blob: a937b20615d9797c2ff748eb08d23cdb8c5aa8a3 [file] [log] [blame]
// Copyright 2015 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 "third_party/blink/renderer/core/paint/paint_property_tree_builder.h"
#include <memory>
#include "third_party/blink/renderer/core/animation/scroll_timeline.h"
#include "third_party/blink/renderer/core/dom/dom_node_ids.h"
#include "third_party/blink/renderer/core/frame/link_highlights.h"
#include "third_party/blink/renderer/core/frame/local_frame.h"
#include "third_party/blink/renderer/core/frame/local_frame_view.h"
#include "third_party/blink/renderer/core/frame/settings.h"
#include "third_party/blink/renderer/core/frame/visual_viewport.h"
#include "third_party/blink/renderer/core/layout/fragmentainer_iterator.h"
#include "third_party/blink/renderer/core/layout/layout_image.h"
#include "third_party/blink/renderer/core/layout/layout_inline.h"
#include "third_party/blink/renderer/core/layout/layout_table_row.h"
#include "third_party/blink/renderer/core/layout/layout_table_section.h"
#include "third_party/blink/renderer/core/layout/layout_view.h"
#include "third_party/blink/renderer/core/layout/svg/layout_svg_resource_masker.h"
#include "third_party/blink/renderer/core/layout/svg/layout_svg_root.h"
#include "third_party/blink/renderer/core/layout/svg/layout_svg_viewport_container.h"
#include "third_party/blink/renderer/core/layout/svg/svg_layout_support.h"
#include "third_party/blink/renderer/core/layout/svg/svg_resources.h"
#include "third_party/blink/renderer/core/layout/svg/svg_resources_cache.h"
#include "third_party/blink/renderer/core/page/page.h"
#include "third_party/blink/renderer/core/page/scrolling/snap_coordinator.h"
#include "third_party/blink/renderer/core/paint/clip_path_clipper.h"
#include "third_party/blink/renderer/core/paint/compositing/composited_layer_mapping.h"
#include "third_party/blink/renderer/core/paint/compositing/compositing_reason_finder.h"
#include "third_party/blink/renderer/core/paint/css_mask_painter.h"
#include "third_party/blink/renderer/core/paint/find_paint_offset_and_visual_rect_needing_update.h"
#include "third_party/blink/renderer/core/paint/find_properties_needing_update.h"
#include "third_party/blink/renderer/core/paint/object_paint_properties.h"
#include "third_party/blink/renderer/core/paint/paint_layer.h"
#include "third_party/blink/renderer/core/paint/paint_layer_scrollable_area.h"
#include "third_party/blink/renderer/core/paint/paint_property_tree_printer.h"
#include "third_party/blink/renderer/core/paint/svg_root_painter.h"
#include "third_party/blink/renderer/platform/graphics/bitmap_image.h"
#include "third_party/blink/renderer/platform/scroll/overscroll_behavior.h"
#include "third_party/blink/renderer/platform/transforms/transform_state.h"
#include "third_party/blink/renderer/platform/transforms/transformation_matrix.h"
namespace blink {
namespace {
bool AreSubtreeUpdateReasonsIsolationPiercing(unsigned reasons) {
// This is written to mean that if we have any reason other than the specified
// ones then the reasons are isolation piercing. This means that if new
// reasons are added, they will be isolation piercing by default.
// - Isolation establishes a containing block for all descendants, so it is
// not piercing.
// TODO(vmpstr): Investigate if transform style is also isolated.
return reasons &
~(static_cast<unsigned>(
SubtreePaintPropertyUpdateReason::kContainerChainMayChange));
}
} // namespace
PaintPropertyTreeBuilderFragmentContext::
PaintPropertyTreeBuilderFragmentContext()
: current_effect(&EffectPaintPropertyNode::Root()) {
current.clip = absolute_position.clip = fixed_position.clip =
&ClipPaintPropertyNode::Root();
current.transform = absolute_position.transform = fixed_position.transform =
&TransformPaintPropertyNode::Root();
current.scroll = absolute_position.scroll = fixed_position.scroll =
&ScrollPaintPropertyNode::Root();
}
PaintPropertyTreeBuilderContext::PaintPropertyTreeBuilderContext()
: force_subtree_update_reasons(0u),
clip_changed(false),
is_repeating_fixed_position(false),
has_svg_hidden_container_ancestor(false),
supports_composited_raster_invalidation(true) {}
void VisualViewportPaintPropertyTreeBuilder::Update(
VisualViewport& visual_viewport,
PaintPropertyTreeBuilderContext& full_context) {
if (full_context.fragments.IsEmpty())
full_context.fragments.push_back(PaintPropertyTreeBuilderFragmentContext());
PaintPropertyTreeBuilderFragmentContext& context = full_context.fragments[0];
visual_viewport.UpdatePaintPropertyNodesIfNeeded(context);
context.current.transform = visual_viewport.GetScrollTranslationNode();
context.absolute_position.transform =
visual_viewport.GetScrollTranslationNode();
context.fixed_position.transform = visual_viewport.GetScrollTranslationNode();
context.current.scroll = visual_viewport.GetScrollNode();
context.absolute_position.scroll = visual_viewport.GetScrollNode();
context.fixed_position.scroll = visual_viewport.GetScrollNode();
#if DCHECK_IS_ON()
paint_property_tree_printer::UpdateDebugNames(visual_viewport);
#endif
}
void PaintPropertyTreeBuilder::SetupContextForFrame(
LocalFrameView& frame_view,
PaintPropertyTreeBuilderContext& full_context) {
if (full_context.fragments.IsEmpty())
full_context.fragments.push_back(PaintPropertyTreeBuilderFragmentContext());
PaintPropertyTreeBuilderFragmentContext& context = full_context.fragments[0];
context.current.paint_offset.MoveBy(frame_view.Location());
context.current.rendering_context_id = 0;
context.current.should_flatten_inherited_transform = true;
context.absolute_position = context.current;
full_context.container_for_absolute_position = nullptr;
full_context.container_for_fixed_position = nullptr;
context.fixed_position = context.current;
context.fixed_position.fixed_position_children_fixed_to_root = true;
}
namespace {
class FragmentPaintPropertyTreeBuilder {
public:
FragmentPaintPropertyTreeBuilder(
const LayoutObject& object,
PaintPropertyTreeBuilderContext& full_context,
PaintPropertyTreeBuilderFragmentContext& context,
FragmentData& fragment_data)
: object_(object),
full_context_(full_context),
context_(context),
fragment_data_(fragment_data),
properties_(fragment_data.PaintProperties()) {}
~FragmentPaintPropertyTreeBuilder() {
if (property_added_or_removed_) {
// Tree topology changes are blocked by isolation.
full_context_.force_subtree_update_reasons |=
PaintPropertyTreeBuilderContext::kSubtreeUpdateIsolationBlocked;
}
#if DCHECK_IS_ON()
if (properties_)
paint_property_tree_printer::UpdateDebugNames(object_, *properties_);
#endif
}
ALWAYS_INLINE void UpdateForSelf();
ALWAYS_INLINE void UpdateForChildren();
bool PropertyChanged() const { return property_changed_; }
bool PropertyAddedOrRemoved() const { return property_added_or_removed_; }
bool HasIsolationNodes() const {
// All or nothing check on the isolation nodes.
DCHECK(!properties_ ||
(properties_->TransformIsolationNode() &&
properties_->ClipIsolationNode() &&
properties_->EffectIsolationNode()) ||
(!properties_->TransformIsolationNode() &&
!properties_->ClipIsolationNode() &&
!properties_->EffectIsolationNode()));
return properties_ && properties_->TransformIsolationNode();
}
private:
ALWAYS_INLINE void UpdatePaintOffset();
ALWAYS_INLINE void UpdateForPaintOffsetTranslation(base::Optional<IntPoint>&);
ALWAYS_INLINE void UpdatePaintOffsetTranslation(
const base::Optional<IntPoint>&);
ALWAYS_INLINE void SetNeedsPaintPropertyUpdateIfNeeded();
ALWAYS_INLINE void UpdateForObjectLocationAndSize(
base::Optional<IntPoint>& paint_offset_translation);
ALWAYS_INLINE void UpdateClipPathCache();
ALWAYS_INLINE void UpdateStickyTranslation();
ALWAYS_INLINE void UpdateTransform();
ALWAYS_INLINE void UpdateTransformForNonRootSVG();
ALWAYS_INLINE bool EffectCanUseCurrentClipAsOutputClip() const;
ALWAYS_INLINE void UpdateEffect();
ALWAYS_INLINE void UpdateLinkHighlightEffect();
ALWAYS_INLINE void UpdateFilter();
ALWAYS_INLINE void UpdateFragmentClip();
ALWAYS_INLINE void UpdateCssClip();
ALWAYS_INLINE void UpdateClipPathClip(bool spv1_compositing_specific_pass);
ALWAYS_INLINE void UpdateLocalBorderBoxContext();
ALWAYS_INLINE bool NeedsOverflowControlsClip() const;
ALWAYS_INLINE void UpdateOverflowControlsClip();
ALWAYS_INLINE void UpdateInnerBorderRadiusClip();
ALWAYS_INLINE void UpdateOverflowClip();
ALWAYS_INLINE void UpdatePerspective();
ALWAYS_INLINE void UpdateReplacedContentTransform();
ALWAYS_INLINE void UpdateScrollAndScrollTranslation();
ALWAYS_INLINE void UpdateOutOfFlowContext();
// See core/paint/README.md for the description of isolation nodes.
ALWAYS_INLINE void UpdateTransformIsolationNode();
ALWAYS_INLINE void UpdateEffectIsolationNode();
ALWAYS_INLINE void UpdateClipIsolationNode();
bool NeedsPaintPropertyUpdate() const {
return object_.NeedsPaintPropertyUpdate() ||
full_context_.force_subtree_update_reasons;
}
void OnUpdate(const ObjectPaintProperties::UpdateResult& result) {
property_added_or_removed_ |= result.NewNodeCreated();
property_changed_ |= !result.Unchanged();
}
// Like |OnUpdate| but sets |clip_changed| if the clip values change.
void OnUpdateClip(const ObjectPaintProperties::UpdateResult& result,
bool only_updated_hit_test_values = false) {
OnUpdate(result);
full_context_.clip_changed |=
!(result.Unchanged() || only_updated_hit_test_values);
}
void OnClear(bool cleared) {
property_added_or_removed_ |= cleared;
property_changed_ |= cleared;
}
void OnClearClip(bool cleared) {
OnClear(cleared);
full_context_.clip_changed |= cleared;
}
const LayoutObject& object_;
// The tree builder context for the whole object.
PaintPropertyTreeBuilderContext& full_context_;
// The tree builder context for the current fragment, which is one of the
// entries in |full_context.fragments|.
PaintPropertyTreeBuilderFragmentContext& context_;
FragmentData& fragment_data_;
ObjectPaintProperties* properties_;
bool property_changed_ = false;
bool property_added_or_removed_ = false;
};
static bool IsRootScroller(const LayoutBox& box) {
auto* scrollable_area = box.GetScrollableArea();
DCHECK(scrollable_area);
auto* layer = scrollable_area->Layer();
return layer &&
CompositingReasonFinder::RequiresCompositingForRootScroller(*layer);
}
static bool HasScrollsOverflow(const LayoutBox& box) {
// TODO(crbug.com/839341): Remove ScrollTimeline check once we support
// main-thread AnimationWorklet and don't need to promote the scroll-source.
return box.GetScrollableArea()->ScrollsOverflow() ||
ScrollTimeline::HasActiveScrollTimeline(box.GetNode());
}
static bool NeedsScrollNode(const LayoutObject& object) {
if (!object.HasOverflowClip())
return false;
const LayoutBox& box = ToLayoutBox(object);
// TODO(pdr): SPV2 has invalidation issues (crbug.com/732611) as well as
// subpixel issues (crbug.com/693741) which prevent us from compositing the
// root scroller.
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled())
return HasScrollsOverflow(box);
return HasScrollsOverflow(box) || IsRootScroller(box);
}
static CompositingReasons CompositingReasonsForScroll(const LayoutBox& box) {
CompositingReasons compositing_reasons = CompositingReason::kNone;
if (IsRootScroller(box))
compositing_reasons |= CompositingReason::kRootScroller;
// TODO(pdr): Set other compositing reasons for scroll here, see:
// PaintLayerScrollableArea::ComputeNeedsCompositedScrolling.
return compositing_reasons;
}
// True if a scroll translation is needed for static scroll offset (e.g.,
// overflow hidden with scroll), or if a scroll node is needed for composited
// scrolling.
static bool NeedsScrollOrScrollTranslation(const LayoutObject& object) {
if (!object.HasOverflowClip())
return false;
IntSize scroll_offset = ToLayoutBox(object).ScrolledContentOffset();
return !scroll_offset.IsZero() || NeedsScrollNode(object);
}
static bool NeedsReplacedContentTransform(const LayoutObject& object) {
// Quick reject.
if (!object.IsLayoutReplaced())
return false;
if (object.IsSVGRoot())
return true;
// Only directly composited images need a transform node to scale contents
// to the object-fit box. Note that we don't actually know whether the image
// will be directly composited. This condition is relaxed to stay on the
// safe side.
// TODO(crbug.com/875110): Figure out the condition for SPv2.
bool is_spv1_composited =
object.HasLayer() &&
ToLayoutBoxModelObject(object).Layer()->GetCompositedLayerMapping();
if (object.IsImage() && is_spv1_composited)
return true;
return false;
}
static bool NeedsPaintOffsetTranslationForScrollbars(
const LayoutBoxModelObject& object) {
if (auto* area = object.GetScrollableArea()) {
if (area->HorizontalScrollbar() || area->VerticalScrollbar())
return true;
}
return false;
}
static bool NeedsIsolationNodes(const LayoutObject& object) {
if (!object.HasLayer())
return false;
// Paint containment establishes isolation.
if (object.ShouldApplyPaintContainment())
return true;
// Layout view establishes isolation with the exception of local roots (since
// they are already essentially isolated).
if (RuntimeEnabledFeatures::LayoutViewIsolationNodesEnabled() &&
object.IsLayoutView()) {
const auto* parent_frame = object.GetFrame()->Tree().Parent();
return parent_frame && parent_frame->IsLocalFrame();
}
return false;
}
static bool NeedsStickyTranslation(const LayoutObject& object) {
if (!object.IsBoxModelObject())
return false;
return object.StyleRef().HasStickyConstrainedPosition();
}
static bool NeedsPaintOffsetTranslation(const LayoutObject& object) {
if (!object.IsBoxModelObject())
return false;
// <foreignObject> inherits no paint offset, because there is no such
// concept within SVG. However, the foreign object can have its own paint
// offset due to the x and y parameters of the element. This affects the
// offset of painting of the <foreignObject> element and its children.
// However, <foreignObject> otherwise behaves like other SVG elements, in
// that the x and y offset is applied *after* any transform, instead of
// before. Therefore there is no paint offset translation needed.
if (object.IsSVGForeignObject())
return false;
const LayoutBoxModelObject& box_model = ToLayoutBoxModelObject(object);
if (box_model.IsLayoutView()) {
// A translation node for LayoutView is always created to ensure fixed and
// absolute contexts use the correct transform space.
return true;
}
if (NeedsIsolationNodes(box_model)) {
DCHECK(box_model.HasLayer());
return true;
}
if (box_model.HasLayer() && box_model.Layer()->PaintsWithTransform(
kGlobalPaintFlattenCompositingLayers)) {
return true;
}
if (NeedsScrollOrScrollTranslation(object))
return true;
if (NeedsStickyTranslation(object))
return true;
if (NeedsPaintOffsetTranslationForScrollbars(box_model))
return true;
if (NeedsReplacedContentTransform(object))
return true;
// Don't let paint offset cross composited layer boundaries, to avoid
// unnecessary full layer paint/raster invalidation when paint offset in
// ancestor transform node changes which should not affect the descendants
// of the composited layer.
// TODO(wangxianzhu): For SPv2, we also need a avoid unnecessary paint/raster
// invalidation in composited layers when their paint offset changes.
if (!RuntimeEnabledFeatures::SlimmingPaintV2Enabled() &&
// For only LayoutBlocks that won't be escaped by floating objects and
// column spans when finding their containing blocks.
// TODO(crbug.com/780242): This can be avoided if we have fully correct
// paint property tree states for floating objects and column spans.
(object.IsLayoutBlock() || object.IsLayoutReplaced()) &&
object.HasLayer() &&
!ToLayoutBoxModelObject(object).Layer()->EnclosingPaginationLayer() &&
object.GetCompositingState() == kPaintsIntoOwnBacking)
return true;
return false;
}
void FragmentPaintPropertyTreeBuilder::UpdateForPaintOffsetTranslation(
base::Optional<IntPoint>& paint_offset_translation) {
if (!NeedsPaintOffsetTranslation(object_))
return;
// We should use the same subpixel paint offset values for snapping
// regardless of whether a transform is present. If there is a transform
// we round the paint offset but keep around the residual fractional
// component for the transformed content to paint with. In spv1 this was
// called "subpixel accumulation". For more information, see
// PaintLayer::subpixelAccumulation() and
// PaintLayerPainter::paintFragmentByApplyingTransform.
paint_offset_translation = RoundedIntPoint(context_.current.paint_offset);
LayoutPoint fractional_paint_offset =
LayoutPoint(context_.current.paint_offset - *paint_offset_translation);
if (fractional_paint_offset != LayoutPoint()) {
// If the object has a non-translation transform, discard the fractional
// paint offset which can't be transformed by the transform.
TransformationMatrix matrix;
object_.StyleRef().ApplyTransform(
matrix, LayoutSize(), ComputedStyle::kExcludeTransformOrigin,
ComputedStyle::kIncludeMotionPath,
ComputedStyle::kIncludeIndependentTransformProperties);
if (!matrix.IsIdentityOrTranslation())
fractional_paint_offset = LayoutPoint();
}
context_.current.paint_offset = fractional_paint_offset;
}
void FragmentPaintPropertyTreeBuilder::UpdatePaintOffsetTranslation(
const base::Optional<IntPoint>& paint_offset_translation) {
DCHECK(properties_);
if (paint_offset_translation) {
TransformPaintPropertyNode::State state;
state.matrix.Translate(paint_offset_translation->X(),
paint_offset_translation->Y());
state.flattens_inherited_transform =
context_.current.should_flatten_inherited_transform;
state.is_identity_or_2d_translation = true;
state.affected_by_outer_viewport_bounds_delta =
object_.StyleRef().GetPosition() == EPosition::kFixed &&
object_.StyleRef().IsFixedToBottom();
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled())
state.rendering_context_id = context_.current.rendering_context_id;
OnUpdate(properties_->UpdatePaintOffsetTranslation(
*context_.current.transform, std::move(state)));
context_.current.transform = properties_->PaintOffsetTranslation();
if (object_.IsLayoutView()) {
context_.absolute_position.transform =
properties_->PaintOffsetTranslation();
context_.fixed_position.transform = properties_->PaintOffsetTranslation();
}
} else {
OnClear(properties_->ClearPaintOffsetTranslation());
}
}
void FragmentPaintPropertyTreeBuilder::UpdateStickyTranslation() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (NeedsStickyTranslation(object_)) {
const auto& box_model = ToLayoutBoxModelObject(object_);
FloatSize sticky_offset(box_model.StickyPositionOffset());
TransformPaintPropertyNode::State state{AffineTransform::Translation(
sticky_offset.Width(), sticky_offset.Height())};
state.is_identity_or_2d_translation = true;
state.compositor_element_id = CompositorElementIdFromUniqueObjectId(
box_model.UniqueId(),
CompositorElementIdNamespace::kStickyTranslation);
auto* layer = box_model.Layer();
const auto* scroller_properties = layer->AncestorOverflowLayer()
->GetLayoutObject()
.FirstFragment()
.PaintProperties();
// A scroll node is only created if an object can be scrolled manually,
// while sticky position attaches to anything that clips overflow.
// No need to (actually can't) setup composited sticky constraint if
// the clipping ancestor we attach to doesn't have a scroll node.
// TODO(crbug.com/881555): If the clipping ancestor does have a scroll
// node, this really should be a DCHECK the current scrolll node
// matches it. i.e.
// if (scroller_properties && scroller_properties->Scroll()) {
// DCHECK_EQ(scroller_properties->Scroll(), context_.current.scroll);
// However there is a bug that AncestorOverflowLayer() may be computed
// incorrectly with clip escaping involved.
if (scroller_properties &&
scroller_properties->Scroll() == context_.current.scroll) {
const StickyPositionScrollingConstraints& layout_constraint =
layer->AncestorOverflowLayer()
->GetScrollableArea()
->GetStickyConstraintsMap()
.at(layer);
auto constraint = std::make_unique<CompositorStickyConstraint>();
constraint->is_sticky = true;
constraint->is_anchored_left = layout_constraint.is_anchored_left;
constraint->is_anchored_right = layout_constraint.is_anchored_right;
constraint->is_anchored_top = layout_constraint.is_anchored_top;
constraint->is_anchored_bottom = layout_constraint.is_anchored_bottom;
constraint->left_offset = layout_constraint.left_offset;
constraint->right_offset = layout_constraint.right_offset;
constraint->top_offset = layout_constraint.top_offset;
constraint->bottom_offset = layout_constraint.bottom_offset;
constraint->constraint_box_rect =
box_model.ComputeStickyConstrainingRect();
constraint->scroll_container_relative_sticky_box_rect = RoundedIntRect(
layout_constraint.scroll_container_relative_sticky_box_rect);
constraint
->scroll_container_relative_containing_block_rect = RoundedIntRect(
layout_constraint.scroll_container_relative_containing_block_rect);
if (PaintLayer* sticky_box_shifting_ancestor =
layout_constraint.nearest_sticky_layer_shifting_sticky_box) {
constraint->nearest_element_shifting_sticky_box =
CompositorElementIdFromUniqueObjectId(
sticky_box_shifting_ancestor->GetLayoutObject().UniqueId(),
CompositorElementIdNamespace::kStickyTranslation);
}
if (PaintLayer* containing_block_shifting_ancestor =
layout_constraint
.nearest_sticky_layer_shifting_containing_block) {
constraint->nearest_element_shifting_containing_block =
CompositorElementIdFromUniqueObjectId(
containing_block_shifting_ancestor->GetLayoutObject()
.UniqueId(),
CompositorElementIdNamespace::kStickyTranslation);
}
state.sticky_constraint = std::move(constraint);
}
OnUpdate(properties_->UpdateStickyTranslation(*context_.current.transform,
std::move(state)));
} else {
OnClear(properties_->ClearStickyTranslation());
}
}
if (properties_->StickyTranslation())
context_.current.transform = properties_->StickyTranslation();
}
static bool NeedsTransformForNonRootSVG(const LayoutObject& object) {
// TODO(pdr): Check for the presence of a transform instead of the value.
// Checking for an identity matrix will cause the property tree structure
// to change during animations if the animation passes through the
// identity matrix.
return object.IsSVGChild() &&
!object.LocalToSVGParentTransform().IsIdentity();
}
// SVG does not use the general transform update of |UpdateTransform|, instead
// creating a transform node for SVG-specific transforms without 3D.
void FragmentPaintPropertyTreeBuilder::UpdateTransformForNonRootSVG() {
DCHECK(properties_);
DCHECK(object_.IsSVGChild());
// SVG does not use paint offset internally, except for SVGForeignObject which
// has different SVG and HTML coordinate spaces.
DCHECK(object_.IsSVGForeignObject() ||
context_.current.paint_offset == LayoutPoint());
if (NeedsPaintPropertyUpdate()) {
AffineTransform transform = object_.LocalToSVGParentTransform();
if (NeedsTransformForNonRootSVG(object_)) {
// The origin is included in the local transform, so leave origin empty.
OnUpdate(properties_->UpdateTransform(
*context_.current.transform,
TransformPaintPropertyNode::State{transform}));
} else {
OnClear(properties_->ClearTransform());
}
}
if (properties_->Transform()) {
context_.current.transform = properties_->Transform();
context_.current.should_flatten_inherited_transform = false;
context_.current.rendering_context_id = 0;
}
}
static CompositingReasons CompositingReasonsForTransform(const LayoutBox& box) {
if (!box.HasLayer())
return CompositingReason::kNone;
const ComputedStyle& style = box.StyleRef();
CompositingReasons compositing_reasons = CompositingReason::kNone;
if (CompositingReasonFinder::RequiresCompositingForTransform(box))
compositing_reasons |= CompositingReason::k3DTransform;
// Currently, we create transform nodes for an element whenever any property
// is being animated so that the existence of the effect node implies the
// existence of all nodes.
// TODO(flackr): Check for nodes for each KeyframeModel target
// property instead of creating all nodes and only create a transform node
// if needed, https://crbug.com/900241
compositing_reasons |=
CompositingReasonFinder::CompositingReasonsForAnimation(style);
if (style.HasWillChangeCompositingHint() &&
!style.SubtreeWillChangeContents())
compositing_reasons |= CompositingReason::kWillChangeCompositingHint;
if (box.HasLayer() && box.Layer()->Has3DTransformedDescendant()) {
if (style.HasPerspective())
compositing_reasons |= CompositingReason::kPerspectiveWith3DDescendants;
if (style.UsedTransformStyle3D() == ETransformStyle3D::kPreserve3d)
compositing_reasons |= CompositingReason::kPreserve3DWith3DDescendants;
}
return compositing_reasons;
}
static FloatPoint3D TransformOrigin(const LayoutBox& box) {
const ComputedStyle& style = box.StyleRef();
// Transform origin has no effect without a transform or motion path.
if (!style.HasTransform())
return FloatPoint3D();
FloatSize border_box_size(box.Size());
return FloatPoint3D(
FloatValueForLength(style.TransformOriginX(), border_box_size.Width()),
FloatValueForLength(style.TransformOriginY(), border_box_size.Height()),
style.TransformOriginZ());
}
static bool NeedsTransform(const LayoutObject& object) {
if ((RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) &&
object.StyleRef().BackfaceVisibility() == EBackfaceVisibility::kHidden)
return true;
if (!object.IsBox())
return false;
return object.StyleRef().HasTransform() || object.StyleRef().Preserves3D() ||
CompositingReasonsForTransform(ToLayoutBox(object)) !=
CompositingReason::kNone;
}
void FragmentPaintPropertyTreeBuilder::UpdateTransform() {
if (object_.IsSVGChild()) {
UpdateTransformForNonRootSVG();
return;
}
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
const ComputedStyle& style = object_.StyleRef();
// A transform node is allocated for transforms, preserves-3d and any
// direct compositing reason. The latter is required because this is the
// only way to represent compositing both an element and its stacking
// descendants.
if (NeedsTransform(object_)) {
TransformPaintPropertyNode::State state;
if (object_.IsBox()) {
auto& box = ToLayoutBox(object_);
state.origin = TransformOrigin(box);
style.ApplyTransform(
state.matrix, box.Size(), ComputedStyle::kExcludeTransformOrigin,
ComputedStyle::kIncludeMotionPath,
ComputedStyle::kIncludeIndependentTransformProperties);
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
// TODO(trchen): transform-style should only be respected if a
// PaintLayer is created. If a node with transform-style: preserve-3d
// does not exist in an existing rendering context, it establishes a
// new one.
state.rendering_context_id = context_.current.rendering_context_id;
if (style.Preserves3D() && !state.rendering_context_id) {
state.rendering_context_id =
PtrHash<const LayoutObject>::GetHash(&object_);
}
state.direct_compositing_reasons =
CompositingReasonsForTransform(box);
}
}
state.flattens_inherited_transform =
context_.current.should_flatten_inherited_transform;
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
state.backface_visibility =
object_.HasHiddenBackface()
? TransformPaintPropertyNode::BackfaceVisibility::kHidden
: TransformPaintPropertyNode::BackfaceVisibility::kVisible;
state.compositor_element_id = CompositorElementIdFromUniqueObjectId(
object_.UniqueId(),
CompositorElementIdNamespace::kPrimaryTransform);
}
OnUpdate(properties_->UpdateTransform(*context_.current.transform,
std::move(state)));
} else {
OnClear(properties_->ClearTransform());
}
}
if (properties_->Transform()) {
context_.current.transform = properties_->Transform();
if (object_.StyleRef().Preserves3D()) {
context_.current.rendering_context_id =
properties_->Transform()->RenderingContextId();
context_.current.should_flatten_inherited_transform = false;
} else {
context_.current.rendering_context_id = 0;
context_.current.should_flatten_inherited_transform = true;
}
}
}
static bool NeedsClipPathClip(const LayoutObject& object) {
if (!object.StyleRef().ClipPath())
return false;
return object.FirstFragment().ClipPathPath();
}
static bool NeedsEffect(const LayoutObject& object) {
const ComputedStyle& style = object.StyleRef();
// For now some objects (e.g. LayoutTableCol) with stacking context style
// don't create layer thus are not actual stacking contexts, so the HasLayer()
// condition. TODO(crbug.com/892734): Support effects for LayoutTableCol.
const bool is_css_isolated_group =
object.HasLayer() && style.IsStackingContext();
if (!is_css_isolated_group && !object.IsSVG())
return false;
if (object.IsSVG()) {
if (SVGLayoutSupport::IsIsolationRequired(&object))
return true;
if (SVGResources* resources =
SVGResourcesCache::CachedResourcesForLayoutObject(object)) {
if (resources->Masker()) {
return true;
}
}
}
if (is_css_isolated_group) {
if (object.IsSVGRoot() && object.HasNonIsolatedBlendingDescendants())
return true;
const auto* layer = ToLayoutBoxModelObject(object).Layer();
DCHECK(layer);
if (layer->HasNonIsolatedDescendantWithBlendMode())
return true;
// In SPv1* a mask layer can be created for clip-path in absence of mask,
// and a mask effect node must be created whether the clip-path is
// path-based or not.
if (layer->GetCompositedLayerMapping() &&
layer->GetCompositedLayerMapping()->MaskLayer())
return true;
// An effect node is required by cc if the layer flattens its subtree but it
// is treated as a 3D object by its parent.
if (RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled() &&
!layer->Preserves3D() && layer->HasSelfPaintingLayerDescendant() &&
layer->Parent() && layer->Parent()->Preserves3D())
return true;
}
SkBlendMode blend_mode = object.IsBlendingAllowed()
? WebCoreCompositeToSkiaComposite(
kCompositeSourceOver, style.GetBlendMode())
: SkBlendMode::kSrcOver;
if (blend_mode != SkBlendMode::kSrcOver)
return true;
if (style.Opacity() != 1.0f || style.HasWillChangeOpacityHint())
return true;
// Currently, we create effect nodes for an element whenever any property
// is being animated so that the existence of the effect node implies the
// existence of all nodes.
// TODO(flackr): Check for nodes for each KeyframeModel target
// property instead of creating all nodes and only create an effect node
// if needed, https://crbug.com/900241
if (CompositingReasonFinder::CompositingReasonsForAnimation(style))
return true;
if (object.StyleRef().HasMask())
return true;
if (object.StyleRef().ClipPath() &&
object.FirstFragment().ClipPathBoundingBox() &&
!object.FirstFragment().ClipPathPath()) {
// If the object has a valid clip-path but can't use path-based clip-path,
// a clip-path effect node must be created.
return true;
}
return false;
}
// An effect node can use the current clip as its output clip if the clip won't
// end before the effect ends. Having explicit output clip can let the later
// stages use more optimized code path.
bool FragmentPaintPropertyTreeBuilder::EffectCanUseCurrentClipAsOutputClip()
const {
DCHECK(NeedsEffect(object_));
if (!object_.HasLayer()) {
// An SVG object's effect never interleaves with clips.
DCHECK(object_.IsSVG());
return true;
}
const auto* layer = ToLayoutBoxModelObject(object_).Layer();
// Out-of-flow descendants not contained by this object may escape clips.
if (layer->HasNonContainedAbsolutePositionDescendant() &&
object_.ContainerForAbsolutePosition()
->FirstFragment()
.PostOverflowClip() != context_.current.clip)
return false;
if (layer->HasFixedPositionDescendant() &&
!object_.CanContainFixedPositionObjects() &&
object_.ContainerForFixedPosition()->FirstFragment().PostOverflowClip() !=
context_.current.clip)
return false;
// Some descendants under a pagination container (e.g. composited objects
// in SPv1 and column spanners) may escape fragment clips.
if (layer->EnclosingPaginationLayer())
return false;
return true;
}
void FragmentPaintPropertyTreeBuilder::UpdateEffect() {
DCHECK(properties_);
const ComputedStyle& style = object_.StyleRef();
if (NeedsPaintPropertyUpdate()) {
if (NeedsEffect(object_)) {
base::Optional<IntRect> mask_clip = CSSMaskPainter::MaskBoundingBox(
object_, context_.current.paint_offset);
bool has_clip_path =
style.ClipPath() && fragment_data_.ClipPathBoundingBox();
bool is_spv1_composited =
object_.HasLayer() &&
ToLayoutBoxModelObject(object_).Layer()->GetCompositedLayerMapping();
bool has_spv1_composited_clip_path = has_clip_path && is_spv1_composited;
bool has_mask_based_clip_path =
has_clip_path && !fragment_data_.ClipPathPath();
base::Optional<IntRect> clip_path_clip;
if (has_spv1_composited_clip_path || has_mask_based_clip_path) {
clip_path_clip = fragment_data_.ClipPathBoundingBox();
} else if (!mask_clip && is_spv1_composited &&
ToLayoutBoxModelObject(object_)
.Layer()
->GetCompositedLayerMapping()
->MaskLayer()) {
// TODO(crbug.com/856818): This should never happen.
// This is a band-aid to avoid nullptr properties on the mask layer
// crashing the renderer, but will result in incorrect rendering.
NOTREACHED();
has_spv1_composited_clip_path = true;
clip_path_clip = IntRect();
}
const auto* output_clip = EffectCanUseCurrentClipAsOutputClip()
? context_.current.clip
: nullptr;
if (mask_clip || clip_path_clip) {
IntRect combined_clip = mask_clip ? *mask_clip : *clip_path_clip;
if (mask_clip && clip_path_clip)
combined_clip.Intersect(*clip_path_clip);
OnUpdateClip(properties_->UpdateMaskClip(
*context_.current.clip,
ClipPaintPropertyNode::State{context_.current.transform,
FloatRoundedRect(combined_clip)}));
output_clip = properties_->MaskClip();
} else {
OnClearClip(properties_->ClearMaskClip());
}
EffectPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
state.output_clip = output_clip;
state.opacity = style.Opacity();
if (object_.IsBlendingAllowed()) {
state.blend_mode = WebCoreCompositeToSkiaComposite(
kCompositeSourceOver, style.GetBlendMode());
}
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
// We may begin to composite our subtree prior to an animation starts,
// but a compositor element ID is only needed when an animation is
// current.
//
// Currently, we use the existence of this id to check if effect nodes
// have been created for animations on this element.
// TODO(flackr): Check for nodes for each KeyframeModel target
// property instead of creating all nodes and create each type of
// node as needed, https://crbug.com/900241
state.direct_compositing_reasons =
CompositingReasonFinder::CompositingReasonsForAnimation(style);
if (state.direct_compositing_reasons) {
state.compositor_element_id = CompositorElementIdFromUniqueObjectId(
object_.UniqueId(), CompositorElementIdNamespace::kPrimaryEffect);
} else {
// The effect node CompositorElementId is used to uniquely identify
// renderpasses so even if we don't need one for animations we still
// need to set an id. Using kPrimary avoids confusing cc::Animation
// into thinking the element has been composited for animations.
state.compositor_element_id = CompositorElementIdFromUniqueObjectId(
object_.UniqueId(), CompositorElementIdNamespace::kPrimary);
}
}
OnUpdate(properties_->UpdateEffect(*context_.current_effect,
std::move(state)));
if (mask_clip || has_spv1_composited_clip_path) {
EffectPaintPropertyNode::State mask_state;
mask_state.local_transform_space = context_.current.transform;
mask_state.output_clip = output_clip;
mask_state.color_filter = CSSMaskPainter::MaskColorFilter(object_);
mask_state.blend_mode = SkBlendMode::kDstIn;
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
mask_state.compositor_element_id =
CompositorElementIdFromUniqueObjectId(
object_.UniqueId(),
CompositorElementIdNamespace::kEffectMask);
}
OnUpdate(properties_->UpdateMask(*properties_->Effect(),
std::move(mask_state)));
} else {
OnClear(properties_->ClearMask());
}
if (has_mask_based_clip_path) {
const EffectPaintPropertyNode& parent = has_spv1_composited_clip_path
? *properties_->Mask()
: *properties_->Effect();
EffectPaintPropertyNode::State clip_path_state;
clip_path_state.local_transform_space = context_.current.transform;
clip_path_state.output_clip = output_clip;
clip_path_state.blend_mode = SkBlendMode::kDstIn;
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
clip_path_state.compositor_element_id =
CompositorElementIdFromUniqueObjectId(
object_.UniqueId(),
CompositorElementIdNamespace::kEffectClipPath);
}
OnUpdate(
properties_->UpdateClipPath(parent, std::move(clip_path_state)));
} else {
OnClear(properties_->ClearClipPath());
}
} else {
OnClear(properties_->ClearEffect());
OnClear(properties_->ClearMask());
OnClear(properties_->ClearClipPath());
OnClearClip(properties_->ClearMaskClip());
}
}
if (properties_->Effect()) {
context_.current_effect = properties_->Effect();
if (properties_->MaskClip()) {
context_.current.clip = context_.absolute_position.clip =
context_.fixed_position.clip = properties_->MaskClip();
}
}
}
static bool NeedsLinkHighlightEffect(const LayoutObject& object) {
auto* page = object.GetFrame()->GetPage();
return page->GetLinkHighlights().NeedsHighlightEffect(object);
}
void FragmentPaintPropertyTreeBuilder::UpdateLinkHighlightEffect() {
if (NeedsPaintPropertyUpdate()) {
if (NeedsLinkHighlightEffect(object_)) {
// While the link highlight uses the current transform space for
// positioning, it's parent effect is the root so that it is not affected
// by enclosing filters.
const auto& parent = EffectPaintPropertyNode::Root();
EffectPaintPropertyNode::State link_highlight_state;
link_highlight_state.local_transform_space = context_.current.transform;
link_highlight_state.compositor_element_id =
object_.GetFrame()->GetPage()->GetLinkHighlights().element_id(
object_);
link_highlight_state.direct_compositing_reasons =
CompositingReason::kActiveOpacityAnimation;
// Unlike other property nodes, link highlight effect nodes are guaranteed
// to be leaf nodes and do not require subtree invalidation, so we do not
// call |OnUpdate| here.
properties_->UpdateLinkHighlightEffect(parent,
std::move(link_highlight_state));
} else {
// Unlike other property nodes, link highlight effect nodes are guaranteed
// to be leaf nodes and do not require subtree invalidation, so we do not
// call |OnClear| here.
properties_->ClearLinkHighlightEffect();
}
}
}
static bool NeedsFilter(const LayoutObject& object) {
// Currently, we create filter nodes for an element whenever any property
// is being animated so that the existence of the effect node implies the
// existence of all animation nodes.
// TODO(flackr): Check for nodes for each KeyframeModel target
// property instead of creating all nodes and only create a filter node
// if needed, https://crbug.com/900241
// TODO(trchen): SVG caches filters in SVGResources. Implement it.
return (object.IsBoxModelObject() && ToLayoutBoxModelObject(object).Layer() &&
(object.StyleRef().HasFilter() || object.HasReflection() ||
object.HasBackdropFilter() ||
CompositingReasonFinder::CompositingReasonsForAnimation(
object.StyleRef())));
}
void FragmentPaintPropertyTreeBuilder::UpdateFilter() {
DCHECK(properties_);
const ComputedStyle& style = object_.StyleRef();
if (NeedsPaintPropertyUpdate()) {
if (NeedsFilter(object_)) {
EffectPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
state.filters_origin = FloatPoint(context_.current.paint_offset);
if (auto* layer = ToLayoutBoxModelObject(object_).Layer()) {
// Try to use the cached filter.
if (properties_->Filter())
state.filter = properties_->Filter()->Filter();
layer->UpdateCompositorFilterOperationsForFilter(state.filter);
layer->UpdateCompositorFilterOperationsForBackdropFilter(
state.backdrop_filter);
layer->ClearFilterOnEffectNodeDirty();
}
// The CSS filter spec didn't specify how filters interact with overflow
// clips. The implementation here mimics the old Blink/WebKit behavior for
// backward compatibility.
// Basically the output of the filter will be affected by clips that
// applies to the current element. The descendants that paints into the
// input of the filter ignores any clips collected so far. For example:
// <div style="overflow:scroll">
// <div style="filter:blur(1px);">
// <div>A</div>
// <div style="position:absolute;">B</div>
// </div>
// </div>
// In this example "A" should be clipped if the filter was not present.
// With the filter, "A" will be rastered without clipping, but instead
// the blurred result will be clipped.
// On the other hand, "B" should not be clipped because the overflow clip
// is not in its containing block chain, but as the filter output will be
// clipped, so a blurred "B" may still be invisible.
state.output_clip = context_.current.clip;
// TODO(trchen): A filter may contain spatial operations such that an
// output pixel may depend on an input pixel outside of the output clip.
// We should generate a special clip node to represent this expansion.
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
// We may begin to composite our subtree prior to an animation starts,
// but a compositor element ID is only needed when an animation is
// current.
// TODO(flackr): Only set a compositing reason for filter animation
// once we no longer need to create all nodes, https://crbug.com/900241
state.direct_compositing_reasons =
CompositingReasonFinder::CompositingReasonsForAnimation(style);
DCHECK(!style.HasCurrentFilterAnimation() ||
state.direct_compositing_reasons != CompositingReason::kNone);
state.compositor_element_id = CompositorElementIdFromUniqueObjectId(
object_.UniqueId(), CompositorElementIdNamespace::kEffectFilter);
}
OnUpdate(properties_->UpdateFilter(*context_.current_effect,
std::move(state)));
} else {
OnClear(properties_->ClearFilter());
}
}
if (properties_->Filter()) {
context_.current_effect = properties_->Filter();
// TODO(trchen): Change input clip to expansion hint once implemented.
const ClipPaintPropertyNode* input_clip =
properties_->Filter()->OutputClip();
context_.current.clip = context_.absolute_position.clip =
context_.fixed_position.clip = input_clip;
}
}
static FloatRoundedRect ToClipRect(const LayoutRect& rect) {
return FloatRoundedRect(FloatRect(PixelSnappedIntRect(rect)));
}
void FragmentPaintPropertyTreeBuilder::UpdateFragmentClip() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (context_.fragment_clip) {
OnUpdateClip(properties_->UpdateFragmentClip(
*context_.current.clip,
ClipPaintPropertyNode::State{context_.current.transform,
ToClipRect(*context_.fragment_clip)}));
} else {
OnClearClip(properties_->ClearFragmentClip());
}
}
if (properties_->FragmentClip())
context_.current.clip = properties_->FragmentClip();
}
static bool NeedsCssClip(const LayoutObject& object) {
return object.HasClip();
}
void FragmentPaintPropertyTreeBuilder::UpdateCssClip() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (NeedsCssClip(object_)) {
// Create clip node for descendants that are not fixed position.
// We don't have to setup context.absolutePosition.clip here because this
// object must be a container for absolute position descendants, and will
// copy from in-flow context later at updateOutOfFlowContext() step.
DCHECK(object_.CanContainAbsolutePositionObjects());
OnUpdateClip(properties_->UpdateCssClip(
*context_.current.clip,
ClipPaintPropertyNode::State{context_.current.transform,
ToClipRect(ToLayoutBox(object_).ClipRect(
context_.current.paint_offset))}));
} else {
OnClearClip(properties_->ClearCssClip());
}
}
if (properties_->CssClip())
context_.current.clip = properties_->CssClip();
}
void FragmentPaintPropertyTreeBuilder::UpdateClipPathClip(
bool spv1_compositing_specific_pass) {
// In SPv1*, composited path-based clip-path applies to a mask paint chunk
// instead of actual contents. We have to delay until mask clip node has been
// created first so we can parent under it.
bool is_spv1_composited =
object_.HasLayer() &&
ToLayoutBoxModelObject(object_).Layer()->GetCompositedLayerMapping();
if (is_spv1_composited != spv1_compositing_specific_pass)
return;
if (NeedsPaintPropertyUpdate()) {
if (!NeedsClipPathClip(object_)) {
OnClearClip(properties_->ClearClipPathClip());
} else {
ClipPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
state.clip_rect =
FloatRoundedRect(FloatRect(*fragment_data_.ClipPathBoundingBox()));
state.clip_path = fragment_data_.ClipPathPath();
OnUpdateClip(properties_->UpdateClipPathClip(*context_.current.clip,
std::move(state)));
}
}
if (properties_->ClipPathClip() && !spv1_compositing_specific_pass) {
context_.current.clip = context_.absolute_position.clip =
context_.fixed_position.clip = properties_->ClipPathClip();
}
}
// Returns true if we are printing which was initiated by the frame. We should
// ignore clipping and scroll transform on contents. WebLocalFrameImpl will
// issue artificial page clip for each page, and always print from the origin
// of the contents for which no scroll offset should be applied.
static bool IsPrintingRootLayoutView(const LayoutObject& object) {
if (!object.IsLayoutView())
return false;
const auto& frame = *object.GetFrame();
if (!frame.GetDocument()->Printing())
return false;
const auto* parent_frame = frame.Tree().Parent();
if (!parent_frame)
return true;
// TODO(crbug.com/455764): The local frame may be not the root frame of
// printing when it's printing under a remote frame.
if (!parent_frame->IsLocalFrame())
return true;
// If the parent frame is printing, this frame should clip normally.
return !ToLocalFrame(parent_frame)->GetDocument()->Printing();
}
static bool NeedsOverflowClipForReplacedContents(
const LayoutReplaced& replaced) {
// <svg> may optionally allow overflow. If an overflow clip is required,
// always create it without checking whether the actual content overflows.
if (replaced.IsSVGRoot())
return ToLayoutSVGRoot(replaced).ShouldApplyViewportClip();
if (replaced.StyleRef().HasBorderRadius())
return true;
// Non-composited images have a micro-optimization to embed clip rects into
// the drawings instead of using a clip node.
bool is_spv1_composited =
replaced.HasLayer() && replaced.Layer()->GetCompositedLayerMapping();
if (replaced.IsImage() && !is_spv1_composited)
return false;
// Embedded objects are always sized to fit the content rect.
if (replaced.IsLayoutEmbeddedContent())
return false;
return true;
}
static bool NeedsOverflowClip(const LayoutObject& object) {
if (object.IsLayoutReplaced())
return NeedsOverflowClipForReplacedContents(ToLayoutReplaced(object));
if (object.IsSVGViewportContainer() &&
SVGLayoutSupport::IsOverflowHidden(object))
return true;
return object.IsBox() && ToLayoutBox(object).ShouldClipOverflow() &&
!IsPrintingRootLayoutView(object);
}
void FragmentPaintPropertyTreeBuilder::UpdateLocalBorderBoxContext() {
if (!NeedsPaintPropertyUpdate())
return;
if (!object_.HasLayer() && !NeedsPaintOffsetTranslation(object_) &&
!NeedsFilter(object_) && !NeedsOverflowClip(object_)) {
fragment_data_.ClearLocalBorderBoxProperties();
} else {
PropertyTreeState local_border_box =
PropertyTreeState(context_.current.transform, context_.current.clip,
context_.current_effect);
if (!fragment_data_.HasLocalBorderBoxProperties() ||
local_border_box != fragment_data_.LocalBorderBoxProperties())
property_added_or_removed_ = true;
fragment_data_.SetLocalBorderBoxProperties(std::move(local_border_box));
}
}
bool FragmentPaintPropertyTreeBuilder::NeedsOverflowControlsClip() const {
if (!object_.HasOverflowClip())
return false;
const auto& box = ToLayoutBox(object_);
const auto* scrollable_area = box.GetScrollableArea();
IntRect scroll_controls_bounds =
scrollable_area->ScrollCornerAndResizerRect();
if (const auto* scrollbar = scrollable_area->HorizontalScrollbar())
scroll_controls_bounds.Unite(scrollbar->FrameRect());
if (const auto* scrollbar = scrollable_area->VerticalScrollbar())
scroll_controls_bounds.Unite(scrollbar->FrameRect());
auto pixel_snapped_border_box_rect = box.PixelSnappedBorderBoxRect(
ToLayoutSize(context_.current.paint_offset));
pixel_snapped_border_box_rect.SetLocation(IntPoint());
return !pixel_snapped_border_box_rect.Contains(scroll_controls_bounds);
}
static bool NeedsInnerBorderRadiusClip(const LayoutObject& object) {
// Replaced elements don't have scrollbars thus needs no separate clip
// for the padding box (InnerBorderRadiusClip) and the client box (padding
// box minus scrollbar, OverflowClip).
// Furthermore, replaced elements clip to the content box instead,
if (object.IsLayoutReplaced())
return false;
return object.StyleRef().HasBorderRadius() && object.IsBox() &&
NeedsOverflowClip(object);
}
static LayoutPoint VisualOffsetFromPaintOffsetRoot(
const PaintPropertyTreeBuilderFragmentContext& context,
const PaintLayer* child) {
const LayoutObject* paint_offset_root = context.current.paint_offset_root;
PaintLayer* painting_layer = paint_offset_root->PaintingLayer();
LayoutPoint result = child->VisualOffsetFromAncestor(painting_layer);
if (!paint_offset_root->HasLayer() ||
ToLayoutBoxModelObject(paint_offset_root)->Layer() != painting_layer) {
result.Move(-paint_offset_root->OffsetFromAncestor(
&painting_layer->GetLayoutObject()));
}
// Convert the result into the space of the scrolling contents space.
if (const auto* properties =
paint_offset_root->FirstFragment().PaintProperties()) {
if (const auto* scroll_translation = properties->ScrollTranslation()) {
DCHECK(scroll_translation->Matrix().IsIdentityOr2DTranslation());
result += -LayoutSize(scroll_translation->Matrix().To2DTranslation());
}
}
return result;
}
void FragmentPaintPropertyTreeBuilder::UpdateOverflowControlsClip() {
DCHECK(properties_);
if (!NeedsPaintPropertyUpdate())
return;
if (NeedsOverflowControlsClip()) {
// Clip overflow controls to the border box rect. Not wrapped with
// OnUpdateClip() because this clip doesn't affect descendants.
properties_->UpdateOverflowControlsClip(
*context_.current.clip,
ClipPaintPropertyNode::State{
context_.current.transform,
ToClipRect(LayoutRect(context_.current.paint_offset,
ToLayoutBox(object_).Size()))});
} else {
properties_->ClearOverflowControlsClip();
}
// No need to set force_subtree_update_reasons and clip_changed because
// OverflowControlsClip applies to overflow controls only, not descendants.
// We also don't walk into custom scrollbars in PrePaintTreeWalk and
// LayoutObjects under custom scrollbars don't support paint properties.
}
void FragmentPaintPropertyTreeBuilder::UpdateInnerBorderRadiusClip() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (NeedsInnerBorderRadiusClip(object_)) {
const LayoutBox& box = ToLayoutBox(object_);
ClipPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
state.clip_rect = box.StyleRef().GetRoundedInnerBorderFor(
LayoutRect(context_.current.paint_offset, box.Size()));
OnUpdateClip(properties_->UpdateInnerBorderRadiusClip(
*context_.current.clip, std::move(state)));
} else {
OnClearClip(properties_->ClearInnerBorderRadiusClip());
}
}
if (auto* border_radius_clip = properties_->InnerBorderRadiusClip())
context_.current.clip = border_radius_clip;
}
static bool CanOmitOverflowClip(const LayoutObject& object) {
DCHECK(NeedsOverflowClip(object));
// Some non-block boxes and SVG objects have special overflow rules.
if (!object.IsLayoutBlock() || object.IsSVG())
return false;
const auto& block = ToLayoutBlock(object);
// This is a heuristic to avoid costly paint property subtree rebuild on
// CanOmitOverflowClip() changes, e.g. on selection. This also avoids omitting
// overflow clip when there is any self-painting descendant which is not
// covered by ContentsVisualOverflowRect().
if (block.HasLayer() && block.Layer()->FirstChild())
return false;
// Selection may overflow.
if (block.IsSelected())
return false;
// Other cases that the contents may overflow. The conditions are copied from
// BlockPainter for SPv1 clip. TODO(wangxianzhu): clean up.
if (block.HasControlClip() || block.ShouldPaintCarets())
return false;
if (object.IsLayoutReplaced()) {
const LayoutReplaced& replaced = ToLayoutReplaced(object);
if (replaced.StyleRef().HasBorderRadius())
return false;
LayoutRect replaced_content_rect = replaced.ReplacedContentRect();
return replaced_content_rect.IsEmpty() ||
replaced.PhysicalContentBoxRect().Contains(replaced_content_rect);
}
// We need OverflowClip for hit-testing if the clip rect excluding overlay
// scrollbars is different from the normal clip rect.
auto clip_rect = block.OverflowClipRect(LayoutPoint());
auto clip_rect_excluding_overlay_scrollbars = block.OverflowClipRect(
LayoutPoint(), kExcludeOverlayScrollbarSizeForHitTesting);
if (clip_rect != clip_rect_excluding_overlay_scrollbars)
return false;
return clip_rect.Contains(block.ContentsVisualOverflowRect());
}
void FragmentPaintPropertyTreeBuilder::UpdateOverflowClip() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (NeedsOverflowClip(object_) && !CanOmitOverflowClip(object_)) {
ClipPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
if (object_.IsLayoutReplaced()) {
const LayoutReplaced& replaced = ToLayoutReplaced(object_);
// LayoutReplaced clips the foreground by rounded content box.
state.clip_rect = replaced.StyleRef().GetRoundedInnerBorderFor(
LayoutRect(context_.current.paint_offset, replaced.Size()),
LayoutRectOutsets(
-(replaced.PaddingTop() + replaced.BorderTop()),
-(replaced.PaddingRight() + replaced.BorderRight()),
-(replaced.PaddingBottom() + replaced.BorderBottom()),
-(replaced.PaddingLeft() + replaced.BorderLeft())));
if (replaced.IsLayoutEmbeddedContent()) {
// Embedded objects are always sized to fit the content rect, but
// they could overflow by 1px due to pre-snapping. Adjust clip rect
// to match pre-snapped box as a special case.
FloatRect adjusted_rect = state.clip_rect.Rect();
adjusted_rect.SetSize(
FloatSize(replaced.ReplacedContentRect().Size()));
state.clip_rect.SetRect(adjusted_rect);
}
} else if (object_.IsBox()) {
state.clip_rect = ToClipRect(ToLayoutBox(object_).OverflowClipRect(
context_.current.paint_offset));
state.clip_rect_excluding_overlay_scrollbars =
ToClipRect(ToLayoutBox(object_).OverflowClipRect(
context_.current.paint_offset,
kExcludeOverlayScrollbarSizeForHitTesting));
} else {
DCHECK(object_.IsSVGViewportContainer());
const auto& viewport_container = ToLayoutSVGViewportContainer(object_);
state.clip_rect = FloatRoundedRect(
viewport_container.LocalToSVGParentTransform().Inverse().MapRect(
viewport_container.Viewport()));
}
const ClipPaintPropertyNode* existing = properties_->OverflowClip();
bool equal_ignoring_hit_test_rects =
!!existing &&
existing->EqualIgnoringHitTestRects(context_.current.clip, state);
OnUpdateClip(properties_->UpdateOverflowClip(*context_.current.clip,
std::move(state)),
equal_ignoring_hit_test_rects);
} else {
OnClearClip(properties_->ClearOverflowClip());
}
}
if (auto* overflow_clip = properties_->OverflowClip())
context_.current.clip = overflow_clip;
}
static FloatPoint PerspectiveOrigin(const LayoutBox& box) {
const ComputedStyle& style = box.StyleRef();
// Perspective origin has no effect without perspective.
DCHECK(style.HasPerspective());
FloatSize border_box_size(box.Size());
return FloatPointForLengthPoint(style.PerspectiveOrigin(), border_box_size);
}
static bool NeedsPerspective(const LayoutObject& object) {
return object.IsBox() && object.StyleRef().HasPerspective();
}
void FragmentPaintPropertyTreeBuilder::UpdatePerspective() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (NeedsPerspective(object_)) {
const ComputedStyle& style = object_.StyleRef();
// The perspective node must not flatten (else nothing will get
// perspective), but it should still extend the rendering context as
// most transform nodes do.
TransformPaintPropertyNode::State state;
state.matrix.ApplyPerspective(style.Perspective());
state.origin = PerspectiveOrigin(ToLayoutBox(object_)) +
ToLayoutSize(context_.current.paint_offset);
state.flattens_inherited_transform =
context_.current.should_flatten_inherited_transform;
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled())
state.rendering_context_id = context_.current.rendering_context_id;
OnUpdate(properties_->UpdatePerspective(*context_.current.transform,
std::move(state)));
} else {
OnClear(properties_->ClearPerspective());
}
}
if (properties_->Perspective()) {
context_.current.transform = properties_->Perspective();
context_.current.should_flatten_inherited_transform = false;
}
}
static bool ImageWasTransposed(const LayoutImage& layout_image,
const Image& image) {
return LayoutObject::ShouldRespectImageOrientation(&layout_image) ==
kRespectImageOrientation &&
image.IsBitmapImage() &&
ToBitmapImage(image).CurrentFrameOrientation().UsesWidthAsHeight();
}
static AffineTransform RectToRect(const FloatRect& src_rect,
const FloatRect& dst_rect) {
float x_scale = dst_rect.Width() / src_rect.Width();
float y_scale = dst_rect.Height() / src_rect.Height();
float x_offset = dst_rect.X() - src_rect.X() * x_scale;
float y_offset = dst_rect.Y() - src_rect.Y() * y_scale;
return AffineTransform(x_scale, 0.f, 0.f, y_scale, x_offset, y_offset);
}
void FragmentPaintPropertyTreeBuilder::UpdateReplacedContentTransform() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate() && !NeedsReplacedContentTransform(object_)) {
OnClear(properties_->ClearReplacedContentTransform());
} else if (NeedsPaintPropertyUpdate()) {
AffineTransform content_to_parent_space;
if (object_.IsSVGRoot()) {
content_to_parent_space =
SVGRootPainter(ToLayoutSVGRoot(object_))
.TransformToPixelSnappedBorderBox(context_.current.paint_offset);
} else if (object_.IsImage()) {
const LayoutImage& layout_image = ToLayoutImage(object_);
LayoutRect layout_replaced_rect = layout_image.ReplacedContentRect();
layout_replaced_rect.MoveBy(context_.current.paint_offset);
IntRect replaced_rect = PixelSnappedIntRect(layout_replaced_rect);
scoped_refptr<Image> image = layout_image.ImageResource()->GetImage(
LayoutSize(replaced_rect.Size()));
if (image && !image->IsNull()) {
IntRect src_rect = image->Rect();
if (ImageWasTransposed(layout_image, *image))
src_rect = src_rect.TransposedRect();
content_to_parent_space =
RectToRect(FloatRect(src_rect), FloatRect(replaced_rect));
}
} else {
NOTREACHED();
}
if (!content_to_parent_space.IsIdentity()) {
OnUpdate(properties_->UpdateReplacedContentTransform(
*context_.current.transform,
TransformPaintPropertyNode::State{content_to_parent_space}));
} else {
OnClear(properties_->ClearReplacedContentTransform());
}
}
if (object_.IsSVGRoot()) {
// SVG painters don't use paint offset. The paint offset is baked into
// the transform node instead.
context_.current.paint_offset = LayoutPoint();
// Only <svg> paints its subtree as replaced contents. Other replaced
// element type may have shadow DOM that should not be affected by the
// replaced object fit.
if (properties_->ReplacedContentTransform()) {
context_.current.transform = properties_->ReplacedContentTransform();
context_.current.should_flatten_inherited_transform = false;
context_.current.rendering_context_id = 0;
}
}
}
static MainThreadScrollingReasons GetMainThreadScrollingReasons(
const LayoutObject& object,
MainThreadScrollingReasons ancestor_reasons) {
// The current main thread scrolling reasons implementation only changes
// reasons at frame boundaries, so we can early-out when not at a LayoutView.
// TODO(pdr): Need to find a solution to the style-related main thread
// scrolling reasons such as opacity and transform which violate this.
if (!object.IsLayoutView())
return ancestor_reasons;
auto reasons = ancestor_reasons;
if (!object.GetFrame()->GetSettings()->GetThreadedScrollingEnabled())
reasons |= MainThreadScrollingReason::kThreadedScrollingDisabled;
if (object.GetFrameView()->HasBackgroundAttachmentFixedObjects())
reasons |= MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects;
return reasons;
}
void FragmentPaintPropertyTreeBuilder::UpdateScrollAndScrollTranslation() {
DCHECK(properties_);
if (NeedsPaintPropertyUpdate()) {
if (NeedsScrollNode(object_)) {
const LayoutBox& box = ToLayoutBox(object_);
PaintLayerScrollableArea* scrollable_area = box.GetScrollableArea();
ScrollPaintPropertyNode::State state;
// The container bounds are snapped to integers to match the equivalent
// bounds on cc::ScrollNode. The offset is snapped to match the current
// integer offsets used in CompositedLayerMapping.
state.container_rect = PixelSnappedIntRect(
box.OverflowClipRect(context_.current.paint_offset));
state.contents_size = scrollable_area->PixelSnappedContentsSize(
context_.current.paint_offset);
state.user_scrollable_horizontal =
scrollable_area->UserInputScrollable(kHorizontalScrollbar);
state.user_scrollable_vertical =
scrollable_area->UserInputScrollable(kVerticalScrollbar);
auto ancestor_reasons =
context_.current.scroll->GetMainThreadScrollingReasons();
state.main_thread_scrolling_reasons =
GetMainThreadScrollingReasons(object_, ancestor_reasons);
// Main thread scrolling reasons depend on their ancestor's reasons
// so ensure the entire subtree is updated when reasons change.
if (auto* existing_scroll = properties_->Scroll()) {
if (existing_scroll->GetMainThreadScrollingReasons() !=
state.main_thread_scrolling_reasons) {
// Main thread scrolling reasons cross into isolation.
full_context_.force_subtree_update_reasons |=
PaintPropertyTreeBuilderContext::kSubtreeUpdateIsolationPiercing;
}
}
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled())
state.compositor_element_id = scrollable_area->GetCompositorElementId();
state.overscroll_behavior = OverscrollBehavior(
static_cast<OverscrollBehavior::OverscrollBehaviorType>(
box.StyleRef().OverscrollBehaviorX()),
static_cast<OverscrollBehavior::OverscrollBehaviorType>(
box.StyleRef().OverscrollBehaviorY()));
auto* snap_coordinator = box.GetDocument().GetSnapCoordinator();
if (snap_coordinator) {
state.snap_container_data = snap_coordinator->GetSnapContainerData(box);
}
OnUpdate(properties_->UpdateScroll(*context_.current.scroll,
std::move(state)));
if (scrollable_area->VerticalScrollbar() ||
scrollable_area->HasLayerForVerticalScrollbar()) {
EffectPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
state.direct_compositing_reasons =
CompositingReason::kActiveOpacityAnimation;
state.compositor_element_id = scrollable_area->GetScrollbarElementId(
ScrollbarOrientation::kVerticalScrollbar);
OnUpdate(properties_->UpdateVerticalScrollbarEffect(
*context_.current_effect, std::move(state)));
} else {
OnClear(properties_->ClearVerticalScrollbarEffect());
}
if (scrollable_area->HorizontalScrollbar() ||
scrollable_area->HasLayerForHorizontalScrollbar()) {
EffectPaintPropertyNode::State state;
state.local_transform_space = context_.current.transform;
state.direct_compositing_reasons =
CompositingReason::kActiveOpacityAnimation;
state.compositor_element_id = scrollable_area->GetScrollbarElementId(
ScrollbarOrientation::kHorizontalScrollbar);
OnUpdate(properties_->UpdateHorizontalScrollbarEffect(
*context_.current_effect, std::move(state)));
} else {
OnClear(properties_->ClearHorizontalScrollbarEffect());
}
} else {
OnClear(properties_->ClearScroll());
OnClear(properties_->ClearVerticalScrollbarEffect());
OnClear(properties_->ClearHorizontalScrollbarEffect());
}
// A scroll translation node is created for static offset (e.g., overflow
// hidden with scroll offset) or cases that scroll and have a scroll node.
if (NeedsScrollOrScrollTranslation(object_)) {
const auto& box = ToLayoutBox(object_);
TransformPaintPropertyNode::State state;
// Bake ScrollOrigin into ScrollTranslation. See comments for
// ScrollTranslation in object_paint_properties.h for details.
auto scroll_position = box.ScrollOrigin() + box.ScrolledContentOffset();
state.matrix.Translate(-scroll_position.X(), -scroll_position.Y());
state.flattens_inherited_transform =
context_.current.should_flatten_inherited_transform;
state.is_identity_or_2d_translation = true;
state.direct_compositing_reasons = CompositingReasonsForScroll(box);
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
RuntimeEnabledFeatures::BlinkGenPropertyTreesEnabled()) {
state.rendering_context_id = context_.current.rendering_context_id;
}
state.scroll = properties_->Scroll();
OnUpdate(properties_->UpdateScrollTranslation(*context_.current.transform,
std::move(state)));
} else {
OnClear(properties_->ClearScrollTranslation());
}
}
if (properties_->Scroll())
context_.current.scroll = properties_->Scroll();
if (properties_->ScrollTranslation()) {
context_.current.transform = properties_->ScrollTranslation();
// See comments for ScrollTranslation in object_paint_properties.h for the
// reason of adding ScrollOrigin().
context_.current.paint_offset += ToLayoutBox(object_).ScrollOrigin();
}
}
void FragmentPaintPropertyTreeBuilder::UpdateOutOfFlowContext() {
if (!object_.IsBoxModelObject() && !properties_)
return;
if (object_.IsLayoutBlock())
context_.paint_offset_for_float = context_.current.paint_offset;
if (object_.CanContainAbsolutePositionObjects())
context_.absolute_position = context_.current;
if (object_.IsLayoutView()) {
const auto* initial_fixed_transform = context_.fixed_position.transform;
const auto* initial_fixed_scroll = context_.fixed_position.scroll;
context_.fixed_position = context_.current;
context_.fixed_position.fixed_position_children_fixed_to_root = true;
// Fixed position transform and scroll nodes should not be affected.
context_.fixed_position.transform = initial_fixed_transform;
context_.fixed_position.scroll = initial_fixed_scroll;
if (properties_->ScrollTranslation()) {
// Also undo the ScrollOrigin part in paint offset that was added when
// ScrollTranslation was updated.
context_.fixed_position.paint_offset -=
ToLayoutBox(object_).ScrollOrigin();
}
} else if (object_.CanContainFixedPositionObjects()) {
context_.fixed_position = context_.current;
context_.fixed_position.fixed_position_children_fixed_to_root = false;
} else if (properties_ && properties_->CssClip()) {
// CSS clip applies to all descendants, even if this object is not a
// containing block ancestor of the descendant. It is okay for
// absolute-position descendants because having CSS clip implies being
// absolute position container. However for fixed-position descendants we
// need to insert the clip here if we are not a containing block ancestor of
// them.
auto* css_clip = properties_->CssClip();
// Before we actually create anything, check whether in-flow context and
// fixed-position context has exactly the same clip. Reuse if possible.
if (context_.fixed_position.clip == css_clip->Parent()) {
context_.fixed_position.clip = css_clip;
} else {
if (NeedsPaintPropertyUpdate()) {
OnUpdate(properties_->UpdateCssClipFixedPosition(
*context_.fixed_position.clip,
ClipPaintPropertyNode::State{css_clip->LocalTransformSpace(),
css_clip->ClipRect()}));
}
if (properties_->CssClipFixedPosition())
context_.fixed_position.clip = properties_->CssClipFixedPosition();
return;
}
}
if (NeedsPaintPropertyUpdate() && properties_)
OnClear(properties_->ClearCssClipFixedPosition());
}
void FragmentPaintPropertyTreeBuilder::UpdateTransformIsolationNode() {
if (NeedsPaintPropertyUpdate()) {
if (NeedsIsolationNodes(object_)) {
OnUpdate(properties_->UpdateTransformIsolationNode(
*context_.current.transform, TransformPaintPropertyNode::State{},
true /* is_parent_alias */));
} else {
OnClear(properties_->ClearTransformIsolationNode());
}
}
if (properties_->TransformIsolationNode())
context_.current.transform = properties_->TransformIsolationNode();
}
void FragmentPaintPropertyTreeBuilder::UpdateEffectIsolationNode() {
if (NeedsPaintPropertyUpdate()) {
if (NeedsIsolationNodes(object_)) {
OnUpdate(properties_->UpdateEffectIsolationNode(
*context_.current_effect, EffectPaintPropertyNode::State{},
true /* is_parent_alias */));
} else {
OnClear(properties_->ClearEffectIsolationNode());
}
}
if (properties_->EffectIsolationNode())
context_.current_effect = properties_->EffectIsolationNode();
}
void FragmentPaintPropertyTreeBuilder::UpdateClipIsolationNode() {
if (NeedsPaintPropertyUpdate()) {
if (NeedsIsolationNodes(object_)) {
OnUpdate(properties_->UpdateClipIsolationNode(
*context_.current.clip, ClipPaintPropertyNode::State{},
true /* is_parent_alias */));
} else {
OnClear(properties_->ClearClipIsolationNode());
}
}
if (properties_->ClipIsolationNode())
context_.current.clip = properties_->ClipIsolationNode();
}
static LayoutRect MapLocalRectToAncestorLayer(
const LayoutBox& box,
const LayoutRect& local_rect,
const PaintLayer& ancestor_layer) {
TransformState transform_state(TransformState::kApplyTransformDirection,
FloatPoint(local_rect.Location()));
box.MapLocalToAncestor(&ancestor_layer.GetLayoutObject(), transform_state,
kApplyContainerFlip);
transform_state.Flatten();
return LayoutRect(LayoutPoint(transform_state.LastPlanarPoint()),
local_rect.Size());
}
static bool IsRepeatingTableSection(const LayoutObject& object) {
if (!object.IsTableSection())
return false;
const auto& section = ToLayoutTableSection(object);
return section.IsRepeatingHeaderGroup() || section.IsRepeatingFooterGroup();
}
static LayoutRect BoundingBoxInPaginationContainer(
const LayoutObject& object,
const PaintLayer& enclosing_pagination_layer) {
// The special path for fragmented layers ensures that the bounding box also
// covers contents visual overflow, so that the fragments will cover all
// fragments of contents except for self-painting layers, because we initiate
// fragment painting of contents from the layer.
if (object.HasLayer() &&
ToLayoutBoxModelObject(object)
.Layer()
->ShouldFragmentCompositedBounds() &&
// Table section may repeat, and doesn't need the special layer path
// because it doesn't have contents visual overflow.
!object.IsTableSection()) {
return ToLayoutBoxModelObject(object).Layer()->PhysicalBoundingBox(
&enclosing_pagination_layer);
}
// Non-boxes paint in the space of their containing block.
if (!object.IsBox()) {
const LayoutBox& containining_block = *object.ContainingBlock();
LayoutRect bounds_rect;
// For non-SVG we can get a more accurate result with LocalVisualRect,
// instead of falling back to the bounds of the enclosing block.
if (!object.IsSVG()) {
bounds_rect = object.LocalVisualRect();
containining_block.FlipForWritingMode(bounds_rect);
} else {
bounds_rect = LayoutRect(SVGLayoutSupport::LocalVisualRect(object));
}
return MapLocalRectToAncestorLayer(containining_block, bounds_rect,
enclosing_pagination_layer);
}
// Compute the bounding box without transforms.
// The object is guaranteed to be a box due to the logic above.
const LayoutBox& box = ToLayoutBox(object);
auto bounding_box = MapLocalRectToAncestorLayer(box, box.BorderBoxRect(),
enclosing_pagination_layer);
if (!IsRepeatingTableSection(object))
return bounding_box;
const auto& section = ToLayoutTableSection(object);
const auto& table = *section.Table();
if (section.IsRepeatingHeaderGroup()) {
// Now bounding_box covers the original header. Expand it to intersect
// with all fragments containing the original and repeatings, i.e. to
// intersect any fragment containing any row.
if (const auto* bottom_section = table.BottomNonEmptySection()) {
bounding_box.Unite(MapLocalRectToAncestorLayer(
*bottom_section, bottom_section->BorderBoxRect(),
enclosing_pagination_layer));
}
return bounding_box;
}
DCHECK(section.IsRepeatingFooterGroup());
// Similar to repeating header, expand bounding_box to intersect any
// fragment containing any row first.
if (const auto* top_section = table.TopNonEmptySection()) {
bounding_box.Unite(MapLocalRectToAncestorLayer(*top_section,
top_section->BorderBoxRect(),
enclosing_pagination_layer));
// However, the first fragment intersecting the expanded bounding_box may
// not have enough space to contain the repeating footer. Exclude the
// total height of the first row and repeating footers from the top of
// bounding_box to exclude the first fragment without enough space.
auto top_exclusion = table.RowOffsetFromRepeatingFooter();
if (top_section != section) {
top_exclusion +=
top_section->FirstRow()->LogicalHeight() + table.VBorderSpacing();
}
// Subtract 1 to ensure overlap of 1 px for a fragment that has exactly
// one row plus space for the footer.
if (top_exclusion)
top_exclusion -= 1;
bounding_box.ShiftYEdgeTo(bounding_box.Y() + top_exclusion);
}
return bounding_box;
}
static LayoutPoint PaintOffsetInPaginationContainer(
const LayoutObject& object,
const PaintLayer& enclosing_pagination_layer) {
// Non-boxes use their containing blocks' paint offset.
if (!object.IsBox() && !object.HasLayer()) {
return PaintOffsetInPaginationContainer(*object.ContainingBlock(),
enclosing_pagination_layer);
}
TransformState transform_state(TransformState::kApplyTransformDirection,
FloatPoint());
object.MapLocalToAncestor(&enclosing_pagination_layer.GetLayoutObject(),
transform_state, kApplyContainerFlip);
transform_state.Flatten();
return LayoutPoint(transform_state.LastPlanarPoint());
}
void FragmentPaintPropertyTreeBuilder::UpdatePaintOffset() {
// Paint offsets for fragmented content are computed from scratch.
const auto* enclosing_pagination_layer =
full_context_.painting_layer->EnclosingPaginationLayer();
if (enclosing_pagination_layer &&
// Except if the paint_offset_root is below the pagination container,
// in which case fragmentation offsets are already baked into the paint
// offset transform for paint_offset_root.
!context_.current.paint_offset_root->PaintingLayer()
->EnclosingPaginationLayer()) {
// Set fragment visual paint offset.
LayoutPoint paint_offset =
PaintOffsetInPaginationContainer(object_, *enclosing_pagination_layer);
paint_offset.MoveBy(fragment_data_.PaginationOffset());
paint_offset.Move(context_.repeating_paint_offset_adjustment);
paint_offset.MoveBy(
VisualOffsetFromPaintOffsetRoot(context_, enclosing_pagination_layer));
// The paint offset root can have a subpixel paint offset adjustment.
// The paint offset root always has one fragment.
const auto& paint_offset_root_fragment =
context_.current.paint_offset_root->FirstFragment();
paint_offset.MoveBy(paint_offset_root_fragment.PaintOffset());
context_.current.paint_offset = paint_offset;
return;
}
if (object_.IsFloating())
context_.current.paint_offset = context_.paint_offset_for_float;
// Multicolumn spanners are painted starting at the multicolumn container (but
// still inherit properties in layout-tree order) so reset the paint offset.
if (object_.IsColumnSpanAll()) {
context_.current.paint_offset =
object_.Container()->FirstFragment().PaintOffset();
}
if (object_.IsBoxModelObject()) {
const LayoutBoxModelObject& box_model_object =
ToLayoutBoxModelObject(object_);
switch (box_model_object.StyleRef().GetPosition()) {
case EPosition::kStatic:
break;
case EPosition::kRelative:
context_.current.paint_offset +=
box_model_object.OffsetForInFlowPosition();
break;
case EPosition::kAbsolute: {
DCHECK(full_context_.container_for_absolute_position ==
box_model_object.Container());
context_.current = context_.absolute_position;
// Absolutely positioned content in an inline should be positioned
// relative to the inline.
const auto* container = full_context_.container_for_absolute_position;
if (container && container->IsLayoutInline()) {
DCHECK(container->CanContainAbsolutePositionObjects());
DCHECK(box_model_object.IsBox());
context_.current.paint_offset +=
ToLayoutInline(container)->OffsetForInFlowPositionedInline(
ToLayoutBox(box_model_object));
}
break;
}
case EPosition::kSticky:
break;
case EPosition::kFixed: {
DCHECK(full_context_.container_for_fixed_position ==
box_model_object.Container());
context_.current = context_.fixed_position;
// Fixed-position elements that are fixed to the vieport have a
// transform above the scroll of the LayoutView. Child content is
// relative to that transform, and hence the fixed-position element.
if (context_.fixed_position.fixed_position_children_fixed_to_root)
context_.current.paint_offset_root = &box_model_object;
const auto* container = full_context_.container_for_fixed_position;
if (container && container->IsLayoutInline()) {
DCHECK(container->CanContainFixedPositionObjects());
DCHECK(box_model_object.IsBox());
context_.current.paint_offset +=
ToLayoutInline(container)->OffsetForInFlowPositionedInline(
ToLayoutBox(box_model_object));
}
break;
}
default:
NOTREACHED();
}
}
if (object_.IsBox()) {
// TODO(pdr): Several calls in this function walk back up the tree to
// calculate containers (e.g., physicalLocation, offsetForInFlowPosition*).
// The containing block and other containers can be stored on
// PaintPropertyTreeBuilderFragmentContext instead of recomputing them.
context_.current.paint_offset.MoveBy(
ToLayoutBox(object_).PhysicalLocation());
// This is a weird quirk that table cells paint as children of table rows,
// but their location have the row's location baked-in.
// Similar adjustment is done in LayoutTableCell::offsetFromContainer().
if (object_.IsTableCell()) {
LayoutObject* parent_row = object_.Parent();
DCHECK(parent_row && parent_row->IsTableRow());
context_.current.paint_offset.MoveBy(
-ToLayoutBox(parent_row)->PhysicalLocation());
}
}
context_.current.paint_offset.Move(
context_.repeating_paint_offset_adjustment);
}
void FragmentPaintPropertyTreeBuilder::SetNeedsPaintPropertyUpdateIfNeeded() {
if (!object_.IsBox())
return;
const LayoutBox& box = ToLayoutBox(object_);
if (NeedsOverflowClip(box)) {
bool had_overflow_clip = properties_ && properties_->OverflowClip();
if (had_overflow_clip == CanOmitOverflowClip(box))
box.GetMutableForPainting().SetNeedsPaintPropertyUpdate();
}
if (box.IsLayoutReplaced() &&
box.PreviousPhysicalContentBoxRect() != box.PhysicalContentBoxRect())
box.GetMutableForPainting().SetNeedsPaintPropertyUpdate();
if (box.Size() == box.PreviousSize())
return;
// CSS mask and clip-path comes with an implicit clip to the border box.
// Currently only SPv2 generate and take advantage of those.
const bool box_generates_property_nodes_for_mask_and_clip_path =
box.HasMask() || box.HasClipPath();
// The overflow clip paint property depends on the border box rect through
// overflowClipRect(). The border box rect's size equals the frame rect's
// size so we trigger a paint property update when the frame rect changes.
if (NeedsOverflowClip(box) || NeedsInnerBorderRadiusClip(box) ||
// The used value of CSS clip may depend on size of the box, e.g. for
// clip: rect(auto auto auto -5px).
NeedsCssClip(box) ||
// Relative lengths (e.g., percentage values) in transform, perspective,
// transform-origin, and perspective-origin can depend on the size of the
// frame rect, so force a property update if it changes. TODO(pdr): We
// only need to update properties if there are relative lengths.
box.StyleRef().HasTransform() || NeedsPerspective(box) ||
box_generates_property_nodes_for_mask_and_clip_path) {
box.GetMutableForPainting().SetNeedsPaintPropertyUpdate();
}
if (box.HasClipPath())
box.GetMutableForPainting().InvalidateClipPathCache();
// The filter generated for reflection depends on box size.
if (box.HasReflection()) {
DCHECK(box.HasLayer());
box.Layer()->SetFilterOnEffectNodeDirty();
box.GetMutableForPainting().SetNeedsPaintPropertyUpdate();
}
}
void FragmentPaintPropertyTreeBuilder::UpdateForObjectLocationAndSize(
base::Optional<IntPoint>& paint_offset_translation) {
context_.old_paint_offset = fragment_data_.PaintOffset();
UpdatePaintOffset();
UpdateForPaintOffsetTranslation(paint_offset_translation);
if (fragment_data_.PaintOffset() != context_.current.paint_offset) {
// Many paint properties depend on paint offset so we force an update of
// the entire subtree on paint offset changes.
// However, they are blocked by isolation.
full_context_.force_subtree_update_reasons |=
PaintPropertyTreeBuilderContext::kSubtreeUpdateIsolationBlocked;
object_.GetMutableForPainting().SetShouldCheckForPaintInvalidation();
fragment_data_.SetPaintOffset(context_.current.paint_offset);
fragment_data_.InvalidateClipPathCache();
object_.GetFrameView()->SetIntersectionObservationState(
LocalFrameView::kDesired);
}
if (paint_offset_translation)
context_.current.paint_offset_root = &ToLayoutBoxModelObject(object_);
}
void FragmentPaintPropertyTreeBuilder::UpdateClipPathCache() {
if (fragment_data_.IsClipPathCacheValid())
return;
if (!object_.StyleRef().ClipPath())
return;
base::Optional<FloatRect> bounding_box =
ClipPathClipper::LocalClipPathBoundingBox(object_);
if (!bounding_box) {
fragment_data_.SetClipPathCache(base::nullopt, nullptr);
return;
}
bounding_box->MoveBy(FloatPoint(fragment_data_.PaintOffset()));
bool is_valid = false;
base::Optional<Path> path = ClipPathClipper::PathBasedClip(
object_, object_.IsSVGChild(),
ClipPathClipper::LocalReferenceBox(object_), is_valid);
DCHECK(is_valid);
if (path)
path->Translate(ToFloatSize(FloatPoint(fragment_data_.PaintOffset())));
fragment_data_.SetClipPathCache(
EnclosingIntRect(*bounding_box),
path ? AdoptRef(new RefCountedPath(std::move(*path))) : nullptr);
}
void FragmentPaintPropertyTreeBuilder::UpdateForSelf() {
#if DCHECK_IS_ON()
FindPaintOffsetNeedingUpdateScope check_paint_offset(
object_, fragment_data_, full_context_.is_actually_needed);
#endif
// This is not in FindObjectPropertiesNeedingUpdateScope because paint offset
// can change without NeedsPaintPropertyUpdate.
base::Optional<IntPoint> paint_offset_translation;
UpdateForObjectLocationAndSize(paint_offset_translation);
if (&fragment_data_ == &object_.FirstFragment())
SetNeedsPaintPropertyUpdateIfNeeded();
UpdateClipPathCache();
if (properties_) {
{
#if DCHECK_IS_ON()
FindPropertiesNeedingUpdateScope check_fragment_clip(
object_, fragment_data_, full_context_.force_subtree_update_reasons);
#endif
UpdateFragmentClip();
}
// Update of PaintOffsetTranslation is checked by
// FindPaintOffsetNeedingUpdateScope.
UpdatePaintOffsetTranslation(paint_offset_translation);
}
#if DCHECK_IS_ON()
FindPropertiesNeedingUpdateScope check_paint_properties(
object_, fragment_data_, full_context_.force_subtree_update_reasons);
#endif
if (properties_) {
UpdateStickyTranslation();
UpdateTransform();
UpdateClipPathClip(false);
UpdateEffect();
UpdateLinkHighlightEffect();
UpdateClipPathClip(true); // Special pass for SPv1 composited clip-path.
UpdateCssClip();
UpdateFilter();
UpdateOverflowControlsClip();
}
UpdateLocalBorderBoxContext();
}
void FragmentPaintPropertyTreeBuilder::UpdateForChildren() {
#if DCHECK_IS_ON()
// Paint offset should not change during this function.
const bool needs_paint_offset_update = false;
FindPaintOffsetNeedingUpdateScope check_paint_offset(
object_, fragment_data_, needs_paint_offset_update);
FindPropertiesNeedingUpdateScope check_paint_properties(
object_, fragment_data_, full_context_.force_subtree_update_reasons);
#endif
if (properties_) {
UpdateInnerBorderRadiusClip();
UpdateOverflowClip();
UpdatePerspective();
UpdateReplacedContentTransform();
UpdateScrollAndScrollTranslation();
UpdateTransformIsolationNode();
UpdateEffectIsolationNode();
UpdateClipIsolationNode();
}
UpdateOutOfFlowContext();
#if DCHECK_IS_ON()
if (properties_)
properties_->Validate();
#endif
}
} // namespace
void PaintPropertyTreeBuilder::InitFragmentPaintProperties(
FragmentData& fragment,
bool needs_paint_properties,
const LayoutPoint& pagination_offset,
LayoutUnit logical_top_in_flow_thread) {
if (needs_paint_properties) {
fragment.EnsurePaintProperties();
} else if (fragment.PaintProperties()) {
// Tree topology changes are blocked by isolation.
context_.force_subtree_update_reasons |=
PaintPropertyTreeBuilderContext::kSubtreeUpdateIsolationBlocked;
fragment.ClearPaintProperties();
}
fragment.SetPaginationOffset(pagination_offset);
fragment.SetLogicalTopInFlowThread(logical_top_in_flow_thread);
}
void PaintPropertyTreeBuilder::InitSingleFragmentFromParent(
bool needs_paint_properties) {
FragmentData& first_fragment =
object_.GetMutableForPainting().FirstFragment();
first_fragment.ClearNextFragment();
InitFragmentPaintProperties(first_fragment, needs_paint_properties);
if (context_.fragments.IsEmpty()) {
context_.fragments.push_back(PaintPropertyTreeBuilderFragmentContext());
} else {
context_.fragments.resize(1);
context_.fragments[0].fragment_clip.reset();
context_.fragments[0].logical_top_in_flow_thread = LayoutUnit();
}
// Column-span:all skips pagination container in the tree hierarchy, so it
// should also skip any fragment clip created by the skipped pagination
// container. We also need to skip fragment clip if the object is a paint
// invalidation container which doesn't allow fragmentation.
if (object_.IsColumnSpanAll() ||
(!RuntimeEnabledFeatures::SlimmingPaintV2Enabled() &&
object_.IsPaintInvalidationContainer() &&
ToLayoutBoxModelObject(object_).Layer()->EnclosingPaginationLayer())) {
if (const auto* pagination_layer_in_tree_hierarchy =
object_.Parent()->EnclosingLayer()->EnclosingPaginationLayer()) {
const auto* properties =
pagination_layer_in_tree_hierarchy->GetLayoutObject()
.FirstFragment()
.PaintProperties();
if (properties && properties->FragmentClip()) {
context_.fragments[0].current.clip =
properties->FragmentClip()->Parent();
}
}
}
}
void PaintPropertyTreeBuilder::UpdateCompositedLayerPaginationOffset() {
if (RuntimeEnabledFeatures::SlimmingPaintV2Enabled())
return;
const auto* enclosing_pagination_layer =
context_.painting_layer->EnclosingPaginationLayer();
if (!enclosing_pagination_layer)
return;
// We reach here because context_.painting_layer is in a composited layer
// under the pagination layer. SPv1* doesn't fragment composited layers,
// but we still need to set correct pagination offset for correct paint
// offset calculation.
DCHECK(!context_.painting_layer->ShouldFragmentCompositedBounds());
FragmentData& first_fragment =
object_.GetMutableForPainting().FirstFragment();
bool is_paint_invalidation_container = object_.IsPaintInvalidationContainer();
const auto* parent_composited_layer =
context_.painting_layer->EnclosingLayerWithCompositedLayerMapping(
is_paint_invalidation_container ? kExcludeSelf : kIncludeSelf);
if (is_paint_invalidation_container &&
(!parent_composited_layer ||
!parent_composited_layer->EnclosingPaginationLayer())) {
// |object_| establishes the top level composited layer under the
// pagination layer.
FragmentainerIterator iterator(
ToLayoutFlowThread(enclosing_pagination_layer->GetLayoutObject()),
BoundingBoxInPaginationContainer(object_, *enclosing_pagination_layer));
if (!iterator.AtEnd()) {
first_fragment.SetPaginationOffset(
ToLayoutPoint(iterator.PaginationOffset()));
first_fragment.SetLogicalTopInFlowThread(
iterator.FragmentainerLogicalTopInFlowThread());
}
} else if (parent_composited_layer) {
// All objects under the composited layer use the same pagination offset.
const auto& fragment =
parent_composited_layer->GetLayoutObject().FirstFragment();
first_fragment.SetPaginationOffset(fragment.PaginationOffset());
first_fragment.SetLogicalTopInFlowThread(fragment.LogicalTopInFlowThread());
}
}
void PaintPropertyTreeBuilder::
UpdateRepeatingTableSectionPaintOffsetAdjustment() {
if (!context_.repeating_table_section)
return;
if (object_ == context_.repeating_table_section) {
if (ToLayoutTableSection(object_).IsRepeatingHeaderGroup())
UpdateRepeatingTableHeaderPaintOffsetAdjustment();
else if (ToLayoutTableSection(object_).IsRepeatingFooterGroup())
UpdateRepeatingTableFooterPaintOffsetAdjustment();
} else if (!context_.painting_layer->EnclosingPaginationLayer()) {
// When repeating a table section in paged media, paint_offset is inherited
// by descendants, so we only need to adjust point offset for the table
// section.
for (auto& fragment_context : context_.fragments) {
fragment_context.repeating_paint_offset_adjustment = LayoutSize();
}
}
// Otherwise the object is a descendant of the object which initiated the
// repeating. It just uses repeating_paint_offset_adjustment in its fragment
// contexts inherited from the initiating object.
}
// TODO(wangxianzhu): For now this works for horizontal-bt writing mode only.
// Need to support vertical writing modes.
void PaintPropertyTreeBuilder::
UpdateRepeatingTableHeaderPaintOffsetAdjustment() {
const auto& section = ToLayoutTableSection(object_);
DCHECK(section.IsRepeatingHeaderGroup());
LayoutUnit fragment_height;
LayoutUnit original_offset_in_flow_thread =
context_.repeating_table_section_bounding_box.Y();
LayoutUnit original_offset_in_fragment;
const LayoutFlowThread* flow_thread = nullptr;
if (const auto* pagination_layer =
context_.painting_layer->EnclosingPaginationLayer()) {
flow_thread = &ToLayoutFlowThread(pagination_layer->GetLayoutObject());
// TODO(crbug.com/757947): This shouldn't be possible but happens to
// column-spanners in nested multi-col contexts.
if (!flow_thread->IsPageLogicalHeightKnown())
return;
fragment_height =
flow_thread->PageLogicalHeightForOffset(original_offset_in_flow_thread);
original_offset_in_fragment =
fragment_height - flow_thread->PageRemainingLogicalHeightForOffset(
original_offset_in_flow_thread,
LayoutBox::kAssociateWithLatterPage);
} else {
// The containing LayoutView serves as the virtual pagination container
// for repeating table section in paged media.
fragment_height = object_.View()->PageLogicalHeight();
original_offset_in_fragment =
IntMod(original_offset_in_flow_thread, fragment_height);
}
// This is total height of repeating headers seen by the table - height of
// this header (which is the lowest repeating header seen by this table.
auto repeating_offset_in_fragment =
section.Table()->RowOffsetFromRepeatingHeader() - section.LogicalHeight();
// For a repeating table header, the original location (which may be in the
// middle of the fragment) and repeated locations (which should be always,
// together with repeating headers of outer tables, aligned to the top of
// the fragments) may be different. Therefore, for fragments other than the
// first, adjust by |alignment_offset|.
auto adjustment = repeating_offset_in_fragment - original_offset_in_fragment;
auto fragment_offset_in_flow_thread =
original_offset_in_flow_thread - original_offset_in_fragment;
for (wtf_size_t i = 0; i < context_.fragments.size(); ++i) {
auto& fragment_context = context_.fragments[i];
fragment_context.repeating_paint_offset_adjustment = LayoutSize();
// Adjust paint offsets of repeatings (not including the original).
if (i)
fragment_context.repeating_paint_offset_adjustment.SetHeight(adjustment);
// Calculate the adjustment for the repeating which will appear in the next
// fragment.
adjustment += fragment_height;
// Calculate the offset of the next fragment in flow thread. It's used to
// get the height of that fragment.
fragment_offset_in_flow_thread += fragment_height;
if (flow_thread) {
fragment_height = flow_thread->PageLogicalHeightForOffset(
fragment_offset_in_flow_thread);
}
}
}
void PaintPropertyTreeBuilder::
UpdateRepeatingTableFooterPaintOffsetAdjustment() {
const auto& section = ToLayoutTableSection(object_);
DCHECK(section.IsRepeatingFooterGroup());
LayoutUnit fragment_height;
LayoutUnit original_offset_in_flow_thread =
context_.repeating_table_section_bounding_box.MaxY() -
section.LogicalHeight();
LayoutUnit original_offset_in_fragment;
const LayoutFlowThread* flow_thread = nullptr;
if (const auto* pagination_layer =
context_.painting_layer->EnclosingPaginationLayer()) {
flow_thread = &ToLayoutFlowThread(pagination_layer->GetLayoutObject());
// TODO(crbug.com/757947): This shouldn't be possible but happens to
// column-spanners in nested multi-col contexts.
if (!flow_thread->IsPageLogicalHeightKnown())
return;
fragment_height =
flow_thread->PageLogicalHeightForOffset(original_offset_in_flow_thread);
original_offset_in_fragment =
fragment_height - flow_thread->PageRemainingLogicalHeightForOffset(
original_offset_in_flow_thread,
LayoutBox::kAssociateWithLatterPage);
} else {
// The containing LayoutView serves as the virtual pagination container
// for repeating table section in paged media.
fragment_height = object_.View()->PageLogicalHeight();
original_offset_in_fragment =
IntMod(original_offset_in_flow_thread, fragment_height);
}
const auto& table = *section.Table();
// TODO(crbug.com/798153): This keeps the existing behavior of repeating
// footer painting in TableSectionPainter. Should change both places when
// tweaking border-spacing for repeating footers.
auto repeating_offset_in_fragment = fragment_height -
table.RowOffsetFromRepeatingFooter() -
table.VBorderSpacing();
// We should show the whole bottom border instead of half if the table
// collapses borders.
if (table.ShouldCollapseBorders())
repeating_offset_in_fragment -= table.BorderBottom();
// Similar to repeating header, this is to adjust the repeating footer from
// its original location to the repeating location.
auto adjustment = repeating_offset_in_fragment - original_offset_in_fragment;
auto fragment_offset_in_flow_thread =
original_offset_in_flow_thread - original_offset_in_fragment;
for (auto i = context_.fragments.size(); i > 0; --i) {
auto& fragment_context = context_.fragments[i - 1];
fragment_context.repeating_paint_offset_adjustment = LayoutSize();
// Adjust paint offsets of repeatings.
if (i != context_.fragments.size())
fragment_context.repeating_paint_offset_adjustment.SetHeight(adjustment);
// Calculate the adjustment for the repeating which will appear in the
// previous fragment.
adjustment -= fragment_height;
// Calculate the offset of the previous fragment in flow thread. It's used
// to get the height of that fragment.
fragment_offset_in_flow_thread -= fragment_height;
if (flow_thread) {
fragment_height = flow_thread->PageLogicalHeightForOffset(
fragment_offset_in_flow_thread);
}
}
}
static LayoutUnit FragmentLogicalTopInParentFlowThread(
const LayoutFlowThread& flow_thread,
LayoutUnit logical_top_in_current_flow_thread) {
const auto* parent_pagination_layer =
flow_thread.Layer()->Parent()->EnclosingPaginationLayer();
if (!parent_pagination_layer)
return LayoutUnit();
const auto* parent_flow_thread =
&ToLayoutFlowThread(parent_pagination_layer->GetLayoutObject());
LayoutPoint location(LayoutUnit(), logical_top_in_current_flow_thread);
// TODO(crbug.com/467477): Should we flip for writing-mode? For now regardless
// of flipping, fast/multicol/vertical-rl/nested-columns.html fails.
if (!flow_thread.IsHorizontalWritingMode())
location = location.TransposedPoint();
// Convert into parent_flow_thread's coordinates.
location = LayoutPoint(flow_thread.LocalToAncestorPoint(FloatPoint(location),
parent_flow_thread));
if (!parent_flow_thread->IsHorizontalWritingMode())
location = location.TransposedPoint();
if (location.X() >= parent_flow_thread->LogicalWidth()) {
// TODO(crbug.com/803649): We hit this condition for
// external/wpt/css/css-multicol/multicol-height-block-child-001.xht.
// The normal path would cause wrong FragmentClip hierarchy.
// Return -1 to force standalone FragmentClip in the case.
return LayoutUnit(-1);
}
// Return the logical top of the containing fragment in parent_flow_thread.
return location.Y() +
parent_flow_thread->PageRemainingLogicalHeightForOffset(
location.Y(), LayoutBox::kAssociateWithLatterPage) -
parent_flow_thread->PageLogicalHeightForOffset(location.Y());
}
// Find from parent contexts with matching |logical_top_in_flow_thread|, if any,
// to allow for correct property tree parenting of fragments.
PaintPropertyTreeBuilderFragmentContext
PaintPropertyTreeBuilder::ContextForFragment(
const base::Optional<LayoutRect>& fragment_clip,
LayoutUnit logical_top_in_flow_thread) const {
const auto& parent_fragments = context_.fragments;
if (parent_fragments.IsEmpty())
return PaintPropertyTreeBuilderFragmentContext();
// This will be used in the loop finding matching fragment from ancestor flow
// threads after no matching from parent_fragments.
LayoutUnit logical_top_in_containing_flow_thread;
if (object_.IsLayoutFlowThread()) {
const auto& flow_thread = ToLayoutFlowThread(object_);
// If this flow thread is under another flow thread, find the fragment in
// the parent flow thread containing this fragment. Otherwise, the following
// code will just match parent_contexts[0].
logical_top_in_containing_flow_thread =
FragmentLogicalTopInParentFlowThread(flow_thread,
logical_top_in_flow_thread);
for (const auto& parent_context : parent_fragments) {
if (logical_top_in_containing_flow_thread ==
parent_context.logical_top_in_flow_thread) {
auto context = parent_context;
context.fragment_clip = fragment_clip;
context.logical_top_in_flow_thread = logical_top_in_flow_thread;
return context;
}
}
} else {
bool parent_is_under_same_flow_thread;
auto* pagination_layer =
context_.painting_layer->EnclosingPaginationLayer();
if (object_.IsColumnSpanAll()) {
parent_is_under_same_flow_thread = false;
} else if (object_.IsOutOfFlowPositioned()) {
parent_is_under_same_flow_thread =
(object_.Parent()->PaintingLayer()->EnclosingPaginationLayer() ==
pagination_layer);
} else {
parent_is_under_same_flow_thread = true;
}
// Match against parent_fragments if the fragment and parent_fragments are
// under the same flow thread.
if (parent_is_under_same_flow_thread) {
DCHECK(object_.Parent()->PaintingLayer()->EnclosingPaginationLayer() ==
pagination_layer);
for (const auto& parent_context : parent_fragments) {
if (logical_top_in_flow_thread ==
parent_context.logical_top_in_flow_thread) {
auto context = parent_context;
// The context inherits fragment clip from parent so we don't need
// to issue fragment clip again.
context.fragment_clip = base::nullopt;
return context;
}
}
}
logical_top_in_containing_flow_thread = logical_top_in_flow_thread;
}
// Found no matching parent fragment. Use parent_fragments[0] to inherit
// transforms and effects from ancestors, and adjust the clip state.
// TODO(crbug.com/803649): parent_fragments[0] is not always correct because
// some ancestor transform/effect may be missing in the fragment if the
// ancestor doesn't intersect with the first fragment of the flow thread.
auto context = parent_fragments[0];
context.logical_top_in_flow_thread = logical_top_in_flow_thread;
context.fragment_clip = fragment_clip;
// We reach here because of the following reasons:
// 1. the parent doesn't have the corresponding fragment because the fragment
// overflows the parent;
// 2. the fragment and parent_fragments are not under the same flow thread
// (e.g. column-span:all or some out-of-flow positioned).
// For each case, we need to adjust context.current.clip. For now it's the
// first parent fragment's FragmentClip which is not the correct clip for
// object_.
for (const <