flutter::ContainerLayer Class Reference

#include <container_layer.h>

Inheritance diagram for flutter::ContainerLayer:

Public Member Functions
	ContainerLayer ()
void	Diff (DiffContext *context, const Layer *old_layer) override
void	PreservePaintRegion (DiffContext *context) override
virtual void	Add (std::shared_ptr< Layer > layer)
void	Preroll (PrerollContext *context) override
void	Paint (PaintContext &context) const override
const std::vector< std::shared_ptr< Layer > > &	layers () const
virtual void	DiffChildren (DiffContext *context, const ContainerLayer *old_layer)
void	PaintChildren (PaintContext &context) const override
const ContainerLayer *	as_container_layer () const override
const SkRect &	child_paint_bounds () const
void	set_child_paint_bounds (const SkRect &bounds)
int	children_renderable_state_flags () const
void	set_children_renderable_state_flags (int flags)
Public Member Functions inherited from flutter::Layer
	Layer ()
virtual	~Layer ()
void	AssignOldLayer (Layer *old_layer)
virtual bool	IsReplacing (DiffContext *context, const Layer *old_layer) const
bool	subtree_has_platform_view () const
void	set_subtree_has_platform_view (bool value)
const SkRect &	paint_bounds () const
void	set_paint_bounds (const SkRect &paint_bounds)
bool	is_empty () const
bool	needs_painting (PaintContext &context) const
uint64_t	original_layer_id () const
uint64_t	unique_id () const
virtual RasterCacheKeyID	caching_key_id () const
virtual const DisplayListLayer *	as_display_list_layer () const
virtual const TextureLayer *	as_texture_layer () const
virtual const PerformanceOverlayLayer *	as_performance_overlay_layer () const
virtual const testing::MockLayer *	as_mock_layer () const

Protected Member Functions
void	PrerollChildren (PrerollContext *context, SkRect *child_paint_bounds)

Additional Inherited Members
Static Public Attributes inherited from flutter::Layer
static constexpr int	kSaveLayerRenderFlags
static constexpr int	kRasterCacheRenderFlags

Detailed Description

Definition at line 14 of file container_layer.h.

Constructor & Destructor Documentation

ContainerLayer()

flutter::ContainerLayer::ContainerLayer

(

)

Definition at line 11 of file container_layer.cc.

: child_paint_bounds_(SkRect::MakeEmpty()) {}

Member Function Documentation

Add()

void flutter::ContainerLayer::Add ( std::shared_ptr< Layer >  layer )

virtual

Definition at line 106 of file container_layer.cc.

                                                   {
  layers_.emplace_back(std::move(layer));
}

as_container_layer()

const ContainerLayer * flutter::ContainerLayer::as_container_layer ( ) const

inlineoverridevirtual

Reimplemented from flutter::Layer.

Definition at line 33 of file container_layer.h.

{ return this; }

child_paint_bounds()

const SkRect & flutter::ContainerLayer::child_paint_bounds ( ) const

inline

Definition at line 35 of file container_layer.h.

{ return child_paint_bounds_; }

children_renderable_state_flags()

int flutter::ContainerLayer::children_renderable_state_flags ( ) const

inline

Definition at line 40 of file container_layer.h.

                                              {
    return children_renderable_state_flags_;
  }

Diff()

void flutter::ContainerLayer::Diff ( DiffContext *  context, const Layer *  old_layer  )

overridevirtual

Reimplemented from flutter::Layer.

Reimplemented in flutter::ImageFilterLayer, flutter::OpacityLayer, flutter::ShaderMaskLayer, and flutter::TransformLayer.

Definition at line 13 of file container_layer.cc.

                                                                      {
  auto old_container = static_cast<const ContainerLayer*>(old_layer);
  DiffContext::AutoSubtreeRestore subtree(context);
  DiffChildren(context, old_container);
  context->SetLayerPaintRegion(this, context->CurrentSubtreeRegion());
}

DiffChildren()

void flutter::ContainerLayer::DiffChildren ( DiffContext *  context, const ContainerLayer *  old_layer  )

virtual

Definition at line 27 of file container_layer.cc.

                                                                   {
  if (context->IsSubtreeDirty()) {
    for (auto& layer : layers_) {
      layer->Diff(context, nullptr);
    }
    return;
  }
  FML_DCHECK(old_layer);
 
  const auto& prev_layers = old_layer->layers_;
 
  // first mismatched element
  int new_children_top = 0;
  int old_children_top = 0;
 
  // last mismatched element
  int new_children_bottom = layers_.size() - 1;
  int old_children_bottom = prev_layers.size() - 1;
 
  while ((old_children_top <= old_children_bottom) &&
         (new_children_top <= new_children_bottom)) {
    if (!layers_[new_children_top]->IsReplacing(
            context, prev_layers[old_children_top].get())) {
      break;
    }
    ++new_children_top;
    ++old_children_top;
  }
 
  while ((old_children_top <= old_children_bottom) &&
         (new_children_top <= new_children_bottom)) {
    if (!layers_[new_children_bottom]->IsReplacing(
            context, prev_layers[old_children_bottom].get())) {
      break;
    }
    --new_children_bottom;
    --old_children_bottom;
  }
 
  // old layers that don't match
  for (int i = old_children_top; i <= old_children_bottom; ++i) {
    auto layer = prev_layers[i];
    context->AddDamage(context->GetOldLayerPaintRegion(layer.get()));
  }
 
  for (int i = 0; i < static_cast<int>(layers_.size()); ++i) {
    if (i < new_children_top || i > new_children_bottom) {
      int i_prev =
          i < new_children_top ? i : prev_layers.size() - (layers_.size() - i);
      auto layer = layers_[i];
      auto prev_layer = prev_layers[i_prev];
      auto paint_region = context->GetOldLayerPaintRegion(prev_layer.get());
      if (layer == prev_layer && !paint_region.has_readback() &&
          !paint_region.has_texture()) {
        // for retained layers, stop processing the subtree and add existing
        // region; We know current subtree is not dirty (every ancestor up to
        // here matches) so the retained subtree will render identically to
        // previous frame; We can only do this if there is no readback in the
        // subtree. Layers that do readback must be able to register readback
        // inside Diff
        context->AddExistingPaintRegion(paint_region);
 
        // While we don't need to diff retained layers, we still need to
        // associate their paint region with current layer tree so that we can
        // retrieve it in next frame diff
        layer->PreservePaintRegion(context);
      } else {
        layer->Diff(context, prev_layer.get());
      }
    } else {
      DiffContext::AutoSubtreeRestore subtree(context);
      context->MarkSubtreeDirty();
      auto layer = layers_[i];
      layer->Diff(context, nullptr);
    }
  }
}

layers()

const std::vector< std::shared_ptr< Layer > > & flutter::ContainerLayer::layers ( ) const

inline

Definition at line 26 of file container_layer.h.

{ return layers_; }

Paint()

void flutter::ContainerLayer::Paint ( PaintContext &  context ) const

overridevirtual

Implements flutter::Layer.

Reimplemented in flutter::ImageFilterLayer, flutter::OpacityLayer, flutter::ShaderMaskLayer, and flutter::TransformLayer.

Definition at line 116 of file container_layer.cc.

                                                      {
  FML_DCHECK(needs_painting(context));
 
  PaintChildren(context);
}

PaintChildren()

void flutter::ContainerLayer::PaintChildren ( PaintContext &  context ) const

overridevirtual

Reimplemented from flutter::Layer.

Definition at line 176 of file container_layer.cc.

                                                              {
  // We can no longer call FML_DCHECK here on the needs_painting(context)
  // condition as that test is only valid for the PaintContext that
  // is initially handed to a layer's Paint() method. By the time the
  // layer calls PaintChildren(), though, it may have modified the
  // PaintContext so the test doesn't work in this "context".
 
  // Apply any outstanding state that the children cannot individually
  // and collectively handle.
  auto restore = context.state_stack.applyState(
      child_paint_bounds(), children_renderable_state_flags());
 
  // Intentionally not tracing here as there should be no self-time
  // and the trace event on this common function has a small overhead.
  for (auto& layer : layers_) {
    if (layer->needs_painting(context)) {
      layer->Paint(context);
    }
  }
}

Preroll()

void flutter::ContainerLayer::Preroll ( PrerollContext *  context )

overridevirtual

Implements flutter::Layer.

Reimplemented in flutter::ImageFilterLayer, flutter::OpacityLayer, flutter::ShaderMaskLayer, flutter::TransformLayer, and flutter::testing::MockCacheableContainerLayer.

Definition at line 110 of file container_layer.cc.

                                                    {
  SkRect child_paint_bounds = SkRect::MakeEmpty();
  PrerollChildren(context, &child_paint_bounds);
  set_paint_bounds(child_paint_bounds);
}

PrerollChildren()

void flutter::ContainerLayer::PrerollChildren ( PrerollContext *  context, SkRect *  child_paint_bounds  )

protected

Definition at line 129 of file container_layer.cc.

                                                                 {
  // Platform views have no children, so context->has_platform_view should
  // always be false.
  FML_DCHECK(!context->has_platform_view);
  FML_DCHECK(!context->has_texture_layer);
 
  bool child_has_platform_view = false;
  bool child_has_texture_layer = false;
  bool all_renderable_state_flags = LayerStateStack::kCallerCanApplyAnything;
 
  for (auto& layer : layers_) {
    // Reset context->has_platform_view and context->has_texture_layer to false
    // so that layers aren't treated as if they have a platform view or texture
    // layer based on one being previously found in a sibling tree.
    context->has_platform_view = false;
    context->has_texture_layer = false;
 
    // Initialize the renderable state flags to false to force the layer to
    // opt-in to applying state attributes during its |Preroll|
    context->renderable_state_flags = 0;
 
    layer->Preroll(context);
 
    all_renderable_state_flags &= context->renderable_state_flags;
    if (safe_intersection_test(child_paint_bounds, layer->paint_bounds())) {
      // This will allow inheritance by a linear sequence of non-overlapping
      // children, but will fail with a grid or other arbitrary 2D layout.
      // See https://github.com/flutter/flutter/issues/93899
      all_renderable_state_flags = 0;
    }
    child_paint_bounds->join(layer->paint_bounds());
 
    child_has_platform_view =
        child_has_platform_view || context->has_platform_view;
    child_has_texture_layer =
        child_has_texture_layer || context->has_texture_layer;
  }
 
  context->has_platform_view = child_has_platform_view;
  context->has_texture_layer = child_has_texture_layer;
  context->renderable_state_flags = all_renderable_state_flags;
  set_subtree_has_platform_view(child_has_platform_view);
  set_children_renderable_state_flags(all_renderable_state_flags);
  set_child_paint_bounds(*child_paint_bounds);
}

PreservePaintRegion()

void flutter::ContainerLayer::PreservePaintRegion ( DiffContext *  context )

overridevirtual

Reimplemented from flutter::Layer.

Definition at line 20 of file container_layer.cc.

                                                             {
  Layer::PreservePaintRegion(context);
  for (auto& layer : layers_) {
    layer->PreservePaintRegion(context);
  }
}

set_child_paint_bounds()

void flutter::ContainerLayer::set_child_paint_bounds ( const SkRect &  bounds )

inline

Definition at line 36 of file container_layer.h.

                                                    {
    child_paint_bounds_ = bounds;
  }

set_children_renderable_state_flags()

void flutter::ContainerLayer::set_children_renderable_state_flags ( int  flags )

inline

Definition at line 43 of file container_layer.h.

                                                      {
    children_renderable_state_flags_ = flags;
  }

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The documentation for this class was generated from the following files:

• flow/layers/container_layer.h
• flow/layers/container_layer.cc