| /* |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_TEXT_AUTOSIZER_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_TEXT_AUTOSIZER_H_ |
| |
| #include <unicode/uchar.h> |
| #include <memory> |
| #include "base/macros.h" |
| #include "third_party/blink/renderer/core/core_export.h" |
| #include "third_party/blink/renderer/platform/geometry/layout_unit.h" |
| #include "third_party/blink/renderer/platform/heap/handle.h" |
| #include "third_party/blink/renderer/platform/wtf/hash_map.h" |
| #include "third_party/blink/renderer/platform/wtf/hash_set.h" |
| |
| namespace blink { |
| |
| class ComputedStyle; |
| class Document; |
| class IntSize; |
| class LayoutBlock; |
| class LayoutObject; |
| class LayoutTable; |
| class LayoutText; |
| class LocalFrame; |
| class NGBlockNode; |
| class Page; |
| class SubtreeLayoutScope; |
| |
| // Single-pass text autosizer. Documentation at: |
| // http://tinyurl.com/TextAutosizer |
| |
| class CORE_EXPORT TextAutosizer final |
| : public GarbageCollectedFinalized<TextAutosizer> { |
| public: |
| ~TextAutosizer(); |
| static TextAutosizer* Create(const Document* document) { |
| return new TextAutosizer(document); |
| } |
| |
| // computed_size should include zoom. |
| static float ComputeAutosizedFontSize(float computed_size, |
| float multiplier, |
| float effective_zoom); |
| |
| void UpdatePageInfoInAllFrames(); |
| void UpdatePageInfo(); |
| void Record(LayoutBlock*); |
| void Record(LayoutText*); |
| void Destroy(LayoutBlock*); |
| |
| bool PageNeedsAutosizing() const; |
| |
| void Trace(blink::Visitor*); |
| |
| class LayoutScope { |
| STACK_ALLOCATED(); |
| |
| public: |
| explicit LayoutScope(LayoutBlock*, SubtreeLayoutScope* = nullptr); |
| ~LayoutScope(); |
| |
| protected: |
| Member<TextAutosizer> text_autosizer_; |
| LayoutBlock* block_; |
| }; |
| |
| class TableLayoutScope : LayoutScope { |
| STACK_ALLOCATED(); |
| |
| public: |
| explicit TableLayoutScope(LayoutTable*); |
| }; |
| |
| class NGLayoutScope { |
| STACK_ALLOCATED(); |
| |
| public: |
| explicit NGLayoutScope(const NGBlockNode& node, LayoutUnit inline_size); |
| ~NGLayoutScope(); |
| |
| protected: |
| Member<TextAutosizer> text_autosizer_; |
| LayoutBlock* block_; |
| }; |
| |
| class CORE_EXPORT DeferUpdatePageInfo { |
| STACK_ALLOCATED(); |
| |
| public: |
| explicit DeferUpdatePageInfo(Page*); |
| ~DeferUpdatePageInfo(); |
| |
| private: |
| Member<LocalFrame> main_frame_; |
| }; |
| |
| private: |
| typedef HashSet<LayoutBlock*> BlockSet; |
| typedef HashSet<const LayoutBlock*> ConstBlockSet; |
| |
| enum HasEnoughTextToAutosize { |
| kUnknownAmountOfText, |
| kHasEnoughText, |
| kNotEnoughText |
| }; |
| |
| enum RelayoutBehavior { |
| kAlreadyInLayout, // The default; appropriate if we are already in layout. |
| kLayoutNeeded // Use this if changing a multiplier outside of layout. |
| }; |
| |
| enum BeginLayoutBehavior { kStopLayout, kContinueLayout }; |
| |
| enum InflateBehavior { kThisBlockOnly, kDescendToInnerBlocks }; |
| |
| enum BlockFlag { |
| // A block that is evaluated for becoming a cluster root. |
| POTENTIAL_ROOT = 1 << 0, |
| // A cluster root that establishes an independent multiplier. |
| INDEPENDENT = 1 << 1, |
| // A cluster root with an explicit width. These are likely to be |
| // independent. |
| EXPLICIT_WIDTH = 1 << 2, |
| // A cluster that is wider or narrower than its parent. These also create an |
| // independent multiplier, but this state cannot be determined until layout. |
| WIDER_OR_NARROWER = 1 << 3, |
| // A cluster that suppresses autosizing. |
| SUPPRESSING = 1 << 4 |
| }; |
| |
| enum InheritParentMultiplier { |
| kUnknown, |
| kInheritMultiplier, |
| kDontInheritMultiplier |
| }; |
| |
| typedef unsigned BlockFlags; |
| |
| // A supercluster represents autosizing information about a set of two or |
| // more blocks that all have the same fingerprint. Clusters whose roots |
| // belong to a supercluster will share a common multiplier and |
| // text-length-based autosizing status. |
| struct Supercluster { |
| USING_FAST_MALLOC(Supercluster); |
| |
| public: |
| explicit Supercluster(const BlockSet* roots) |
| : roots_(roots), |
| has_enough_text_to_autosize_(kUnknownAmountOfText), |
| multiplier_(0), |
| inherit_parent_multiplier_(kUnknown) {} |
| |
| const BlockSet* roots_; |
| HasEnoughTextToAutosize has_enough_text_to_autosize_; |
| float multiplier_; |
| InheritParentMultiplier inherit_parent_multiplier_; |
| }; |
| |
| struct Cluster { |
| USING_FAST_MALLOC(Cluster); |
| |
| public: |
| explicit Cluster(const LayoutBlock* root, |
| BlockFlags, |
| Cluster* parent, |
| Supercluster* = nullptr); |
| |
| const LayoutBlock* const root_; |
| BlockFlags flags_; |
| // The deepest block containing all text is computed lazily (see: |
| // deepestBlockContainingAllText). A value of 0 indicates the value has not |
| // been computed yet. |
| const LayoutBlock* deepest_block_containing_all_text_; |
| Cluster* parent_; |
| // The multiplier is computed lazily (see: clusterMultiplier) because it |
| // must be calculated after the lowest block containing all text has entered |
| // layout (the m_blocksThatHaveBegunLayout assertions cover this). Note: the |
| // multiplier is still calculated when m_autosize is false because child |
| // clusters may depend on this multiplier. |
| float multiplier_; |
| HasEnoughTextToAutosize has_enough_text_to_autosize_; |
| // A set of blocks that are similar to this block. |
| Supercluster* supercluster_; |
| bool has_table_ancestor_; |
| }; |
| |
| enum TextLeafSearch { kFirst, kLast }; |
| |
| struct FingerprintSourceData { |
| STACK_ALLOCATED(); |
| |
| public: |
| FingerprintSourceData() |
| : parent_hash_(0), |
| qualified_name_hash_(0), |
| packed_style_properties_(0), |
| column_(0), |
| width_(0) {} |
| |
| unsigned parent_hash_; |
| unsigned qualified_name_hash_; |
| // Style specific selection of signals |
| unsigned packed_style_properties_; |
| unsigned column_; |
| float width_; |
| }; |
| // Ensures efficient hashing using StringHasher. |
| static_assert(!(sizeof(FingerprintSourceData) % sizeof(UChar)), |
| "sizeof(FingerprintSourceData) must be a multiple of UChar"); |
| |
| typedef unsigned Fingerprint; |
| typedef Vector<std::unique_ptr<Cluster>> ClusterStack; |
| |
| // Fingerprints are computed during style recalc, for (some subset of) |
| // blocks that will become cluster roots. |
| // Clusters whose roots share the same fingerprint use the same multiplier |
| class FingerprintMapper { |
| DISALLOW_NEW(); |
| |
| public: |
| void Add(LayoutObject*, Fingerprint); |
| void AddTentativeClusterRoot(LayoutBlock*, Fingerprint); |
| // Returns true if any BlockSet was modified or freed by the removal. |
| bool Remove(LayoutObject*); |
| Fingerprint Get(const LayoutObject*); |
| BlockSet* GetTentativeClusterRoots(Fingerprint); |
| Supercluster* CreateSuperclusterIfNeeded(LayoutBlock*, bool& is_new_entry); |
| bool HasFingerprints() const { return !fingerprints_.IsEmpty(); } |
| HashSet<Supercluster*>& GetPotentiallyInconsistentSuperclusters() { |
| return potentially_inconsistent_superclusters_; |
| } |
| |
| private: |
| typedef HashMap<const LayoutObject*, Fingerprint> FingerprintMap; |
| typedef HashMap<Fingerprint, std::unique_ptr<BlockSet>> |
| ReverseFingerprintMap; |
| typedef HashMap<Fingerprint, std::unique_ptr<Supercluster>> SuperclusterMap; |
| |
| FingerprintMap fingerprints_; |
| ReverseFingerprintMap blocks_for_fingerprint_; |
| // Maps fingerprints to superclusters. Superclusters persist across layouts. |
| SuperclusterMap superclusters_; |
| // Superclusters that need to be checked for consistency at the start of the |
| // next layout. |
| HashSet<Supercluster*> potentially_inconsistent_superclusters_; |
| #if DCHECK_IS_ON() |
| void AssertMapsAreConsistent(); |
| #endif |
| }; |
| |
| struct PageInfo { |
| DISALLOW_NEW(); |
| PageInfo() |
| : frame_width_(0), |
| layout_width_(0), |
| accessibility_font_scale_factor_(1), |
| device_scale_adjustment_(1), |
| page_needs_autosizing_(false), |
| has_autosized_(false), |
| setting_enabled_(false) {} |
| |
| int frame_width_; // LocalFrame width in density-independent pixels (DIPs). |
| int layout_width_; // Layout width in CSS pixels. |
| float accessibility_font_scale_factor_; |
| float device_scale_adjustment_; |
| bool page_needs_autosizing_; |
| bool has_autosized_; |
| bool setting_enabled_; |
| }; |
| |
| explicit TextAutosizer(const Document*); |
| |
| void BeginLayout(LayoutBlock*, SubtreeLayoutScope*); |
| void EndLayout(LayoutBlock*); |
| void InflateAutoTable(LayoutTable*); |
| float Inflate(LayoutObject*, |
| SubtreeLayoutScope*, |
| InflateBehavior = kThisBlockOnly, |
| float multiplier = 0); |
| bool ShouldHandleLayout() const; |
| IntSize WindowSize() const; |
| void SetAllTextNeedsLayout(LayoutBlock* container = nullptr); |
| void ResetMultipliers(); |
| BeginLayoutBehavior PrepareForLayout(LayoutBlock*); |
| void PrepareClusterStack(LayoutObject*); |
| bool ClusterHasEnoughTextToAutosize( |
| Cluster*, |
| const LayoutBlock* width_provider = nullptr); |
| bool SuperclusterHasEnoughTextToAutosize( |
| Supercluster*, |
| const LayoutBlock* width_provider = nullptr, |
| bool skip_layouted_nodes = false); |
| bool ClusterWouldHaveEnoughTextToAutosize( |
| const LayoutBlock* root, |
| const LayoutBlock* width_provider = nullptr); |
| Fingerprint GetFingerprint(LayoutObject*); |
| Fingerprint ComputeFingerprint(const LayoutObject*); |
| Cluster* MaybeCreateCluster(LayoutBlock*); |
| float ClusterMultiplier(Cluster*); |
| float SuperclusterMultiplier(Cluster*); |
| // A cluster's width provider is typically the deepest block containing all |
| // text. There are exceptions, such as tables and table cells which use the |
| // table itself for width. |
| const LayoutBlock* ClusterWidthProvider(const LayoutBlock*) const; |
| const LayoutBlock* MaxClusterWidthProvider( |
| Supercluster*, |
| const LayoutBlock* current_root) const; |
| // Typically this returns a block's computed width. In the case of tables |
| // layout, this width is not yet known so the fixed width is used if it's |
| // available, or the containing block's width otherwise. |
| float WidthFromBlock(const LayoutBlock*) const; |
| float MultiplierFromBlock(const LayoutBlock*); |
| void ApplyMultiplier(LayoutObject*, |
| float, |
| SubtreeLayoutScope*, |
| RelayoutBehavior = kAlreadyInLayout); |
| bool IsWiderOrNarrowerDescendant(Cluster*); |
| Cluster* CurrentCluster() const; |
| const LayoutBlock* DeepestBlockContainingAllText(Cluster*); |
| const LayoutBlock* DeepestBlockContainingAllText(const LayoutBlock*) const; |
| // Returns the first text leaf that is in the current cluster. We attempt to |
| // not include text from descendant clusters but because descendant clusters |
| // may not exist, this is only an approximation. The TraversalDirection |
| // controls whether we return the first or the last text leaf. |
| const LayoutObject* FindTextLeaf(const LayoutObject*, |
| size_t&, |
| TextLeafSearch) const; |
| BlockFlags ClassifyBlock(const LayoutObject*, |
| BlockFlags mask = UINT_MAX) const; |
| // Must be called at the start of layout. |
| void CheckSuperclusterConsistency(); |
| // Mark the nearest non-inheritance supercluser |
| void MarkSuperclusterForConsistencyCheck(LayoutObject*); |
| |
| Member<const Document> document_; |
| const LayoutBlock* first_block_to_begin_layout_; |
| #if DCHECK_IS_ON() |
| // Used to ensure we don't compute properties of a block before beginLayout() |
| // is called on it. |
| ConstBlockSet blocks_that_have_begun_layout_; |
| #endif |
| |
| // Clusters are created and destroyed during layout |
| ClusterStack cluster_stack_; |
| FingerprintMapper fingerprint_mapper_; |
| Vector<scoped_refptr<const ComputedStyle>> styles_retained_during_layout_; |
| // FIXME: All frames should share the same m_pageInfo instance. |
| PageInfo page_info_; |
| bool update_page_info_deferred_; |
| DISALLOW_COPY_AND_ASSIGN(TextAutosizer); |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_TEXT_AUTOSIZER_H_ |