the scroll
-    // so that the callbacks that are invoked on the Delegate are consistent.
-    // Completing the animation may destroy WindowSlider through the animation
-    // callback, so we can't continue processing the scroll event here.
-    delta_x_ += x_offset;
-    CompleteActiveAnimations();
-    return;
-  }
-
-  float old_delta = delta_x_;
-  delta_x_ += x_offset;
-  if (fabs(delta_x_) < active_start_threshold_ && !slider_.get())
-    return;
-
-  if ((old_delta < 0 && delta_x_ > 0) ||
-      (old_delta > 0 && delta_x_ < 0)) {
-    slider_.reset();
-    shadow_.reset();
-  }
-
-  float translate = 0.f;
-  ui::Layer* translate_layer = NULL;
-
-  if (!slider_.get()) {
-    slider_.reset(delta_x_ < 0 ? delegate_->CreateFrontLayer() :
-                                 delegate_->CreateBackLayer());
-    if (!slider_.get())
-      return;
-    SetupSliderLayer();
-  }
-
-  if (delta_x_ <= -active_start_threshold_) {
-    translate = owner_->bounds().width() +
-        std::max(delta_x_ + active_start_threshold_,
-                 static_cast<float>(-owner_->bounds().width()));
-    translate_layer = slider_.get();
-  } else if (delta_x_ >= active_start_threshold_) {
-    translate = std::min(delta_x_ - active_start_threshold_,
-                         static_cast<float>(owner_->bounds().width()));
-    translate_layer = owner_->layer();
-  } else {
-    return;
-  }
-
-  if (!shadow_.get())
-    shadow_.reset(new ShadowLayerDelegate(translate_layer));
-
-  gfx::Transform transform;
-  transform.Translate(translate, 0);
-  translate_layer->SetTransform(transform);
-}
-
-void WindowSlider::CompleteOrResetSlide() {
-  if (!slider_.get())
-    return;
-
-  int width = owner_->bounds().width();
-  float ratio = (fabs(delta_x_) - active_start_threshold_) / width;
-  if (ratio < complete_threshold_) {
-    ResetSlide();
-    return;
-  }
-
-  ui::Layer* sliding = delta_x_ < 0 ? slider_.get() : owner_->layer();
-  active_animator_ = sliding->GetAnimator();
-
-  ui::ScopedLayerAnimationSettings settings(active_animator_);
-  settings.SetPreemptionStrategy(
-      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-  settings.SetTweenType(gfx::Tween::EASE_OUT);
-  settings.AddObserver(new CallbackAnimationObserver(
-      base::Bind(&WindowSlider::SlideAnimationCompleted,
-                 weak_factory_.GetWeakPtr(),
-                 base::Passed(&slider_),
-                 base::Passed(&shadow_))));
-
-  gfx::Transform transform;
-  transform.Translate(delta_x_ < 0 ? 0 : width, 0);
-  delta_x_ = 0;
-  delegate_->OnWindowSlideCompleting();
-  sliding->SetTransform(transform);
-}
-
-void WindowSlider::CompleteActiveAnimations() {
-  if (active_animator_)
-    active_animator_->StopAnimating();
-}
-
-void WindowSlider::ResetSlide() {
-  if (!slider_.get())
-    return;
-
-  // Reset the state of the sliding layer.
-  if (slider_.get()) {
-    ui::Layer* translate_layer;
-    gfx::Transform transform;
-    if (delta_x_ < 0) {
-      translate_layer = slider_.get();
-      transform.Translate(translate_layer->bounds().width(), 0);
-    } else {
-      translate_layer = owner_->layer();
-    }
-
-    active_animator_ = translate_layer->GetAnimator();
-    ui::ScopedLayerAnimationSettings settings(active_animator_);
-    settings.SetPreemptionStrategy(
-        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-    settings.SetTweenType(gfx::Tween::EASE_OUT);
-    settings.AddObserver(new CallbackAnimationObserver(
-        base::Bind(&WindowSlider::ResetSlideAnimationCompleted,
-                   weak_factory_.GetWeakPtr(),
-                   base::Passed(&slider_),
-                   base::Passed(&shadow_))));
-    translate_layer->SetTransform(transform);
-  }
-
-  delta_x_ = 0.f;
-}
-
-void WindowSlider::SlideAnimationCompleted(
-    scoped_ptr<ui::Layer> layer, scoped_ptr<ShadowLayerDelegate> shadow) {
-  active_animator_ = NULL;
-  shadow.reset();
-  delegate_->OnWindowSlideCompleted(layer.Pass());
-}
-
-void WindowSlider::ResetSlideAnimationCompleted(
-    scoped_ptr<ui::Layer> layer, scoped_ptr<ShadowLayerDelegate> shadow) {
-  active_animator_ = NULL;
-  shadow.reset();
-  layer.reset();
-  delegate_->OnWindowSlideAborted();
-}
-
-void WindowSlider::OnKeyEvent(ui::KeyEvent* event) {
-  ResetSlide();
-}
-
-void WindowSlider::OnMouseEvent(ui::MouseEvent* event) {
-  if (!(event->flags() & ui::EF_IS_SYNTHESIZED))
-    ResetSlide();
-}
-
-void WindowSlider::OnScrollEvent(ui::ScrollEvent* event) {
-  active_start_threshold_ = start_threshold_touchpad_;
-  if (event->type() == ui::ET_SCROLL)
-    UpdateForScroll(event->x_offset_ordinal(), event->y_offset_ordinal());
-  else if (event->type() == ui::ET_SCROLL_FLING_START)
-    CompleteOrResetSlide();
-  else
-    ResetSlide();
-  event->SetHandled();
-}
-
-void WindowSlider::OnGestureEvent(ui::GestureEvent* event) {
-  active_start_threshold_ = start_threshold_touchscreen_;
-  const ui::GestureEventDetails& details = event->details();
-  switch (event->type()) {
-    case ui::ET_GESTURE_SCROLL_BEGIN:
-      CompleteActiveAnimations();
-      break;
-
-    case ui::ET_GESTURE_SCROLL_UPDATE:
-      UpdateForScroll(details.scroll_x(), details.scroll_y());
-      break;
-
-    case ui::ET_GESTURE_SCROLL_END:
-      CompleteOrResetSlide();
-      break;
-
-    case ui::ET_SCROLL_FLING_START:
-      CompleteOrResetSlide();
-      break;
-
-    case ui::ET_GESTURE_PINCH_BEGIN:
-    case ui::ET_GESTURE_PINCH_UPDATE:
-    case ui::ET_GESTURE_PINCH_END:
-      ResetSlide();
-      break;
-
-    default:
-      break;
-  }
-
-  event->SetHandled();
-}
-
-void WindowSlider::OnWindowRemovingFromRootWindow(aura::Window* window,
-                                                  aura::Window* new_root) {
-  if (window == event_window_) {
-    window->RemoveObserver(this);
-    window->RemovePreTargetHandler(this);
-    event_window_ = NULL;
-  } else if (window == owner_) {
-    window->RemoveObserver(this);
-    owner_ = NULL;
-    delete this;
-  } else {
-    NOTREACHED();
-  }
-}
-
-}  // namespace content