[Android] Use the platform SwipeRefreshLayout

content/browser/android/overscroll_refresh.cc

Index: content/browser/android/overscroll_refresh.cc
diff --git a/content/browser/android/overscroll_refresh.cc b/content/browser/android/overscroll_refresh.cc
index 58962f6356ecfbe02fcd43984416ae843daffaca..c2a1453bc1750eea5e49f337c65f9601f7fe1667 100644
--- a/content/browser/android/overscroll_refresh.cc
+++ b/content/browser/android/overscroll_refresh.cc
@@ -4,418 +4,23 @@
 
 #include "content/browser/android/overscroll_refresh.h"
 
-#include "cc/animation/timing_function.h"
-#include "cc/layers/ui_resource_layer.h"
-#include "cc/trees/layer_tree_host.h"
-#include "content/browser/android/animation_utils.h"
-#include "ui/android/resources/resource_manager.h"
-#include "ui/android/resources/system_ui_resource_type.h"
-#include "ui/gfx/geometry/size_conversions.h"
-
-using std::abs;
-using std::max;
-using std::min;
+#include "base/logging.h"
 
 namespace content {
 namespace {
 
-const ui::SystemUIResourceType kIdleResourceId = ui::OVERSCROLL_REFRESH_IDLE;
-const ui::SystemUIResourceType kActiveResourceId =
-    ui::OVERSCROLL_REFRESH_ACTIVE;
-
-// Drag movement multiplier between user input and effect translation.
-const float kDragRate = .5f;
-
-// Animation duration after the effect is released without triggering a refresh.
-const int kRecedeTimeMs = 300;
-
-// Animation duration immediately after the effect is released and activated.
-const int kActivationStartTimeMs = 150;
-
-// Animation duration after the effect is released and triggers a refresh.
-const int kActivationTimeMs = 850;
-
-// Max animation duration after the effect is released and triggers a refresh.
-const int kMaxActivationTimeMs = kActivationTimeMs * 4;
-
-// Animation duration after the refresh activated phase has completed.
-const int kActivationRecedeTimeMs = 250;
-
-// Input threshold required to start glowing.
-const float kGlowActivationThreshold = 0.85f;
-
-// Minimum alpha for the effect layer.
-const float kMinAlpha = 0.3f;
-
 // Experimentally determined constant used to allow activation even if touch
 // release results in a small upward fling (quite common during a slow scroll).
 const float kMinFlingVelocityForActivation = -500.f;
 
-const float kEpsilon = 0.005f;
-
-void UpdateLayer(cc::UIResourceLayer* layer,
-                 cc::Layer* parent,
-                 cc::UIResourceId res_id,
-                 const gfx::Size& size,
-                 const gfx::Vector2dF& offset,
-                 float opacity,
-                 float rotation,
-                 bool mirror) {
-  DCHECK(layer);
-  DCHECK(parent);
-  DCHECK(parent->layer_tree_host());
-  if (layer->parent() != parent)
-    parent->AddChild(layer);
-
-  if (size.IsEmpty()) {
-    layer->SetIsDrawable(false);
-    return;
-  }
-
-  if (!res_id) {
-    layer->SetIsDrawable(false);
-    return;
-  }
-
-  if (opacity == 0) {
-    layer->SetIsDrawable(false);
-    layer->SetOpacity(0);
-    return;
-  }
-
-  layer->SetUIResourceId(res_id);
-  layer->SetIsDrawable(true);
-  layer->SetTransformOrigin(
-      gfx::Point3F(size.width() * 0.5f, size.height() * 0.5f, 0));
-  layer->SetBounds(size);
-  layer->SetContentsOpaque(false);
-  layer->SetOpacity(Clamp(opacity, 0.f, 1.f));
-
-  float offset_x = offset.x() - size.width() * 0.5f;
-  float offset_y = offset.y() - size.height() * 0.5f;
-  gfx::Transform transform;
-  transform.Translate(offset_x, offset_y);
-  if (mirror)
-    transform.Scale(-1.f, 1.f);
-  transform.Rotate(rotation);
-  layer->SetTransform(transform);
-}
-
 }  // namespace
 
-class OverscrollRefresh::Effect {
- public:
-  Effect(ui::ResourceManager* resource_manager, float target_drag, bool mirror)
-      : resource_manager_(resource_manager),
-        idle_layer_(cc::UIResourceLayer::Create()),
-        active_layer_(cc::UIResourceLayer::Create()),
-        target_drag_(target_drag),
-        mirror_(mirror),
-        drag_(0),
-        idle_alpha_(0),
-        active_alpha_(0),
-        offset_(0),
-        rotation_(0),
-        size_scale_(1),
-        idle_alpha_start_(0),
-        idle_alpha_finish_(0),
-        active_alpha_start_(0),
-        active_alpha_finish_(0),
-        offset_start_(0),
-        offset_finish_(0),
-        rotation_start_(0),
-        rotation_finish_(0),
-        size_scale_start_(1),
-        size_scale_finish_(1),
-        state_(STATE_IDLE),
-        ease_out_(cc::EaseOutTimingFunction::Create()),
-        ease_in_out_(cc::EaseInOutTimingFunction::Create()) {
-    DCHECK(target_drag_);
-    idle_layer_->SetIsDrawable(false);
-    active_layer_->SetIsDrawable(false);
-  }
-
-  ~Effect() { Detach(); }
-
-  void Pull(float delta) {
-    if (state_ != STATE_PULL)
-      drag_ = 0;
-
-    state_ = STATE_PULL;
-
-    delta *= kDragRate;
-    float max_delta = target_drag_ / OverscrollRefresh::kMinPullsToActivate;
-    delta = Clamp(delta, -max_delta, max_delta);
-
-    drag_ += delta;
-    drag_ = Clamp(drag_, 0.f, target_drag_ * 3.f);
-
-    // The following logic and constants were taken from Android's refresh
-    // effect (see SwipeRefreshLayout.java from v4 of the AppCompat library).
-    float original_drag_percent = drag_ / target_drag_;
-    float drag_percent = min(1.f, abs(original_drag_percent));
-    float adjusted_percent = max(drag_percent - .4f, 0.f) * 5.f / 3.f;
-    float extra_os = abs(drag_) - target_drag_;
-    float slingshot_dist = target_drag_;
-    float tension_slingshot_percent =
-        max(0.f, min(extra_os, slingshot_dist * 2) / slingshot_dist);
-    float tension_percent = ((tension_slingshot_percent / 4) -
-                             std::pow((tension_slingshot_percent / 4), 2.f)) *
-                            2.f;
-    float extra_move = slingshot_dist * tension_percent * 2;
-
-    offset_ = slingshot_dist * drag_percent + extra_move;
-
-    rotation_ =
-        360.f * ((-0.25f + .4f * adjusted_percent + tension_percent * 2) * .5f);
-
-    idle_alpha_ =
-        kMinAlpha + (1.f - kMinAlpha) * drag_percent / kGlowActivationThreshold;
-    active_alpha_ = (drag_percent - kGlowActivationThreshold) /
-                    (1.f - kGlowActivationThreshold);
-    idle_alpha_ = Clamp(idle_alpha_, 0.f, 1.f);
-    active_alpha_ = Clamp(active_alpha_, 0.f, 1.f);
-
-    size_scale_ = 1;
-  }
-
-  bool Animate(base::TimeTicks current_time, bool still_refreshing) {
-    if (IsFinished())
-      return false;
-
-    if (state_ == STATE_PULL)
-      return true;
-
-    const double dt = (current_time - start_time_).InMilliseconds();
-    const double t = dt / duration_.InMilliseconds();
-    const float interp = ease_out_->GetValue(min(t, 1.));
-
-    idle_alpha_ = Lerp(idle_alpha_start_, idle_alpha_finish_, interp);
-    active_alpha_ = Lerp(active_alpha_start_, active_alpha_finish_, interp);
-    offset_ = Lerp(offset_start_, offset_finish_, interp);
-    size_scale_ = Lerp(size_scale_start_, size_scale_finish_, interp);
-
-    if (state_ == STATE_ACTIVATED || state_ == STATE_ACTIVATED_RECEDE) {
-      float adjusted_interp = ease_in_out_->GetValue(min(t, 1.));
-      rotation_ = Lerp(rotation_start_, rotation_finish_, adjusted_interp);
-      // Add a small constant rotational velocity during activation.
-      rotation_ += dt * 90.f / kActivationTimeMs;
-    } else {
-      rotation_ = Lerp(rotation_start_, rotation_finish_, interp);
-    }
-
-    if (t < 1.f - kEpsilon)
-      return true;
-
-    switch (state_) {
-      case STATE_IDLE:
-      case STATE_PULL:
-        NOTREACHED() << "Invalidate state for animation.";
-        break;
-      case STATE_ACTIVATED_START:
-        // Briefly pause the animation after the rapid initial translation.
-        if (t < 1.5f)
-          break;
-        state_ = STATE_ACTIVATED;
-        start_time_ = current_time;
-        duration_ = base::TimeDelta::FromMilliseconds(kActivationTimeMs);
-        activated_start_time_ = current_time;
-        offset_start_ = offset_finish_ = offset_;
-        rotation_start_ = rotation_;
-        rotation_finish_ = rotation_start_ + 270.f;
-        size_scale_start_ = size_scale_finish_ = size_scale_;
-        break;
-      case STATE_ACTIVATED:
-        start_time_ = current_time;
-        if (still_refreshing &&
-            (current_time - activated_start_time_ <
-             base::TimeDelta::FromMilliseconds(kMaxActivationTimeMs))) {
-          offset_start_ = offset_finish_ = offset_;
-          rotation_start_ = rotation_;
-          rotation_finish_ = rotation_start_ + 270.f;
-          break;
-        }
-        state_ = STATE_ACTIVATED_RECEDE;
-        duration_ = base::TimeDelta::FromMilliseconds(kActivationRecedeTimeMs);
-        rotation_start_ = rotation_finish_ = rotation_;
-        offset_start_ = offset_finish_ = offset_;
-        size_scale_start_ = size_scale_;
-        size_scale_finish_ = 0;
-        break;
-      case STATE_ACTIVATED_RECEDE:
-        Finish();
-        break;
-      case STATE_RECEDE:
-        Finish();
-        break;
-    };
-
-    return !IsFinished();
-  }
-
-  bool Release(base::TimeTicks current_time, bool allow_activation) {
-    switch (state_) {
-      case STATE_PULL:
-        break;
-
-      case STATE_ACTIVATED:
-      case STATE_ACTIVATED_START:
-        // Avoid redundant activations.
-        if (allow_activation)
-          return false;
-        break;
-
-      case STATE_IDLE:
-      case STATE_ACTIVATED_RECEDE:
-      case STATE_RECEDE:
-        // These states have already been "released" in some fashion.
-        return false;
-    }
-
-    start_time_ = current_time;
-    idle_alpha_start_ = idle_alpha_;
-    active_alpha_start_ = active_alpha_;
-    offset_start_ = offset_;
-    rotation_start_ = rotation_;
-    size_scale_start_ = size_scale_finish_ = size_scale_;
-
-    if (drag_ < target_drag_ || !allow_activation) {
-      state_ = STATE_RECEDE;
-      duration_ = base::TimeDelta::FromMilliseconds(kRecedeTimeMs);
-      idle_alpha_finish_ = 0;
-      active_alpha_finish_ = 0;
-      offset_finish_ = 0;
-      rotation_finish_ = rotation_start_ - 180.f;
-      return false;
-    }
-
-    state_ = STATE_ACTIVATED_START;
-    duration_ = base::TimeDelta::FromMilliseconds(kActivationStartTimeMs);
-    activated_start_time_ = current_time;
-    idle_alpha_finish_ = idle_alpha_start_;
-    active_alpha_finish_ = active_alpha_start_;
-    offset_finish_ = target_drag_;
-    rotation_finish_ = rotation_start_;
-    return true;
-  }
-
-  void Finish() {
-    Detach();
-    idle_layer_->SetIsDrawable(false);
-    active_layer_->SetIsDrawable(false);
-    offset_ = 0;
-    idle_alpha_ = 0;
-    active_alpha_ = 0;
-    rotation_ = 0;
-    size_scale_ = 1;
-    state_ = STATE_IDLE;
-  }
-
-  void ApplyToLayers(const gfx::SizeF& viewport_size, cc::Layer* parent) {
-    if (IsFinished())
-      return;
-
-    if (!parent->layer_tree_host())
-      return;
-
-    // An empty window size, while meaningless, is also relatively harmless, and
-    // will simply prevent any drawing of the layers.
-    if (viewport_size.IsEmpty()) {
-      idle_layer_->SetIsDrawable(false);
-      active_layer_->SetIsDrawable(false);
-      return;
-    }
-
-    cc::UIResourceId idle_resource = resource_manager_->GetUIResourceId(
-        ui::ANDROID_RESOURCE_TYPE_SYSTEM, kIdleResourceId);
-    cc::UIResourceId active_resource = resource_manager_->GetUIResourceId(
-        ui::ANDROID_RESOURCE_TYPE_SYSTEM, kActiveResourceId);
-
-    gfx::Size idle_size =
-        parent->layer_tree_host()->GetUIResourceSize(idle_resource);
-    gfx::Size active_size =
-        parent->layer_tree_host()->GetUIResourceSize(active_resource);
-    gfx::Size scaled_idle_size =
-        gfx::ToRoundedSize(gfx::ScaleSize(idle_size, size_scale_));
-    gfx::Size scaled_active_size =
-        gfx::ToRoundedSize(gfx::ScaleSize(active_size, size_scale_));
-
-    gfx::Vector2dF idle_offset(viewport_size.width() * 0.5f,
-                               offset_ - idle_size.height() * 0.5f);
-    gfx::Vector2dF active_offset(viewport_size.width() * 0.5f,
-                                 offset_ - active_size.height() * 0.5f);
-
-    UpdateLayer(idle_layer_.get(), parent, idle_resource, scaled_idle_size,
-                idle_offset, idle_alpha_, rotation_, mirror_);
-    UpdateLayer(active_layer_.get(), parent, active_resource,
-                scaled_active_size, active_offset, active_alpha_, rotation_,
-                mirror_);
-  }
-
-  bool IsFinished() const { return state_ == STATE_IDLE; }
-
- private:
-  enum State {
-    STATE_IDLE = 0,
-    STATE_PULL,
-    STATE_ACTIVATED_START,
-    STATE_ACTIVATED,
-    STATE_ACTIVATED_RECEDE,
-    STATE_RECEDE
-  };
-
-  void Detach() {
-    idle_layer_->RemoveFromParent();
-    active_layer_->RemoveFromParent();
-  }
-
-  ui::ResourceManager* const resource_manager_;
-
-  scoped_refptr<cc::UIResourceLayer> idle_layer_;
-  scoped_refptr<cc::UIResourceLayer> active_layer_;
-
-  const float target_drag_;
-  const bool mirror_;
-  float drag_;
-  float idle_alpha_;
-  float active_alpha_;
-  float offset_;
-  float rotation_;
-  float size_scale_;
-
-  float idle_alpha_start_;
-  float idle_alpha_finish_;
-  float active_alpha_start_;
-  float active_alpha_finish_;
-  float offset_start_;
-  float offset_finish_;
-  float rotation_start_;
-  float rotation_finish_;
-  float size_scale_start_;
-  float size_scale_finish_;
-
-  base::TimeTicks start_time_;
-  base::TimeTicks activated_start_time_;
-  base::TimeDelta duration_;
-
-  State state_;
-
-  scoped_ptr<cc::TimingFunction> ease_out_;
-  scoped_ptr<cc::TimingFunction> ease_in_out_;
-
-  DISALLOW_COPY_AND_ASSIGN(Effect);
-};
-
-OverscrollRefresh::OverscrollRefresh(ui::ResourceManager* resource_manager,
-                                     OverscrollRefreshClient* client,
-                                     float target_drag_offset_pixels,
-                                     bool mirror)
-    : client_(client),
-      scrolled_to_top_(true),
+OverscrollRefresh::OverscrollRefresh(OverscrollRefreshHandler* handler)
+    : scrolled_to_top_(true),
       overflow_y_hidden_(false),
       scroll_consumption_state_(DISABLED),
-      effect_(new Effect(resource_manager, target_drag_offset_pixels, mirror)) {
-  DCHECK(client);
+      handler_(handler) {
+  DCHECK(handler);
 }
 
 OverscrollRefresh::~OverscrollRefresh() {
@@ -423,7 +28,7 @@ OverscrollRefresh::~OverscrollRefresh() {
 
 void OverscrollRefresh::Reset() {
   scroll_consumption_state_ = DISABLED;
-  effect_->Finish();
+  handler_->PullReset();
 }
 
 void OverscrollRefresh::OnScrollBegin() {
@@ -441,14 +46,16 @@ void OverscrollRefresh::OnScrollUpdateAck(bool was_consumed) {
   if (scroll_consumption_state_ != AWAITING_SCROLL_UPDATE_ACK)
     return;
 
-  scroll_consumption_state_ = was_consumed ? DISABLED : ENABLED;
+  if (was_consumed) {
+    scroll_consumption_state_ = DISABLED;
+    return;
+  }
+
+  scroll_consumption_state_ = handler_->PullStart() ? ENABLED : DISABLED;
 }
 
 bool OverscrollRefresh::WillHandleScrollUpdate(
     const gfx::Vector2dF& scroll_delta) {
-  if (viewport_size_.IsEmpty())
-    return false;
-
   switch (scroll_consumption_state_) {
     case DISABLED:
       return false;
@@ -459,10 +66,9 @@ bool OverscrollRefresh::WillHandleScrollUpdate(
         scroll_consumption_state_ = DISABLED;
       return false;
 
-    case ENABLED: {
-      effect_->Pull(scroll_delta.y());
+    case ENABLED:
+      handler_->PullUpdate(scroll_delta.y());
       return true;
-    }
   }
 
   NOTREACHED() << "Invalid overscroll state: " << scroll_consumption_state_;
@@ -474,40 +80,24 @@ void OverscrollRefresh::ReleaseWithoutActivation() {
   Release(allow_activation);
 }
 
-bool OverscrollRefresh::Animate(base::TimeTicks current_time,
-                                cc::Layer* parent_layer) {
-  DCHECK(parent_layer);
-  if (effect_->IsFinished())
-    return false;
-
-  if (effect_->Animate(current_time, client_->IsStillRefreshing()))
-    effect_->ApplyToLayers(viewport_size_, parent_layer);
-
-  return !effect_->IsFinished();
-}
-
 bool OverscrollRefresh::IsActive() const {
-  return scroll_consumption_state_ == ENABLED || !effect_->IsFinished();
+  return scroll_consumption_state_ == ENABLED;
 }
 
 bool OverscrollRefresh::IsAwaitingScrollUpdateAck() const {
   return scroll_consumption_state_ == AWAITING_SCROLL_UPDATE_ACK;
 }
 
-void OverscrollRefresh::UpdateDisplay(
-    const gfx::SizeF& viewport_size,
+void OverscrollRefresh::OnFrameUpdated(
     const gfx::Vector2dF& content_scroll_offset,
     bool root_overflow_y_hidden) {
-  viewport_size_ = viewport_size;
   scrolled_to_top_ = content_scroll_offset.y() == 0;
   overflow_y_hidden_ = root_overflow_y_hidden;
 }
 
-void OverscrollRefresh::Release(bool allow_activation) {
-  if (scroll_consumption_state_ == ENABLED) {
-    if (effect_->Release(base::TimeTicks::Now(), allow_activation))
-      client_->TriggerRefresh();
-  }
+void OverscrollRefresh::Release(bool allow_refresh) {
+  if (scroll_consumption_state_ == ENABLED)
+    handler_->PullRelease(allow_refresh);
   scroll_consumption_state_ = DISABLED;
 }