| /* |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * Copyright (C) 2014 Apple 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_DOM_ELEMENT_DATA_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_DOM_ELEMENT_DATA_H_ |
| |
| #include "build/build_config.h" |
| #include "third_party/blink/renderer/core/dom/attribute.h" |
| #include "third_party/blink/renderer/core/dom/attribute_collection.h" |
| #include "third_party/blink/renderer/core/dom/space_split_string.h" |
| #include "third_party/blink/renderer/platform/heap/garbage_collected.h" |
| #include "third_party/blink/renderer/platform/heap/member.h" |
| #include "third_party/blink/renderer/platform/wtf/bit_field.h" |
| #include "third_party/blink/renderer/platform/wtf/casting.h" |
| #include "third_party/blink/renderer/platform/wtf/text/atomic_string.h" |
| |
| namespace blink { |
| |
| class ShareableElementData; |
| class CSSPropertyValueSet; |
| class UniqueElementData; |
| |
| // ElementData represents very common, but not necessarily unique to an element, |
| // data such as attributes, inline style, and parsed class names and ids. |
| class ElementData : public GarbageCollected<ElementData> { |
| public: |
| // Override GarbageCollected's finalizeGarbageCollectedObject to |
| // dispatch to the correct subclass destructor. |
| void FinalizeGarbageCollectedObject(); |
| |
| void ClearClass() const { class_names_.Clear(); } |
| void SetClass(const AtomicString& class_name, bool should_fold_case) const { |
| AtomicString lower_class_name; |
| if (should_fold_case && !class_name.IsLowerASCII()) |
| lower_class_name = class_name.LowerASCII(); |
| class_names_.Set(lower_class_name ? lower_class_name : class_name); |
| } |
| const SpaceSplitString& ClassNames() const { return class_names_; } |
| |
| const AtomicString& IdForStyleResolution() const { |
| return id_for_style_resolution_; |
| } |
| AtomicString SetIdForStyleResolution(AtomicString new_id) const { |
| return std::exchange(id_for_style_resolution_, std::move(new_id)); |
| } |
| |
| const CSSPropertyValueSet* InlineStyle() const { return inline_style_.Get(); } |
| |
| const CSSPropertyValueSet* PresentationAttributeStyle() const; |
| |
| AttributeCollection Attributes() const; |
| |
| bool HasID() const { return !id_for_style_resolution_.IsNull(); } |
| bool HasClass() const { return !class_names_.IsNull(); } |
| |
| bool IsEquivalent(const ElementData* other) const; |
| |
| bool IsUnique() const { return bit_field_.get<IsUniqueFlag>(); } |
| |
| void TraceAfterDispatch(blink::Visitor*) const; |
| void Trace(Visitor*) const; |
| |
| protected: |
| using BitField = WTF::ConcurrentlyReadBitField<uint32_t>; |
| using IsUniqueFlag = |
| BitField::DefineFirstValue<bool, 1, WTF::BitFieldValueConstness::kConst>; |
| using ArraySize = IsUniqueFlag:: |
| DefineNextValue<uint32_t, 28, WTF::BitFieldValueConstness::kConst>; |
| using PresentationAttributeStyleIsDirty = ArraySize::DefineNextValue<bool, 1>; |
| using StyleAttributeIsDirty = |
| PresentationAttributeStyleIsDirty::DefineNextValue<bool, 1>; |
| using SvgAttributesAreDirty = StyleAttributeIsDirty::DefineNextValue<bool, 1>; |
| |
| ElementData(); |
| explicit ElementData(unsigned array_size); |
| ElementData(const ElementData&, bool is_unique); |
| |
| bool presentation_attribute_style_is_dirty() const { |
| return bit_field_.get<PresentationAttributeStyleIsDirty>(); |
| } |
| bool style_attribute_is_dirty() const { |
| return bit_field_.get<StyleAttributeIsDirty>(); |
| } |
| bool svg_attributes_are_dirty() const { |
| return bit_field_.get<SvgAttributesAreDirty>(); |
| } |
| |
| // Following 3 fields are meant to be mutable and can change even when const. |
| void SetPresentationAttributeStyleIsDirty( |
| bool presentation_attribute_style_is_dirty) const { |
| const_cast<BitField*>(&bit_field_) |
| ->set<PresentationAttributeStyleIsDirty>( |
| presentation_attribute_style_is_dirty); |
| } |
| void SetStyleAttributeIsDirty(bool style_attribute_is_dirty) const { |
| const_cast<BitField*>(&bit_field_) |
| ->set<StyleAttributeIsDirty>(style_attribute_is_dirty); |
| } |
| void SetSvgAttributesAreDirty(bool svg_attributes_are_dirty) const { |
| const_cast<BitField*>(&bit_field_) |
| ->set<SvgAttributesAreDirty>(svg_attributes_are_dirty); |
| } |
| |
| BitField bit_field_; |
| |
| mutable Member<CSSPropertyValueSet> inline_style_; |
| mutable SpaceSplitString class_names_; |
| mutable AtomicString id_for_style_resolution_; |
| |
| private: |
| friend class Element; |
| friend class HTMLImageElement; |
| friend class ShareableElementData; |
| friend class UniqueElementData; |
| friend class SVGElement; |
| friend struct DowncastTraits<UniqueElementData>; |
| friend struct DowncastTraits<ShareableElementData>; |
| |
| UniqueElementData* MakeUniqueCopy() const; |
| }; |
| |
| #if defined(COMPILER_MSVC) |
| #pragma warning(push) |
| // Disable "zero-sized array in struct/union" warning |
| #pragma warning(disable : 4200) |
| #endif |
| |
| // SharableElementData is managed by ElementDataCache and is produced by |
| // the parser during page load for elements that have identical attributes. This |
| // is a memory optimization since it's very common for many elements to have |
| // duplicate sets of attributes (ex. the same classes). |
| class ShareableElementData final : public ElementData { |
| public: |
| static ShareableElementData* CreateWithAttributes( |
| const Vector<Attribute, kAttributePrealloc>&); |
| |
| explicit ShareableElementData(const Vector<Attribute, kAttributePrealloc>&); |
| explicit ShareableElementData(const UniqueElementData&); |
| ~ShareableElementData(); |
| |
| void TraceAfterDispatch(blink::Visitor* visitor) const { |
| ElementData::TraceAfterDispatch(visitor); |
| } |
| |
| AttributeCollection Attributes() const; |
| |
| Attribute attribute_array_[0]; |
| }; |
| |
| template <> |
| struct DowncastTraits<ShareableElementData> { |
| static bool AllowFrom(const ElementData& data) { |
| return !data.bit_field_.get<ElementData::IsUniqueFlag>(); |
| } |
| }; |
| |
| #if defined(COMPILER_MSVC) |
| #pragma warning(pop) |
| #endif |
| |
| // UniqueElementData is created when an element needs to mutate its attributes |
| // or gains presentation attribute style (ex. width="10"). It does not need to |
| // be created to fill in values in the ElementData that are derived from |
| // attributes. For example populating the inline_style_ from the style attribute |
| // doesn't require a UniqueElementData as all elements with the same style |
| // attribute will have the same inline style. |
| class UniqueElementData final : public ElementData { |
| public: |
| ShareableElementData* MakeShareableCopy() const; |
| |
| MutableAttributeCollection Attributes(); |
| AttributeCollection Attributes() const; |
| |
| UniqueElementData(); |
| explicit UniqueElementData(const ShareableElementData&); |
| explicit UniqueElementData(const UniqueElementData&); |
| |
| void TraceAfterDispatch(blink::Visitor*) const; |
| |
| // FIXME: We might want to support sharing element data for elements with |
| // presentation attribute style. Lots of table cells likely have the same |
| // attributes. Most modern pages don't use presentation attributes though |
| // so this might not make sense. |
| mutable Member<CSSPropertyValueSet> presentation_attribute_style_; |
| AttributeVector attribute_vector_; |
| }; |
| |
| template <> |
| struct DowncastTraits<UniqueElementData> { |
| static bool AllowFrom(const ElementData& data) { |
| return data.bit_field_.get<ElementData::IsUniqueFlag>(); |
| } |
| }; |
| |
| inline const CSSPropertyValueSet* ElementData::PresentationAttributeStyle() |
| const { |
| if (!bit_field_.get<IsUniqueFlag>()) |
| return nullptr; |
| return To<UniqueElementData>(this)->presentation_attribute_style_.Get(); |
| } |
| |
| inline AttributeCollection ElementData::Attributes() const { |
| if (auto* unique_element_data = DynamicTo<UniqueElementData>(this)) |
| return unique_element_data->Attributes(); |
| return To<ShareableElementData>(this)->Attributes(); |
| } |
| |
| inline AttributeCollection ShareableElementData::Attributes() const { |
| return AttributeCollection(attribute_array_, bit_field_.get<ArraySize>()); |
| } |
| |
| inline AttributeCollection UniqueElementData::Attributes() const { |
| return AttributeCollection(attribute_vector_.data(), |
| attribute_vector_.size()); |
| } |
| |
| inline MutableAttributeCollection UniqueElementData::Attributes() { |
| return MutableAttributeCollection(attribute_vector_); |
| } |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_CORE_DOM_ELEMENT_DATA_H_ |