| // Copyright 2015 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "cobalt/layout/container_box.h" |
| |
| #include <algorithm> |
| |
| #include "cobalt/cssom/keyword_value.h" |
| #include "cobalt/cssom/number_value.h" |
| #include "cobalt/layout/used_style.h" |
| #include "cobalt/math/transform_2d.h" |
| |
| namespace cobalt { |
| namespace layout { |
| |
| ContainerBox::ContainerBox( |
| const scoped_refptr<cssom::CSSComputedStyleDeclaration>& |
| css_computed_style_declaration, |
| UsedStyleProvider* used_style_provider, |
| LayoutStatTracker* layout_stat_tracker) |
| : Box(css_computed_style_declaration, used_style_provider, |
| layout_stat_tracker), |
| update_size_results_valid_(false), |
| are_cross_references_valid_(false), |
| are_bidi_levels_runs_split_(false), |
| next_draw_order_position_(0) {} |
| |
| ContainerBox::~ContainerBox() {} |
| |
| // Given a non-const container and a const iterator from that container, this |
| // will return a non-const iterator. |
| Boxes::iterator ContainerBox::RemoveConst(Boxes* container, |
| Boxes::const_iterator const_iter) { |
| // Since ChildBoxes is a vector, std::distance and std::advance are both |
| // constant time. |
| Boxes::iterator iter = container->begin(); |
| std::advance(iter, std::distance<Boxes::const_iterator>(iter, const_iter)); |
| return iter; |
| } |
| |
| void ContainerBox::PushBackDirectChild(const scoped_refptr<Box>& child_box) { |
| // Verify that the child doesn't have a pre-existing parent. |
| DCHECK(!child_box->parent()); |
| |
| // Verify that this container hasn't had its sizes and cross references |
| // already updated. This is because children should only ever be added to |
| // containers created during the current box generation run. |
| DCHECK(!update_size_results_valid_); |
| DCHECK(!are_cross_references_valid_); |
| |
| child_box->parent_ = this; |
| child_boxes_.push_back(child_box); |
| } |
| |
| Boxes::const_iterator ContainerBox::InsertSplitSiblingOfDirectChild( |
| Boxes::const_iterator child_position) { |
| Box* split_sibling = (*child_position)->GetSplitSibling(); |
| |
| // Verify that the split sibling exists and that it doesn't have a |
| // pre-existing parent. |
| DCHECK(split_sibling); |
| DCHECK(!split_sibling->parent()); |
| |
| // Set the parent of the split sibling to this container. |
| split_sibling->parent_ = this; |
| |
| // Add the split sibling to this container after it's sibling. |
| Boxes::const_iterator split_sibling_position = child_boxes_.insert( |
| RemoveConst(&child_boxes_, ++child_position), split_sibling); |
| |
| // Invalidate the size now that the children have changed. |
| update_size_results_valid_ = false; |
| |
| // Check to see if the split sibling is positioned, which means that it |
| // needs to invalidate its containing block's cross references. |
| bool is_positioned = split_sibling->IsPositioned(); |
| if (is_positioned) { |
| split_sibling->GetContainingBlock()->are_cross_references_valid_ = false; |
| } |
| // Check to see if the split sibling is a stacking context child, which means |
| // that it needs to invalidate its stacking context's cross references. |
| if (is_positioned || split_sibling->IsStackingContext()) { |
| split_sibling->GetStackingContext()->are_cross_references_valid_ = false; |
| } |
| |
| // Invalidate the render tree nodes now that the children have changed. |
| InvalidateRenderTreeNodesOfBoxAndAncestors(); |
| |
| return split_sibling_position; |
| } |
| |
| void ContainerBox::MoveDirectChildrenToSplitSibling( |
| Boxes::const_iterator start_position) { |
| // Verify that the move includes children. |
| DCHECK(start_position != child_boxes_.end()); |
| |
| ContainerBox* split_sibling = GetSplitSibling()->AsContainerBox(); |
| |
| // Verify that the split sibling exists and that it hasn't been processed yet. |
| DCHECK(split_sibling); |
| DCHECK(!split_sibling->parent()); |
| DCHECK(!split_sibling->update_size_results_valid_); |
| DCHECK(!split_sibling->are_cross_references_valid_); |
| |
| // Update the parent of the children being moved. |
| for (Boxes::const_iterator iter = start_position; iter != child_boxes_.end(); |
| ++iter) { |
| (*iter)->parent_ = split_sibling; |
| } |
| |
| // Add the children to the split sibling's list of children. |
| Boxes::iterator source_start_non_const = |
| RemoveConst(&child_boxes_, start_position); |
| Boxes::iterator source_end_non_const = |
| RemoveConst(&child_boxes_, child_boxes_.end()); |
| split_sibling->child_boxes_.insert( |
| RemoveConst(&split_sibling->child_boxes_, |
| split_sibling->child_boxes_.end()), |
| source_start_non_const, source_end_non_const); |
| |
| // Erase the children from this container's list of children. |
| child_boxes_.erase(source_start_non_const, source_end_non_const); |
| |
| // Invalidate the size now that the children have changed. |
| update_size_results_valid_ = false; |
| |
| // Handle invalidating cross references. Children are only being removed from |
| // this container, so cross references only need to be invalidated if there is |
| // a non-empty cross reference list that can potentially be impacted. |
| |
| // If there are any positioned boxes, then they need to be re-generated. |
| if (!positioned_child_boxes_.empty()) { |
| are_cross_references_valid_ = false; |
| } |
| |
| // There are two cases where the stacking context's cross references can be |
| // impacted by children moving from one container to another. With both cases, |
| // stacking context children must exist or there is nothing to update. |
| // 1. Stacking context children are potentially moving from this child |
| // container to the split sibling child container. |
| // 2. Stacking context children contained within this overflow hidden |
| // container are potentially moving to the split sibling overflow hidden |
| // container. |
| if (HasStackingContextChildren() || |
| computed_style()->overflow() == cssom::KeywordValue::GetHidden()) { |
| // Walk up the tree until the nearest stacking context is found. If this box |
| // is a stacking context, then it will be used. |
| ContainerBox* nearest_stacking_context = this; |
| while (!nearest_stacking_context->IsStackingContext()) { |
| nearest_stacking_context = nearest_stacking_context->parent(); |
| } |
| if (nearest_stacking_context->HasStackingContextChildren()) { |
| nearest_stacking_context->are_cross_references_valid_ = false; |
| } |
| } |
| |
| // Invalidate the render tree nodes now that the children have changed. |
| InvalidateRenderTreeNodesOfBoxAndAncestors(); |
| } |
| |
| bool ContainerBox::IsContainingBlockForPositionAbsoluteElements() const { |
| return parent() == NULL || IsPositioned() || IsTransformed(); |
| } |
| |
| bool ContainerBox::IsContainingBlockForPositionFixedElements() const { |
| return parent() == NULL || IsTransformed(); |
| } |
| |
| bool ContainerBox::IsStackingContext() const { |
| // The core stacking context creation criteria is given here |
| // (https://www.w3.org/TR/CSS21/visuren.html#z-index) however it is extended |
| // by various other specification documents such as those describing opacity |
| // (https://www.w3.org/TR/css3-color/#transparency) and transforms |
| // (https://www.w3.org/TR/css3-transforms/#transform-rendering). |
| // NOTE: Fixed position elements are treated as stacking contexts. While the |
| // spec does not specify that they create a stacking context, this is the |
| // functionality of Chrome, Firefox, Edge, and Safari. |
| return parent() == NULL || |
| (base::polymorphic_downcast<const cssom::NumberValue*>( |
| computed_style()->opacity().get()) |
| ->value() < 1.0f) || |
| IsTransformed() || |
| (IsPositioned() && |
| computed_style()->z_index() != cssom::KeywordValue::GetAuto()) || |
| computed_style()->position() == cssom::KeywordValue::GetFixed(); |
| } |
| |
| void ContainerBox::UpdateCrossReferences() { |
| if (!are_cross_references_valid_) { |
| // If this point is reached, then the cross references for this container |
| // box are being re-generated. |
| layout_stat_tracker()->OnUpdateCrossReferences(); |
| |
| bool is_stacking_context = IsStackingContext(); |
| |
| // Cross references are not cleared when they are invalidated. This is |
| // because they can be invalidated while they are being walked if a |
| // relatively positioned descendant is split. Therefore, they need to be |
| // cleared now before they are regenerated. |
| positioned_child_boxes_.clear(); |
| if (is_stacking_context) { |
| negative_z_index_stacking_context_children_.clear(); |
| non_negative_z_index_stacking_context_children_.clear(); |
| } |
| |
| // This stack tracks all container boxes within the stacking context. The |
| // container boxes will only be pushed and popped if the current box is |
| // their stacking context. |
| StackingContextContainerBoxStack stacking_context_container_box_stack; |
| |
| const RelationshipToBox kNearestContainingBlockOfChildren = kIsBox; |
| RelationshipToBox nearest_absolute_containing_block = |
| IsContainingBlockForPositionAbsoluteElements() ? kIsBox |
| : kIsBoxAncestor; |
| RelationshipToBox nearest_fixed_containing_block = |
| IsContainingBlockForPositionFixedElements() ? kIsBox : kIsBoxAncestor; |
| RelationshipToBox nearest_stacking_context = |
| is_stacking_context ? kIsBox : kIsBoxAncestor; |
| |
| for (Boxes::const_iterator child_box_iterator = child_boxes_.begin(); |
| child_box_iterator != child_boxes_.end(); ++child_box_iterator) { |
| Box* child_box = *child_box_iterator; |
| child_box->UpdateCrossReferencesOfContainerBox( |
| this, kNearestContainingBlockOfChildren, |
| nearest_absolute_containing_block, nearest_fixed_containing_block, |
| nearest_stacking_context, &stacking_context_container_box_stack); |
| } |
| |
| are_cross_references_valid_ = true; |
| } |
| } |
| |
| void ContainerBox::AddContainingBlockChild(Box* child_box) { |
| DCHECK_NE(this, child_box); |
| DCHECK_EQ(this, child_box->GetContainingBlock()); |
| positioned_child_boxes_.push_back(child_box); |
| } |
| |
| void ContainerBox::AddStackingContextChild( |
| Box* child_box, int child_z_index, |
| RelationshipToBox containing_block_relationship, |
| const ContainingBlocksWithOverflowHidden& overflow_hidden_to_apply) { |
| DCHECK_NE(this, child_box); |
| DCHECK_EQ(child_z_index, child_box->GetZIndex()); |
| // If this is a stacking context, then verify that the child box's stacking |
| // context is this stacking context. |
| // Otherwise, verify that this box's stacking context is also the child box's |
| // stacking context and that the z_index of the child is 0 (non-zero z-index |
| // children must be added directly to the stacking context). |
| DCHECK(this->IsStackingContext() |
| ? this == child_box->GetStackingContext() |
| : this->GetStackingContext() == child_box->GetStackingContext() && |
| child_z_index == 0); |
| |
| ZIndexSortedList& stacking_context_children = |
| child_z_index < 0 ? negative_z_index_stacking_context_children_ |
| : non_negative_z_index_stacking_context_children_; |
| stacking_context_children.insert(StackingContextChildInfo( |
| child_box, child_z_index, containing_block_relationship, |
| overflow_hidden_to_apply)); |
| } |
| |
| bool ContainerBox::HasStackingContextChildren() const { |
| return !negative_z_index_stacking_context_children_.empty() || |
| !non_negative_z_index_stacking_context_children_.empty(); |
| } |
| |
| namespace { |
| |
| Vector2dLayoutUnit GetOffsetFromContainingBlockToParent(Box* child_box) { |
| Vector2dLayoutUnit relative_position; |
| for (Box *ancestor_box = child_box->parent(), |
| *containing_block = child_box->GetContainingBlock(); |
| ancestor_box != containing_block; |
| ancestor_box = ancestor_box->parent()) { |
| DCHECK(ancestor_box) |
| << "Unable to find containing block while traversing parents."; |
| // It is not possible for the containing block to be more distant than an |
| // ancestor that is transformed. |
| DCHECK(!ancestor_box->IsTransformed()); |
| |
| relative_position += ancestor_box->GetContentBoxOffsetFromMarginBox(); |
| relative_position += |
| ancestor_box->margin_box_offset_from_containing_block(); |
| } |
| return relative_position; |
| } |
| |
| } // namespace |
| |
| bool ContainerBox::ValidateUpdateSizeInputs(const LayoutParams& params) { |
| // Take into account whether our children have been modified to determine |
| // if our sizes are invalid and need to be recomputed. |
| if (Box::ValidateUpdateSizeInputs(params) && update_size_results_valid_) { |
| return true; |
| } else { |
| update_size_results_valid_ = true; |
| return false; |
| } |
| } |
| |
| void ContainerBox::InvalidateCrossReferencesOfBoxAndAncestors() { |
| // NOTE: The cross reference containers are not cleared here. Instead they are |
| // cleared when the cross references are updated. |
| are_cross_references_valid_ = false; |
| Box::InvalidateCrossReferencesOfBoxAndAncestors(); |
| } |
| |
| ContainerBox* ContainerBox::AsContainerBox() { return this; } |
| const ContainerBox* ContainerBox::AsContainerBox() const { return this; } |
| |
| void ContainerBox::UpdateRectOfPositionedChildBoxes( |
| const LayoutParams& relative_child_layout_params, |
| const LayoutParams& absolute_child_layout_params) { |
| // Ensure that the cross references are up to date. |
| UpdateCrossReferences(); |
| |
| for (std::vector<Box*>::const_iterator child_box_iterator = |
| positioned_child_boxes_.begin(); |
| child_box_iterator != positioned_child_boxes_.end(); |
| ++child_box_iterator) { |
| Box* child_box = *child_box_iterator; |
| DCHECK_EQ(this, child_box->GetContainingBlock()); |
| |
| const scoped_refptr<cssom::PropertyValue>& child_box_position = |
| child_box->computed_style()->position(); |
| |
| if (child_box_position == cssom::KeywordValue::GetAbsolute()) { |
| UpdateRectOfAbsolutelyPositionedChildBox(child_box, |
| absolute_child_layout_params); |
| } else if (child_box_position == cssom::KeywordValue::GetFixed()) { |
| UpdateRectOfAbsolutelyPositionedChildBox(child_box, |
| relative_child_layout_params); |
| } else { |
| DCHECK(child_box_position == cssom::KeywordValue::GetRelative()); |
| UpdateOffsetOfRelativelyPositionedChildBox(child_box, |
| relative_child_layout_params); |
| } |
| |
| // Verify that the positioned child boxes didn't get cleared during the |
| // walk. This should never happen because the cross references being |
| // invalidated should not cause them to be cleared. |
| DCHECK_GT(positioned_child_boxes_.size(), size_t(0)); |
| } |
| } |
| |
| void ContainerBox::UpdateOffsetOfRelativelyPositionedChildBox( |
| Box* child_box, const LayoutParams& child_layout_params) { |
| DCHECK_EQ(child_box->computed_style()->position(), |
| cssom::KeywordValue::GetRelative()); |
| |
| base::optional<LayoutUnit> maybe_left = GetUsedLeftIfNotAuto( |
| child_box->computed_style(), child_layout_params.containing_block_size); |
| base::optional<LayoutUnit> maybe_right = GetUsedRightIfNotAuto( |
| child_box->computed_style(), child_layout_params.containing_block_size); |
| base::optional<LayoutUnit> maybe_top = GetUsedTopIfNotAuto( |
| child_box->computed_style(), child_layout_params.containing_block_size); |
| base::optional<LayoutUnit> maybe_bottom = GetUsedBottomIfNotAuto( |
| child_box->computed_style(), child_layout_params.containing_block_size); |
| |
| Vector2dLayoutUnit offset; |
| |
| // The following steps are performed according to the procedure described |
| // here: https://www.w3.org/TR/CSS21/visuren.html#relative-positioning |
| |
| // For relatively positioned elements, 'left' and 'right' move the box(es) |
| // horizontally, without changing their size. |
| if (!maybe_left && !maybe_right) { |
| // If both 'left' and 'right' are 'auto' (their initial values), the used |
| // values are '0' (i.e., the boxes stay in their original position). |
| offset.set_x(LayoutUnit()); |
| } else if (maybe_left && !maybe_right) { |
| // If 'right' is 'auto', its used value is minus the value of 'left'. |
| offset.set_x(*maybe_left); |
| } else if (!maybe_left && maybe_right) { |
| // If 'left' is 'auto', its used value is minus the value of 'right' |
| offset.set_x(-*maybe_right); |
| } else { |
| // If neither 'left' nor 'right' is 'auto', the position is |
| // over-constrained, and one of them has to be ignored. If the 'direction' |
| // property of the containing block is 'ltr', the value of 'left' wins and |
| // 'right' becomes -'left'. If 'direction' of the containing block is 'rtl', |
| // 'right' wins and 'left' is ignored. |
| |
| // TODO: Take into account the value of the 'direction' property, which |
| // doesn't exist at the time of this writing. |
| offset.set_x(*maybe_left); |
| } |
| |
| // The 'top' and 'bottom' properties move relatively positioned element(s) up |
| // or down without changing their size. |
| if (!maybe_top && !maybe_bottom) { |
| // If both are 'auto', their used values are both '0'. |
| offset.set_y(LayoutUnit()); |
| } else if (maybe_top && !maybe_bottom) { |
| // If one of them is 'auto', it becomes the negative of the other. |
| offset.set_y(*maybe_top); |
| } else if (!maybe_top && maybe_bottom) { |
| // If one of them is 'auto', it becomes the negative of the other. |
| offset.set_y(-*maybe_bottom); |
| } else { |
| // If neither is 'auto', 'bottom' is ignored (i.e., the used value of |
| // 'bottom' will be minus the value of 'top'). |
| offset.set_y(*maybe_top); |
| } |
| |
| child_box->set_left(child_box->left() + offset.x()); |
| child_box->set_top(child_box->top() + offset.y()); |
| } |
| |
| void ContainerBox::UpdateRectOfAbsolutelyPositionedChildBox( |
| Box* child_box, const LayoutParams& child_layout_params) { |
| Vector2dLayoutUnit offset_from_containing_block_to_parent = |
| GetOffsetFromContainingBlockToParent(child_box); |
| // The containing block is formed by the padding box instead of the content |
| // box, as described in |
| // http://www.w3.org/TR/CSS21/visudet.html#containing-block-details. |
| // NOTE: While not explicitly stated in the spec, which specifies that |
| // the containing block of a 'fixed' position element must always be the |
| // viewport, all major browsers use the padding box of a transformed ancestor |
| // as the containing block for 'fixed' position elements. |
| offset_from_containing_block_to_parent += GetContentBoxOffsetFromPaddingBox(); |
| child_box->SetStaticPositionLeftFromContainingBlockToParent( |
| offset_from_containing_block_to_parent.x()); |
| child_box->SetStaticPositionTopFromContainingBlockToParent( |
| offset_from_containing_block_to_parent.y()); |
| child_box->UpdateSize(child_layout_params); |
| } |
| |
| namespace { |
| |
| // This class handles all logic involved with calling RenderAndAnimate() on |
| // stacking context children., including determining their offset from the child |
| // container and applying overflow hidden from its containing blocks. |
| class RenderAndAnimateStackingContextChildrenCoordinator { |
| public: |
| RenderAndAnimateStackingContextChildrenCoordinator( |
| ContainerBox* stacking_context, const ContainerBox* child_container, |
| const Vector2dLayoutUnit& child_container_offset_from_parent_node, |
| render_tree::CompositionNode::Builder* base_node_builder) |
| : stacking_context_(stacking_context), |
| child_container_(child_container), |
| child_container_offset_from_parent_node_( |
| child_container_offset_from_parent_node), |
| base_node_builder_(base_node_builder) {} |
| |
| // The destructor handles generating filter nodes for any remaining entries in |
| // |overflow_hidden_stack_|. |
| ~RenderAndAnimateStackingContextChildrenCoordinator(); |
| |
| // Applies overflow hidden from the child's containing blocks and then calls |
| // RenderAndAnimate() on it. |
| void RenderAndAnimateChild( |
| const ContainerBox::StackingContextChildInfo& child_info); |
| |
| private: |
| struct OverflowHiddenInfo { |
| explicit OverflowHiddenInfo(ContainerBox* containing_block) |
| : node_builder(math::Vector2dF()), containing_block(containing_block) {} |
| |
| render_tree::CompositionNode::Builder node_builder; |
| ContainerBox* containing_block; |
| }; |
| |
| typedef std::vector<OverflowHiddenInfo> OverflowHiddenStack; |
| |
| // Updates |overflow_hidden_stack_| with the overflow hidden containing blocks |
| // of the current child. Any entries in |overflow_hidden_stack_| that are no |
| // longer valid are popped. All entries that remain valid are retained, so |
| // that filter nodes can be shared across stacking context children. |
| void ApplyOverflowHiddenForChild( |
| const Box::ContainingBlocksWithOverflowHidden& overflow_hidden_to_apply); |
| |
| // Generates a filter node from the top entry in |overflow_hidden_stack_| and |
| // adds it to the active node builder after the top entry is popped. |
| void PopOverflowHiddenEntryFromStack(); |
| |
| // Returns the node builder from the top entry in |overflow_hidden_stack_| if |
| // it is not empty; otherwise, returns |base_node_builder_|. |
| render_tree::CompositionNode::Builder* GetActiveNodeBuilder(); |
| |
| Vector2dLayoutUnit GetOffsetFromChildContainerToContainingBlock( |
| const Box* containing_block, |
| const Box::RelationshipToBox |
| containing_block_relationship_to_child_container) const; |
| |
| ContainerBox* stacking_context_; |
| const ContainerBox* child_container_; |
| const Vector2dLayoutUnit& child_container_offset_from_parent_node_; |
| |
| render_tree::CompositionNode::Builder* base_node_builder_; |
| OverflowHiddenStack overflow_hidden_stack_; |
| }; |
| |
| RenderAndAnimateStackingContextChildrenCoordinator:: |
| ~RenderAndAnimateStackingContextChildrenCoordinator() { |
| while (!overflow_hidden_stack_.empty()) { |
| PopOverflowHiddenEntryFromStack(); |
| } |
| } |
| |
| void RenderAndAnimateStackingContextChildrenCoordinator::RenderAndAnimateChild( |
| const ContainerBox::StackingContextChildInfo& child_info) { |
| ApplyOverflowHiddenForChild(child_info.overflow_hidden_to_apply); |
| |
| // Generate the offset from the child container to the child box. |
| const ContainerBox* child_containing_block = |
| child_info.box->GetContainingBlock(); |
| Vector2dLayoutUnit position_offset = |
| GetOffsetFromChildContainerToContainingBlock( |
| child_containing_block, child_info.containing_block_relationship) + |
| child_container_offset_from_parent_node_; |
| if (child_info.box->IsAbsolutelyPositioned()) { |
| // The containing block is formed by the padding box instead of the content |
| // box, as described in |
| // http://www.w3.org/TR/CSS21/visudet.html#containing-block-details. |
| // NOTE: While not explicitly stated in the spec, which specifies that |
| // the containing block of a 'fixed' position element must always be the |
| // viewport, all major browsers use the padding box of a transformed |
| // ancestor as the containing block for 'fixed' position elements. |
| position_offset -= |
| child_containing_block->GetContentBoxOffsetFromPaddingBox(); |
| } |
| |
| child_info.box->RenderAndAnimate(GetActiveNodeBuilder(), position_offset, |
| stacking_context_); |
| } |
| |
| void RenderAndAnimateStackingContextChildrenCoordinator:: |
| ApplyOverflowHiddenForChild(const Box::ContainingBlocksWithOverflowHidden& |
| overflow_hidden_to_apply) { |
| // Walk the overflow hidden list being applied and the active overflow hidden |
| // stack looking for the first index where there's a mismatch. All entries |
| // prior to this are retained. This allows as many FilterNodes as possible to |
| // be shared between the stacking context children. |
| size_t index = 0; |
| for (; index < overflow_hidden_to_apply.size() && |
| index < overflow_hidden_stack_.size(); |
| ++index) { |
| if (overflow_hidden_to_apply[index] != |
| overflow_hidden_stack_[index].containing_block) { |
| break; |
| } |
| } |
| |
| // Pop all entries in the active overflow hidden stack that follow the index |
| // mismatch. They're no longer contained within the overflow hidden list being |
| // applied. |
| while (index < overflow_hidden_stack_.size()) { |
| PopOverflowHiddenEntryFromStack(); |
| } |
| |
| // Add the new overflow hidden entries to the active stack. |
| for (; index < overflow_hidden_to_apply.size(); ++index) { |
| overflow_hidden_stack_.push_back( |
| OverflowHiddenInfo(overflow_hidden_to_apply[index])); |
| } |
| } |
| |
| void RenderAndAnimateStackingContextChildrenCoordinator:: |
| PopOverflowHiddenEntryFromStack() { |
| DCHECK(!overflow_hidden_stack_.empty()); |
| // Before popping the top of the stack, a filter node is generated from it |
| // that is added to next node builder. |
| OverflowHiddenInfo& overflow_hidden_info = overflow_hidden_stack_.back(); |
| |
| ContainerBox* containing_block = overflow_hidden_info.containing_block; |
| DCHECK_EQ(containing_block->computed_style()->overflow(), |
| cssom::KeywordValue::GetHidden()); |
| |
| // Determine the offset from the child container to this containing block's |
| // margin box. |
| Vector2dLayoutUnit containing_block_border_offset = |
| GetOffsetFromChildContainerToContainingBlock(containing_block, |
| Box::kIsBoxAncestor) + |
| Vector2dLayoutUnit(containing_block->margin_left(), |
| containing_block->margin_top()); |
| |
| // Apply the overflow hidden from this containing block to its composition |
| // node; the resulting filter node is added to the next active node builder. |
| scoped_refptr<render_tree::Node> filter_node = |
| containing_block->RenderAndAnimateOverflow( |
| new render_tree::CompositionNode( |
| overflow_hidden_info.node_builder.Pass()), |
| math::Vector2dF(containing_block_border_offset.x().toFloat(), |
| containing_block_border_offset.y().toFloat())); |
| |
| overflow_hidden_stack_.pop_back(); |
| GetActiveNodeBuilder()->AddChild(filter_node); |
| } |
| |
| render_tree::CompositionNode::Builder* |
| RenderAndAnimateStackingContextChildrenCoordinator::GetActiveNodeBuilder() { |
| return overflow_hidden_stack_.empty() |
| ? base_node_builder_ |
| : &(overflow_hidden_stack_.back().node_builder); |
| } |
| |
| Vector2dLayoutUnit RenderAndAnimateStackingContextChildrenCoordinator:: |
| GetOffsetFromChildContainerToContainingBlock( |
| const Box* containing_block, |
| const Box::RelationshipToBox |
| containing_block_relationship_to_child_container) const { |
| if (containing_block_relationship_to_child_container == Box::kIsBox) { |
| DCHECK_EQ(child_container_, containing_block); |
| return Vector2dLayoutUnit(); |
| } |
| |
| Vector2dLayoutUnit relative_position; |
| const Box* current_box = |
| containing_block_relationship_to_child_container == Box::kIsBoxAncestor |
| ? child_container_ |
| : containing_block; |
| const Box* end_box = |
| containing_block_relationship_to_child_container == Box::kIsBoxAncestor |
| ? containing_block |
| : child_container_; |
| |
| // Walk up the containing blocks from |current_box| to |end_box| adding the |
| // offsets from each box to its containing block. |
| // NOTE: |end_box| can be skipped during this walk both when |end_box| is not |
| // positioned and when a fixed position box is encountered during the walk. In |
| // this case, the walk will end when a box is found that either does not have |
| // a parent (meaning that it's the root box) or is transformed (it is |
| // impossible for |end_box| to be a more distant ancestor than a transformed |
| // box). |
| while (current_box != end_box && current_box->parent() && |
| !current_box->IsTransformed()) { |
| relative_position += current_box->GetContentBoxOffsetFromMarginBox(); |
| relative_position += current_box->margin_box_offset_from_containing_block(); |
| |
| const Box* next_box = current_box->GetContainingBlock(); |
| if (current_box->IsAbsolutelyPositioned()) { |
| relative_position -= next_box->GetContentBoxOffsetFromPaddingBox(); |
| } |
| current_box = next_box; |
| } |
| |
| // If |current_box| does not equal |end_box|, then |end_box| was skipped |
| // during the walk up the tree. Initiate a second walk up the tree from the |
| // end box to the box where the first walk ended, subtracting the offsets |
| // during this walk to remove the extra offsets added after passing |end_box| |
| // during the first walk. |
| std::swap(current_box, end_box); |
| while (current_box != end_box) { |
| DCHECK(current_box->parent()); |
| DCHECK(!current_box->IsTransformed()); |
| |
| relative_position -= current_box->GetContentBoxOffsetFromMarginBox(); |
| relative_position -= current_box->margin_box_offset_from_containing_block(); |
| |
| const Box* next_box = current_box->GetContainingBlock(); |
| if (current_box->IsAbsolutelyPositioned()) { |
| relative_position += next_box->GetContentBoxOffsetFromPaddingBox(); |
| } |
| current_box = next_box; |
| } |
| |
| // If the containing block is an ancestor of the child container, then |
| // reverse the relative position now. The earlier calculations were for the |
| // containing block being a descendant of the child container. |
| if (containing_block_relationship_to_child_container == Box::kIsBoxAncestor) { |
| relative_position = -relative_position; |
| } |
| |
| return relative_position; |
| } |
| |
| } // namespace |
| |
| void ContainerBox::RenderAndAnimateStackingContextChildren( |
| const ZIndexSortedList& stacking_context_child_list, |
| render_tree::CompositionNode::Builder* content_node_builder, |
| const Vector2dLayoutUnit& offset_from_parent_node, |
| ContainerBox* stacking_context) const { |
| // Create a coordinator that handles all logic involved with calling |
| // RenderAndAnimate() on stacking context children., including determining |
| // their offset from the child container and applying overflow hidden from the |
| // child's containing blocks. |
| RenderAndAnimateStackingContextChildrenCoordinator coordinator( |
| stacking_context, this, offset_from_parent_node, content_node_builder); |
| |
| // Render all children of the passed in list in sorted order. |
| for (ZIndexSortedList::const_iterator iter = |
| stacking_context_child_list.begin(); |
| iter != stacking_context_child_list.end(); ++iter) { |
| const StackingContextChildInfo& child_info = *iter; |
| |
| // If this container box is a stacking context, then verify that this child |
| // box belongs to it; otherwise, verify that the container box and the child |
| // box share the same stacking context and that the child's z-index is 0. |
| DCHECK(this->IsStackingContext() |
| ? this == child_info.box->GetStackingContext() |
| : this->GetStackingContext() == |
| child_info.box->GetStackingContext() && |
| child_info.z_index == 0); |
| |
| coordinator.RenderAndAnimateChild(child_info); |
| } |
| } |
| |
| size_t ContainerBox::AddToDrawOrderInThisStackingContext() { |
| return next_draw_order_position_++; |
| } |
| |
| void ContainerBox::SplitBidiLevelRuns() { |
| // Only split the child boxes if the bidi level runs haven't already been |
| // split. |
| if (!are_bidi_levels_runs_split_) { |
| are_bidi_levels_runs_split_ = true; |
| |
| for (Boxes::const_iterator child_box_iterator = child_boxes_.begin(); |
| child_box_iterator != child_boxes_.end(); ++child_box_iterator) { |
| Box* child_box = *child_box_iterator; |
| child_box->SplitBidiLevelRuns(); |
| } |
| } |
| } |
| |
| void ContainerBox::UpdateCrossReferencesOfContainerBox( |
| ContainerBox* source_box, RelationshipToBox nearest_containing_block, |
| RelationshipToBox nearest_absolute_containing_block, |
| RelationshipToBox nearest_fixed_containing_block, |
| RelationshipToBox nearest_stacking_context, |
| StackingContextContainerBoxStack* stacking_context_container_box_stack) { |
| // First update the source container box's cross references with this box. |
| Box::UpdateCrossReferencesOfContainerBox( |
| source_box, nearest_containing_block, nearest_absolute_containing_block, |
| nearest_fixed_containing_block, nearest_stacking_context, |
| stacking_context_container_box_stack); |
| |
| // In addition to updating the source container box's cross references with |
| // this box, we also recursively update it with our children. |
| |
| // Set the nearest flags for the children. If this container box is any of the |
| // specified types, then the target container box cannot be the nearest box of |
| // that type for the children. |
| |
| const RelationshipToBox kNearestContainingBlockOfChildren = kIsBoxDescendant; |
| RelationshipToBox nearest_absolute_containing_block_of_children = |
| nearest_absolute_containing_block != kIsBoxDescendant && |
| IsContainingBlockForPositionAbsoluteElements() |
| ? kIsBoxDescendant |
| : nearest_absolute_containing_block; |
| RelationshipToBox nearest_fixed_containing_block_of_children = |
| nearest_fixed_containing_block != kIsBoxDescendant && |
| IsContainingBlockForPositionFixedElements() |
| ? kIsBoxDescendant |
| : nearest_fixed_containing_block; |
| RelationshipToBox nearest_stacking_context_of_children = |
| nearest_stacking_context != kIsBoxDescendant && IsStackingContext() |
| ? kIsBoxDescendant |
| : nearest_stacking_context; |
| |
| // If the source box is the stacking context for this container box, then |
| // clear out this box's stacking context children. They are being set now by |
| // the stacking context. Additionally, add this container to the stack, so |
| // that it will be considered as a possible destination for the stacking |
| // context children. |
| if (nearest_stacking_context_of_children == kIsBox) { |
| negative_z_index_stacking_context_children_.clear(); |
| non_negative_z_index_stacking_context_children_.clear(); |
| |
| bool has_absolute_position = |
| computed_style()->position() == cssom::KeywordValue::GetAbsolute(); |
| bool has_overflow_hidden = |
| computed_style()->overflow() == cssom::KeywordValue::GetHidden(); |
| |
| stacking_context_container_box_stack->push_back( |
| StackingContextContainerBoxInfo( |
| this, IsContainingBlockForPositionAbsoluteElements(), |
| has_absolute_position, has_overflow_hidden)); |
| } |
| |
| // Only process the children if the target container box is still the nearest |
| // box of one of the types. If it is not, then it is impossible for any of the |
| // children to be added to the cross references. |
| if (nearest_absolute_containing_block_of_children == kIsBox || |
| nearest_fixed_containing_block_of_children == kIsBox || |
| nearest_stacking_context_of_children == kIsBox) { |
| for (Boxes::const_iterator child_box_iterator = child_boxes_.begin(); |
| child_box_iterator != child_boxes_.end(); ++child_box_iterator) { |
| Box* child_box = *child_box_iterator; |
| child_box->UpdateCrossReferencesOfContainerBox( |
| source_box, kNearestContainingBlockOfChildren, |
| nearest_absolute_containing_block_of_children, |
| nearest_fixed_containing_block_of_children, |
| nearest_stacking_context_of_children, |
| stacking_context_container_box_stack); |
| } |
| } |
| |
| // Pop this container from the stack if it was previously added. |
| if (nearest_stacking_context_of_children == kIsBox) { |
| stacking_context_container_box_stack->pop_back(); |
| } |
| } |
| |
| void ContainerBox::AddBoxAndDescendantsToDrawOrderInStackingContext( |
| ContainerBox* stacking_context) { |
| Box::AddBoxAndDescendantsToDrawOrderInStackingContext(stacking_context); |
| // If this is a stacking context, then there's no more work to do. None of |
| // the stacking context children can be part of the ancestor stacking context. |
| // If this is not a stacking context, then all of the stacking context |
| // children are still part of the same stacking context. |
| if (!IsStackingContext()) { |
| // Non-stacking contexts can only have stacking context children with a |
| // z-index of zero. Any child with non-zero z-index, must be added to the |
| // stacking context itself. |
| DCHECK(negative_z_index_stacking_context_children_.empty()); |
| for (ZIndexSortedList::const_iterator iter = |
| non_negative_z_index_stacking_context_children_.begin(); |
| iter != non_negative_z_index_stacking_context_children_.end(); |
| ++iter) { |
| DCHECK_EQ(iter->z_index, 0); |
| iter->box->AddBoxAndDescendantsToDrawOrderInStackingContext( |
| stacking_context); |
| } |
| } |
| } |
| |
| void ContainerBox::RenderAndAnimateContent( |
| render_tree::CompositionNode::Builder* content_node_builder, |
| ContainerBox* stacking_context) const { |
| // Update the stacking context if this is found to be a stacking context. |
| ContainerBox* this_as_stacking_context = const_cast<ContainerBox*>(this); |
| |
| // Reset the draw order for this box. Even if it isn't explictly a stacking |
| // context, it'll be used as one for in-flow, non-positioned child boxes. |
| this_as_stacking_context->next_draw_order_position_ = 0; |
| |
| // If this is a stacking context, then ensure that the |
| // stacking context children are up to date. This will also update the |
| // stacking context children for any descendant container boxes that are |
| // part of this stacking context. |
| if (IsStackingContext()) { |
| stacking_context = this_as_stacking_context; |
| stacking_context->UpdateCrossReferences(); |
| } |
| |
| Vector2dLayoutUnit content_box_offset(border_left_width() + padding_left(), |
| border_top_width() + padding_top()); |
| |
| // Render all child stacking contexts and positioned children in our stacking |
| // context that have negative z-index values. |
| // https://www.w3.org/TR/CSS21/visuren.html#z-index |
| RenderAndAnimateStackingContextChildren( |
| negative_z_index_stacking_context_children_, content_node_builder, |
| content_box_offset, stacking_context); |
| |
| // Render in-flow, non-positioned child boxes. |
| // https://www.w3.org/TR/CSS21/visuren.html#z-index |
| for (Boxes::const_iterator child_box_iterator = child_boxes_.begin(); |
| child_box_iterator != child_boxes_.end(); ++child_box_iterator) { |
| Box* child_box = *child_box_iterator; |
| if (!child_box->IsPositioned() && !child_box->IsStackingContext()) { |
| child_box->RenderAndAnimate(content_node_builder, content_box_offset, |
| this_as_stacking_context); |
| } |
| } |
| |
| // Render all child stacking contexts and positioned children in our stacking |
| // context that have non-negative z-index values. |
| // https://www.w3.org/TR/CSS21/visuren.html#z-index |
| RenderAndAnimateStackingContextChildren( |
| non_negative_z_index_stacking_context_children_, content_node_builder, |
| content_box_offset, stacking_context); |
| } |
| |
| #ifdef COBALT_BOX_DUMP_ENABLED |
| |
| void ContainerBox::DumpChildrenWithIndent(std::ostream* stream, |
| int indent) const { |
| Box::DumpChildrenWithIndent(stream, indent); |
| |
| for (Boxes::const_iterator child_box_iterator = child_boxes_.begin(); |
| child_box_iterator != child_boxes_.end(); ++child_box_iterator) { |
| Box* child_box = *child_box_iterator; |
| child_box->DumpWithIndent(stream, indent); |
| } |
| } |
| |
| #endif // COBALT_BOX_DUMP_ENABLED |
| |
| } // namespace layout |
| } // namespace cobalt |