| // Copyright 2016 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. |
| |
| #ifndef NGOutOfFlowLayoutPart_h |
| #define NGOutOfFlowLayoutPart_h |
| |
| #include "third_party/blink/renderer/core/core_export.h" |
| |
| #include "base/optional.h" |
| #include "third_party/blink/renderer/core/layout/ng/geometry/ng_physical_offset.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_absolute_utils.h" |
| #include "third_party/blink/renderer/core/style/computed_style_base_constants.h" |
| #include "third_party/blink/renderer/platform/wtf/hash_map.h" |
| |
| namespace blink { |
| |
| class ComputedStyle; |
| class LayoutBox; |
| class LayoutObject; |
| class NGBlockNode; |
| class NGBoxFragmentBuilder; |
| class NGConstraintSpace; |
| class NGLayoutResult; |
| struct NGOutOfFlowPositionedDescendant; |
| |
| // Helper class for positioning of out-of-flow blocks. |
| // It should be used together with NGBoxFragmentBuilder. |
| // See NGBoxFragmentBuilder::AddOutOfFlowChildCandidate documentation |
| // for example of using these classes together. |
| class CORE_EXPORT NGOutOfFlowLayoutPart { |
| STACK_ALLOCATED(); |
| |
| public: |
| // The container_builder, borders_and_scrollers, container_space and |
| // container_style parameters are all with respect to the containing block of |
| // the relevant out-of-flow positioned descendants. If the CSS "containing |
| // block" of such an out-of-flow positioned descendant isn't a true block (but |
| // e.g. a relatively positioned inline instead), the containing block here is |
| // the containing block of said non-block. |
| NGOutOfFlowLayoutPart( |
| NGBoxFragmentBuilder* container_builder, |
| bool contains_absolute, |
| bool contains_fixed, |
| const NGBoxStrut& borders_and_scrollers, |
| const NGConstraintSpace& container_space, |
| const ComputedStyle& container_style, |
| base::Optional<NGLogicalSize> initial_containing_block_fixed_size = |
| base::nullopt); |
| |
| // Normally this function lays out and positions all out-of-flow objects |
| // from the container_builder and additional ones it discovers through laying |
| // out those objects. However, if only_layout is specified, only that object |
| // will get laid out; any additional ones will be stored as out-of-flow |
| // descendants in the builder for use via |
| // LayoutResult::OutOfFlowPositionedDescendants. |
| void Run(LayoutBox* only_layout = nullptr); |
| |
| private: |
| // Information needed to position descendant within a containing block. |
| // Geometry expressed here is complicated: |
| // There are two types of containing blocks: |
| // 1) Default containing block (DCB) |
| // Containing block passed in NGOutOfFlowLayoutPart constructor. |
| // It is the block element inside which this algorighm runs. |
| // All OOF descendants not in inline containing block are placed in DCB. |
| // 2) Inline containing block |
| // OOF descendants might be positioned wrt inline containing block. |
| // Inline containing block is positioned wrt default containing block. |
| struct ContainingBlockInfo { |
| STACK_ALLOCATED(); |
| |
| public: |
| // Containing block style. |
| const ComputedStyle* style; |
| // Logical in containing block coordinates. |
| NGLogicalSize content_size_for_absolute; |
| // Content size for fixed is different for the ICB. |
| NGLogicalSize content_size_for_fixed; |
| |
| // Offsets (both logical and physical) of the container's padding-box, wrt. |
| // the default container's border-box. |
| NGLogicalOffset container_offset; |
| NGPhysicalOffset physical_container_offset; |
| |
| NGLogicalSize ContentSize(EPosition position) const { |
| return position == EPosition::kAbsolute ? content_size_for_absolute |
| : content_size_for_fixed; |
| } |
| }; |
| |
| ContainingBlockInfo GetContainingBlockInfo( |
| const NGOutOfFlowPositionedDescendant&) const; |
| |
| void ComputeInlineContainingBlocks(Vector<NGOutOfFlowPositionedDescendant>); |
| |
| scoped_refptr<NGLayoutResult> LayoutDescendant( |
| const NGOutOfFlowPositionedDescendant&, |
| NGLogicalOffset* offset); |
| |
| bool IsContainingBlockForDescendant( |
| const NGOutOfFlowPositionedDescendant& descendant); |
| |
| scoped_refptr<NGLayoutResult> GenerateFragment( |
| NGBlockNode node, |
| const ContainingBlockInfo&, |
| const base::Optional<LayoutUnit>& block_estimate, |
| const NGAbsolutePhysicalPosition& node_position); |
| |
| NGBoxFragmentBuilder* container_builder_; |
| bool contains_absolute_; |
| bool contains_fixed_; |
| ContainingBlockInfo default_containing_block_; |
| HashMap<const LayoutObject*, ContainingBlockInfo> containing_blocks_map_; |
| }; |
| |
| } // namespace blink |
| |
| #endif |