| // 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 NGConstraintSpace_h |
| #define NGConstraintSpace_h |
| |
| #include "base/optional.h" |
| #include "third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.h" |
| #include "third_party/blink/renderer/core/core_export.h" |
| #include "third_party/blink/renderer/core/layout/geometry/logical_size.h" |
| #include "third_party/blink/renderer/core/layout/geometry/physical_size.h" |
| #include "third_party/blink/renderer/core/layout/ng/exclusions/ng_exclusion_space.h" |
| #include "third_party/blink/renderer/core/layout/ng/geometry/ng_bfc_offset.h" |
| #include "third_party/blink/renderer/core/layout/ng/geometry/ng_margin_strut.h" |
| #include "third_party/blink/renderer/core/layout/ng/inline/ng_baseline.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_break_appeal.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_floats_utils.h" |
| #include "third_party/blink/renderer/platform/text/text_direction.h" |
| #include "third_party/blink/renderer/platform/text/writing_mode.h" |
| #include "third_party/blink/renderer/platform/wtf/ref_counted.h" |
| #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h" |
| |
| namespace blink { |
| |
| class LayoutBlock; |
| class NGConstraintSpaceBuilder; |
| |
| enum NGFragmentationType { |
| kFragmentNone, |
| kFragmentPage, |
| kFragmentColumn, |
| kFragmentRegion |
| }; |
| |
| // "adjoining" objects (either floats or inline-level OOF-positioned nodes) are |
| // used to indicate that a particular node might need a relayout once its BFC |
| // block-offset is resvoled. E.g. their position depends on the final BFC |
| // block-offset being known. |
| enum NGAdjoiningObjectTypeValue { |
| kAdjoiningNone = 0b000, |
| kAdjoiningFloatLeft = 0b001, |
| kAdjoiningFloatRight = 0b010, |
| kAdjoiningFloatBoth = 0b011, |
| kAdjoiningInlineOutOfFlow = 0b100 |
| }; |
| typedef int NGAdjoiningObjectTypes; |
| |
| // Tables have two passes, a "measure" pass (for determining the table row |
| // height), and a "layout" pass. |
| // See: https://drafts.csswg.org/css-tables-3/#row-layout |
| // |
| // This enum is used for communicating to *direct* children of table cells, |
| // which layout mode the table cell is in. |
| enum class NGTableCellChildLayoutMode { |
| kNotTableCellChild, // The node isn't a table cell child. |
| kMeasure, // A table cell child, in the "measure" mode. |
| kMeasureRestricted, // A table cell child, in the "restricted-measure" mode. |
| kLayout // A table cell child, in the "layout" mode. |
| }; |
| |
| // Percentages are frequently the same as the available-size, zero, or |
| // indefinite (thanks non-quirks mode)! This enum encodes this information. |
| enum NGPercentageStorage { |
| kSameAsAvailable, |
| kZero, |
| kIndefinite, |
| kRareDataPercentage |
| }; |
| |
| // The NGConstraintSpace represents a set of constraints and available space |
| // which a layout algorithm may produce a NGFragment within. |
| class CORE_EXPORT NGConstraintSpace final { |
| USING_FAST_MALLOC(NGConstraintSpace); |
| |
| public: |
| // To ensure that the bfc_offset_, rare_data_ union doesn't get polluted, |
| // always initialize the bfc_offset_. |
| NGConstraintSpace() : bfc_offset_() {} |
| |
| NGConstraintSpace(const NGConstraintSpace& other) |
| : available_size_(other.available_size_), |
| exclusion_space_(other.exclusion_space_), |
| bitfields_(other.bitfields_) { |
| if (HasRareData()) |
| rare_data_ = new RareData(*other.rare_data_); |
| else |
| bfc_offset_ = other.bfc_offset_; |
| } |
| NGConstraintSpace(NGConstraintSpace&& other) |
| : available_size_(other.available_size_), |
| exclusion_space_(std::move(other.exclusion_space_)), |
| bitfields_(other.bitfields_) { |
| if (HasRareData()) { |
| rare_data_ = other.rare_data_; |
| other.rare_data_ = nullptr; |
| } else { |
| bfc_offset_ = other.bfc_offset_; |
| } |
| } |
| |
| NGConstraintSpace& operator=(const NGConstraintSpace& other) { |
| available_size_ = other.available_size_; |
| if (HasRareData()) |
| delete rare_data_; |
| if (other.HasRareData()) |
| rare_data_ = new RareData(*other.rare_data_); |
| else |
| bfc_offset_ = other.bfc_offset_; |
| exclusion_space_ = other.exclusion_space_; |
| bitfields_ = other.bitfields_; |
| return *this; |
| } |
| NGConstraintSpace& operator=(NGConstraintSpace&& other) { |
| available_size_ = other.available_size_; |
| if (HasRareData()) |
| delete rare_data_; |
| if (other.HasRareData()) { |
| rare_data_ = other.rare_data_; |
| other.rare_data_ = nullptr; |
| } else { |
| bfc_offset_ = other.bfc_offset_; |
| } |
| exclusion_space_ = std::move(other.exclusion_space_); |
| bitfields_ = other.bitfields_; |
| return *this; |
| } |
| |
| ~NGConstraintSpace() { |
| if (HasRareData()) |
| delete rare_data_; |
| } |
| |
| // Creates NGConstraintSpace representing LayoutObject's containing block. |
| // This should live on NGBlockNode or another layout bridge and probably take |
| // a root NGConstraintSpace. |
| static NGConstraintSpace CreateFromLayoutObject(const LayoutBlock&, |
| bool is_layout_root); |
| |
| const NGExclusionSpace& ExclusionSpace() const { return exclusion_space_; } |
| |
| TextDirection Direction() const { |
| return static_cast<TextDirection>(bitfields_.direction); |
| } |
| |
| WritingMode GetWritingMode() const { |
| return static_cast<WritingMode>(bitfields_.writing_mode); |
| } |
| |
| bool IsOrthogonalWritingModeRoot() const { |
| return bitfields_.is_orthogonal_writing_mode_root; |
| } |
| |
| // The available space size. |
| // See: https://drafts.csswg.org/css-sizing/#available |
| LogicalSize AvailableSize() const { return available_size_; } |
| |
| // The size to use for percentage resolution. |
| // See: https://drafts.csswg.org/css-sizing/#percentage-sizing |
| LayoutUnit PercentageResolutionInlineSize() const { |
| switch (static_cast<NGPercentageStorage>( |
| bitfields_.percentage_inline_storage)) { |
| default: |
| NOTREACHED(); |
| U_FALLTHROUGH; |
| case kSameAsAvailable: |
| return available_size_.inline_size; |
| case kZero: |
| return LayoutUnit(); |
| case kIndefinite: |
| return kIndefiniteSize; |
| case kRareDataPercentage: |
| DCHECK(HasRareData()); |
| return rare_data_->percentage_resolution_size.inline_size; |
| } |
| } |
| |
| LayoutUnit PercentageResolutionBlockSize() const { |
| switch ( |
| static_cast<NGPercentageStorage>(bitfields_.percentage_block_storage)) { |
| default: |
| NOTREACHED(); |
| U_FALLTHROUGH; |
| case kSameAsAvailable: |
| return available_size_.block_size; |
| case kZero: |
| return LayoutUnit(); |
| case kIndefinite: |
| return kIndefiniteSize; |
| case kRareDataPercentage: |
| DCHECK(HasRareData()); |
| return rare_data_->percentage_resolution_size.block_size; |
| } |
| } |
| |
| LogicalSize PercentageResolutionSize() const { |
| return {PercentageResolutionInlineSize(), PercentageResolutionBlockSize()}; |
| } |
| |
| LayoutUnit ReplacedPercentageResolutionInlineSize() const { |
| return PercentageResolutionInlineSize(); |
| } |
| |
| LayoutUnit ReplacedPercentageResolutionBlockSize() const { |
| switch (static_cast<NGPercentageStorage>( |
| bitfields_.replaced_percentage_block_storage)) { |
| case kSameAsAvailable: |
| return available_size_.block_size; |
| case kZero: |
| return LayoutUnit(); |
| case kIndefinite: |
| return kIndefiniteSize; |
| case kRareDataPercentage: |
| DCHECK(HasRareData()); |
| return rare_data_->replaced_percentage_resolution_block_size; |
| default: |
| NOTREACHED(); |
| } |
| |
| return available_size_.block_size; |
| } |
| |
| // The size to use for percentage resolution of replaced elements. |
| LogicalSize ReplacedPercentageResolutionSize() const { |
| return {ReplacedPercentageResolutionInlineSize(), |
| ReplacedPercentageResolutionBlockSize()}; |
| } |
| |
| // The size to use for percentage resolution for margin/border/padding. |
| // They are always get computed relative to the inline size, in the parent |
| // writing mode. |
| LayoutUnit PercentageResolutionInlineSizeForParentWritingMode() const { |
| if (!IsOrthogonalWritingModeRoot()) |
| return PercentageResolutionInlineSize(); |
| if (PercentageResolutionBlockSize() != kIndefiniteSize) |
| return PercentageResolutionBlockSize(); |
| // TODO(mstensho): Figure out why we get here. It seems wrong, but we do get |
| // here in some grid layout situations. |
| return LayoutUnit(); |
| } |
| |
| // Return the borders which should be used for a table-cell. |
| NGBoxStrut TableCellBorders() const { |
| return HasRareData() ? rare_data_->TableCellBorders() : NGBoxStrut(); |
| } |
| |
| // Return the "intrinsic" padding for a table-cell. |
| NGBoxStrut TableCellIntrinsicPadding() const { |
| return HasRareData() ? rare_data_->TableCellIntrinsicPadding() |
| : NGBoxStrut(); |
| } |
| |
| LayoutUnit FragmentainerBlockSize() const { |
| return HasRareData() ? rare_data_->fragmentainer_block_size |
| : kIndefiniteSize; |
| } |
| |
| // Return the block space that was available in the current fragmentainer at |
| // the start of the current block formatting context. Note that if the start |
| // of the current block formatting context is in a previous fragmentainer, the |
| // size of the current fragmentainer is returned instead. |
| LayoutUnit FragmentainerSpaceAtBfcStart() const { |
| DCHECK(HasBlockFragmentation()); |
| return HasRareData() ? rare_data_->fragmentainer_space_at_bfc_start |
| : kIndefiniteSize; |
| } |
| |
| // Whether the current constraint space is for the newly established |
| // Formatting Context. |
| bool IsNewFormattingContext() const { |
| return bitfields_.is_new_formatting_context; |
| } |
| |
| // Whether the current node is a table-cell. |
| bool IsTableCell() const { return bitfields_.is_table_cell; } |
| |
| // Whether the fragment produced from layout should be anonymous, (e.g. it |
| // may be a column in a multi-column layout). In such cases it shouldn't have |
| // any borders or padding. |
| bool IsAnonymous() const { return bitfields_.is_anonymous; } |
| |
| // Whether to use the ':first-line' style or not. |
| // Note, this is not about the first line of the content to layout, but |
| // whether the constraint space itself is on the first line, such as when it's |
| // an inline block. |
| // Also note this is true only when the document has ':first-line' rules. |
| bool UseFirstLineStyle() const { return bitfields_.use_first_line_style; } |
| |
| // Returns true if an ancestor had clearance past adjoining floats. |
| // |
| // Typically this can be detected by seeing if a |ForcedBfcBlockOffset| is |
| // set. However new formatting contexts may require additional passes (if |
| // margins are adjoining or not), and without this extra bit of information |
| // can get into a bad state. |
| bool AncestorHasClearancePastAdjoiningFloats() const { |
| return bitfields_.ancestor_has_clearance_past_adjoining_floats; |
| } |
| |
| // Some layout modes “stretch” their children to a fixed size (e.g. flex, |
| // grid). These flags represented whether a layout needs to produce a |
| // fragment that satisfies a fixed constraint in the inline and block |
| // direction respectively. |
| // |
| // If these flags are true, the AvailableSize() is interpreted as the fixed |
| // border-box size of this box in the respective dimension. |
| bool IsFixedInlineSize() const { return bitfields_.is_fixed_inline_size; } |
| |
| bool IsFixedBlockSize() const { return bitfields_.is_fixed_block_size; } |
| |
| // Whether a fixed block-size should be considered indefinite. |
| bool IsFixedBlockSizeIndefinite() const { |
| return bitfields_.is_fixed_block_size_indefinite; |
| } |
| |
| // Whether an auto inline-size should be interpreted as shrink-to-fit |
| // (ie. fit-content). This is used for inline-block, floats, etc. |
| bool IsShrinkToFit() const { return bitfields_.is_shrink_to_fit; } |
| |
| // Whether this constraint space is used for an intermediate layout in a |
| // multi-pass layout. In such a case, we should not copy back the resulting |
| // layout data to the legacy tree or create a paint fragment from it. |
| bool IsIntermediateLayout() const { |
| return bitfields_.is_intermediate_layout; |
| } |
| |
| // If specified a layout should produce a Fragment which fragments at the |
| // blockSize if possible. |
| NGFragmentationType BlockFragmentationType() const { |
| return HasRareData() ? static_cast<NGFragmentationType>( |
| rare_data_->block_direction_fragmentation_type) |
| : kFragmentNone; |
| } |
| |
| // Return true if this constraint space participates in a fragmentation |
| // context. |
| bool HasBlockFragmentation() const { |
| return BlockFragmentationType() != kFragmentNone; |
| } |
| |
| // Return true if there's an ancestor multicol container with balanced |
| // columns. |
| bool IsInsideBalancedColumns() const { |
| return HasRareData() && rare_data_->is_inside_balanced_columns; |
| } |
| |
| // Return true if we're participating in the same block formatting context as |
| // the one established by the nearest ancestor multicol container. |
| bool IsInColumnBfc() const { |
| return HasRareData() && rare_data_->is_in_column_bfc; |
| } |
| |
| // Get the appeal of the best breakpoint found so far. When progressing |
| // through layout, we know that we don't need to consider less appealing |
| // breakpoints than this. |
| NGBreakAppeal EarlyBreakAppeal() const { |
| if (!HasRareData()) |
| return kBreakAppealLastResort; |
| return static_cast<NGBreakAppeal>(rare_data_->early_break_appeal); |
| } |
| |
| // Returns if this node is a table cell child, and which table layout mode |
| // is occurring. |
| NGTableCellChildLayoutMode TableCellChildLayoutMode() const { |
| return static_cast<NGTableCellChildLayoutMode>( |
| bitfields_.table_cell_child_layout_mode); |
| } |
| |
| // Return true if the block size of the table-cell should be considered |
| // restricted (e.g. height of the cell or its table is non-auto). |
| bool IsRestrictedBlockSizeTableCell() const { |
| return bitfields_.is_restricted_block_size_table_cell; |
| } |
| |
| NGMarginStrut MarginStrut() const { |
| return HasRareData() ? rare_data_->MarginStrut() : NGMarginStrut(); |
| } |
| |
| // The BfcOffset is where the MarginStrut is placed within the block |
| // formatting context. |
| // |
| // The current layout or a descendant layout may "resolve" the BFC offset, |
| // i.e. decide where the current fragment should be placed within the BFC. |
| // |
| // This is done by: |
| // bfc_block_offset = |
| // space.BfcOffset().block_offset + space.MarginStrut().Sum(); |
| // |
| // The BFC offset can get "resolved" in many circumstances (including, but |
| // not limited to): |
| // - block_start border or padding in the current layout. |
| // - Text content, atomic inlines, (see NGLineBreaker). |
| // - The current layout having a block_size. |
| // - Clearance before a child. |
| NGBfcOffset BfcOffset() const { |
| return HasRareData() ? rare_data_->bfc_offset : bfc_offset_; |
| } |
| |
| // If present, and the current layout hasn't resolved its BFC block-offset |
| // yet (see BfcOffset), the layout should position all of its floats at this |
| // offset. |
| // |
| // This value is present if: |
| // - An ancestor had clearance past adjoining floats. In this case this |
| // value is calculated ahead of time. |
| // - A second layout pass is required as there were adjoining-floats |
| // within the tree, and an arbitrary sibling determined their BFC |
| // block-offset. |
| // |
| // This value should be propagated to child layouts if the current layout |
| // hasn't resolved its BFC offset yet. |
| base::Optional<LayoutUnit> ForcedBfcBlockOffset() const { |
| return HasRareData() ? rare_data_->ForcedBfcBlockOffset() : base::nullopt; |
| } |
| |
| // If present, this is a hint as to where place any adjoining objects. This |
| // isn't necessarily the final position, just where they ended up in a |
| // previous layout pass. |
| base::Optional<LayoutUnit> OptimisticBfcBlockOffset() const { |
| return HasRareData() ? rare_data_->OptimisticBfcBlockOffset() |
| : base::nullopt; |
| } |
| |
| // The "expected" BFC block-offset is: |
| // - The |ForcedBfcBlockOffset| if set. |
| // - The |OptimisticBfcBlockOffset| if set. |
| // - Otherwise the |BfcOffset|. |
| // |
| // This represents where any adjoining-objects should be placed (potentially |
| // optimistically) |
| LayoutUnit ExpectedBfcBlockOffset() const { |
| // A short-circuit optimization (must equivalent to below). |
| if (!HasRareData()) { |
| DCHECK(!ForcedBfcBlockOffset()); |
| DCHECK(!OptimisticBfcBlockOffset()); |
| return bfc_offset_.block_offset; |
| } |
| |
| return ForcedBfcBlockOffset().value_or( |
| OptimisticBfcBlockOffset().value_or(BfcOffset().block_offset)); |
| } |
| |
| SerializedScriptValue* CustomLayoutData() const { |
| return HasRareData() ? rare_data_->CustomLayoutData() : nullptr; |
| } |
| |
| // Returns the types of preceding adjoining objects. |
| // See |NGAdjoiningObjectTypes|. |
| // |
| // Adjoining floats are positioned at their correct position if the |
| // |ForcedBfcBlockOffset()| is known. |
| // |
| // Adjoining floats should be treated differently when calculating clearance |
| // on a block with adjoining block-start margin (in such cases we will know |
| // up front that the block will need clearance, since, if it doesn't, the |
| // float will be pulled along with the block, and the block will fail to |
| // clear). |
| NGAdjoiningObjectTypes AdjoiningObjectTypes() const { |
| return bitfields_.adjoining_object_types; |
| } |
| |
| // Return true if there were any earlier floats that may affect the current |
| // layout. |
| bool HasFloats() const { return !ExclusionSpace().IsEmpty(); } |
| |
| bool HasClearanceOffset() const { |
| return HasRareData() && rare_data_->ClearanceOffset() != LayoutUnit::Min(); |
| } |
| LayoutUnit ClearanceOffset() const { |
| return HasRareData() ? rare_data_->ClearanceOffset() : LayoutUnit::Min(); |
| } |
| |
| const NGBaselineRequestList BaselineRequests() const { |
| return NGBaselineRequestList(bitfields_.baseline_requests); |
| } |
| |
| // Return true if the two constraint spaces are similar enough that it *may* |
| // be possible to skip re-layout. If true is returned, the caller is expected |
| // to verify that any constraint space size (available size, percentage size, |
| // and so on) and BFC offset changes won't require re-layout, before skipping. |
| bool MaySkipLayout(const NGConstraintSpace& other) const { |
| if (!bitfields_.MaySkipLayout(other.bitfields_)) |
| return false; |
| |
| if (!HasRareData() && !other.HasRareData()) |
| return true; |
| |
| if (HasRareData() && other.HasRareData()) |
| return rare_data_->MaySkipLayout(*other.rare_data_); |
| |
| if (HasRareData()) |
| return rare_data_->IsInitialForMaySkipLayout(); |
| |
| DCHECK(other.HasRareData()); |
| return other.rare_data_->IsInitialForMaySkipLayout(); |
| } |
| |
| // Returns true if the size constraints (shrink-to-fit, fixed-inline-size) |
| // are equal. |
| bool AreSizeConstraintsEqual(const NGConstraintSpace& other) const { |
| return bitfields_.AreSizeConstraintsEqual(other.bitfields_); |
| } |
| |
| bool AreSizesEqual(const NGConstraintSpace& other) const { |
| if (available_size_ != other.available_size_) |
| return false; |
| |
| if (bitfields_.percentage_inline_storage != |
| other.bitfields_.percentage_inline_storage) |
| return false; |
| |
| if (bitfields_.percentage_block_storage != |
| other.bitfields_.percentage_block_storage) |
| return false; |
| |
| if (bitfields_.replaced_percentage_block_storage != |
| other.bitfields_.replaced_percentage_block_storage) |
| return false; |
| |
| // The rest of this method just checks the percentage resolution sizes. If |
| // neither space has rare data, we know that they must equal now. |
| if (!HasRareData() && !other.HasRareData()) |
| return true; |
| |
| if (bitfields_.percentage_inline_storage == kRareDataPercentage && |
| other.bitfields_.percentage_inline_storage == kRareDataPercentage && |
| rare_data_->percentage_resolution_size.inline_size != |
| other.rare_data_->percentage_resolution_size.inline_size) |
| return false; |
| |
| if (bitfields_.percentage_block_storage == kRareDataPercentage && |
| other.bitfields_.percentage_block_storage == kRareDataPercentage && |
| rare_data_->percentage_resolution_size.block_size != |
| other.rare_data_->percentage_resolution_size.block_size) |
| return false; |
| |
| if (bitfields_.replaced_percentage_block_storage == kRareDataPercentage && |
| other.bitfields_.replaced_percentage_block_storage == |
| kRareDataPercentage && |
| rare_data_->replaced_percentage_resolution_block_size != |
| other.rare_data_->replaced_percentage_resolution_block_size) |
| return false; |
| |
| return true; |
| } |
| |
| String ToString() const; |
| |
| private: |
| friend class NGConstraintSpaceBuilder; |
| |
| explicit NGConstraintSpace(WritingMode writing_mode) |
| : bfc_offset_(), bitfields_(writing_mode) {} |
| |
| // This struct defines all of the inputs to layout which we consider rare. |
| // Primarily this is: |
| // - Percentage resolution sizes which differ from the available size or |
| // aren't indefinite. |
| // - The margin strut. |
| // - Anything to do with floats (the exclusion space, clearance offset, etc). |
| // - Anything to do with fragmentation. |
| // |
| // This information is kept in a separate in this heap-allocated struct to |
| // reduce memory usage. Over time this may have to change based on usage data. |
| struct RareData { |
| USING_FAST_MALLOC(RareData); |
| |
| public: |
| explicit RareData(const NGBfcOffset bfc_offset) |
| : bfc_offset(bfc_offset), |
| data_union_type(static_cast<unsigned>(kNone)), |
| block_direction_fragmentation_type( |
| static_cast<unsigned>(kFragmentNone)), |
| is_inside_balanced_columns(false), |
| is_in_column_bfc(false), |
| early_break_appeal(kBreakAppealLastResort) {} |
| RareData(const RareData& other) |
| : percentage_resolution_size(other.percentage_resolution_size), |
| replaced_percentage_resolution_block_size( |
| other.replaced_percentage_resolution_block_size), |
| bfc_offset(other.bfc_offset), |
| fragmentainer_block_size(other.fragmentainer_block_size), |
| fragmentainer_space_at_bfc_start( |
| other.fragmentainer_space_at_bfc_start), |
| data_union_type(other.data_union_type), |
| block_direction_fragmentation_type( |
| other.block_direction_fragmentation_type), |
| is_inside_balanced_columns(other.is_inside_balanced_columns), |
| is_in_column_bfc(other.is_in_column_bfc), |
| early_break_appeal(other.early_break_appeal) { |
| switch (data_union_type) { |
| case kNone: |
| break; |
| case kBlockData: |
| new (&block_data_) BlockData(other.block_data_); |
| break; |
| case kTableCellData: |
| new (&table_cell_data_) TableCellData(other.table_cell_data_); |
| break; |
| case kCustomData: |
| new (&custom_data_) CustomData(other.custom_data_); |
| break; |
| default: |
| NOTREACHED(); |
| } |
| } |
| ~RareData() { |
| switch (data_union_type) { |
| case kNone: |
| break; |
| case kBlockData: |
| block_data_.~BlockData(); |
| break; |
| case kTableCellData: |
| table_cell_data_.~TableCellData(); |
| break; |
| case kCustomData: |
| custom_data_.~CustomData(); |
| break; |
| default: |
| NOTREACHED(); |
| } |
| } |
| |
| // |RareData| unions different types of data which are mutually exclusive. |
| // They fall into the following categories: |
| enum DataUnionType { |
| kNone, |
| kBlockData, // An inflow block which doesn't establish a new FC. |
| kTableCellData, // A table-cell (display: table-cell). |
| kCustomData // A custom layout (display: layout(foo)). |
| }; |
| |
| LogicalSize percentage_resolution_size; |
| LayoutUnit replaced_percentage_resolution_block_size; |
| NGBfcOffset bfc_offset; |
| |
| LayoutUnit fragmentainer_block_size = kIndefiniteSize; |
| LayoutUnit fragmentainer_space_at_bfc_start = kIndefiniteSize; |
| |
| unsigned data_union_type : 2; |
| unsigned block_direction_fragmentation_type : 2; |
| unsigned is_inside_balanced_columns : 1; |
| unsigned is_in_column_bfc : 1; |
| unsigned early_break_appeal : 2; // NGBreakAppeal |
| |
| bool MaySkipLayout(const RareData& other) const { |
| if (fragmentainer_block_size != other.fragmentainer_block_size || |
| fragmentainer_space_at_bfc_start != |
| other.fragmentainer_space_at_bfc_start || |
| data_union_type != other.data_union_type || |
| block_direction_fragmentation_type != |
| other.block_direction_fragmentation_type || |
| is_inside_balanced_columns != other.is_inside_balanced_columns || |
| is_in_column_bfc != other.is_in_column_bfc || |
| early_break_appeal != other.early_break_appeal) |
| return false; |
| |
| if (data_union_type == kNone) |
| return true; |
| |
| if (data_union_type == kBlockData) |
| return true; |
| |
| if (data_union_type == kTableCellData) |
| return table_cell_data_.MaySkipLayout(other.table_cell_data_); |
| |
| DCHECK_EQ(data_union_type, kCustomData); |
| return custom_data_.MaySkipLayout(other.custom_data_); |
| } |
| |
| // Must be kept in sync with members checked within |MaySkipLayout|. |
| bool IsInitialForMaySkipLayout() const { |
| if (fragmentainer_block_size != kIndefiniteSize || |
| fragmentainer_space_at_bfc_start != kIndefiniteSize || |
| block_direction_fragmentation_type != kFragmentNone || |
| is_inside_balanced_columns || is_in_column_bfc || |
| early_break_appeal != kBreakAppealLastResort) |
| return false; |
| |
| if (data_union_type == kNone) |
| return true; |
| |
| if (data_union_type == kBlockData) |
| return true; |
| |
| if (data_union_type == kTableCellData) |
| return table_cell_data_.IsInitialForMaySkipLayout(); |
| |
| DCHECK_EQ(data_union_type, kCustomData); |
| return custom_data_.IsInitialForMaySkipLayout(); |
| } |
| |
| NGMarginStrut MarginStrut() const { |
| return data_union_type == kBlockData ? block_data_.margin_strut |
| : NGMarginStrut(); |
| } |
| |
| void SetMarginStrut(const NGMarginStrut& margin_strut) { |
| EnsureBlockData()->margin_strut = margin_strut; |
| } |
| |
| base::Optional<LayoutUnit> OptimisticBfcBlockOffset() const { |
| return data_union_type == kBlockData |
| ? block_data_.optimistic_bfc_block_offset |
| : base::nullopt; |
| } |
| |
| void SetOptimisticBfcBlockOffset(LayoutUnit optimistic_bfc_block_offset) { |
| EnsureBlockData()->optimistic_bfc_block_offset = |
| optimistic_bfc_block_offset; |
| } |
| |
| base::Optional<LayoutUnit> ForcedBfcBlockOffset() const { |
| return data_union_type == kBlockData ? block_data_.forced_bfc_block_offset |
| : base::nullopt; |
| } |
| |
| void SetForcedBfcBlockOffset(LayoutUnit forced_bfc_block_offset) { |
| EnsureBlockData()->forced_bfc_block_offset = forced_bfc_block_offset; |
| } |
| |
| LayoutUnit ClearanceOffset() const { |
| return data_union_type == kBlockData ? block_data_.clearance_offset |
| : LayoutUnit::Min(); |
| } |
| |
| void SetClearanceOffset(LayoutUnit clearance_offset) { |
| EnsureBlockData()->clearance_offset = clearance_offset; |
| } |
| |
| NGBoxStrut TableCellBorders() const { |
| return data_union_type == kTableCellData |
| ? table_cell_data_.table_cell_borders |
| : NGBoxStrut(); |
| } |
| |
| void SetTableCellBorders(const NGBoxStrut& table_cell_borders) { |
| EnsureTableCellData()->table_cell_borders = table_cell_borders; |
| } |
| |
| NGBoxStrut TableCellIntrinsicPadding() const { |
| return data_union_type == kTableCellData |
| ? NGBoxStrut( |
| LayoutUnit(), LayoutUnit(), |
| table_cell_data_ |
| .table_cell_intrinsic_padding_block_start, |
| table_cell_data_.table_cell_intrinsic_padding_block_end) |
| : NGBoxStrut(); |
| } |
| |
| void SetTableCellIntrinsicPadding( |
| const NGBoxStrut& table_cell_intrinsic_padding) { |
| EnsureTableCellData()->table_cell_intrinsic_padding_block_start = |
| table_cell_intrinsic_padding.block_start; |
| EnsureTableCellData()->table_cell_intrinsic_padding_block_end = |
| table_cell_intrinsic_padding.block_end; |
| } |
| |
| SerializedScriptValue* CustomLayoutData() const { |
| return data_union_type == kCustomData ? custom_data_.data.get() : nullptr; |
| } |
| |
| void SetCustomLayoutData( |
| scoped_refptr<SerializedScriptValue> custom_layout_data) { |
| EnsureCustomData()->data = std::move(custom_layout_data); |
| } |
| |
| private: |
| struct BlockData { |
| NGMarginStrut margin_strut; |
| base::Optional<LayoutUnit> optimistic_bfc_block_offset; |
| base::Optional<LayoutUnit> forced_bfc_block_offset; |
| LayoutUnit clearance_offset = LayoutUnit::Min(); |
| }; |
| |
| BlockData* EnsureBlockData() { |
| DCHECK(data_union_type == kNone || data_union_type == kBlockData); |
| if (data_union_type != kBlockData) { |
| data_union_type = kBlockData; |
| new (&block_data_) BlockData(); |
| } |
| return &block_data_; |
| } |
| |
| struct TableCellData { |
| NGBoxStrut table_cell_borders; |
| LayoutUnit table_cell_intrinsic_padding_block_start; |
| LayoutUnit table_cell_intrinsic_padding_block_end; |
| |
| bool MaySkipLayout(const TableCellData& other) const { |
| return table_cell_borders == other.table_cell_borders && |
| table_cell_intrinsic_padding_block_start == |
| other.table_cell_intrinsic_padding_block_start && |
| table_cell_intrinsic_padding_block_end == |
| other.table_cell_intrinsic_padding_block_end; |
| } |
| |
| bool IsInitialForMaySkipLayout() const { |
| return table_cell_borders == NGBoxStrut() && |
| table_cell_intrinsic_padding_block_start == LayoutUnit() && |
| table_cell_intrinsic_padding_block_end == LayoutUnit(); |
| } |
| }; |
| |
| TableCellData* EnsureTableCellData() { |
| DCHECK(data_union_type == kNone || data_union_type == kTableCellData); |
| if (data_union_type != kTableCellData) { |
| data_union_type = kTableCellData; |
| new (&table_cell_data_) TableCellData(); |
| } |
| return &table_cell_data_; |
| } |
| |
| struct CustomData { |
| scoped_refptr<SerializedScriptValue> data; |
| |
| bool MaySkipLayout(const CustomData& other) const { |
| return data == other.data; |
| } |
| |
| bool IsInitialForMaySkipLayout() const { return !data; } |
| }; |
| |
| CustomData* EnsureCustomData() { |
| DCHECK(data_union_type == kNone || data_union_type == kCustomData); |
| if (data_union_type != kCustomData) { |
| data_union_type = kCustomData; |
| new (&custom_data_) CustomData(); |
| } |
| return &custom_data_; |
| } |
| |
| union { |
| BlockData block_data_; |
| TableCellData table_cell_data_; |
| CustomData custom_data_; |
| }; |
| }; |
| |
| // This struct simply allows us easily copy, compare, and initialize all the |
| // bitfields without having to explicitly copy, compare, and initialize each |
| // one (see the outer class constructors, and assignment operators). |
| struct Bitfields { |
| DISALLOW_NEW(); |
| |
| public: |
| Bitfields() : Bitfields(WritingMode::kHorizontalTb) {} |
| |
| explicit Bitfields(WritingMode writing_mode) |
| : has_rare_data(false), |
| adjoining_object_types(static_cast<unsigned>(kAdjoiningNone)), |
| writing_mode(static_cast<unsigned>(writing_mode)), |
| direction(static_cast<unsigned>(TextDirection::kLtr)), |
| is_table_cell(false), |
| is_anonymous(false), |
| is_new_formatting_context(false), |
| is_orthogonal_writing_mode_root(false), |
| is_intermediate_layout(false), |
| is_fixed_block_size_indefinite(false), |
| is_restricted_block_size_table_cell(false), |
| use_first_line_style(false), |
| ancestor_has_clearance_past_adjoining_floats(false), |
| is_shrink_to_fit(false), |
| is_fixed_inline_size(false), |
| is_fixed_block_size(false), |
| table_cell_child_layout_mode(static_cast<unsigned>( |
| NGTableCellChildLayoutMode::kNotTableCellChild)), |
| percentage_inline_storage(kSameAsAvailable), |
| percentage_block_storage(kSameAsAvailable), |
| replaced_percentage_block_storage(kSameAsAvailable) {} |
| |
| bool MaySkipLayout(const Bitfields& other) const { |
| return adjoining_object_types == other.adjoining_object_types && |
| writing_mode == other.writing_mode && |
| direction == other.direction && |
| is_table_cell == other.is_table_cell && |
| is_anonymous == other.is_anonymous && |
| is_new_formatting_context == other.is_new_formatting_context && |
| is_orthogonal_writing_mode_root == |
| other.is_orthogonal_writing_mode_root && |
| is_intermediate_layout == other.is_intermediate_layout && |
| is_fixed_block_size_indefinite == |
| other.is_fixed_block_size_indefinite && |
| is_restricted_block_size_table_cell == |
| other.is_restricted_block_size_table_cell && |
| use_first_line_style == other.use_first_line_style && |
| ancestor_has_clearance_past_adjoining_floats == |
| other.ancestor_has_clearance_past_adjoining_floats && |
| baseline_requests == other.baseline_requests; |
| } |
| |
| bool AreSizeConstraintsEqual(const Bitfields& other) const { |
| return is_shrink_to_fit == other.is_shrink_to_fit && |
| is_fixed_inline_size == other.is_fixed_inline_size && |
| is_fixed_block_size == other.is_fixed_block_size && |
| table_cell_child_layout_mode == other.table_cell_child_layout_mode; |
| } |
| |
| unsigned has_rare_data : 1; |
| unsigned adjoining_object_types : 3; // NGAdjoiningObjectTypes |
| unsigned writing_mode : 3; |
| unsigned direction : 1; |
| |
| unsigned is_table_cell : 1; |
| unsigned is_anonymous : 1; |
| unsigned is_new_formatting_context : 1; |
| unsigned is_orthogonal_writing_mode_root : 1; |
| unsigned is_intermediate_layout : 1; |
| |
| unsigned is_fixed_block_size_indefinite : 1; |
| unsigned is_restricted_block_size_table_cell : 1; |
| unsigned use_first_line_style : 1; |
| unsigned ancestor_has_clearance_past_adjoining_floats : 1; |
| |
| unsigned baseline_requests : NGBaselineRequestList::kSerializedBits; |
| |
| // Size constraints. |
| unsigned is_shrink_to_fit : 1; |
| unsigned is_fixed_inline_size : 1; |
| unsigned is_fixed_block_size : 1; |
| unsigned table_cell_child_layout_mode : 2; // NGTableCellChildLayoutMode |
| |
| unsigned percentage_inline_storage : 2; // NGPercentageStorage |
| unsigned percentage_block_storage : 2; // NGPercentageStorage |
| unsigned replaced_percentage_block_storage : 2; // NGPercentageStorage |
| }; |
| |
| inline bool HasRareData() const { return bitfields_.has_rare_data; } |
| |
| RareData* EnsureRareData() { |
| if (!HasRareData()) { |
| rare_data_ = new RareData(bfc_offset_); |
| bitfields_.has_rare_data = true; |
| } |
| |
| return rare_data_; |
| } |
| |
| LogicalSize available_size_; |
| |
| // To save a little space, we union these two fields. rare_data_ is valid if |
| // the |has_rare_data| bit is set, otherwise bfc_offset_ is valid. |
| union { |
| NGBfcOffset bfc_offset_; |
| RareData* rare_data_; |
| }; |
| |
| NGExclusionSpace exclusion_space_; |
| Bitfields bitfields_; |
| }; |
| |
| inline std::ostream& operator<<(std::ostream& stream, |
| const NGConstraintSpace& value) { |
| return stream << value.ToString(); |
| } |
| |
| } // namespace blink |
| |
| #endif // NGConstraintSpace_h |
