xref: /external/chromium_org/third_party/WebKit/Source/core/css/invalidation/DescendantInvalidationSet.h

/*
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#ifndef DescendantInvalidationSet_h
#define DescendantInvalidationSet_h

#include "platform/heap/Handle.h"
#include "wtf/Forward.h"
#include "wtf/HashSet.h"
#include "wtf/RefCounted.h"
#include "wtf/RefPtr.h"
#include "wtf/text/AtomicStringHash.h"
#include "wtf/text/StringHash.h"

namespace blink {

class Element;

// Tracks data to determine which elements of a DOM subtree need to have style
// recalculated.
class DescendantInvalidationSet FINAL : public RefCountedWillBeGarbageCollected<DescendantInvalidationSet> {
public:
    static PassRefPtrWillBeRawPtr<DescendantInvalidationSet> create()
    {
        return adoptRefWillBeNoop(new DescendantInvalidationSet);
    }

    bool invalidatesElement(Element&) const;

    void combine(const DescendantInvalidationSet& other);

    void addClass(const AtomicString& className);
    void addId(const AtomicString& id);
    void addTagName(const AtomicString& tagName);
    void addAttribute(const AtomicString& attributeLocalName);

    void setWholeSubtreeInvalid();
    bool wholeSubtreeInvalid() const { return m_allDescendantsMightBeInvalid; }

    void setTreeBoundaryCrossing() { m_treeBoundaryCrossing = true; }
    bool treeBoundaryCrossing() const { return m_treeBoundaryCrossing; }

    void setCustomPseudoInvalid() { m_customPseudoInvalid = true; }
    bool customPseudoInvalid() const { return m_customPseudoInvalid; }

    bool isEmpty() const { return !m_classes && !m_ids && !m_tagNames && !m_attributes; }

    void trace(Visitor*);

#ifndef NDEBUG
    void show() const;
#endif

private:
    DescendantInvalidationSet();

    WillBeHeapHashSet<AtomicString>& ensureClassSet();
    WillBeHeapHashSet<AtomicString>& ensureIdSet();
    WillBeHeapHashSet<AtomicString>& ensureTagNameSet();
    WillBeHeapHashSet<AtomicString>& ensureAttributeSet();

    // FIXME: optimize this if it becomes a memory issue.
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString> > m_classes;
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString> > m_ids;
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString> > m_tagNames;
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString> > m_attributes;

    // If true, all descendants might be invalidated, so a full subtree recalc is required.
    unsigned m_allDescendantsMightBeInvalid : 1;

    // If true, all descendants which are custom pseudo elements must be invalidated.
    unsigned m_customPseudoInvalid : 1;

    // If true, the invalidation must traverse into ShadowRoots with this set.
    unsigned m_treeBoundaryCrossing : 1;
};

} // namespace blink

#endif // DescendantInvalidationSet_h