ChangeLog

2012-05-07  Julien Chaffraix  <jchaffraix@webkit.org>

        Move RenderLayers z-index lists dirtying to post style change

        https://bugs.webkit.org/show_bug.cgi?id=85437

        Reviewed by NOBODY (OOPS!).

        No expected change in behavior.

        This change moves the z-order lists to RenderLayer::styleChanged. As part of this

        change, also added proper handling of stacking context transition. This enabled

        us to tighten more of the dirtyZOrderLists / clearZOrderLists code.

        * rendering/RenderBoxModelObject.cpp:

        (WebCore::RenderBoxModelObject::styleWillChange):

        Removed this code, moved to updateStackingContextsAfterStyleChange.

        * rendering/RenderLayer.cpp:

        (WebCore::RenderLayer::RenderLayer):

        Only stacking contexts start with dirty z-order lists.

        (WebCore::RenderLayer::dirtyZOrderLists):

        Added an ASSERT.

        (WebCore::RenderLayer::updateStackingContextsAfterStyleChange):

        Refactored the code to handle the transition between stacking context status.

        (WebCore::RenderLayer::styleChanged):

        Added a call to updateStackingContextsAfterStyleChange.

        * rendering/RenderLayer.h:

        (WebCore::RenderLayer::isStackingContext):

        Added a call to the next function.

        (WebCore::RenderLayer::layerWithStyleIsStackingContext):

        Factored the isStackingContext logic here so that we can reuse it inside

        updateStackingContextsAfterStyleChange.

        (WebCore::RenderLayer::clearZOrderLists):

        Added an ASSERT.

2012-05-07  Raymond Toy  <rtoy@google.com>

        ConvolverNode setBuffer() should not ASSERT on null buffer

Source/WebCore/rendering/RenderBoxModelObject.cpp

@@void RenderBoxModelObject::styleWillChange(StyleDifference diff, const RenderSty

                repaint();

            }

        }

        if (hasLayer()

            && (oldStyle->hasAutoZIndex() != newStyle->hasAutoZIndex()

                || oldStyle->zIndex() != newStyle->zIndex()

                || oldStyle->visibility() != newStyle->visibility())) {

            layer()->dirtyStackingContextZOrderLists();

            if (oldStyle->hasAutoZIndex() != newStyle->hasAutoZIndex() || oldStyle->visibility() != newStyle->visibility())

                layer()->dirtyZOrderLists();

        }

    }

    RenderObject::styleWillChange(diff, newStyle);

Source/WebCore/rendering/RenderLayer.cpp

@@void ClipRects::destroy(RenderArena* renderArena)

RenderLayer::RenderLayer(RenderBoxModelObject* renderer)

    : m_inResizeMode(false)

    , m_scrollDimensionsDirty(true)

150 , m_zOrderListsDirty(true)

    , m_normalFlowListDirty(true)

    , m_usedTransparency(false)

    , m_paintingInsideReflection(false)

@@RenderLayer::RenderLayer(RenderBoxModelObject* renderer)

    , m_resizer(0)

{

    m_isNormalFlowOnly = shouldBeNormalFlowOnly();

195 m_zOrderListsDirty = isStackingContext();

    ScrollableArea::setConstrainsScrollingToContentEdge(false);

@@static inline bool compareZIndex(RenderLayer* first, RenderLayer* second)

void RenderLayer::dirtyZOrderLists()

{

    ASSERT(m_layerListMutationAllowed);

4465 // We cannot assume that we are called on a stacking context as it

4466 // is called when we just got demoted from being a stacking context.

4465 ASSERT(isStackingContext());

    if (m_posZOrderList)

        m_posZOrderList->clear();

@@bool RenderLayer::isSelfPaintingLayer() const

        || renderer()->isRenderIFrame();

}

void RenderLayer::updateStackingContextsAfterStyleChange(const RenderStyle* oldStyle)

{

    if (!oldStyle)

        return;

    bool wasStackingContext = layerWithStyleIsStackingContext(oldStyle);

    bool isStackingContext = this->isStackingContext();

    if (isStackingContext != wasStackingContext) {

        dirtyStackingContextZOrderLists();

        if (isStackingContext)

            dirtyZOrderLists();

        else

            clearZOrderLists();

    }

    // FIXME: RenderLayer already handles visibility changes through our visiblity dirty bits. This logic could

    // likely be folded along with the rest.

    if (oldStyle->zIndex() != renderer()->style()->zIndex() || oldStyle->visibility() != renderer()->style()->visibility()) {

        dirtyStackingContextZOrderLists();

        if (isStackingContext)

            dirtyZOrderLists();

    }

}

static bool overflowCanHaveAScrollbar(EOverflow overflow)

{

    return overflow == OAUTO || overflow == OSCROLL || overflow == OOVERLAY;

@@void RenderLayer::styleChanged(StyleDifference, const RenderStyle* oldStyle)

        delete m_marquee;

        m_marquee = 0;

    }

4736

4759

4760 updateStackingContextsAfterStyleChange(oldStyle);

    updateScrollbarsAfterStyleChange(oldStyle);

    if (!hasReflection() && m_reflection)

Source/WebCore/rendering/RenderLayer.h

@@public:

    // Get the enclosing stacking context for this layer.  A stacking context is a layer

    // that has a non-auto z-index.

    RenderLayer* stackingContext() const;

385 bool isStackingContext() const { return !h~~asAutoZInd~~ex~~() ||~~ renderer()->isR~~enderView~~(); }

385 bool isStackingContext() const { return layerWithStyleIsStackingContext(renderer()->style()); }

    void dirtyZOrderLists();

    void dirtyStackingContextZOrderLists();

@@public:

    void convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutPoint& location) const;

    void convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutRect&) const;

446 bool hasAutoZIndex() const { return renderer()->style()->hasAutoZIndex(); }

    int zIndex() const { return renderer()->style()->zIndex(); }

    enum PaintLayerFlag {

@@private:

    void updateNormalFlowList();

620 bool layerWithStyleIsStackingContext(const RenderStyle* style) const { return !style->hasAutoZIndex() || renderer()->isRenderView(); }

    bool isDirtyStackingContext() const { return m_zOrderListsDirty && isStackingContext(); }

    void computeRepaintRects(LayoutPoint* offsetFromRoot = 0);

@@private:

    bool shouldRepaintAfterLayout() const;

632 void updateStackingContextsAfterStyleChange(const RenderStyle* oldStyle);

633

    void updateScrollbarsAfterStyleChange(const RenderStyle* oldStyle);

    void updateScrollbarsAfterLayout();

@@private:

inline void RenderLayer::clearZOrderLists()

{

941 ASSERT(!isStackingContext());

942

    if (m_posZOrderList) {

        delete m_posZOrderList;

        m_posZOrderList = 0;