/*
 * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
 * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "core/style/ComputedStyle.h"

#include "core/animation/css/CSSAnimationData.h"
#include "core/animation/css/CSSTransitionData.h"
#include "core/css/CSSPaintValue.h"
#include "core/css/CSSPrimitiveValue.h"
#include "core/css/CSSPropertyEquality.h"
#include "core/css/resolver/StyleResolver.h"
#include "core/layout/LayoutTheme.h"
#include "core/layout/TextAutosizer.h"
#include "core/style/AppliedTextDecoration.h"
#include "core/style/BorderEdge.h"
#include "core/style/ComputedStyleConstants.h"
#include "core/style/ContentData.h"
#include "core/style/CursorData.h"
#include "core/style/DataEquivalency.h"
#include "core/style/QuotesData.h"
#include "core/style/ShadowList.h"
#include "core/style/StyleImage.h"
#include "core/style/StyleInheritedData.h"
#include "core/style/StyleVariableData.h"
#include "platform/LengthFunctions.h"
#include "platform/RuntimeEnabledFeatures.h"
#include "platform/fonts/Font.h"
#include "platform/fonts/FontSelector.h"
#include "platform/geometry/FloatRoundedRect.h"
#include "platform/graphics/GraphicsContext.h"
#include "platform/transforms/RotateTransformOperation.h"
#include "platform/transforms/ScaleTransformOperation.h"
#include "platform/transforms/TranslateTransformOperation.h"
#include "wtf/MathExtras.h"
#include "wtf/PtrUtil.h"
#include "wtf/SaturatedArithmetic.h"
#include <algorithm>
#include <memory>

namespace blink {

struct SameSizeAsBorderValue {
    RGBA32 m_color;
    unsigned m_width;
};

static_assert(sizeof(BorderValue) == sizeof(SameSizeAsBorderValue), "BorderValue should stay small");

// Since different compilers/architectures pack ComputedStyle differently,
// re-create the same structure for an accurate size comparison.
struct SameSizeAsComputedStyle : public RefCounted<SameSizeAsComputedStyle> {
    void* dataRefs[7];
    void* ownPtrs[1];
    void* dataRefSvgStyle;

    struct InheritedData {
        unsigned m_bitfields[2];
    } m_inheritedData;

    struct NonInheritedData {
        unsigned m_bitfields[3];
    } m_nonInheritedData;
};

static_assert(sizeof(ComputedStyle) == sizeof(SameSizeAsComputedStyle), "ComputedStyle should stay small");

PassRefPtr<ComputedStyle> ComputedStyle::create()
{
    return adoptRef(new ComputedStyle());
}

PassRefPtr<ComputedStyle> ComputedStyle::createInitialStyle()
{
    return adoptRef(new ComputedStyle(InitialStyle));
}

void ComputedStyle::invalidateInitialStyle()
{
    mutableInitialStyle().setTapHighlightColor(initialTapHighlightColor());
}

PassRefPtr<ComputedStyle> ComputedStyle::createAnonymousStyleWithDisplay(const ComputedStyle& parentStyle, EDisplay display)
{
    RefPtr<ComputedStyle> newStyle = ComputedStyle::create();
    newStyle->inheritFrom(parentStyle);
    newStyle->inheritUnicodeBidiFrom(parentStyle);
    newStyle->setDisplay(display);
    return newStyle;
}

PassRefPtr<ComputedStyle> ComputedStyle::clone(const ComputedStyle& other)
{
    return adoptRef(new ComputedStyle(other));
}

ALWAYS_INLINE ComputedStyle::ComputedStyle()
    : m_box(initialStyle().m_box)
    , m_visual(initialStyle().m_visual)
    , m_background(initialStyle().m_background)
    , m_surround(initialStyle().m_surround)
    , m_rareNonInheritedData(initialStyle().m_rareNonInheritedData)
    , m_rareInheritedData(initialStyle().m_rareInheritedData)
    , m_styleInheritedData(initialStyle().m_styleInheritedData)
    , m_svgStyle(initialStyle().m_svgStyle)
{
    setBitDefaults(); // Would it be faster to copy this from the default style?
    static_assert((sizeof(InheritedData) <= 8), "InheritedData should not grow");
    static_assert((sizeof(NonInheritedData) <= 12), "NonInheritedData should not grow");
}

ALWAYS_INLINE ComputedStyle::ComputedStyle(InitialStyleTag)
{
    setBitDefaults();

    m_box.init();
    m_visual.init();
    m_background.init();
    m_surround.init();
    m_rareNonInheritedData.init();
    m_rareNonInheritedData.access()->m_deprecatedFlexibleBox.init();
    m_rareNonInheritedData.access()->m_flexibleBox.init();
    m_rareNonInheritedData.access()->m_multiCol.init();
    m_rareNonInheritedData.access()->m_transform.init();
    m_rareNonInheritedData.access()->m_willChange.init();
    m_rareNonInheritedData.access()->m_filter.init();
    m_rareNonInheritedData.access()->m_backdropFilter.init();
    m_rareNonInheritedData.access()->m_grid.init();
    m_rareNonInheritedData.access()->m_gridItem.init();
    m_rareNonInheritedData.access()->m_scrollSnap.init();
    m_rareInheritedData.init();
    m_styleInheritedData.init();
    m_svgStyle.init();
}

ALWAYS_INLINE ComputedStyle::ComputedStyle(const ComputedStyle& o)
    : RefCounted<ComputedStyle>()
    , m_box(o.m_box)
    , m_visual(o.m_visual)
    , m_background(o.m_background)
    , m_surround(o.m_surround)
    , m_rareNonInheritedData(o.m_rareNonInheritedData)
    , m_rareInheritedData(o.m_rareInheritedData)
    , m_styleInheritedData(o.m_styleInheritedData)
    , m_svgStyle(o.m_svgStyle)
    , m_inheritedData(o.m_inheritedData)
    , m_nonInheritedData(o.m_nonInheritedData)
{
}

static StyleRecalcChange diffPseudoStyles(const ComputedStyle& oldStyle, const ComputedStyle& newStyle)
{
    // If the pseudoStyles have changed, we want any StyleRecalcChange that is not NoChange
    // because setStyle will do the right thing with anything else.
    if (!oldStyle.hasAnyPublicPseudoStyles())
        return NoChange;
    for (PseudoId pseudoId = FirstPublicPseudoId; pseudoId < FirstInternalPseudoId; pseudoId = static_cast<PseudoId>(pseudoId + 1)) {
        if (!oldStyle.hasPseudoStyle(pseudoId))
            continue;
        const ComputedStyle* newPseudoStyle = newStyle.getCachedPseudoStyle(pseudoId);
        if (!newPseudoStyle)
            return NoInherit;
        const ComputedStyle* oldPseudoStyle = oldStyle.getCachedPseudoStyle(pseudoId);
        if (oldPseudoStyle && *oldPseudoStyle != *newPseudoStyle)
            return NoInherit;
    }
    return NoChange;
}

StyleRecalcChange ComputedStyle::stylePropagationDiff(const ComputedStyle* oldStyle, const ComputedStyle* newStyle)
{
    if ((!oldStyle && newStyle) || (oldStyle && !newStyle))
        return Reattach;

    if (!oldStyle && !newStyle)
        return NoChange;

    if (oldStyle->display() != newStyle->display()
        || oldStyle->hasPseudoStyle(PseudoIdFirstLetter) != newStyle->hasPseudoStyle(PseudoIdFirstLetter)
        || !oldStyle->contentDataEquivalent(newStyle)
        || oldStyle->hasTextCombine() != newStyle->hasTextCombine())
        return Reattach;

    bool independentEqual = oldStyle->independentInheritedEqual(*newStyle);
    bool nonIndependentEqual = oldStyle->nonIndependentInheritedEqual(*newStyle);
    if (!independentEqual || !nonIndependentEqual) {
        if (nonIndependentEqual && !oldStyle->hasExplicitlyInheritedProperties())
            return IndependentInherit;
        return Inherit;
    }

    if (!oldStyle->loadingCustomFontsEqual(*newStyle)
        || oldStyle->alignItems() != newStyle->alignItems()
        || oldStyle->justifyItems() != newStyle->justifyItems())
        return Inherit;

    if (*oldStyle == *newStyle)
        return diffPseudoStyles(*oldStyle, *newStyle);

    if (oldStyle->hasExplicitlyInheritedProperties())
        return Inherit;

    return NoInherit;
}

// TODO(sashab): Generate this function.
void ComputedStyle::propagateIndependentInheritedProperties(const ComputedStyle& parentStyle)
{
    if (m_nonInheritedData.m_isPointerEventsInherited)
        setPointerEvents(parentStyle.pointerEvents());
    if (m_nonInheritedData.m_isVisibilityInherited)
        setVisibility(parentStyle.visibility());
}

StyleSelfAlignmentData resolvedSelfAlignment(const StyleSelfAlignmentData& value, ItemPosition normalValueBehavior)
{
    // To avoid needing to copy the RareNonInheritedData, we repurpose the 'auto' flag to not just mean 'auto' prior to running the StyleAdjuster but also mean 'normal' after running it.
    if (value.position() == ItemPositionNormal || value.position() == ItemPositionAuto)
        return {normalValueBehavior, OverflowAlignmentDefault};
    return value;
}

StyleSelfAlignmentData ComputedStyle::resolvedAlignItems(ItemPosition normalValueBehaviour) const
{
    // We will return the behaviour of 'normal' value if needed, which is specific of each layout model.
    return resolvedSelfAlignment(alignItems(), normalValueBehaviour);
}

StyleSelfAlignmentData ComputedStyle::resolvedAlignSelf(ItemPosition normalValueBehaviour, const ComputedStyle* parentStyle) const
{
    // We will return the behaviour of 'normal' value if needed, which is specific of each layout model.
    if (!parentStyle || alignSelfPosition() != ItemPositionAuto)
        return resolvedSelfAlignment(alignSelf(), normalValueBehaviour);

    // We shouldn't need to resolve any 'auto' value in post-adjusment ComputedStyle, but some layout models
    // can generate anonymous boxes that may need 'auto' value resolution during layout.
    // The 'auto' keyword computes to the parent's align-items computed value.
    return parentStyle->resolvedAlignItems(normalValueBehaviour);
}

StyleSelfAlignmentData ComputedStyle::resolvedJustifyItems(ItemPosition normalValueBehaviour) const
{
    // We will return the behaviour of 'normal' value if needed, which is specific of each layout model.
    return resolvedSelfAlignment(justifyItems(), normalValueBehaviour);
}

StyleSelfAlignmentData ComputedStyle::resolvedJustifySelf(ItemPosition normalValueBehaviour, const ComputedStyle* parentStyle) const
{
    // We will return the behaviour of 'normal' value if needed, which is specific of each layout model.
    if (!parentStyle || justifySelfPosition() != ItemPositionAuto)
        return resolvedSelfAlignment(justifySelf(), normalValueBehaviour);

    // We shouldn't need to resolve any 'auto' value in post-adjusment ComputedStyle, but some layout models
    // can generate anonymous boxes that may need 'auto' value resolution during layout.
    // The auto keyword computes to the parent's justify-items computed value.
    return parentStyle->resolvedJustifyItems(normalValueBehaviour);
}

static inline ContentPosition resolvedContentAlignmentPosition(const StyleContentAlignmentData& value, const StyleContentAlignmentData& normalValueBehavior)
{
    return (value.position() == ContentPositionNormal && value.distribution() == ContentDistributionDefault) ? normalValueBehavior.position() : value.position();
}

static inline ContentDistributionType resolvedContentAlignmentDistribution(const StyleContentAlignmentData& value, const StyleContentAlignmentData& normalValueBehavior)
{
    return (value.position() == ContentPositionNormal && value.distribution() == ContentDistributionDefault) ? normalValueBehavior.distribution() : value.distribution();
}

ContentPosition ComputedStyle::resolvedJustifyContentPosition(const StyleContentAlignmentData& normalValueBehavior) const
{
    return resolvedContentAlignmentPosition(justifyContent(), normalValueBehavior);
}

ContentDistributionType ComputedStyle::resolvedJustifyContentDistribution(const StyleContentAlignmentData& normalValueBehavior) const
{
    return resolvedContentAlignmentDistribution(justifyContent(), normalValueBehavior);
}

ContentPosition ComputedStyle::resolvedAlignContentPosition(const StyleContentAlignmentData& normalValueBehavior) const
{
    return resolvedContentAlignmentPosition(alignContent(), normalValueBehavior);
}

ContentDistributionType ComputedStyle::resolvedAlignContentDistribution(const StyleContentAlignmentData& normalValueBehavior) const
{
    return resolvedContentAlignmentDistribution(alignContent(), normalValueBehavior);
}

void ComputedStyle::inheritFrom(const ComputedStyle& inheritParent, IsAtShadowBoundary isAtShadowBoundary)
{
    if (isAtShadowBoundary == AtShadowBoundary) {
        // Even if surrounding content is user-editable, shadow DOM should act as a single unit, and not necessarily be editable
        EUserModify currentUserModify = userModify();
        m_rareInheritedData = inheritParent.m_rareInheritedData;
        setUserModify(currentUserModify);
    } else {
        m_rareInheritedData = inheritParent.m_rareInheritedData;
    }
    m_styleInheritedData = inheritParent.m_styleInheritedData;
    m_inheritedData = inheritParent.m_inheritedData;
    if (m_svgStyle != inheritParent.m_svgStyle)
        m_svgStyle.access()->inheritFrom(inheritParent.m_svgStyle.get());
}

void ComputedStyle::copyNonInheritedFromCached(const ComputedStyle& other)
{
    m_box = other.m_box;
    m_visual = other.m_visual;
    m_background = other.m_background;
    m_surround = other.m_surround;
    m_rareNonInheritedData = other.m_rareNonInheritedData;

    // The flags are copied one-by-one because m_nonInheritedData.m_contains a bunch of stuff other than real style data.
    // See comments for each skipped flag below.
    m_nonInheritedData.m_effectiveDisplay = other.m_nonInheritedData.m_effectiveDisplay;
    m_nonInheritedData.m_originalDisplay = other.m_nonInheritedData.m_originalDisplay;
    m_nonInheritedData.m_overflowAnchor = other.m_nonInheritedData.m_overflowAnchor;
    m_nonInheritedData.m_overflowX = other.m_nonInheritedData.m_overflowX;
    m_nonInheritedData.m_overflowY = other.m_nonInheritedData.m_overflowY;
    m_nonInheritedData.m_verticalAlign = other.m_nonInheritedData.m_verticalAlign;
    m_nonInheritedData.m_clear = other.m_nonInheritedData.m_clear;
    m_nonInheritedData.m_position = other.m_nonInheritedData.m_position;
    m_nonInheritedData.m_floating = other.m_nonInheritedData.m_floating;
    m_nonInheritedData.m_tableLayout = other.m_nonInheritedData.m_tableLayout;
    m_nonInheritedData.m_unicodeBidi = other.m_nonInheritedData.m_unicodeBidi;
    m_nonInheritedData.m_hasViewportUnits = other.m_nonInheritedData.m_hasViewportUnits;
    m_nonInheritedData.m_breakBefore = other.m_nonInheritedData.m_breakBefore;
    m_nonInheritedData.m_breakAfter = other.m_nonInheritedData.m_breakAfter;
    m_nonInheritedData.m_breakInside = other.m_nonInheritedData.m_breakInside;
    m_nonInheritedData.m_hasRemUnits = other.m_nonInheritedData.m_hasRemUnits;

    // Correctly set during selector matching:
    // m_nonInheritedData.m_styleType
    // m_nonInheritedData.m_pseudoBits

    // Set correctly while computing style for children:
    // m_nonInheritedData.m_explicitInheritance

    // unique() styles are not cacheable.
    DCHECK(!other.m_nonInheritedData.m_unique);

    // styles with non inherited properties that reference variables are not
    // cacheable.
    DCHECK(!other.m_nonInheritedData.m_variableReference);

    // The following flags are set during matching before we decide that we get a
    // match in the MatchedPropertiesCache which in turn calls this method. The
    // reason why we don't copy these flags is that they're already correctly set
    // and that they may differ between elements which have the same set of matched
    // properties. For instance, given the rule:
    //
    // :-webkit-any(:hover, :focus) { background-color: green }"
    //
    // A hovered element, and a focused element may use the same cached matched
    // properties here, but the affectedBy flags will be set differently based on
    // the matching order of the :-webkit-any components.
    //
    // m_nonInheritedData.m_emptyState
    // m_nonInheritedData.m_affectedByFocus
    // m_nonInheritedData.m_affectedByHover
    // m_nonInheritedData.m_affectedByActive
    // m_nonInheritedData.m_affectedByDrag
    // m_nonInheritedData.m_isLink

    // Any properties that are inherited on a style are also inherited on elements
    // that share this style.
    m_nonInheritedData.m_isPointerEventsInherited = other.m_nonInheritedData.m_isPointerEventsInherited;
    m_nonInheritedData.m_isVisibilityInherited = other.m_nonInheritedData.m_isVisibilityInherited;

    if (m_svgStyle != other.m_svgStyle)
        m_svgStyle.access()->copyNonInheritedFromCached(other.m_svgStyle.get());
    DCHECK_EQ(zoom(), initialZoom());
}

bool ComputedStyle::operator==(const ComputedStyle& o) const
{
    return inheritedEqual(o)
        && nonInheritedEqual(o);
}

bool ComputedStyle::isStyleAvailable() const
{
    return this != StyleResolver::styleNotYetAvailable();
}

bool ComputedStyle::hasUniquePseudoStyle() const
{
    if (!m_cachedPseudoStyles || styleType() != PseudoIdNone)
        return false;

    for (size_t i = 0; i < m_cachedPseudoStyles->size(); ++i) {
        const ComputedStyle& pseudoStyle = *m_cachedPseudoStyles->at(i);
        if (pseudoStyle.unique())
            return true;
    }

    return false;
}

ComputedStyle* ComputedStyle::getCachedPseudoStyle(PseudoId pid) const
{
    if (!m_cachedPseudoStyles || !m_cachedPseudoStyles->size())
        return 0;

    if (styleType() != PseudoIdNone)
        return 0;

    for (size_t i = 0; i < m_cachedPseudoStyles->size(); ++i) {
        ComputedStyle* pseudoStyle = m_cachedPseudoStyles->at(i).get();
        if (pseudoStyle->styleType() == pid)
            return pseudoStyle;
    }

    return 0;
}

ComputedStyle* ComputedStyle::addCachedPseudoStyle(PassRefPtr<ComputedStyle> pseudo)
{
    if (!pseudo)
        return 0;

    ASSERT(pseudo->styleType() > PseudoIdNone);

    ComputedStyle* result = pseudo.get();

    if (!m_cachedPseudoStyles)
        m_cachedPseudoStyles = wrapUnique(new PseudoStyleCache);

    m_cachedPseudoStyles->append(pseudo);

    return result;
}

void ComputedStyle::removeCachedPseudoStyle(PseudoId pid)
{
    if (!m_cachedPseudoStyles)
        return;
    for (size_t i = 0; i < m_cachedPseudoStyles->size(); ++i) {
        ComputedStyle* pseudoStyle = m_cachedPseudoStyles->at(i).get();
        if (pseudoStyle->styleType() == pid) {
            m_cachedPseudoStyles->remove(i);
            return;
        }
    }
}

bool ComputedStyle::inheritedEqual(const ComputedStyle& other) const
{
    return independentInheritedEqual(other)
        && nonIndependentInheritedEqual(other);
}

bool ComputedStyle::independentInheritedEqual(const ComputedStyle& other) const
{
    return m_inheritedData.compareEqualIndependent(other.m_inheritedData);
}

bool ComputedStyle::nonIndependentInheritedEqual(const ComputedStyle& other) const
{
    return m_inheritedData.compareEqualNonIndependent(other.m_inheritedData)
        && m_styleInheritedData == other.m_styleInheritedData
        && m_svgStyle->inheritedEqual(*other.m_svgStyle)
        && m_rareInheritedData == other.m_rareInheritedData;
}

bool ComputedStyle::loadingCustomFontsEqual(const ComputedStyle& other) const
{
    return font().loadingCustomFonts() == other.font().loadingCustomFonts();
}

bool ComputedStyle::nonInheritedEqual(const ComputedStyle& other) const
{
    // compare everything except the pseudoStyle pointer
    return m_nonInheritedData == other.m_nonInheritedData
        && m_box == other.m_box
        && m_visual == other.m_visual
        && m_background == other.m_background
        && m_surround == other.m_surround
        && m_rareNonInheritedData == other.m_rareNonInheritedData
        && m_svgStyle->nonInheritedEqual(*other.m_svgStyle);
}

bool ComputedStyle::inheritedDataShared(const ComputedStyle& other) const
{
    // This is a fast check that only looks if the data structures are shared.
    return m_inheritedData == other.m_inheritedData
        && m_styleInheritedData.get() == other.m_styleInheritedData.get()
        && m_svgStyle.get() == other.m_svgStyle.get()
        && m_rareInheritedData.get() == other.m_rareInheritedData.get();
}

static bool dependenceOnContentHeightHasChanged(const ComputedStyle& a, const ComputedStyle& b)
{
    // If top or bottom become auto/non-auto then it means we either have to solve height based
    // on the content or stop doing so (http://www.w3.org/TR/CSS2/visudet.html#abs-non-replaced-height)
    // - either way requires a layout.
    return a.logicalTop().isAuto() != b.logicalTop().isAuto() || a.logicalBottom().isAuto() != b.logicalBottom().isAuto();
}

StyleDifference ComputedStyle::visualInvalidationDiff(const ComputedStyle& other) const
{
    // Note, we use .get() on each DataRef below because DataRef::operator== will do a deep
    // compare, which is duplicate work when we're going to compare each property inside
    // this function anyway.

    StyleDifference diff;
    if (m_svgStyle.get() != other.m_svgStyle.get())
        diff = m_svgStyle->diff(other.m_svgStyle.get());

    if ((!diff.needsFullLayout() || !diff.needsPaintInvalidation()) && diffNeedsFullLayoutAndPaintInvalidation(other)) {
        diff.setNeedsFullLayout();
        diff.setNeedsPaintInvalidationObject();
    }

    if (!diff.needsFullLayout() && diffNeedsFullLayout(other))
        diff.setNeedsFullLayout();

    if (!diff.needsFullLayout() && m_surround->margin != other.m_surround->margin) {
        // Relative-positioned elements collapse their margins so need a full layout.
        if (hasOutOfFlowPosition())
            diff.setNeedsPositionedMovementLayout();
        else
            diff.setNeedsFullLayout();
    }

    if (!diff.needsFullLayout() && position() != StaticPosition && m_surround->offset != other.m_surround->offset) {
        // Optimize for the case where a positioned layer is moving but not changing size.
        if (dependenceOnContentHeightHasChanged(*this, other))
            diff.setNeedsFullLayout();
        else
            diff.setNeedsPositionedMovementLayout();
    }

    if (diffNeedsPaintInvalidationSubtree(other))
        diff.setNeedsPaintInvalidationSubtree();
    else if (diffNeedsPaintInvalidationObject(other))
        diff.setNeedsPaintInvalidationObject();

    updatePropertySpecificDifferences(other, diff);

    // TODO(skobes): Refine the criteria for ScrollAnchor-disabling properties.
    // Some things set needsLayout but shouldn't disable scroll anchoring.
    if (diff.needsLayout() || diff.transformChanged())
        diff.setScrollAnchorDisablingPropertyChanged();

    // Cursors are not checked, since they will be set appropriately in response to mouse events,
    // so they don't need to cause any paint invalidation or layout.

    // Animations don't need to be checked either. We always set the new style on the layoutObject, so we will get a chance to fire off
    // the resulting transition properly.

    return diff;
}

bool ComputedStyle::diffNeedsFullLayoutAndPaintInvalidation(const ComputedStyle& other) const
{
    // FIXME: Not all cases in this method need both full layout and paint invalidation.
    // Should move cases into diffNeedsFullLayout() if
    // - don't need paint invalidation at all;
    // - or the layoutObject knows how to exactly invalidate paints caused by the layout change
    //   instead of forced full paint invalidation.

    if (m_surround.get() != other.m_surround.get()) {
        // If our border widths change, then we need to layout. Other changes to borders only necessitate a paint invalidation.
        if (borderLeftWidth() != other.borderLeftWidth()
            || borderTopWidth() != other.borderTopWidth()
            || borderBottomWidth() != other.borderBottomWidth()
            || borderRightWidth() != other.borderRightWidth())
            return true;
    }

    if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
        if (m_rareNonInheritedData->m_appearance != other.m_rareNonInheritedData->m_appearance
            || m_rareNonInheritedData->marginBeforeCollapse != other.m_rareNonInheritedData->marginBeforeCollapse
            || m_rareNonInheritedData->marginAfterCollapse != other.m_rareNonInheritedData->marginAfterCollapse
            || m_rareNonInheritedData->lineClamp != other.m_rareNonInheritedData->lineClamp
            || m_rareNonInheritedData->textOverflow != other.m_rareNonInheritedData->textOverflow
            || m_rareNonInheritedData->m_shapeMargin != other.m_rareNonInheritedData->m_shapeMargin
            || m_rareNonInheritedData->m_order != other.m_rareNonInheritedData->m_order
            || m_rareNonInheritedData->hasFilters() != other.m_rareNonInheritedData->hasFilters())
            return true;

        if (m_rareNonInheritedData->m_grid.get() != other.m_rareNonInheritedData->m_grid.get()
            && *m_rareNonInheritedData->m_grid.get() != *other.m_rareNonInheritedData->m_grid.get())
            return true;

        if (m_rareNonInheritedData->m_gridItem.get() != other.m_rareNonInheritedData->m_gridItem.get()
            && *m_rareNonInheritedData->m_gridItem.get() != *other.m_rareNonInheritedData->m_gridItem.get())
            return true;

        if (m_rareNonInheritedData->m_deprecatedFlexibleBox.get() != other.m_rareNonInheritedData->m_deprecatedFlexibleBox.get()
            && *m_rareNonInheritedData->m_deprecatedFlexibleBox.get() != *other.m_rareNonInheritedData->m_deprecatedFlexibleBox.get())
            return true;

        if (m_rareNonInheritedData->m_flexibleBox.get() != other.m_rareNonInheritedData->m_flexibleBox.get()
            && *m_rareNonInheritedData->m_flexibleBox.get() != *other.m_rareNonInheritedData->m_flexibleBox.get())
            return true;

        if (m_rareNonInheritedData->m_multiCol.get() != other.m_rareNonInheritedData->m_multiCol.get()
            && *m_rareNonInheritedData->m_multiCol.get() != *other.m_rareNonInheritedData->m_multiCol.get())
            return true;

        // If the counter directives change, trigger a relayout to re-calculate counter values and rebuild the counter node tree.
        const CounterDirectiveMap* mapA = m_rareNonInheritedData->m_counterDirectives.get();
        const CounterDirectiveMap* mapB = other.m_rareNonInheritedData->m_counterDirectives.get();
        if (!(mapA == mapB || (mapA && mapB && *mapA == *mapB)))
            return true;

        // We only need do layout for opacity changes if adding or losing opacity could trigger a change
        // in us being a stacking context.
        if (isStackingContext() != other.isStackingContext() && m_rareNonInheritedData->hasOpacity() != other.m_rareNonInheritedData->hasOpacity()) {
            // FIXME: We would like to use SimplifiedLayout here, but we can't quite do that yet.
            // We need to make sure SimplifiedLayout can operate correctly on LayoutInlines (we will need
            // to add a selfNeedsSimplifiedLayout bit in order to not get confused and taint every line).
            // In addition we need to solve the floating object issue when layers come and go. Right now
            // a full layout is necessary to keep floating object lists sane.
            return true;
        }
    }

    if (m_rareInheritedData.get() != other.m_rareInheritedData.get()) {
        if (m_rareInheritedData->highlight != other.m_rareInheritedData->highlight
            || m_rareInheritedData->indent != other.m_rareInheritedData->indent
            || m_rareInheritedData->m_textAlignLast != other.m_rareInheritedData->m_textAlignLast
            || m_rareInheritedData->m_textIndentLine != other.m_rareInheritedData->m_textIndentLine
            || m_rareInheritedData->m_effectiveZoom != other.m_rareInheritedData->m_effectiveZoom
            || m_rareInheritedData->wordBreak != other.m_rareInheritedData->wordBreak
            || m_rareInheritedData->overflowWrap != other.m_rareInheritedData->overflowWrap
            || m_rareInheritedData->lineBreak != other.m_rareInheritedData->lineBreak
            || m_rareInheritedData->textSecurity != other.m_rareInheritedData->textSecurity
            || m_rareInheritedData->hyphens != other.m_rareInheritedData->hyphens
            || m_rareInheritedData->hyphenationLimitBefore != other.m_rareInheritedData->hyphenationLimitBefore
            || m_rareInheritedData->hyphenationLimitAfter != other.m_rareInheritedData->hyphenationLimitAfter
            || m_rareInheritedData->hyphenationString != other.m_rareInheritedData->hyphenationString
            || m_rareInheritedData->m_respectImageOrientation != other.m_rareInheritedData->m_respectImageOrientation
            || m_rareInheritedData->m_rubyPosition != other.m_rareInheritedData->m_rubyPosition
            || m_rareInheritedData->textEmphasisMark != other.m_rareInheritedData->textEmphasisMark
            || m_rareInheritedData->textEmphasisPosition != other.m_rareInheritedData->textEmphasisPosition
            || m_rareInheritedData->textEmphasisCustomMark != other.m_rareInheritedData->textEmphasisCustomMark
            || m_rareInheritedData->m_textJustify != other.m_rareInheritedData->m_textJustify
            || m_rareInheritedData->m_textOrientation != other.m_rareInheritedData->m_textOrientation
            || m_rareInheritedData->m_textCombine != other.m_rareInheritedData->m_textCombine
            || m_rareInheritedData->m_tabSize != other.m_rareInheritedData->m_tabSize
            || m_rareInheritedData->m_textSizeAdjust != other.m_rareInheritedData->m_textSizeAdjust
            || m_rareInheritedData->listStyleImage != other.m_rareInheritedData->listStyleImage
            || m_rareInheritedData->m_snapHeightUnit != other.m_rareInheritedData->m_snapHeightUnit
            || m_rareInheritedData->m_snapHeightPosition != other.m_rareInheritedData->m_snapHeightPosition
            || m_rareInheritedData->textStrokeWidth != other.m_rareInheritedData->textStrokeWidth)
            return true;

        if (!m_rareInheritedData->shadowDataEquivalent(*other.m_rareInheritedData.get()))
            return true;

        if (!m_rareInheritedData->quotesDataEquivalent(*other.m_rareInheritedData.get()))
            return true;
    }

    if (m_styleInheritedData->textAutosizingMultiplier != other.m_styleInheritedData->textAutosizingMultiplier)
        return true;

    if (m_styleInheritedData->font.loadingCustomFonts() != other.m_styleInheritedData->font.loadingCustomFonts())
        return true;

    if (m_styleInheritedData.get() != other.m_styleInheritedData.get()) {
        if (m_styleInheritedData->line_height != other.m_styleInheritedData->line_height
            || m_styleInheritedData->font != other.m_styleInheritedData->font
            || m_styleInheritedData->horizontal_border_spacing != other.m_styleInheritedData->horizontal_border_spacing
            || m_styleInheritedData->vertical_border_spacing != other.m_styleInheritedData->vertical_border_spacing)
            return true;
    }

    if (m_inheritedData.m_boxDirection != other.m_inheritedData.m_boxDirection
        || m_inheritedData.m_rtlOrdering != other.m_inheritedData.m_rtlOrdering
        || m_inheritedData.m_textAlign != other.m_inheritedData.m_textAlign
        || m_inheritedData.m_textTransform != other.m_inheritedData.m_textTransform
        || m_inheritedData.m_direction != other.m_inheritedData.m_direction
        || m_inheritedData.m_whiteSpace != other.m_inheritedData.m_whiteSpace
        || m_inheritedData.m_writingMode != other.m_inheritedData.m_writingMode)
        return true;

    if (m_nonInheritedData.m_overflowX != other.m_nonInheritedData.m_overflowX
        || m_nonInheritedData.m_overflowY != other.m_nonInheritedData.m_overflowY
        || m_nonInheritedData.m_clear != other.m_nonInheritedData.m_clear
        || m_nonInheritedData.m_unicodeBidi != other.m_nonInheritedData.m_unicodeBidi
        || m_nonInheritedData.m_floating != other.m_nonInheritedData.m_floating
        || m_nonInheritedData.m_originalDisplay != other.m_nonInheritedData.m_originalDisplay)
        return true;

    if (m_nonInheritedData.m_effectiveDisplay >= FIRST_TABLE_DISPLAY && m_nonInheritedData.m_effectiveDisplay <= LAST_TABLE_DISPLAY) {
        if (m_inheritedData.m_borderCollapse != other.m_inheritedData.m_borderCollapse
            || m_inheritedData.m_emptyCells != other.m_inheritedData.m_emptyCells
            || m_inheritedData.m_captionSide != other.m_inheritedData.m_captionSide
            || m_nonInheritedData.m_tableLayout != other.m_nonInheritedData.m_tableLayout)
            return true;

        // In the collapsing border model, 'hidden' suppresses other borders, while 'none'
        // does not, so these style differences can be width differences.
        if (m_inheritedData.m_borderCollapse
            && ((borderTopStyle() == BorderStyleHidden && other.borderTopStyle() == BorderStyleNone)
                || (borderTopStyle() == BorderStyleNone && other.borderTopStyle() == BorderStyleHidden)
                || (borderBottomStyle() == BorderStyleHidden && other.borderBottomStyle() == BorderStyleNone)
                || (borderBottomStyle() == BorderStyleNone && other.borderBottomStyle() == BorderStyleHidden)
                || (borderLeftStyle() == BorderStyleHidden && other.borderLeftStyle() == BorderStyleNone)
                || (borderLeftStyle() == BorderStyleNone && other.borderLeftStyle() == BorderStyleHidden)
                || (borderRightStyle() == BorderStyleHidden && other.borderRightStyle() == BorderStyleNone)
                || (borderRightStyle() == BorderStyleNone && other.borderRightStyle() == BorderStyleHidden)))
            return true;
    } else if (m_nonInheritedData.m_effectiveDisplay == LIST_ITEM) {
        if (m_inheritedData.m_listStyleType != other.m_inheritedData.m_listStyleType
            || m_inheritedData.m_listStylePosition != other.m_inheritedData.m_listStylePosition)
            return true;
    }

    if ((visibility() == EVisibility::Collapse) != (other.visibility() == EVisibility::Collapse))
        return true;

    if (hasPseudoStyle(PseudoIdScrollbar) != other.hasPseudoStyle(PseudoIdScrollbar))
        return true;

    // Movement of non-static-positioned object is special cased in ComputedStyle::visualInvalidationDiff().

    return false;
}

bool ComputedStyle::diffNeedsFullLayout(const ComputedStyle& other) const
{
    if (m_box.get() != other.m_box.get()) {
        if (m_box->width() != other.m_box->width()
            || m_box->minWidth() != other.m_box->minWidth()
            || m_box->maxWidth() != other.m_box->maxWidth()
            || m_box->height() != other.m_box->height()
            || m_box->minHeight() != other.m_box->minHeight()
            || m_box->maxHeight() != other.m_box->maxHeight())
            return true;

        if (m_box->verticalAlign() != other.m_box->verticalAlign())
            return true;

        if (m_box->boxSizing() != other.m_box->boxSizing())
            return true;
    }

    if (m_nonInheritedData.m_verticalAlign != other.m_nonInheritedData.m_verticalAlign
        || m_nonInheritedData.m_position != other.m_nonInheritedData.m_position)
        return true;

    if (m_surround.get() != other.m_surround.get()) {
        if (m_surround->padding != other.m_surround->padding)
            return true;
    }

    if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
        if (m_rareNonInheritedData->m_alignContent != other.m_rareNonInheritedData->m_alignContent
            || m_rareNonInheritedData->m_alignItems != other.m_rareNonInheritedData->m_alignItems
            || m_rareNonInheritedData->m_alignSelf != other.m_rareNonInheritedData->m_alignSelf
            || m_rareNonInheritedData->m_justifyContent != other.m_rareNonInheritedData->m_justifyContent
            || m_rareNonInheritedData->m_justifyItems != other.m_rareNonInheritedData->m_justifyItems
            || m_rareNonInheritedData->m_justifySelf != other.m_rareNonInheritedData->m_justifySelf
            || m_rareNonInheritedData->m_contain != other.m_rareNonInheritedData->m_contain)
            return true;

        if (!RuntimeEnabledFeatures::cssBoxReflectFilterEnabled() && !m_rareNonInheritedData->reflectionDataEquivalent(*other.m_rareNonInheritedData.get()))
            return true;
    }

    return false;
}

bool ComputedStyle::diffNeedsPaintInvalidationSubtree(const ComputedStyle& other) const
{
    if (position() != StaticPosition && (m_visual->clip != other.m_visual->clip || m_visual->hasAutoClip != other.m_visual->hasAutoClip))
        return true;

    if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
        if (m_rareNonInheritedData->m_effectiveBlendMode != other.m_rareNonInheritedData->m_effectiveBlendMode
            || m_rareNonInheritedData->m_isolation != other.m_rareNonInheritedData->m_isolation)
            return true;

        if (m_rareNonInheritedData->m_mask != other.m_rareNonInheritedData->m_mask
            || m_rareNonInheritedData->m_maskBoxImage != other.m_rareNonInheritedData->m_maskBoxImage)
            return true;

        if (!RuntimeEnabledFeatures::cssBoxReflectFilterEnabled() && !m_rareNonInheritedData->reflectionDataEquivalent(*other.m_rareNonInheritedData.get()))
            return true;
    }

    return false;
}

bool ComputedStyle::diffNeedsPaintInvalidationObject(const ComputedStyle& other) const
{
    if (!m_background->outline().visuallyEqual(other.m_background->outline()))
        return true;

    if (m_inheritedData.m_visibility != other.m_inheritedData.m_visibility
        || m_inheritedData.m_printColorAdjust != other.m_inheritedData.m_printColorAdjust
        || m_inheritedData.m_insideLink != other.m_inheritedData.m_insideLink
        || !m_surround->border.visuallyEqual(other.m_surround->border)
        || !m_background->visuallyEqual(*other.m_background))
        return true;

    if (m_rareInheritedData.get() != other.m_rareInheritedData.get()) {
        if (m_rareInheritedData->userModify != other.m_rareInheritedData->userModify
            || m_rareInheritedData->userSelect != other.m_rareInheritedData->userSelect
            || m_rareInheritedData->m_imageRendering != other.m_rareInheritedData->m_imageRendering)
            return true;
    }

    if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
        if (m_rareNonInheritedData->userDrag != other.m_rareNonInheritedData->userDrag
            || m_rareNonInheritedData->m_objectFit != other.m_rareNonInheritedData->m_objectFit
            || m_rareNonInheritedData->m_objectPosition != other.m_rareNonInheritedData->m_objectPosition
            || !m_rareNonInheritedData->shadowDataEquivalent(*other.m_rareNonInheritedData.get())
            || !m_rareNonInheritedData->shapeOutsideDataEquivalent(*other.m_rareNonInheritedData.get())
            || !m_rareNonInheritedData->clipPathDataEquivalent(*other.m_rareNonInheritedData.get())
            || (visitedLinkBorderLeftColor() != other.visitedLinkBorderLeftColor() && borderLeftWidth())
            || (visitedLinkBorderRightColor() != other.visitedLinkBorderRightColor() && borderRightWidth())
            || (visitedLinkBorderBottomColor() != other.visitedLinkBorderBottomColor() && borderBottomWidth())
            || (visitedLinkBorderTopColor() != other.visitedLinkBorderTopColor() && borderTopWidth())
            || (visitedLinkOutlineColor() != other.visitedLinkOutlineColor() && outlineWidth())
            || (visitedLinkBackgroundColor() != other.visitedLinkBackgroundColor()))
            return true;
    }

    if (resize() != other.resize())
        return true;

    if (m_rareNonInheritedData->m_paintImages) {
        for (const auto& image : *m_rareNonInheritedData->m_paintImages) {
            if (diffNeedsPaintInvalidationObjectForPaintImage(image, other))
                return true;
        }
    }

    return false;
}

bool ComputedStyle::diffNeedsPaintInvalidationObjectForPaintImage(const StyleImage* image, const ComputedStyle& other) const
{
    CSSPaintValue* value = toCSSPaintValue(image->cssValue());

    // NOTE: If the invalidation properties vectors are null, we are invalid as
    // we haven't yet been painted (and can't provide the invalidation
    // properties yet).
    if (!value->nativeInvalidationProperties() || !value->customInvalidationProperties())
        return true;

    for (CSSPropertyID propertyID : *value->nativeInvalidationProperties()) {
        // TODO(ikilpatrick): remove isInterpolableProperty check once
        // CSSPropertyEquality::propertiesEqual correctly handles all properties.
        if (!CSSPropertyMetadata::isInterpolableProperty(propertyID) || !CSSPropertyEquality::propertiesEqual(propertyID, *this, other))
            return true;
    }

    if (variables() || other.variables()) {
        for (const AtomicString& property : *value->customInvalidationProperties()) {
            CSSVariableData* thisVar = variables() ? variables()->getVariable(property) : nullptr;
            CSSVariableData* otherVar = other.variables() ? other.variables()->getVariable(property) : nullptr;

            if (!dataEquivalent(thisVar, otherVar))
                return true;
        }
    }

    return false;
}

void ComputedStyle::updatePropertySpecificDifferences(const ComputedStyle& other, StyleDifference& diff) const
{
    if (m_box->zIndex() != other.m_box->zIndex() || isStackingContext() != other.isStackingContext())
        diff.setZIndexChanged();

    if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
        if (!transformDataEquivalent(other))
            diff.setTransformChanged();

        if (m_rareNonInheritedData->opacity != other.m_rareNonInheritedData->opacity)
            diff.setOpacityChanged();

        if (m_rareNonInheritedData->m_filter != other.m_rareNonInheritedData->m_filter)
            diff.setFilterChanged();

        if (!m_rareNonInheritedData->shadowDataEquivalent(*other.m_rareNonInheritedData.get()))
            diff.setNeedsRecomputeOverflow();

        if (m_rareNonInheritedData->m_backdropFilter != other.m_rareNonInheritedData->m_backdropFilter)
            diff.setBackdropFilterChanged();

        if (RuntimeEnabledFeatures::cssBoxReflectFilterEnabled() && !m_rareNonInheritedData->reflectionDataEquivalent(*other.m_rareNonInheritedData.get()))
            diff.setFilterChanged();
    }

    if (!m_background->outline().visuallyEqual(other.m_background->outline()) || !m_surround->border.visualOverflowEqual(other.m_surround->border))
        diff.setNeedsRecomputeOverflow();

    if (!diff.needsPaintInvalidation()) {
        if (m_styleInheritedData->color != other.m_styleInheritedData->color
            || m_styleInheritedData->visitedLinkColor != other.m_styleInheritedData->visitedLinkColor
            || m_inheritedData.m_textUnderline != other.m_inheritedData.m_textUnderline
            || m_visual->textDecoration != other.m_visual->textDecoration) {
            diff.setTextDecorationOrColorChanged();
        } else if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()
            && (m_rareNonInheritedData->m_textDecorationStyle != other.m_rareNonInheritedData->m_textDecorationStyle
                || m_rareNonInheritedData->m_textDecorationColor != other.m_rareNonInheritedData->m_textDecorationColor
                || m_rareNonInheritedData->m_visitedLinkTextDecorationColor != other.m_rareNonInheritedData->m_visitedLinkTextDecorationColor)) {
                diff.setTextDecorationOrColorChanged();
        } else if (m_rareInheritedData.get() != other.m_rareInheritedData.get()
            && (m_rareInheritedData->textFillColor() != other.m_rareInheritedData->textFillColor()
                || m_rareInheritedData->textStrokeColor() != other.m_rareInheritedData->textStrokeColor()
                || m_rareInheritedData->textEmphasisColor() != other.m_rareInheritedData->textEmphasisColor()
                || m_rareInheritedData->visitedLinkTextFillColor() != other.m_rareInheritedData->visitedLinkTextFillColor()
                || m_rareInheritedData->visitedLinkTextStrokeColor() != other.m_rareInheritedData->visitedLinkTextStrokeColor()
                || m_rareInheritedData->visitedLinkTextEmphasisColor() != other.m_rareInheritedData->visitedLinkTextEmphasisColor()
                || m_rareInheritedData->textEmphasisFill != other.m_rareInheritedData->textEmphasisFill
                || m_rareInheritedData->appliedTextDecorations != other.m_rareInheritedData->appliedTextDecorations)) {
                diff.setTextDecorationOrColorChanged();
        }
    }
}

void ComputedStyle::addPaintImage(StyleImage* image)
{
    if (!m_rareNonInheritedData.access()->m_paintImages)
        m_rareNonInheritedData.access()->m_paintImages = WTF::wrapUnique(new Vector<Persistent<StyleImage>>());
    m_rareNonInheritedData.access()->m_paintImages->append(image);
}

void ComputedStyle::addCursor(StyleImage* image, bool hotSpotSpecified, const IntPoint& hotSpot)
{
    if (!m_rareInheritedData.access()->cursorData)
        m_rareInheritedData.access()->cursorData = new CursorList;
    m_rareInheritedData.access()->cursorData->append(CursorData(image, hotSpotSpecified, hotSpot));
}

void ComputedStyle::setCursorList(CursorList* other)
{
    m_rareInheritedData.access()->cursorData = other;
}

void ComputedStyle::setQuotes(PassRefPtr<QuotesData> q)
{
    m_rareInheritedData.access()->quotes = q;
}

void ComputedStyle::clearCursorList()
{
    if (m_rareInheritedData->cursorData)
        m_rareInheritedData.access()->cursorData = nullptr;
}

static bool hasPropertyThatCreatesStackingContext(const Vector<CSSPropertyID>& properties)
{
    for (CSSPropertyID property : properties) {
        switch (property) {
        case CSSPropertyOpacity:
        case CSSPropertyTransform:
        case CSSPropertyAliasWebkitTransform:
        case CSSPropertyTransformStyle:
        case CSSPropertyAliasWebkitTransformStyle:
        case CSSPropertyPerspective:
        case CSSPropertyAliasWebkitPerspective:
        case CSSPropertyWebkitMask:
        case CSSPropertyWebkitMaskBoxImage:
        case CSSPropertyWebkitClipPath:
        case CSSPropertyWebkitBoxReflect:
        case CSSPropertyFilter:
        case CSSPropertyAliasWebkitFilter:
        case CSSPropertyBackdropFilter:
        case CSSPropertyZIndex:
        case CSSPropertyPosition:
        case CSSPropertyMixBlendMode:
        case CSSPropertyIsolation:
            return true;
        default:
            break;
        }
    }
    return false;
}

void ComputedStyle::updateIsStackingContext(bool isDocumentElement, bool isInTopLayer)
{
    if (isStackingContext())
        return;

    if (isDocumentElement
        || isInTopLayer
        || styleType() == PseudoIdBackdrop
        || hasOpacity()
        || hasTransformRelatedProperty()
        || hasMask()
        || clipPath()
        || boxReflect()
        || hasFilterInducingProperty()
        || hasBlendMode()
        || hasIsolation()
        || hasViewportConstrainedPosition()
        || hasPropertyThatCreatesStackingContext(willChangeProperties())
        || containsPaint()) {
        setIsStackingContext(true);
    }
}

void ComputedStyle::addCallbackSelector(const String& selector)
{
    if (!m_rareNonInheritedData->m_callbackSelectors.contains(selector))
        m_rareNonInheritedData.access()->m_callbackSelectors.append(selector);
}

void ComputedStyle::setContent(ContentData* contentData)
{
    SET_VAR(m_rareNonInheritedData, m_content, contentData);
}

bool ComputedStyle::hasWillChangeCompositingHint() const
{
    for (size_t i = 0; i < m_rareNonInheritedData->m_willChange->m_properties.size(); ++i) {
        switch (m_rareNonInheritedData->m_willChange->m_properties[i]) {
        case CSSPropertyOpacity:
        case CSSPropertyTransform:
        case CSSPropertyAliasWebkitTransform:
        case CSSPropertyTop:
        case CSSPropertyLeft:
        case CSSPropertyBottom:
        case CSSPropertyRight:
            return true;
        default:
            break;
        }
    }
    return false;
}

bool ComputedStyle::hasWillChangeTransformHint() const
{
    for (const auto& property: m_rareNonInheritedData->m_willChange->m_properties) {
        switch (property) {
        case CSSPropertyTransform:
        case CSSPropertyAliasWebkitTransform:
            return true;
        default:
            break;
        }
    }
    return false;
}

bool ComputedStyle::requireTransformOrigin(ApplyTransformOrigin applyOrigin, ApplyMotionPath applyMotionPath) const
{
    const Vector<RefPtr<TransformOperation>>& transformOperations = transform().operations();

    // transform-origin brackets the transform with translate operations.
    // Optimize for the case where the only transform is a translation, since the transform-origin is irrelevant
    // in that case.
    if (applyOrigin != IncludeTransformOrigin)
        return false;

    if (applyMotionPath == IncludeMotionPath)
        return true;

    unsigned size = transformOperations.size();
    for (unsigned i = 0; i < size; ++i) {
        TransformOperation::OperationType type = transformOperations[i]->type();
        if (type != TransformOperation::TranslateX
            && type != TransformOperation::TranslateY
            && type != TransformOperation::Translate
            && type != TransformOperation::TranslateZ
            && type != TransformOperation::Translate3D)
            return true;
    }

    return scale() || rotate();
}

void ComputedStyle::applyTransform(TransformationMatrix& result, const LayoutSize& borderBoxSize, ApplyTransformOrigin applyOrigin, ApplyMotionPath applyMotionPath, ApplyIndependentTransformProperties applyIndependentTransformProperties) const
{
    applyTransform(result, FloatRect(FloatPoint(), FloatSize(borderBoxSize)), applyOrigin, applyMotionPath, applyIndependentTransformProperties);
}

void ComputedStyle::applyTransform(TransformationMatrix& result, const FloatRect& boundingBox, ApplyTransformOrigin applyOrigin, ApplyMotionPath applyMotionPath, ApplyIndependentTransformProperties applyIndependentTransformProperties) const
{
    if (!hasMotionPath())
        applyMotionPath = ExcludeMotionPath;
    bool applyTransformOrigin = requireTransformOrigin(applyOrigin, applyMotionPath);

    float offsetX = transformOriginX().type() == Percent ? boundingBox.x() : 0;
    float offsetY = transformOriginY().type() == Percent ? boundingBox.y() : 0;

    float originX = 0;
    float originY = 0;
    float originZ = 0;

    if (applyTransformOrigin) {
        originX = floatValueForLength(transformOriginX(), boundingBox.width()) + offsetX;
        originY = floatValueForLength(transformOriginY(), boundingBox.height()) + offsetY;
        originZ = transformOriginZ();
        result.translate3d(originX, originY, originZ);
    }

    if (applyIndependentTransformProperties == IncludeIndependentTransformProperties) {
        if (translate())
            translate()->apply(result, boundingBox.size());

        if (rotate())
            rotate()->apply(result, boundingBox.size());

        if (scale())
            scale()->apply(result, boundingBox.size());
    }

    if (applyMotionPath == ComputedStyle::IncludeMotionPath)
        applyMotionPathTransform(originX, originY, result);

    const Vector<RefPtr<TransformOperation>>& transformOperations = transform().operations();
    unsigned size = transformOperations.size();
    for (unsigned i = 0; i < size; ++i)
        transformOperations[i]->apply(result, boundingBox.size());

    if (applyTransformOrigin) {
        result.translate3d(-originX, -originY, -originZ);
    }
}

void ComputedStyle::applyMotionPathTransform(float originX, float originY, TransformationMatrix& transform) const
{
    const StyleMotionData& motionData = m_rareNonInheritedData->m_transform->m_motion;
    ASSERT(motionData.m_path);
    const StylePath& motionPath = *motionData.m_path;
    float pathLength = motionPath.length();
    float distance = floatValueForLength(motionData.m_offset, pathLength);
    float computedDistance;
    if (motionPath.isClosed() && pathLength > 0) {
        computedDistance = fmod(distance, pathLength);
        if (computedDistance < 0)
            computedDistance += pathLength;
    } else {
        computedDistance = clampTo<float>(distance, 0, pathLength);
    }

    FloatPoint point;
    float angle;
    motionPath.path().pointAndNormalAtLength(computedDistance, point, angle);

    if (motionData.m_rotation.type == MotionRotationFixed)
        angle = 0;

    transform.translate(point.x() - originX, point.y() - originY);
    transform.rotate(angle + motionData.m_rotation.angle);
}

void ComputedStyle::setTextShadow(PassRefPtr<ShadowList> s)
{
    m_rareInheritedData.access()->textShadow = s;
}

void ComputedStyle::setBoxShadow(PassRefPtr<ShadowList> s)
{
    m_rareNonInheritedData.access()->m_boxShadow = s;
}

static FloatRoundedRect::Radii calcRadiiFor(const BorderData& border, LayoutSize size)
{
    return FloatRoundedRect::Radii(
        FloatSize(floatValueForLength(border.topLeft().width(), size.width().toFloat()),
            floatValueForLength(border.topLeft().height(), size.height().toFloat())),
        FloatSize(floatValueForLength(border.topRight().width(), size.width().toFloat()),
            floatValueForLength(border.topRight().height(), size.height().toFloat())),
        FloatSize(floatValueForLength(border.bottomLeft().width(), size.width().toFloat()),
            floatValueForLength(border.bottomLeft().height(), size.height().toFloat())),
        FloatSize(floatValueForLength(border.bottomRight().width(), size.width().toFloat()),
            floatValueForLength(border.bottomRight().height(), size.height().toFloat())));
}

StyleImage* ComputedStyle::listStyleImage() const { return m_rareInheritedData->listStyleImage.get(); }
void ComputedStyle::setListStyleImage(StyleImage* v)
{
    if (m_rareInheritedData->listStyleImage != v)
        m_rareInheritedData.access()->listStyleImage = v;
}

Color ComputedStyle::color() const { return m_styleInheritedData->color; }
Color ComputedStyle::visitedLinkColor() const { return m_styleInheritedData->visitedLinkColor; }
void ComputedStyle::setColor(const Color& v) { SET_VAR(m_styleInheritedData, color, v); }
void ComputedStyle::setVisitedLinkColor(const Color& v) { SET_VAR(m_styleInheritedData, visitedLinkColor, v); }

short ComputedStyle::horizontalBorderSpacing() const { return m_styleInheritedData->horizontal_border_spacing; }
short ComputedStyle::verticalBorderSpacing() const { return m_styleInheritedData->vertical_border_spacing; }
void ComputedStyle::setHorizontalBorderSpacing(short v) { SET_VAR(m_styleInheritedData, horizontal_border_spacing, v); }
void ComputedStyle::setVerticalBorderSpacing(short v) { SET_VAR(m_styleInheritedData, vertical_border_spacing, v); }

FloatRoundedRect ComputedStyle::getRoundedBorderFor(const LayoutRect& borderRect,
    bool includeLogicalLeftEdge, bool includeLogicalRightEdge) const
{
    FloatRoundedRect roundedRect(pixelSnappedIntRect(borderRect));
    if (hasBorderRadius()) {
        FloatRoundedRect::Radii radii = calcRadiiFor(m_surround->border, borderRect.size());
        roundedRect.includeLogicalEdges(radii, isHorizontalWritingMode(), includeLogicalLeftEdge, includeLogicalRightEdge);
        roundedRect.constrainRadii();
    }
    return roundedRect;
}

FloatRoundedRect ComputedStyle::getRoundedInnerBorderFor(const LayoutRect& borderRect, bool includeLogicalLeftEdge, bool includeLogicalRightEdge) const
{
    bool horizontal = isHorizontalWritingMode();

    int leftWidth = (!horizontal || includeLogicalLeftEdge) ? borderLeftWidth() : 0;
    int rightWidth = (!horizontal || includeLogicalRightEdge) ? borderRightWidth() : 0;
    int topWidth = (horizontal || includeLogicalLeftEdge) ? borderTopWidth() : 0;
    int bottomWidth = (horizontal || includeLogicalRightEdge) ? borderBottomWidth() : 0;

    return getRoundedInnerBorderFor(borderRect,
        LayoutRectOutsets(-topWidth, -rightWidth, -bottomWidth, -leftWidth),
        includeLogicalLeftEdge, includeLogicalRightEdge);
}

FloatRoundedRect ComputedStyle::getRoundedInnerBorderFor(const LayoutRect& borderRect,
    const LayoutRectOutsets insets, bool includeLogicalLeftEdge, bool includeLogicalRightEdge) const
{
    LayoutRect innerRect(borderRect);
    innerRect.expand(insets);

    FloatRoundedRect roundedRect(pixelSnappedIntRect(innerRect));

    if (hasBorderRadius()) {
        FloatRoundedRect::Radii radii = getRoundedBorderFor(borderRect).getRadii();
        // Insets use negative values.
        radii.shrink(
            -insets.top().toFloat(),
            -insets.bottom().toFloat(),
            -insets.left().toFloat(),
            -insets.right().toFloat());
        roundedRect.includeLogicalEdges(radii, isHorizontalWritingMode(), includeLogicalLeftEdge, includeLogicalRightEdge);
    }
    return roundedRect;
}

static bool allLayersAreFixed(const FillLayer& layer)
{
    for (const FillLayer* currLayer = &layer; currLayer; currLayer = currLayer->next()) {
        if (!currLayer->image() || currLayer->attachment() != FixedBackgroundAttachment)
            return false;
    }

    return true;
}

bool ComputedStyle::hasEntirelyFixedBackground() const
{
    return allLayersAreFixed(backgroundLayers());
}

bool ComputedStyle::hasEntirelyLocalBackground() const
{
    const FillLayer* layer = &backgroundLayers();
    for (; layer; layer = layer->next()) {
        if (layer->attachment() == LocalBackgroundAttachment)
            continue;
        // Solid color layers with a background clip of the padding box can be treated
        // as local.
        // TODO(flackr): We can handle other fill boxes with solid colors as long as they
        // are essentially the same (i.e. PaddingFillBox == ContentFillBox when padding = 0).
        if (!layer->image() && !layer->next() && layer->clip() == PaddingFillBox)
            continue;
        return false;
    }
    return true;
}

const CounterDirectiveMap* ComputedStyle::counterDirectives() const
{
    return m_rareNonInheritedData->m_counterDirectives.get();
}

CounterDirectiveMap& ComputedStyle::accessCounterDirectives()
{
    std::unique_ptr<CounterDirectiveMap>& map = m_rareNonInheritedData.access()->m_counterDirectives;
    if (!map)
        map = wrapUnique(new CounterDirectiveMap);
    return *map;
}

const CounterDirectives ComputedStyle::getCounterDirectives(const AtomicString& identifier) const
{
    if (const CounterDirectiveMap* directives = counterDirectives())
        return directives->get(identifier);
    return CounterDirectives();
}

void ComputedStyle::clearIncrementDirectives()
{
    if (!counterDirectives())
        return;

    // This makes us copy even if we may not be removing any items.
    CounterDirectiveMap& map = accessCounterDirectives();
    typedef CounterDirectiveMap::iterator Iterator;

    Iterator end = map.end();
    for (Iterator it = map.begin(); it != end; ++it)
        it->value.clearIncrement();
}

void ComputedStyle::clearResetDirectives()
{
    if (!counterDirectives())
        return;

    // This makes us copy even if we may not be removing any items.
    CounterDirectiveMap& map = accessCounterDirectives();
    typedef CounterDirectiveMap::iterator Iterator;

    Iterator end = map.end();
    for (Iterator it = map.begin(); it != end; ++it)
        it->value.clearReset();
}

Hyphenation* ComputedStyle::getHyphenation() const
{
    return getHyphens() == HyphensAuto
        ? getFontDescription().localeOrDefault().getHyphenation() : nullptr;
}

const AtomicString& ComputedStyle::hyphenString() const
{
    const AtomicString& hyphenationString = m_rareInheritedData.get()->hyphenationString;
    if (!hyphenationString.isNull())
        return hyphenationString;

    // FIXME: This should depend on locale.
    DEFINE_STATIC_LOCAL(AtomicString, hyphenMinusString, (&hyphenMinusCharacter, 1));
    DEFINE_STATIC_LOCAL(AtomicString, hyphenString, (&hyphenCharacter, 1));
    const SimpleFontData* primaryFont = font().primaryFont();
    ASSERT(primaryFont);
    return primaryFont->glyphForCharacter(hyphenCharacter) ? hyphenString : hyphenMinusString;
}

const AtomicString& ComputedStyle::textEmphasisMarkString() const
{
    switch (getTextEmphasisMark()) {
    case TextEmphasisMarkNone:
        return nullAtom;
    case TextEmphasisMarkCustom:
        return textEmphasisCustomMark();
    case TextEmphasisMarkDot: {
        DEFINE_STATIC_LOCAL(AtomicString, filledDotString, (&bulletCharacter, 1));
        DEFINE_STATIC_LOCAL(AtomicString, openDotString, (&whiteBulletCharacter, 1));
        return getTextEmphasisFill() == TextEmphasisFillFilled ? filledDotString : openDotString;
    }
    case TextEmphasisMarkCircle: {
        DEFINE_STATIC_LOCAL(AtomicString, filledCircleString, (&blackCircleCharacter, 1));
        DEFINE_STATIC_LOCAL(AtomicString, openCircleString, (&whiteCircleCharacter, 1));
        return getTextEmphasisFill() == TextEmphasisFillFilled ? filledCircleString : openCircleString;
    }
    case TextEmphasisMarkDoubleCircle: {
        DEFINE_STATIC_LOCAL(AtomicString, filledDoubleCircleString, (&fisheyeCharacter, 1));
        DEFINE_STATIC_LOCAL(AtomicString, openDoubleCircleString, (&bullseyeCharacter, 1));
        return getTextEmphasisFill() == TextEmphasisFillFilled ? filledDoubleCircleString : openDoubleCircleString;
    }
    case TextEmphasisMarkTriangle: {
        DEFINE_STATIC_LOCAL(AtomicString, filledTriangleString, (&blackUpPointingTriangleCharacter, 1));
        DEFINE_STATIC_LOCAL(AtomicString, openTriangleString, (&whiteUpPointingTriangleCharacter, 1));
        return getTextEmphasisFill() == TextEmphasisFillFilled ? filledTriangleString : openTriangleString;
    }
    case TextEmphasisMarkSesame: {
        DEFINE_STATIC_LOCAL(AtomicString, filledSesameString, (&sesameDotCharacter, 1));
        DEFINE_STATIC_LOCAL(AtomicString, openSesameString, (&whiteSesameDotCharacter, 1));
        return getTextEmphasisFill() == TextEmphasisFillFilled ? filledSesameString : openSesameString;
    }
    case TextEmphasisMarkAuto:
        ASSERT_NOT_REACHED();
        return nullAtom;
    }

    ASSERT_NOT_REACHED();
    return nullAtom;
}

CSSAnimationData& ComputedStyle::accessAnimations()
{
    if (!m_rareNonInheritedData.access()->m_animations)
        m_rareNonInheritedData.access()->m_animations = CSSAnimationData::create();
    return *m_rareNonInheritedData->m_animations;
}

CSSTransitionData& ComputedStyle::accessTransitions()
{
    if (!m_rareNonInheritedData.access()->m_transitions)
        m_rareNonInheritedData.access()->m_transitions = CSSTransitionData::create();
    return *m_rareNonInheritedData->m_transitions;
}

const Font& ComputedStyle::font() const { return m_styleInheritedData->font; }
const FontMetrics& ComputedStyle::getFontMetrics() const { return m_styleInheritedData->font.getFontMetrics(); }
const FontDescription& ComputedStyle::getFontDescription() const { return m_styleInheritedData->font.getFontDescription(); }
float ComputedStyle::specifiedFontSize() const { return getFontDescription().specifiedSize(); }
float ComputedStyle::computedFontSize() const { return getFontDescription().computedSize(); }
int ComputedStyle::fontSize() const { return getFontDescription().computedPixelSize(); }
float ComputedStyle::fontSizeAdjust() const { return getFontDescription().sizeAdjust(); }
bool ComputedStyle::hasFontSizeAdjust() const { return getFontDescription().hasSizeAdjust(); }
FontWeight ComputedStyle::fontWeight() const { return getFontDescription().weight(); }
FontStretch ComputedStyle::fontStretch() const { return getFontDescription().stretch(); }

TextDecoration ComputedStyle::textDecorationsInEffect() const
{
    int decorations = 0;

    const Vector<AppliedTextDecoration>& applied = appliedTextDecorations();

    for (size_t i = 0; i < applied.size(); ++i)
        decorations |= applied[i].line();

    return static_cast<TextDecoration>(decorations);
}

const Vector<AppliedTextDecoration>& ComputedStyle::appliedTextDecorations() const
{
    if (!m_inheritedData.m_textUnderline && !m_rareInheritedData->appliedTextDecorations) {
        DEFINE_STATIC_LOCAL(Vector<AppliedTextDecoration>, empty, ());
        return empty;
    }
    if (m_inheritedData.m_textUnderline) {
        DEFINE_STATIC_LOCAL(Vector<AppliedTextDecoration>, underline, (1, AppliedTextDecoration(TextDecorationUnderline)));
        return underline;
    }

    return m_rareInheritedData->appliedTextDecorations->vector();
}

StyleVariableData* ComputedStyle::variables() const
{
    return m_rareInheritedData->variables.get();
}

void ComputedStyle::setVariable(const AtomicString& name, PassRefPtr<CSSVariableData> value)
{
    RefPtr<StyleVariableData>& variables = m_rareInheritedData.access()->variables;
    if (!variables)
        variables = StyleVariableData::create();
    else if (!variables->hasOneRef())
        variables = variables->copy();
    variables->setVariable(name, value);
}

void ComputedStyle::removeVariable(const AtomicString& name)
{
    RefPtr<StyleVariableData>& variables = m_rareInheritedData.access()->variables;
    if (!variables)
        return;
    if (!variables->hasOneRef())
        variables = variables->copy();
    variables->removeVariable(name);
}

float ComputedStyle::wordSpacing() const { return getFontDescription().wordSpacing(); }
float ComputedStyle::letterSpacing() const { return getFontDescription().letterSpacing(); }

bool ComputedStyle::setFontDescription(const FontDescription& v)
{
    if (m_styleInheritedData->font.getFontDescription() != v) {
        m_styleInheritedData.access()->font = Font(v);
        return true;
    }
    return false;
}

void ComputedStyle::setFont(const Font& font)
{
    m_styleInheritedData.access()->font = font;
}

const Length& ComputedStyle::specifiedLineHeight() const { return m_styleInheritedData->line_height; }
Length ComputedStyle::lineHeight() const
{
    const Length& lh = m_styleInheritedData->line_height;
    // Unlike getFontDescription().computedSize() and hence fontSize(), this is
    // recalculated on demand as we only store the specified line height.
    // FIXME: Should consider scaling the fixed part of any calc expressions
    // too, though this involves messily poking into CalcExpressionLength.
    if (lh.isFixed()) {
        float multiplier = textAutosizingMultiplier();
        return Length(TextAutosizer::computeAutosizedFontSize(lh.value(), multiplier), Fixed);
    }

    return lh;
}

void ComputedStyle::setLineHeight(const Length& specifiedLineHeight) { SET_VAR(m_styleInheritedData, line_height, specifiedLineHeight); }

int ComputedStyle::computedLineHeight() const
{
    const Length& lh = lineHeight();

    // Negative value means the line height is not set. Use the font's built-in
    // spacing, if avalible.
    if (lh.isNegative() && font().primaryFont())
        return getFontMetrics().lineSpacing();

    if (lh.hasPercent())
        return minimumValueForLength(lh, LayoutUnit(computedFontSize())).toInt();

    return std::min(lh.value(), LayoutUnit::max().toFloat());
}

void ComputedStyle::setWordSpacing(float wordSpacing)
{
    FontSelector* currentFontSelector = font().getFontSelector();
    FontDescription desc(getFontDescription());
    desc.setWordSpacing(wordSpacing);
    setFontDescription(desc);
    font().update(currentFontSelector);
}

void ComputedStyle::setLetterSpacing(float letterSpacing)
{
    FontSelector* currentFontSelector = font().getFontSelector();
    FontDescription desc(getFontDescription());
    desc.setLetterSpacing(letterSpacing);
    setFontDescription(desc);
    font().update(currentFontSelector);
}

void ComputedStyle::setTextAutosizingMultiplier(float multiplier)
{
    SET_VAR(m_styleInheritedData, textAutosizingMultiplier, multiplier);

    float size = specifiedFontSize();

    ASSERT(std::isfinite(size));
    if (!std::isfinite(size) || size < 0)
        size = 0;
    else
        size = std::min(maximumAllowedFontSize, size);

    FontSelector* currentFontSelector = font().getFontSelector();
    FontDescription desc(getFontDescription());
    desc.setSpecifiedSize(size);
    desc.setComputedSize(size);

    float autosizedFontSize = TextAutosizer::computeAutosizedFontSize(size, multiplier);
    desc.setComputedSize(std::min(maximumAllowedFontSize, autosizedFontSize));

    setFontDescription(desc);
    font().update(currentFontSelector);
}

void ComputedStyle::addAppliedTextDecoration(const AppliedTextDecoration& decoration)
{
    RefPtr<AppliedTextDecorationList>& list = m_rareInheritedData.access()->appliedTextDecorations;

    if (!list)
        list = AppliedTextDecorationList::create();
    else if (!list->hasOneRef())
        list = list->copy();

    if (m_inheritedData.m_textUnderline) {
        m_inheritedData.m_textUnderline = false;
        list->append(AppliedTextDecoration(TextDecorationUnderline));
    }

    list->append(decoration);
}

void ComputedStyle::applyTextDecorations()
{
    if (getTextDecoration() == TextDecorationNone)
        return;

    TextDecorationStyle style = getTextDecorationStyle();
    StyleColor styleColor = decorationColorIncludingFallback(insideLink() == InsideVisitedLink);

    int decorations = getTextDecoration();

    if (decorations & TextDecorationUnderline) {
        // To save memory, we don't use AppliedTextDecoration objects in the
        // common case of a single simple underline.
        AppliedTextDecoration underline(TextDecorationUnderline, style, styleColor);

        if (!m_rareInheritedData->appliedTextDecorations && underline.isSimpleUnderline())
            m_inheritedData.m_textUnderline = true;
        else
            addAppliedTextDecoration(underline);
    }
    if (decorations & TextDecorationOverline)
        addAppliedTextDecoration(AppliedTextDecoration(TextDecorationOverline, style, styleColor));
    if (decorations & TextDecorationLineThrough)
        addAppliedTextDecoration(AppliedTextDecoration(TextDecorationLineThrough, style, styleColor));
}

void ComputedStyle::clearAppliedTextDecorations()
{
    m_inheritedData.m_textUnderline = false;

    if (m_rareInheritedData->appliedTextDecorations)
        m_rareInheritedData.access()->appliedTextDecorations = nullptr;
}

void ComputedStyle::restoreParentTextDecorations(const ComputedStyle& parentStyle)
{
    m_inheritedData.m_textUnderline = parentStyle.m_inheritedData.m_textUnderline;
    if (m_rareInheritedData->appliedTextDecorations != parentStyle.m_rareInheritedData->appliedTextDecorations)
        m_rareInheritedData.access()->appliedTextDecorations = parentStyle.m_rareInheritedData->appliedTextDecorations;
}

void ComputedStyle::clearMultiCol()
{
    m_rareNonInheritedData.access()->m_multiCol = nullptr;
    m_rareNonInheritedData.access()->m_multiCol.init();
}

StyleColor ComputedStyle::decorationColorIncludingFallback(bool visitedLink) const
{
    StyleColor styleColor = visitedLink ? visitedLinkTextDecorationColor() : textDecorationColor();

    if (!styleColor.isCurrentColor())
        return styleColor;

    if (textStrokeWidth()) {
        // Prefer stroke color if possible, but not if it's fully transparent.
        StyleColor textStrokeStyleColor = visitedLink ? visitedLinkTextStrokeColor() : textStrokeColor();
        if (!textStrokeStyleColor.isCurrentColor() && textStrokeStyleColor.getColor().alpha())
            return textStrokeStyleColor;
    }

    return visitedLink ? visitedLinkTextFillColor() : textFillColor();
}

Color ComputedStyle::colorIncludingFallback(int colorProperty, bool visitedLink) const
{
    StyleColor result(StyleColor::currentColor());
    EBorderStyle borderStyle = BorderStyleNone;
    switch (colorProperty) {
    case CSSPropertyBackgroundColor:
        result = visitedLink ? visitedLinkBackgroundColor() : backgroundColor();
        break;
    case CSSPropertyBorderLeftColor:
        result = visitedLink ? visitedLinkBorderLeftColor() : borderLeftColor();
        borderStyle = borderLeftStyle();
        break;
    case CSSPropertyBorderRightColor:
        result = visitedLink ? visitedLinkBorderRightColor() : borderRightColor();
        borderStyle = borderRightStyle();
        break;
    case CSSPropertyBorderTopColor:
        result = visitedLink ? visitedLinkBorderTopColor() : borderTopColor();
        borderStyle = borderTopStyle();
        break;
    case CSSPropertyBorderBottomColor:
        result = visitedLink ? visitedLinkBorderBottomColor() : borderBottomColor();
        borderStyle = borderBottomStyle();
        break;
    case CSSPropertyColor:
        result = visitedLink ? visitedLinkColor() : color();
        break;
    case CSSPropertyOutlineColor:
        result = visitedLink ? visitedLinkOutlineColor() : outlineColor();
        break;
    case CSSPropertyColumnRuleColor:
        result = visitedLink ? visitedLinkColumnRuleColor() : columnRuleColor();
        break;
    case CSSPropertyWebkitTextEmphasisColor:
        result = visitedLink ? visitedLinkTextEmphasisColor() : textEmphasisColor();
        break;
    case CSSPropertyWebkitTextFillColor:
        result = visitedLink ? visitedLinkTextFillColor() : textFillColor();
        break;
    case CSSPropertyWebkitTextStrokeColor:
        result = visitedLink ? visitedLinkTextStrokeColor() : textStrokeColor();
        break;
    case CSSPropertyFloodColor:
        result = floodColor();
        break;
    case CSSPropertyLightingColor:
        result = lightingColor();
        break;
    case CSSPropertyStopColor:
        result = stopColor();
        break;
    case CSSPropertyWebkitTapHighlightColor:
        result = tapHighlightColor();
        break;
    case CSSPropertyTextDecorationColor:
        result = decorationColorIncludingFallback(visitedLink);
        break;
    default:
        ASSERT_NOT_REACHED();
        break;
    }

    if (!result.isCurrentColor())
        return result.getColor();

    // FIXME: Treating styled borders with initial color differently causes problems
    // See crbug.com/316559, crbug.com/276231
    if (!visitedLink && (borderStyle == BorderStyleInset || borderStyle == BorderStyleOutset || borderStyle == BorderStyleRidge || borderStyle == BorderStyleGroove))
        return Color(238, 238, 238);
    return visitedLink ? visitedLinkColor() : color();
}

Color ComputedStyle::visitedDependentColor(int colorProperty) const
{
    Color unvisitedColor = colorIncludingFallback(colorProperty, false);
    if (insideLink() != InsideVisitedLink)
        return unvisitedColor;

    Color visitedColor = colorIncludingFallback(colorProperty, true);

    // FIXME: Technically someone could explicitly specify the color transparent, but for now we'll just
    // assume that if the background color is transparent that it wasn't set. Note that it's weird that
    // we're returning unvisited info for a visited link, but given our restriction that the alpha values
    // have to match, it makes more sense to return the unvisited background color if specified than it
    // does to return black. This behavior matches what Firefox 4 does as well.
    if (colorProperty == CSSPropertyBackgroundColor && visitedColor == Color::transparent)
        return unvisitedColor;

    // Take the alpha from the unvisited color, but get the RGB values from the visited color.
    return Color(visitedColor.red(), visitedColor.green(), visitedColor.blue(), unvisitedColor.alpha());
}

const BorderValue& ComputedStyle::borderBefore() const
{
    switch (getWritingMode()) {
    case TopToBottomWritingMode:
        return borderTop();
    case LeftToRightWritingMode:
        return borderLeft();
    case RightToLeftWritingMode:
        return borderRight();
    }
    ASSERT_NOT_REACHED();
    return borderTop();
}

const BorderValue& ComputedStyle::borderAfter() const
{
    switch (getWritingMode()) {
    case TopToBottomWritingMode:
        return borderBottom();
    case LeftToRightWritingMode:
        return borderRight();
    case RightToLeftWritingMode:
        return borderLeft();
    }
    ASSERT_NOT_REACHED();
    return borderBottom();
}

const BorderValue& ComputedStyle::borderStart() const
{
    if (isHorizontalWritingMode())
        return isLeftToRightDirection() ? borderLeft() : borderRight();
    return isLeftToRightDirection() ? borderTop() : borderBottom();
}

const BorderValue& ComputedStyle::borderEnd() const
{
    if (isHorizontalWritingMode())
        return isLeftToRightDirection() ? borderRight() : borderLeft();
    return isLeftToRightDirection() ? borderBottom() : borderTop();
}

int ComputedStyle::borderBeforeWidth() const
{
    switch (getWritingMode()) {
    case TopToBottomWritingMode:
        return borderTopWidth();
    case LeftToRightWritingMode:
        return borderLeftWidth();
    case RightToLeftWritingMode:
        return borderRightWidth();
    }
    ASSERT_NOT_REACHED();
    return borderTopWidth();
}

int ComputedStyle::borderAfterWidth() const
{
    switch (getWritingMode()) {
    case TopToBottomWritingMode:
        return borderBottomWidth();
    case LeftToRightWritingMode:
        return borderRightWidth();
    case RightToLeftWritingMode:
        return borderLeftWidth();
    }
    ASSERT_NOT_REACHED();
    return borderBottomWidth();
}

int ComputedStyle::borderStartWidth() const
{
    if (isHorizontalWritingMode())
        return isLeftToRightDirection() ? borderLeftWidth() : borderRightWidth();
    return isLeftToRightDirection() ? borderTopWidth() : borderBottomWidth();
}

int ComputedStyle::borderEndWidth() const
{
    if (isHorizontalWritingMode())
        return isLeftToRightDirection() ? borderRightWidth() : borderLeftWidth();
    return isLeftToRightDirection() ? borderBottomWidth() : borderTopWidth();
}

int ComputedStyle::borderOverWidth() const
{
    return isHorizontalWritingMode() ? borderTopWidth() : borderRightWidth();
}

int ComputedStyle::borderUnderWidth() const
{
    return isHorizontalWritingMode() ? borderBottomWidth() : borderLeftWidth();
}

void ComputedStyle::setMarginStart(const Length& margin)
{
    if (isHorizontalWritingMode()) {
        if (isLeftToRightDirection())
            setMarginLeft(margin);
        else
            setMarginRight(margin);
    } else {
        if (isLeftToRightDirection())
            setMarginTop(margin);
        else
            setMarginBottom(margin);
    }
}

void ComputedStyle::setMarginEnd(const Length& margin)
{
    if (isHorizontalWritingMode()) {
        if (isLeftToRightDirection())
            setMarginRight(margin);
        else
            setMarginLeft(margin);
    } else {
        if (isLeftToRightDirection())
            setMarginBottom(margin);
        else
            setMarginTop(margin);
    }
}

void ComputedStyle::setMotionPath(PassRefPtr<StylePath> path)
{
    m_rareNonInheritedData.access()->m_transform.access()->m_motion.m_path = path;
}

int ComputedStyle::outlineOutsetExtent() const
{
    if (!hasOutline())
        return 0;
    if (outlineStyleIsAuto())
        return GraphicsContext::focusRingOutsetExtent(outlineOffset(), outlineWidth());
    return std::max(0, saturatedAddition(outlineWidth(), outlineOffset()));
}

bool ComputedStyle::columnRuleEquivalent(const ComputedStyle* otherStyle) const
{
    return columnRuleStyle() == otherStyle->columnRuleStyle()
        && columnRuleWidth() == otherStyle->columnRuleWidth()
        && visitedDependentColor(CSSPropertyColumnRuleColor) == otherStyle->visitedDependentColor(CSSPropertyColumnRuleColor);
}

TextEmphasisMark ComputedStyle::getTextEmphasisMark() const
{
    TextEmphasisMark mark = static_cast<TextEmphasisMark>(m_rareInheritedData->textEmphasisMark);
    if (mark != TextEmphasisMarkAuto)
        return mark;

    if (isHorizontalWritingMode())
        return TextEmphasisMarkDot;

    return TextEmphasisMarkSesame;
}

Color ComputedStyle::initialTapHighlightColor()
{
    return LayoutTheme::tapHighlightColor();
}

const FilterOperations& ComputedStyle::initialFilter()
{
    DEFINE_STATIC_LOCAL(FilterOperationsWrapper, ops, (FilterOperationsWrapper::create()));
    return ops.operations();
}

const FilterOperations& ComputedStyle::initialBackdropFilter()
{
    DEFINE_STATIC_LOCAL(FilterOperationsWrapper, ops, (FilterOperationsWrapper::create()));
    return ops.operations();
}

LayoutRectOutsets ComputedStyle::imageOutsets(const NinePieceImage& image) const
{
    return LayoutRectOutsets(
        NinePieceImage::computeOutset(image.outset().top(), borderTopWidth()),
        NinePieceImage::computeOutset(image.outset().right(), borderRightWidth()),
        NinePieceImage::computeOutset(image.outset().bottom(), borderBottomWidth()),
        NinePieceImage::computeOutset(image.outset().left(), borderLeftWidth()));
}

void ComputedStyle::setBorderImageSource(StyleImage* image)
{
    if (m_surround->border.m_image.image() == image)
        return;
    m_surround.access()->border.m_image.setImage(image);
}

void ComputedStyle::setBorderImageSlices(const LengthBox& slices)
{
    if (m_surround->border.m_image.imageSlices() == slices)
        return;
    m_surround.access()->border.m_image.setImageSlices(slices);
}

void ComputedStyle::setBorderImageSlicesFill(bool fill)
{
    if (m_surround->border.m_image.fill() == fill)
        return;
    m_surround.access()->border.m_image.setFill(fill);
}

void ComputedStyle::setBorderImageWidth(const BorderImageLengthBox& slices)
{
    if (m_surround->border.m_image.borderSlices() == slices)
        return;
    m_surround.access()->border.m_image.setBorderSlices(slices);
}

void ComputedStyle::setBorderImageOutset(const BorderImageLengthBox& outset)
{
    if (m_surround->border.m_image.outset() == outset)
        return;
    m_surround.access()->border.m_image.setOutset(outset);
}

bool ComputedStyle::borderObscuresBackground() const
{
    if (!hasBorder())
        return false;

    // Bail if we have any border-image for now. We could look at the image alpha to improve this.
    if (borderImage().image())
        return false;

    BorderEdge edges[4];
    getBorderEdgeInfo(edges);

    for (int i = BSTop; i <= BSLeft; ++i) {
        const BorderEdge& currEdge = edges[i];
        if (!currEdge.obscuresBackground())
            return false;
    }

    return true;
}

void ComputedStyle::getBorderEdgeInfo(BorderEdge edges[], bool includeLogicalLeftEdge, bool includeLogicalRightEdge) const
{
    bool horizontal = isHorizontalWritingMode();

    edges[BSTop] = BorderEdge(borderTopWidth(),
        visitedDependentColor(CSSPropertyBorderTopColor),
        borderTopStyle(),
        horizontal || includeLogicalLeftEdge);

    edges[BSRight] = BorderEdge(borderRightWidth(),
        visitedDependentColor(CSSPropertyBorderRightColor),
        borderRightStyle(),
        !horizontal || includeLogicalRightEdge);

    edges[BSBottom] = BorderEdge(borderBottomWidth(),
        visitedDependentColor(CSSPropertyBorderBottomColor),
        borderBottomStyle(),
        horizontal || includeLogicalRightEdge);

    edges[BSLeft] = BorderEdge(borderLeftWidth(),
        visitedDependentColor(CSSPropertyBorderLeftColor),
        borderLeftStyle(),
        !horizontal || includeLogicalLeftEdge);
}

void ComputedStyle::copyChildDependentFlagsFrom(const ComputedStyle& other)
{
    setEmptyState(other.emptyState());
    if (other.hasExplicitlyInheritedProperties())
        setHasExplicitlyInheritedProperties();
}

bool ComputedStyle::shadowListHasCurrentColor(const ShadowList* shadowList)
{
    if (!shadowList)
        return false;
    for (size_t i = shadowList->shadows().size(); i--; ) {
        if (shadowList->shadows()[i].color().isCurrentColor())
            return true;
    }
    return false;
}

static inline Vector<GridTrackSize> initialGridAutoTracks()
{
    Vector<GridTrackSize> trackSizeList;
    trackSizeList.reserveInitialCapacity(1);
    trackSizeList.uncheckedAppend(GridTrackSize(Length(Auto)));
    return trackSizeList;
}

Vector<GridTrackSize> ComputedStyle::initialGridAutoColumns()
{
    return initialGridAutoTracks();
}

Vector<GridTrackSize> ComputedStyle::initialGridAutoRows()
{
    return initialGridAutoTracks();
}

int adjustForAbsoluteZoom(int value, float zoomFactor)
{
    if (zoomFactor == 1)
        return value;
    // Needed because computeLengthInt truncates (rather than rounds) when scaling up.
    float fvalue = value;
    if (zoomFactor > 1) {
        if (value < 0)
            fvalue -= 0.5f;
        else
            fvalue += 0.5f;
    }

    return roundForImpreciseConversion<int>(fvalue / zoomFactor);
}

} // namespace blink