cc/layers/layer.cc

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This source file includes following definitions.
Create
client_
SetLayerTreeHost
SetNeedsUpdate
SetNeedsCommit
SetNeedsFullTreeSync
SetNextCommitWaitsForActivation
SetNeedsFilterContextIfNeeded
SetNeedsPushProperties
AddDependentNeedsPushProperties
RemoveDependentNeedsPushProperties
IsPropertyChangeAllowed
LayerRectToContentRect
GetPicture
SetParent
AddChild
InsertChild
RemoveFromParent
RemoveChildOrDependent
ReplaceChild
IndexOfChild
SetBounds
RootLayer
RemoveAllChildren
SetChildren
HasAncestor
RequestCopyOfOutput
SetAnchorPoint
SetAnchorPointZ
SetBackgroundColor
SafeOpaqueBackgroundColor
CalculateContentsScale
SetMasksToBounds
SetMaskLayer
SetReplicaLayer
SetFilters
FilterIsAnimating
SetBackgroundFilters
SetOpacity
OpacityIsAnimating
OpacityCanAnimateOnImplThread
SetBlendMode
SetIsRootForIsolatedGroup
SetContentsOpaque
SetPosition
IsContainerForFixedPositionLayers
SetTransform
TransformIsAnimating
SetScrollParent
AddScrollChild
RemoveScrollChild
SetClipParent
AddClipChild
RemoveClipChild
SetScrollOffset
SetScrollOffsetFromImplSide
SetScrollClipLayerId
SetUserScrollable
SetShouldScrollOnMainThread
SetHaveWheelEventHandlers
SetHaveScrollEventHandlers
SetNonFastScrollableRegion
SetTouchEventHandlerRegion
SetDrawCheckerboardForMissingTiles
SetForceRenderSurface
SetDoubleSided
SetIs3dSorted
SetShouldFlattenTransform
SetIsDrawable
SetHideLayerAndSubtree
SetNeedsDisplayRect
DescendantIsFixedToContainerLayer
SetIsContainerForFixedPositionLayers
SetPositionConstraint
RunCopyCallbackOnMainThread
PostCopyCallbackToMainThread
PushPropertiesTo
CreateLayerImpl
DrawsContent
SavePaintProperties
Update
NeedMoreUpdates
TakeDebugInfo
CreateRenderSurface
ClearRenderSurface
ScrollOffsetForAnimation
OnFilterAnimated
OnOpacityAnimated
OnTransformAnimated
OnScrollOffsetAnimated
OnAnimationWaitingForDeletion
IsActive
AddAnimation
PauseAnimation
RemoveAnimation
SetLayerAnimationControllerForTest
HasActiveAnimation
AddLayerAnimationEventObserver
RemoveLayerAnimationEventObserver
VisibleContentOpaqueRegion
ToScrollbarLayer
rendering_stats_instrumentation
SupportsLCDText
RemoveFromScrollTree
RemoveFromClipTree
RunMicroBenchmark
// Copyright 2010 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 "cc/layers/layer.h"

#include <algorithm>

#include "base/debug/trace_event.h"
#include "base/location.h"
#include "base/metrics/histogram.h"
#include "base/single_thread_task_runner.h"
#include "cc/animation/animation.h"
#include "cc/animation/animation_events.h"
#include "cc/animation/keyframed_animation_curve.h"
#include "cc/animation/layer_animation_controller.h"
#include "cc/layers/layer_client.h"
#include "cc/layers/layer_impl.h"
#include "cc/layers/scrollbar_layer_interface.h"
#include "cc/output/copy_output_request.h"
#include "cc/output/copy_output_result.h"
#include "cc/trees/layer_tree_host.h"
#include "cc/trees/layer_tree_impl.h"
#include "third_party/skia/include/core/SkImageFilter.h"
#include "ui/gfx/geometry/vector2d_conversions.h"
#include "ui/gfx/rect_conversions.h"

namespace cc {

static int s_next_layer_id = 1;

scoped_refptr<Layer> Layer::Create() {
  return make_scoped_refptr(new Layer());
}

Layer::Layer()
    : needs_push_properties_(false),
      num_dependents_need_push_properties_(false),
      stacking_order_changed_(false),
      layer_id_(s_next_layer_id++),
      ignore_set_needs_commit_(false),
      parent_(NULL),
      layer_tree_host_(NULL),
      scroll_clip_layer_id_(INVALID_ID),
      should_scroll_on_main_thread_(false),
      have_wheel_event_handlers_(false),
      have_scroll_event_handlers_(false),
      user_scrollable_horizontal_(true),
      user_scrollable_vertical_(true),
      is_root_for_isolated_group_(false),
      is_container_for_fixed_position_layers_(false),
      is_drawable_(false),
      hide_layer_and_subtree_(false),
      masks_to_bounds_(false),
      contents_opaque_(false),
      double_sided_(true),
      should_flatten_transform_(true),
      use_parent_backface_visibility_(false),
      draw_checkerboard_for_missing_tiles_(false),
      force_render_surface_(false),
      is_3d_sorted_(false),
      anchor_point_(0.5f, 0.5f),
      background_color_(0),
      opacity_(1.f),
      blend_mode_(SkXfermode::kSrcOver_Mode),
      anchor_point_z_(0.f),
      scroll_parent_(NULL),
      clip_parent_(NULL),
      replica_layer_(NULL),
      raster_scale_(0.f),
      client_(NULL) {
  if (layer_id_ == INT_MAX) {
    s_next_layer_id = 1;
  }

  layer_animation_controller_ = LayerAnimationController::Create(layer_id_);
  layer_animation_controller_->AddValueObserver(this);
  layer_animation_controller_->set_value_provider(this);
}

Layer::~Layer() {
  // Our parent should be holding a reference to us so there should be no
  // way for us to be destroyed while we still have a parent.
  DCHECK(!parent());
  // Similarly we shouldn't have a layer tree host since it also keeps a
  // reference to us.
  DCHECK(!layer_tree_host());

  layer_animation_controller_->RemoveValueObserver(this);
  layer_animation_controller_->remove_value_provider(this);

  // Remove the parent reference from all children and dependents.
  RemoveAllChildren();
  if (mask_layer_.get()) {
    DCHECK_EQ(this, mask_layer_->parent());
    mask_layer_->RemoveFromParent();
  }
  if (replica_layer_.get()) {
    DCHECK_EQ(this, replica_layer_->parent());
    replica_layer_->RemoveFromParent();
  }

  RemoveFromScrollTree();
  RemoveFromClipTree();
}

void Layer::SetLayerTreeHost(LayerTreeHost* host) {
  if (layer_tree_host_ == host)
    return;

  layer_tree_host_ = host;

  // When changing hosts, the layer needs to commit its properties to the impl
  // side for the new host.
  SetNeedsPushProperties();

  for (size_t i = 0; i < children_.size(); ++i)
    children_[i]->SetLayerTreeHost(host);

  if (mask_layer_.get())
    mask_layer_->SetLayerTreeHost(host);
  if (replica_layer_.get())
    replica_layer_->SetLayerTreeHost(host);

  if (host) {
    layer_animation_controller_->SetAnimationRegistrar(
        host->animation_registrar());

    if (host->settings().layer_transforms_should_scale_layer_contents)
      reset_raster_scale_to_unknown();
  }

  if (host && layer_animation_controller_->has_any_animation())
    host->SetNeedsCommit();
  SetNeedsFilterContextIfNeeded();
}

void Layer::SetNeedsUpdate() {
  if (layer_tree_host_ && !ignore_set_needs_commit_)
    layer_tree_host_->SetNeedsUpdateLayers();
}

void Layer::SetNeedsCommit() {
  if (!layer_tree_host_)
    return;

  SetNeedsPushProperties();

  if (ignore_set_needs_commit_)
    return;

  layer_tree_host_->SetNeedsCommit();
}

void Layer::SetNeedsFullTreeSync() {
  if (!layer_tree_host_)
    return;

  layer_tree_host_->SetNeedsFullTreeSync();
}

void Layer::SetNextCommitWaitsForActivation() {
  if (!layer_tree_host_)
    return;

  layer_tree_host_->SetNextCommitWaitsForActivation();
}

void Layer::SetNeedsFilterContextIfNeeded() {
  if (!layer_tree_host_)
    return;

  if (!filters_.IsEmpty() || !background_filters_.IsEmpty() ||
      !uses_default_blend_mode())
    layer_tree_host_->set_needs_filter_context();
}

void Layer::SetNeedsPushProperties() {
  if (needs_push_properties_)
    return;
  if (!parent_should_know_need_push_properties() && parent_)
    parent_->AddDependentNeedsPushProperties();
  needs_push_properties_ = true;
}

void Layer::AddDependentNeedsPushProperties() {
  DCHECK_GE(num_dependents_need_push_properties_, 0);

  if (!parent_should_know_need_push_properties() && parent_)
    parent_->AddDependentNeedsPushProperties();

  num_dependents_need_push_properties_++;
}

void Layer::RemoveDependentNeedsPushProperties() {
  num_dependents_need_push_properties_--;
  DCHECK_GE(num_dependents_need_push_properties_, 0);

  if (!parent_should_know_need_push_properties() && parent_)
      parent_->RemoveDependentNeedsPushProperties();
}

bool Layer::IsPropertyChangeAllowed() const {
  if (!layer_tree_host_)
    return true;

  if (!layer_tree_host_->settings().strict_layer_property_change_checking)
    return true;

  return !layer_tree_host_->in_paint_layer_contents();
}

gfx::Rect Layer::LayerRectToContentRect(const gfx::RectF& layer_rect) const {
  gfx::RectF content_rect =
      gfx::ScaleRect(layer_rect, contents_scale_x(), contents_scale_y());
  // Intersect with content rect to avoid the extra pixel because for some
  // values x and y, ceil((x / y) * y) may be x + 1.
  content_rect.Intersect(gfx::Rect(content_bounds()));
  return gfx::ToEnclosingRect(content_rect);
}

skia::RefPtr<SkPicture> Layer::GetPicture() const {
  return skia::RefPtr<SkPicture>();
}

void Layer::SetParent(Layer* layer) {
  DCHECK(!layer || !layer->HasAncestor(this));

  if (parent_should_know_need_push_properties()) {
    if (parent_)
      parent_->RemoveDependentNeedsPushProperties();
    if (layer)
      layer->AddDependentNeedsPushProperties();
  }

  parent_ = layer;
  SetLayerTreeHost(parent_ ? parent_->layer_tree_host() : NULL);

  if (!layer_tree_host_)
    return;
  const LayerTreeSettings& settings = layer_tree_host_->settings();
  if (!settings.layer_transforms_should_scale_layer_contents)
    return;

  reset_raster_scale_to_unknown();
  if (mask_layer_.get())
    mask_layer_->reset_raster_scale_to_unknown();
  if (replica_layer_.get() && replica_layer_->mask_layer_.get())
    replica_layer_->mask_layer_->reset_raster_scale_to_unknown();
}

void Layer::AddChild(scoped_refptr<Layer> child) {
  InsertChild(child, children_.size());
}

void Layer::InsertChild(scoped_refptr<Layer> child, size_t index) {
  DCHECK(IsPropertyChangeAllowed());
  child->RemoveFromParent();
  child->SetParent(this);
  child->stacking_order_changed_ = true;

  index = std::min(index, children_.size());
  children_.insert(children_.begin() + index, child);
  SetNeedsFullTreeSync();
}

void Layer::RemoveFromParent() {
  DCHECK(IsPropertyChangeAllowed());
  if (parent_)
    parent_->RemoveChildOrDependent(this);
}

void Layer::RemoveChildOrDependent(Layer* child) {
  if (mask_layer_.get() == child) {
    mask_layer_->SetParent(NULL);
    mask_layer_ = NULL;
    SetNeedsFullTreeSync();
    return;
  }
  if (replica_layer_.get() == child) {
    replica_layer_->SetParent(NULL);
    replica_layer_ = NULL;
    SetNeedsFullTreeSync();
    return;
  }

  for (LayerList::iterator iter = children_.begin();
       iter != children_.end();
       ++iter) {
    if (iter->get() != child)
      continue;

    child->SetParent(NULL);
    children_.erase(iter);
    SetNeedsFullTreeSync();
    return;
  }
}

void Layer::ReplaceChild(Layer* reference, scoped_refptr<Layer> new_layer) {
  DCHECK(reference);
  DCHECK_EQ(reference->parent(), this);
  DCHECK(IsPropertyChangeAllowed());

  if (reference == new_layer.get())
    return;

  int reference_index = IndexOfChild(reference);
  if (reference_index == -1) {
    NOTREACHED();
    return;
  }

  reference->RemoveFromParent();

  if (new_layer.get()) {
    new_layer->RemoveFromParent();
    InsertChild(new_layer, reference_index);
  }
}

int Layer::IndexOfChild(const Layer* reference) {
  for (size_t i = 0; i < children_.size(); ++i) {
    if (children_[i].get() == reference)
      return i;
  }
  return -1;
}

void Layer::SetBounds(const gfx::Size& size) {
  DCHECK(IsPropertyChangeAllowed());
  if (bounds() == size)
    return;

  bounds_ = size;
  SetNeedsCommit();
}

Layer* Layer::RootLayer() {
  Layer* layer = this;
  while (layer->parent())
    layer = layer->parent();
  return layer;
}

void Layer::RemoveAllChildren() {
  DCHECK(IsPropertyChangeAllowed());
  while (children_.size()) {
    Layer* layer = children_[0].get();
    DCHECK_EQ(this, layer->parent());
    layer->RemoveFromParent();
  }
}

void Layer::SetChildren(const LayerList& children) {
  DCHECK(IsPropertyChangeAllowed());
  if (children == children_)
    return;

  RemoveAllChildren();
  for (size_t i = 0; i < children.size(); ++i)
    AddChild(children[i]);
}

bool Layer::HasAncestor(const Layer* ancestor) const {
  for (const Layer* layer = parent(); layer; layer = layer->parent()) {
    if (layer == ancestor)
      return true;
  }
  return false;
}

void Layer::RequestCopyOfOutput(
    scoped_ptr<CopyOutputRequest> request) {
  DCHECK(IsPropertyChangeAllowed());
  if (request->IsEmpty())
    return;
  copy_requests_.push_back(request.Pass());
  SetNeedsCommit();
}

void Layer::SetAnchorPoint(const gfx::PointF& anchor_point) {
  DCHECK(IsPropertyChangeAllowed());
  if (anchor_point_ == anchor_point)
    return;
  anchor_point_ = anchor_point;
  SetNeedsCommit();
}

void Layer::SetAnchorPointZ(float anchor_point_z) {
  DCHECK(IsPropertyChangeAllowed());
  if (anchor_point_z_ == anchor_point_z)
    return;
  anchor_point_z_ = anchor_point_z;
  SetNeedsCommit();
}

void Layer::SetBackgroundColor(SkColor background_color) {
  DCHECK(IsPropertyChangeAllowed());
  if (background_color_ == background_color)
    return;
  background_color_ = background_color;
  SetNeedsCommit();
}

SkColor Layer::SafeOpaqueBackgroundColor() const {
  SkColor color = background_color();
  if (SkColorGetA(color) == 255 && !contents_opaque()) {
    color = SK_ColorTRANSPARENT;
  } else if (SkColorGetA(color) != 255 && contents_opaque()) {
    for (const Layer* layer = parent(); layer;
         layer = layer->parent()) {
      color = layer->background_color();
      if (SkColorGetA(color) == 255)
        break;
    }
    if (SkColorGetA(color) != 255)
      color = layer_tree_host_->background_color();
    if (SkColorGetA(color) != 255)
      color = SkColorSetA(color, 255);
  }
  return color;
}

void Layer::CalculateContentsScale(
    float ideal_contents_scale,
    float device_scale_factor,
    float page_scale_factor,
    bool animating_transform_to_screen,
    float* contents_scale_x,
    float* contents_scale_y,
    gfx::Size* content_bounds) {
  DCHECK(layer_tree_host_);

  *contents_scale_x = 1;
  *contents_scale_y = 1;
  *content_bounds = bounds();
}

void Layer::SetMasksToBounds(bool masks_to_bounds) {
  DCHECK(IsPropertyChangeAllowed());
  if (masks_to_bounds_ == masks_to_bounds)
    return;
  masks_to_bounds_ = masks_to_bounds;
  SetNeedsCommit();
}

void Layer::SetMaskLayer(Layer* mask_layer) {
  DCHECK(IsPropertyChangeAllowed());
  if (mask_layer_.get() == mask_layer)
    return;
  if (mask_layer_.get()) {
    DCHECK_EQ(this, mask_layer_->parent());
    mask_layer_->RemoveFromParent();
  }
  mask_layer_ = mask_layer;
  if (mask_layer_.get()) {
    DCHECK(!mask_layer_->parent());
    mask_layer_->RemoveFromParent();
    mask_layer_->SetParent(this);
    mask_layer_->SetIsMask(true);
  }
  SetNeedsFullTreeSync();
}

void Layer::SetReplicaLayer(Layer* layer) {
  DCHECK(IsPropertyChangeAllowed());
  if (replica_layer_.get() == layer)
    return;
  if (replica_layer_.get()) {
    DCHECK_EQ(this, replica_layer_->parent());
    replica_layer_->RemoveFromParent();
  }
  replica_layer_ = layer;
  if (replica_layer_.get()) {
    DCHECK(!replica_layer_->parent());
    replica_layer_->RemoveFromParent();
    replica_layer_->SetParent(this);
  }
  SetNeedsFullTreeSync();
}

void Layer::SetFilters(const FilterOperations& filters) {
  DCHECK(IsPropertyChangeAllowed());
  if (filters_ == filters)
    return;
  filters_ = filters;
  SetNeedsCommit();
  SetNeedsFilterContextIfNeeded();
}

bool Layer::FilterIsAnimating() const {
  return layer_animation_controller_->IsAnimatingProperty(Animation::Filter);
}

void Layer::SetBackgroundFilters(const FilterOperations& filters) {
  DCHECK(IsPropertyChangeAllowed());
  if (background_filters_ == filters)
    return;
  background_filters_ = filters;
  SetNeedsCommit();
  SetNeedsFilterContextIfNeeded();
}

void Layer::SetOpacity(float opacity) {
  DCHECK(IsPropertyChangeAllowed());
  if (opacity_ == opacity)
    return;
  opacity_ = opacity;
  SetNeedsCommit();
}

bool Layer::OpacityIsAnimating() const {
  return layer_animation_controller_->IsAnimatingProperty(Animation::Opacity);
}

bool Layer::OpacityCanAnimateOnImplThread() const {
  return false;
}

void Layer::SetBlendMode(SkXfermode::Mode blend_mode) {
  DCHECK(IsPropertyChangeAllowed());
  if (blend_mode_ == blend_mode)
    return;

  // Allowing only blend modes that are defined in the CSS Compositing standard:
  // http://dev.w3.org/fxtf/compositing-1/#blending
  switch (blend_mode) {
    case SkXfermode::kSrcOver_Mode:
    case SkXfermode::kScreen_Mode:
    case SkXfermode::kOverlay_Mode:
    case SkXfermode::kDarken_Mode:
    case SkXfermode::kLighten_Mode:
    case SkXfermode::kColorDodge_Mode:
    case SkXfermode::kColorBurn_Mode:
    case SkXfermode::kHardLight_Mode:
    case SkXfermode::kSoftLight_Mode:
    case SkXfermode::kDifference_Mode:
    case SkXfermode::kExclusion_Mode:
    case SkXfermode::kMultiply_Mode:
    case SkXfermode::kHue_Mode:
    case SkXfermode::kSaturation_Mode:
    case SkXfermode::kColor_Mode:
    case SkXfermode::kLuminosity_Mode:
      // supported blend modes
      break;
    case SkXfermode::kClear_Mode:
    case SkXfermode::kSrc_Mode:
    case SkXfermode::kDst_Mode:
    case SkXfermode::kDstOver_Mode:
    case SkXfermode::kSrcIn_Mode:
    case SkXfermode::kDstIn_Mode:
    case SkXfermode::kSrcOut_Mode:
    case SkXfermode::kDstOut_Mode:
    case SkXfermode::kSrcATop_Mode:
    case SkXfermode::kDstATop_Mode:
    case SkXfermode::kXor_Mode:
    case SkXfermode::kPlus_Mode:
    case SkXfermode::kModulate_Mode:
      // Porter Duff Compositing Operators are not yet supported
      // http://dev.w3.org/fxtf/compositing-1/#porterduffcompositingoperators
      NOTREACHED();
      return;
  }

  blend_mode_ = blend_mode;
  SetNeedsCommit();
  SetNeedsFilterContextIfNeeded();
}

void Layer::SetIsRootForIsolatedGroup(bool root) {
  DCHECK(IsPropertyChangeAllowed());
  if (is_root_for_isolated_group_ == root)
    return;
  is_root_for_isolated_group_ = root;
  SetNeedsCommit();
}

void Layer::SetContentsOpaque(bool opaque) {
  DCHECK(IsPropertyChangeAllowed());
  if (contents_opaque_ == opaque)
    return;
  contents_opaque_ = opaque;
  SetNeedsCommit();
}

void Layer::SetPosition(const gfx::PointF& position) {
  DCHECK(IsPropertyChangeAllowed());
  if (position_ == position)
    return;
  position_ = position;
  SetNeedsCommit();
}

bool Layer::IsContainerForFixedPositionLayers() const {
  if (!transform_.IsIdentityOrTranslation())
    return true;
  if (parent_ && !parent_->transform_.IsIdentityOrTranslation())
    return true;
  return is_container_for_fixed_position_layers_;
}

void Layer::SetTransform(const gfx::Transform& transform) {
  DCHECK(IsPropertyChangeAllowed());
  if (transform_ == transform)
    return;
  transform_ = transform;
  SetNeedsCommit();
}

bool Layer::TransformIsAnimating() const {
  return layer_animation_controller_->IsAnimatingProperty(Animation::Transform);
}

void Layer::SetScrollParent(Layer* parent) {
  DCHECK(IsPropertyChangeAllowed());
  if (scroll_parent_ == parent)
    return;

  if (scroll_parent_)
    scroll_parent_->RemoveScrollChild(this);

  scroll_parent_ = parent;

  if (scroll_parent_)
    scroll_parent_->AddScrollChild(this);

  SetNeedsCommit();
}

void Layer::AddScrollChild(Layer* child) {
  if (!scroll_children_)
    scroll_children_.reset(new std::set<Layer*>);
  scroll_children_->insert(child);
  SetNeedsCommit();
}

void Layer::RemoveScrollChild(Layer* child) {
  scroll_children_->erase(child);
  if (scroll_children_->empty())
    scroll_children_.reset();
  SetNeedsCommit();
}

void Layer::SetClipParent(Layer* ancestor) {
  DCHECK(IsPropertyChangeAllowed());
  if (clip_parent_ == ancestor)
    return;

  if (clip_parent_)
    clip_parent_->RemoveClipChild(this);

  clip_parent_ = ancestor;

  if (clip_parent_)
    clip_parent_->AddClipChild(this);

  SetNeedsCommit();
}

void Layer::AddClipChild(Layer* child) {
  if (!clip_children_)
    clip_children_.reset(new std::set<Layer*>);
  clip_children_->insert(child);
  SetNeedsCommit();
}

void Layer::RemoveClipChild(Layer* child) {
  clip_children_->erase(child);
  if (clip_children_->empty())
    clip_children_.reset();
  SetNeedsCommit();
}

void Layer::SetScrollOffset(gfx::Vector2d scroll_offset) {
  DCHECK(IsPropertyChangeAllowed());

  if (scroll_offset_ == scroll_offset)
    return;
  scroll_offset_ = scroll_offset;
  SetNeedsCommit();
}

void Layer::SetScrollOffsetFromImplSide(const gfx::Vector2d& scroll_offset) {
  DCHECK(IsPropertyChangeAllowed());
  // This function only gets called during a BeginMainFrame, so there
  // is no need to call SetNeedsUpdate here.
  DCHECK(layer_tree_host_ && layer_tree_host_->CommitRequested());
  if (scroll_offset_ == scroll_offset)
    return;
  scroll_offset_ = scroll_offset;
  SetNeedsPushProperties();
  if (!did_scroll_callback_.is_null())
    did_scroll_callback_.Run();
  // The callback could potentially change the layer structure:
  // "this" may have been destroyed during the process.
}

void Layer::SetScrollClipLayerId(int clip_layer_id) {
  DCHECK(IsPropertyChangeAllowed());
  if (scroll_clip_layer_id_ == clip_layer_id)
    return;
  scroll_clip_layer_id_ = clip_layer_id;
  SetNeedsCommit();
}

void Layer::SetUserScrollable(bool horizontal, bool vertical) {
  DCHECK(IsPropertyChangeAllowed());
  if (user_scrollable_horizontal_ == horizontal &&
      user_scrollable_vertical_ == vertical)
    return;
  user_scrollable_horizontal_ = horizontal;
  user_scrollable_vertical_ = vertical;
  SetNeedsCommit();
}

void Layer::SetShouldScrollOnMainThread(bool should_scroll_on_main_thread) {
  DCHECK(IsPropertyChangeAllowed());
  if (should_scroll_on_main_thread_ == should_scroll_on_main_thread)
    return;
  should_scroll_on_main_thread_ = should_scroll_on_main_thread;
  SetNeedsCommit();
}

void Layer::SetHaveWheelEventHandlers(bool have_wheel_event_handlers) {
  DCHECK(IsPropertyChangeAllowed());
  if (have_wheel_event_handlers_ == have_wheel_event_handlers)
    return;
  have_wheel_event_handlers_ = have_wheel_event_handlers;
  SetNeedsCommit();
}

void Layer::SetHaveScrollEventHandlers(bool have_scroll_event_handlers) {
  DCHECK(IsPropertyChangeAllowed());
  if (have_scroll_event_handlers_ == have_scroll_event_handlers)
    return;
  have_scroll_event_handlers_ = have_scroll_event_handlers;
  SetNeedsCommit();
}

void Layer::SetNonFastScrollableRegion(const Region& region) {
  DCHECK(IsPropertyChangeAllowed());
  if (non_fast_scrollable_region_ == region)
    return;
  non_fast_scrollable_region_ = region;
  SetNeedsCommit();
}

void Layer::SetTouchEventHandlerRegion(const Region& region) {
  DCHECK(IsPropertyChangeAllowed());
  if (touch_event_handler_region_ == region)
    return;
  touch_event_handler_region_ = region;
  SetNeedsCommit();
}

void Layer::SetDrawCheckerboardForMissingTiles(bool checkerboard) {
  DCHECK(IsPropertyChangeAllowed());
  if (draw_checkerboard_for_missing_tiles_ == checkerboard)
    return;
  draw_checkerboard_for_missing_tiles_ = checkerboard;
  SetNeedsCommit();
}

void Layer::SetForceRenderSurface(bool force) {
  DCHECK(IsPropertyChangeAllowed());
  if (force_render_surface_ == force)
    return;
  force_render_surface_ = force;
  SetNeedsCommit();
}

void Layer::SetDoubleSided(bool double_sided) {
  DCHECK(IsPropertyChangeAllowed());
  if (double_sided_ == double_sided)
    return;
  double_sided_ = double_sided;
  SetNeedsCommit();
}

void Layer::SetIs3dSorted(bool sorted) {
  DCHECK(IsPropertyChangeAllowed());
  if (is_3d_sorted_ == sorted)
    return;
  is_3d_sorted_ = sorted;
  SetNeedsCommit();
}

void Layer::SetShouldFlattenTransform(bool should_flatten) {
  DCHECK(IsPropertyChangeAllowed());
  if (should_flatten_transform_ == should_flatten)
    return;
  should_flatten_transform_ = should_flatten;
  SetNeedsCommit();
}

void Layer::SetIsDrawable(bool is_drawable) {
  DCHECK(IsPropertyChangeAllowed());
  if (is_drawable_ == is_drawable)
    return;

  is_drawable_ = is_drawable;
  SetNeedsCommit();
}

void Layer::SetHideLayerAndSubtree(bool hide) {
  DCHECK(IsPropertyChangeAllowed());
  if (hide_layer_and_subtree_ == hide)
    return;

  hide_layer_and_subtree_ = hide;
  SetNeedsCommit();
}

void Layer::SetNeedsDisplayRect(const gfx::RectF& dirty_rect) {
  if (dirty_rect.IsEmpty())
    return;

  SetNeedsPushProperties();
  update_rect_.Union(dirty_rect);

  if (DrawsContent())
    SetNeedsUpdate();
}

bool Layer::DescendantIsFixedToContainerLayer() const {
  for (size_t i = 0; i < children_.size(); ++i) {
    if (children_[i]->position_constraint_.is_fixed_position() ||
        children_[i]->DescendantIsFixedToContainerLayer())
      return true;
  }
  return false;
}

void Layer::SetIsContainerForFixedPositionLayers(bool container) {
  if (is_container_for_fixed_position_layers_ == container)
    return;
  is_container_for_fixed_position_layers_ = container;

  if (layer_tree_host_ && layer_tree_host_->CommitRequested())
    return;

  // Only request a commit if we have a fixed positioned descendant.
  if (DescendantIsFixedToContainerLayer())
    SetNeedsCommit();
}

void Layer::SetPositionConstraint(const LayerPositionConstraint& constraint) {
  DCHECK(IsPropertyChangeAllowed());
  if (position_constraint_ == constraint)
    return;
  position_constraint_ = constraint;
  SetNeedsCommit();
}

static void RunCopyCallbackOnMainThread(scoped_ptr<CopyOutputRequest> request,
                                        scoped_ptr<CopyOutputResult> result) {
  request->SendResult(result.Pass());
}

static void PostCopyCallbackToMainThread(
    scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
    scoped_ptr<CopyOutputRequest> request,
    scoped_ptr<CopyOutputResult> result) {
  main_thread_task_runner->PostTask(FROM_HERE,
                                    base::Bind(&RunCopyCallbackOnMainThread,
                                               base::Passed(&request),
                                               base::Passed(&result)));
}

void Layer::PushPropertiesTo(LayerImpl* layer) {
  DCHECK(layer_tree_host_);

  // If we did not SavePaintProperties() for the layer this frame, then push the
  // real property values, not the paint property values.
  bool use_paint_properties = paint_properties_.source_frame_number ==
                              layer_tree_host_->source_frame_number();

  layer->SetAnchorPoint(anchor_point_);
  layer->SetAnchorPointZ(anchor_point_z_);
  layer->SetBackgroundColor(background_color_);
  layer->SetBounds(use_paint_properties ? paint_properties_.bounds
                                        : bounds_);
  layer->SetContentBounds(content_bounds());
  layer->SetContentsScale(contents_scale_x(), contents_scale_y());

  bool is_tracing;
  TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
                                     &is_tracing);
  if (is_tracing)
    layer->SetDebugInfo(TakeDebugInfo());

  layer->SetDoubleSided(double_sided_);
  layer->SetDrawCheckerboardForMissingTiles(
      draw_checkerboard_for_missing_tiles_);
  layer->SetForceRenderSurface(force_render_surface_);
  layer->SetDrawsContent(DrawsContent());
  layer->SetHideLayerAndSubtree(hide_layer_and_subtree_);
  if (!layer->FilterIsAnimatingOnImplOnly() && !FilterIsAnimating())
    layer->SetFilters(filters_);
  DCHECK(!(FilterIsAnimating() && layer->FilterIsAnimatingOnImplOnly()));
  layer->SetBackgroundFilters(background_filters());
  layer->SetMasksToBounds(masks_to_bounds_);
  layer->SetShouldScrollOnMainThread(should_scroll_on_main_thread_);
  layer->SetHaveWheelEventHandlers(have_wheel_event_handlers_);
  layer->SetHaveScrollEventHandlers(have_scroll_event_handlers_);
  layer->SetNonFastScrollableRegion(non_fast_scrollable_region_);
  layer->SetTouchEventHandlerRegion(touch_event_handler_region_);
  layer->SetContentsOpaque(contents_opaque_);
  if (!layer->OpacityIsAnimatingOnImplOnly() && !OpacityIsAnimating())
    layer->SetOpacity(opacity_);
  DCHECK(!(OpacityIsAnimating() && layer->OpacityIsAnimatingOnImplOnly()));
  layer->SetBlendMode(blend_mode_);
  layer->SetIsRootForIsolatedGroup(is_root_for_isolated_group_);
  layer->SetPosition(position_);
  layer->SetIsContainerForFixedPositionLayers(
      IsContainerForFixedPositionLayers());
  layer->SetPositionConstraint(position_constraint_);
  layer->SetShouldFlattenTransform(should_flatten_transform_);
  layer->SetIs3dSorted(is_3d_sorted_);
  layer->SetUseParentBackfaceVisibility(use_parent_backface_visibility_);
  if (!layer->TransformIsAnimatingOnImplOnly() && !TransformIsAnimating())
    layer->SetTransform(transform_);
  DCHECK(!(TransformIsAnimating() && layer->TransformIsAnimatingOnImplOnly()));

  layer->SetScrollClipLayer(scroll_clip_layer_id_);
  layer->set_user_scrollable_horizontal(user_scrollable_horizontal_);
  layer->set_user_scrollable_vertical(user_scrollable_vertical_);

  LayerImpl* scroll_parent = NULL;
  if (scroll_parent_) {
    scroll_parent = layer->layer_tree_impl()->LayerById(scroll_parent_->id());
    DCHECK(scroll_parent);
  }

  layer->SetScrollParent(scroll_parent);
  if (scroll_children_) {
    std::set<LayerImpl*>* scroll_children = new std::set<LayerImpl*>;
    for (std::set<Layer*>::iterator it = scroll_children_->begin();
         it != scroll_children_->end();
         ++it) {
      DCHECK_EQ((*it)->scroll_parent(), this);
      LayerImpl* scroll_child =
          layer->layer_tree_impl()->LayerById((*it)->id());
      DCHECK(scroll_child);
      scroll_children->insert(scroll_child);
    }
    layer->SetScrollChildren(scroll_children);
  } else {
    layer->SetScrollChildren(NULL);
  }

  LayerImpl* clip_parent = NULL;
  if (clip_parent_) {
    clip_parent =
        layer->layer_tree_impl()->LayerById(clip_parent_->id());
    DCHECK(clip_parent);
  }

  layer->SetClipParent(clip_parent);
  if (clip_children_) {
    std::set<LayerImpl*>* clip_children = new std::set<LayerImpl*>;
    for (std::set<Layer*>::iterator it = clip_children_->begin();
        it != clip_children_->end(); ++it) {
      DCHECK_EQ((*it)->clip_parent(), this);
      LayerImpl* clip_child = layer->layer_tree_impl()->LayerById((*it)->id());
      DCHECK(clip_child);
      clip_children->insert(clip_child);
    }
    layer->SetClipChildren(clip_children);
  } else {
    layer->SetClipChildren(NULL);
  }

  // Adjust the scroll delta to be just the scrolls that have happened since
  // the BeginMainFrame was sent.  This happens for impl-side painting
  // in LayerImpl::ApplyScrollDeltasSinceBeginMainFrame in a separate tree walk.
  if (layer->layer_tree_impl()->settings().impl_side_painting) {
    layer->SetScrollOffset(scroll_offset_);
  } else {
    layer->SetScrollOffsetAndDelta(
        scroll_offset_, layer->ScrollDelta() - layer->sent_scroll_delta());
    layer->SetSentScrollDelta(gfx::Vector2d());
  }

  // Wrap the copy_requests_ in a PostTask to the main thread.
  ScopedPtrVector<CopyOutputRequest> main_thread_copy_requests;
  for (ScopedPtrVector<CopyOutputRequest>::iterator it = copy_requests_.begin();
       it != copy_requests_.end();
       ++it) {
    scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner =
        layer_tree_host()->proxy()->MainThreadTaskRunner();
    scoped_ptr<CopyOutputRequest> original_request = copy_requests_.take(it);
    const CopyOutputRequest& original_request_ref = *original_request;
    scoped_ptr<CopyOutputRequest> main_thread_request =
        CopyOutputRequest::CreateRelayRequest(
            original_request_ref,
            base::Bind(&PostCopyCallbackToMainThread,
                       main_thread_task_runner,
                       base::Passed(&original_request)));
    main_thread_copy_requests.push_back(main_thread_request.Pass());
  }
  copy_requests_.clear();
  layer->PassCopyRequests(&main_thread_copy_requests);

  // If the main thread commits multiple times before the impl thread actually
  // draws, then damage tracking will become incorrect if we simply clobber the
  // update_rect here. The LayerImpl's update_rect needs to accumulate (i.e.
  // union) any update changes that have occurred on the main thread.
  update_rect_.Union(layer->update_rect());
  layer->SetUpdateRect(update_rect_);

  layer->SetStackingOrderChanged(stacking_order_changed_);

  layer_animation_controller_->PushAnimationUpdatesTo(
      layer->layer_animation_controller());

  // Reset any state that should be cleared for the next update.
  stacking_order_changed_ = false;
  update_rect_ = gfx::RectF();

  needs_push_properties_ = false;
  num_dependents_need_push_properties_ = 0;
}

scoped_ptr<LayerImpl> Layer::CreateLayerImpl(LayerTreeImpl* tree_impl) {
  return LayerImpl::Create(tree_impl, layer_id_);
}

bool Layer::DrawsContent() const {
  return is_drawable_;
}

void Layer::SavePaintProperties() {
  DCHECK(layer_tree_host_);

  // TODO(reveman): Save all layer properties that we depend on not
  // changing until PushProperties() has been called. crbug.com/231016
  paint_properties_.bounds = bounds_;
  paint_properties_.source_frame_number =
      layer_tree_host_->source_frame_number();
}

bool Layer::Update(ResourceUpdateQueue* queue,
                   const OcclusionTracker<Layer>* occlusion) {
  DCHECK(layer_tree_host_);
  DCHECK_EQ(layer_tree_host_->source_frame_number(),
            paint_properties_.source_frame_number) <<
      "SavePaintProperties must be called for any layer that is painted.";
  return false;
}

bool Layer::NeedMoreUpdates() {
  return false;
}

scoped_refptr<base::debug::ConvertableToTraceFormat> Layer::TakeDebugInfo() {
  if (client_)
    return client_->TakeDebugInfo();
  else
    return NULL;
}

void Layer::CreateRenderSurface() {
  DCHECK(!draw_properties_.render_surface);
  draw_properties_.render_surface = make_scoped_ptr(new RenderSurface(this));
  draw_properties_.render_target = this;
}

void Layer::ClearRenderSurface() {
  draw_properties_.render_surface.reset();
}

gfx::Vector2dF Layer::ScrollOffsetForAnimation() const {
  return TotalScrollOffset();
}

// On<Property>Animated is called due to an ongoing accelerated animation.
// Since this animation is also being run on the compositor thread, there
// is no need to request a commit to push this value over, so the value is
// set directly rather than by calling Set<Property>.
void Layer::OnFilterAnimated(const FilterOperations& filters) {
  filters_ = filters;
}

void Layer::OnOpacityAnimated(float opacity) {
  opacity_ = opacity;
}

void Layer::OnTransformAnimated(const gfx::Transform& transform) {
  transform_ = transform;
}

void Layer::OnScrollOffsetAnimated(const gfx::Vector2dF& scroll_offset) {
  // Do nothing. Scroll deltas will be sent from the compositor thread back
  // to the main thread in the same manner as during non-animated
  // compositor-driven scrolling.
}

void Layer::OnAnimationWaitingForDeletion() {
  // Animations are only deleted during PushProperties.
  SetNeedsPushProperties();
}

bool Layer::IsActive() const {
  return true;
}

bool Layer::AddAnimation(scoped_ptr <Animation> animation) {
  if (!layer_animation_controller_->animation_registrar())
    return false;

  UMA_HISTOGRAM_BOOLEAN("Renderer.AnimationAddedToOrphanLayer",
                        !layer_tree_host_);
  layer_animation_controller_->AddAnimation(animation.Pass());
  SetNeedsCommit();
  return true;
}

void Layer::PauseAnimation(int animation_id, double time_offset) {
  layer_animation_controller_->PauseAnimation(animation_id, time_offset);
  SetNeedsCommit();
}

void Layer::RemoveAnimation(int animation_id) {
  layer_animation_controller_->RemoveAnimation(animation_id);
  SetNeedsCommit();
}

void Layer::SetLayerAnimationControllerForTest(
    scoped_refptr<LayerAnimationController> controller) {
  layer_animation_controller_->RemoveValueObserver(this);
  layer_animation_controller_ = controller;
  layer_animation_controller_->AddValueObserver(this);
  SetNeedsCommit();
}

bool Layer::HasActiveAnimation() const {
  return layer_animation_controller_->HasActiveAnimation();
}

void Layer::AddLayerAnimationEventObserver(
    LayerAnimationEventObserver* animation_observer) {
  layer_animation_controller_->AddEventObserver(animation_observer);
}

void Layer::RemoveLayerAnimationEventObserver(
    LayerAnimationEventObserver* animation_observer) {
  layer_animation_controller_->RemoveEventObserver(animation_observer);
}

Region Layer::VisibleContentOpaqueRegion() const {
  if (contents_opaque())
    return visible_content_rect();
  return Region();
}

ScrollbarLayerInterface* Layer::ToScrollbarLayer() {
  return NULL;
}

RenderingStatsInstrumentation* Layer::rendering_stats_instrumentation() const {
  return layer_tree_host_->rendering_stats_instrumentation();
}

bool Layer::SupportsLCDText() const {
  return false;
}

void Layer::RemoveFromScrollTree() {
  if (scroll_children_.get()) {
    for (std::set<Layer*>::iterator it = scroll_children_->begin();
        it != scroll_children_->end(); ++it)
      (*it)->scroll_parent_ = NULL;
  }

  if (scroll_parent_)
    scroll_parent_->RemoveScrollChild(this);

  scroll_parent_ = NULL;
}

void Layer::RemoveFromClipTree() {
  if (clip_children_.get()) {
    for (std::set<Layer*>::iterator it = clip_children_->begin();
        it != clip_children_->end(); ++it)
      (*it)->clip_parent_ = NULL;
  }

  if (clip_parent_)
    clip_parent_->RemoveClipChild(this);

  clip_parent_ = NULL;
}

void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
  benchmark->RunOnLayer(this);
}
}  // namespace cc
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root/cc/layers/layer.cc

DEFINITIONS
