FCL/sf/mw/web: comparison webengine/osswebengine/WebCore/rendering/RenderLayer.cpp

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+:dd21522fd290
+/*
+* Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
+*
+* Portions are Copyright (C) 1998 Netscape Communications Corporation.
+*
+* Other contributors:
+*   Robert O'Callahan <roc+@cs.cmu.edu>
+*   David Baron <dbaron@fas.harvard.edu>
+*   Christian Biesinger <cbiesinger@web.de>
+*   Randall Jesup <rjesup@wgate.com>
+*   Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>
+*   Josh Soref <timeless@mac.com>
+*   Boris Zbarsky <bzbarsky@mit.edu>
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 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
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*
+* Alternatively, the contents of this file may be used under the terms
+* of either the Mozilla Public License Version 1.1, found at
+* http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
+* License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
+* (the "GPL"), in which case the provisions of the MPL or the GPL are
+* applicable instead of those above.  If you wish to allow use of your
+* version of this file only under the terms of one of those two
+* licenses (the MPL or the GPL) and not to allow others to use your
+* version of this file under the LGPL, indicate your decision by
+* deletingthe provisions above and replace them with the notice and
+* other provisions required by the MPL or the GPL, as the case may be.
+* If you do not delete the provisions above, a recipient may use your
+* version of this file under any of the LGPL, the MPL or the GPL.
+*/
+#include "config.h"
+#include "RenderLayer.h"
+#include "CSSPropertyNames.h"
+#include "Document.h"
+#include "EventHandler.h"
+#include "EventNames.h"
+#include "FloatRect.h"
+#include "Frame.h"
+#include "FrameView.h"
+#include "FrameTree.h"
+#include "GraphicsContext.h"
+#include "HTMLMarqueeElement.h"
+#include "HTMLNames.h"
+#include "HitTestRequest.h"
+#include "HitTestResult.h"
+#include "OverflowEvent.h"
+#include "PlatformMouseEvent.h"
+#include "PlatformScrollBar.h"
+#include "RenderArena.h"
+#include "RenderInline.h"
+#include "RenderTheme.h"
+#include "RenderView.h"
+#include "SelectionController.h"
+#if ENABLE(SVG)
+#include "SVGNames.h"
+#endif
+#define MIN_INTERSECT_FOR_REVEAL 32
+using namespace std;
+namespace WebCore {
+using namespace EventNames;
+using namespace HTMLNames;
+#ifndef NDEBUG
+static bool inRenderLayerDestroy;
+#endif
+const RenderLayer::ScrollAlignment RenderLayer::gAlignCenterIfNeeded = { RenderLayer::noScroll, RenderLayer::alignCenter, RenderLayer::alignToClosestEdge };
+const RenderLayer::ScrollAlignment RenderLayer::gAlignToEdgeIfNeeded = { RenderLayer::noScroll, RenderLayer::alignToClosestEdge, RenderLayer::alignToClosestEdge };
+const RenderLayer::ScrollAlignment RenderLayer::gAlignCenterAlways = { RenderLayer::alignCenter, RenderLayer::alignCenter, RenderLayer::alignCenter };
+const RenderLayer::ScrollAlignment RenderLayer::gAlignTopAlways = { RenderLayer::alignTop, RenderLayer::alignTop, RenderLayer::alignTop };
+const RenderLayer::ScrollAlignment RenderLayer::gAlignBottomAlways = { RenderLayer::alignBottom, RenderLayer::alignBottom, RenderLayer::alignBottom };
+const int MinimumWidthWhileResizing = 100;
+const int MinimumHeightWhileResizing = 40;
+void* ClipRects::operator new(size_t sz, RenderArena* renderArena) throw()
+{
+return renderArena->allocate(sz);
+}
+void ClipRects::operator delete(void* ptr, size_t sz)
+{
+// Stash size where destroy can find it.
+*(size_t *)ptr = sz;
+}
+void ClipRects::destroy(RenderArena* renderArena)
+{
+delete this;
+// Recover the size left there for us by operator delete and free the memory.
+renderArena->free(*(size_t *)this, this);
+}
+RenderLayer::RenderLayer(RenderObject* object)
+: m_object(object)
+, m_parent(0)
+, m_previous(0)
+, m_next(0)
+, m_first(0)
+, m_last(0)
+, m_relX(0)
+, m_relY(0)
+, m_x(0)
+, m_y(0)
+, m_width(0)
+, m_height(0)
+, m_scrollX(0)
+, m_scrollY(0)
+, m_scrollOriginX(0)
+, m_scrollLeftOverflow(0)
+, m_scrollWidth(0)
+, m_scrollHeight(0)
+, m_inResizeMode(false)
+, m_posZOrderList(0)
+, m_negZOrderList(0)
+, m_overflowList(0)
+, m_clipRects(0)
+, m_scrollDimensionsDirty(true)
+, m_zOrderListsDirty(true)
+, m_overflowListDirty(true)
+, m_isOverflowOnly(shouldBeOverflowOnly())
+, m_usedTransparency(false)
+, m_inOverflowRelayout(false)
+, m_needsFullRepaint(false)
+, m_overflowStatusDirty(true)
+, m_visibleContentStatusDirty(true)
+, m_hasVisibleContent(false)
+, m_visibleDescendantStatusDirty(false)
+, m_hasVisibleDescendant(false)
+, m_marquee(0)
+, m_staticX(0)
+, m_staticY(0)
+{
+if (!object->firstChild() && object->style()) {
+m_visibleContentStatusDirty = false;
+m_hasVisibleContent = object->style()->visibility() == VISIBLE;
+}
+}
+RenderLayer::~RenderLayer()
+{
+destroyScrollbar(HorizontalScrollbar);
+destroyScrollbar(VerticalScrollbar);
+// Child layers will be deleted by their corresponding render objects, so
+// we don't need to delete them ourselves.
+delete m_posZOrderList;
+delete m_negZOrderList;
+delete m_overflowList;
+delete m_marquee;
+// Make sure we have no lingering clip rects.
+ASSERT(!m_clipRects);
+}
+void RenderLayer::updateLayerPositions(bool doFullRepaint, bool checkForRepaint)
+{
+if (doFullRepaint) {
+m_object->repaint();
+checkForRepaint = doFullRepaint = false;
+}
+updateLayerPosition(); // For relpositioned layers or non-positioned layers,
+// we need to keep in sync, since we may have shifted relative
+// to our parent layer.
+positionOverflowControls();
+updateVisibilityStatus();
+if (m_hasVisibleContent) {
+RenderView* view = m_object->view();
+ASSERT(view);
+// FIXME: Optimize using LayoutState and remove the disableLayoutState() call
+// from updateScrollInfoAfterLayout().
+ASSERT(!view->layoutState());
+IntRect newRect = m_object->absoluteClippedOverflowRect();
+IntRect newOutlineBox = m_object->absoluteOutlineBox();
+if (checkForRepaint) {
+if (view && !view->printing()) {
+if (m_needsFullRepaint) {
+view->repaintViewRectangle(m_repaintRect);
+if (newRect != m_repaintRect)
+view->repaintViewRectangle(newRect);
+} else
+m_object->repaintAfterLayoutIfNeeded(m_repaintRect, m_outlineBox);
+}
+}
+m_repaintRect = newRect;
+m_outlineBox = newOutlineBox;
+} else {
+m_repaintRect = IntRect();
+m_outlineBox = IntRect();
+}
+m_needsFullRepaint = false;
+for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
+child->updateLayerPositions(doFullRepaint, checkForRepaint);
+// With all our children positioned, now update our marquee if we need to.
+if (m_marquee)
+m_marquee->updateMarqueePosition();
+}
+void RenderLayer::setHasVisibleContent(bool b)
+{
+if (m_hasVisibleContent == b && !m_visibleContentStatusDirty)
+return;
+m_visibleContentStatusDirty = false;
+m_hasVisibleContent = b;
+if (m_hasVisibleContent) {
+m_repaintRect = renderer()->absoluteClippedOverflowRect();
+m_outlineBox = renderer()->absoluteOutlineBox();
+}
+if (parent())
+parent()->childVisibilityChanged(m_hasVisibleContent);
+}
+void RenderLayer::dirtyVisibleContentStatus()
+{
+m_visibleContentStatusDirty = true;
+if (parent())
+parent()->dirtyVisibleDescendantStatus();
+}
+void RenderLayer::childVisibilityChanged(bool newVisibility)
+{
+if (m_hasVisibleDescendant == newVisibility || m_visibleDescendantStatusDirty)
+return;
+if (newVisibility) {
+RenderLayer* l = this;
+while (l && !l->m_visibleDescendantStatusDirty && !l->m_hasVisibleDescendant) {
+l->m_hasVisibleDescendant = true;
+l = l->parent();
+}
+} else
+dirtyVisibleDescendantStatus();
+}
+void RenderLayer::dirtyVisibleDescendantStatus()
+{
+RenderLayer* l = this;
+while (l && !l->m_visibleDescendantStatusDirty) {
+l->m_visibleDescendantStatusDirty = true;
+l = l->parent();
+}
+}
+void RenderLayer::updateVisibilityStatus()
+{
+if (m_visibleDescendantStatusDirty) {
+m_hasVisibleDescendant = false;
+for (RenderLayer* child = firstChild(); child; child = child->nextSibling()) {
+child->updateVisibilityStatus();
+if (child->m_hasVisibleContent || child->m_hasVisibleDescendant) {
+m_hasVisibleDescendant = true;
+break;
+}
+}
+m_visibleDescendantStatusDirty = false;
+}
+if (m_visibleContentStatusDirty) {
+if (m_object->style()->visibility() == VISIBLE)
+m_hasVisibleContent = true;
+else {
+// layer may be hidden but still have some visible content, check for this
+m_hasVisibleContent = false;
+RenderObject* r = m_object->firstChild();
+while (r) {
+if (r->style()->visibility() == VISIBLE && !r->hasLayer()) {
+m_hasVisibleContent = true;
+break;
+}
+if (r->firstChild() && !r->hasLayer())
+r = r->firstChild();
+else if (r->nextSibling())
+r = r->nextSibling();
+else {
+do {
+r = r->parent();
+if (r==m_object)
+r = 0;
+} while (r && !r->nextSibling());
+if (r)
+r = r->nextSibling();
+}
+}
+}
+m_visibleContentStatusDirty = false;
+}
+}
+void RenderLayer::updateLayerPosition()
+{
+// Clear our cached clip rect information.
+clearClipRect();
+int x = m_object->xPos();
+int y = m_object->yPos() - m_object->borderTopExtra();
+if (!m_object->isPositioned() && m_object->parent()) {
+// We must adjust our position by walking up the render tree looking for the
+// nearest enclosing object with a layer.
+RenderObject* curr = m_object->parent();
+while (curr && !curr->hasLayer()) {
+if (!curr->isTableRow()) {
+// Rows and cells share the same coordinate space (that of the section).
+// Omit them when computing our xpos/ypos.
+x += curr->xPos();
+y += curr->yPos();
+}
+curr = curr->parent();
+}
+y += curr->borderTopExtra();
+if (curr->isTableRow()) {
+// Put ourselves into the row coordinate space.
+x -= curr->xPos();
+y -= curr->yPos();
+}
+}
+m_relX = m_relY = 0;
+if (m_object->isRelPositioned()) {
+m_relX = static_cast<RenderBox*>(m_object)->relativePositionOffsetX();
+m_relY = static_cast<RenderBox*>(m_object)->relativePositionOffsetY();
+x += m_relX; y += m_relY;
+}
+// Subtract our parent's scroll offset.
+if (m_object->isPositioned() && enclosingPositionedAncestor()) {
+RenderLayer* positionedParent = enclosingPositionedAncestor();
+// For positioned layers, we subtract out the enclosing positioned layer's scroll offset.
+positionedParent->subtractScrollOffset(x, y);
+if (m_object->isPositioned()) {
+IntSize offset = static_cast<RenderBox*>(m_object)->offsetForPositionedInContainer(positionedParent->renderer());
+x += offset.width();
+y += offset.height();
+}
+} else if (parent())
+parent()->subtractScrollOffset(x, y);
+setPos(x,y);
+setWidth(m_object->width());
+setHeight(m_object->height() + m_object->borderTopExtra() + m_object->borderBottomExtra());
+if (!m_object->hasOverflowClip()) {
+if (m_object->overflowWidth() > m_object->width())
+setWidth(m_object->overflowWidth());
+if (m_object->overflowHeight() > m_object->height())
+setHeight(m_object->overflowHeight());
+}
+}
+RenderLayer *RenderLayer::stackingContext() const
+{
+RenderLayer* curr = parent();
+for ( ; curr && !curr->m_object->isRenderView() && !curr->m_object->isRoot() &&
+curr->m_object->style()->hasAutoZIndex();
+curr = curr->parent());
+return curr;
+}
+RenderLayer*
+RenderLayer::enclosingPositionedAncestor() const
+{
+RenderLayer* curr = parent();
+for ( ; curr && !curr->m_object->isRenderView() && !curr->m_object->isRoot() &&
+!curr->m_object->isPositioned() && !curr->m_object->isRelPositioned();
+curr = curr->parent());
+return curr;
+}
+bool
+RenderLayer::isTransparent() const
+{
+#if ENABLE(SVG)
+if (m_object->node()->namespaceURI() == SVGNames::svgNamespaceURI)
+return false;
+#endif
+return m_object->isTransparent();
+}
+RenderLayer*
+RenderLayer::transparentAncestor()
+{
+RenderLayer* curr = parent();
+for ( ; curr && !curr->isTransparent(); curr = curr->parent());
+return curr;
+}
+static IntRect transparencyClipBox(RenderLayer* l)
+{
+// FIXME: Although this completely ignores clipping, we ultimately intersect with the
+// paintDirtyRect, and that should cut down on the amount we have to paint.  Still it
+// would be better to respect clips.
+IntRect clipRect = l->absoluteBoundingBox();
+// Note: we don't have to walk z-order lists since transparent elements always establish
+// a stacking context.  This means we can just walk the layer tree directly.
+for (RenderLayer* curr = l->firstChild(); curr; curr = curr->nextSibling())
+clipRect.unite(transparencyClipBox(curr));
+return clipRect;
+}
+void RenderLayer::beginTransparencyLayers(GraphicsContext* p, const IntRect& paintDirtyRect)
+{
+if (p->paintingDisabled() || (isTransparent() && m_usedTransparency))
+return;
+RenderLayer* ancestor = transparentAncestor();
+if (ancestor)
+ancestor->beginTransparencyLayers(p, paintDirtyRect);
+if (isTransparent()) {
+m_usedTransparency = true;
+IntRect clipRect = transparencyClipBox(this);
+clipRect.intersect(paintDirtyRect);
+p->save();
+p->clip(clipRect);
+p->beginTransparencyLayer(renderer()->opacity());
+}
+}
+void* RenderLayer::operator new(size_t sz, RenderArena* renderArena) throw()
+{
+return renderArena->allocate(sz);
+}
+void RenderLayer::operator delete(void* ptr, size_t sz)
+{
+ASSERT(inRenderLayerDestroy);
+// Stash size where destroy can find it.
+*(size_t *)ptr = sz;
+}
+void RenderLayer::destroy(RenderArena* renderArena)
+{
+#ifndef NDEBUG
+inRenderLayerDestroy = true;
+#endif
+delete this;
+#ifndef NDEBUG
+inRenderLayerDestroy = false;
+#endif
+// Recover the size left there for us by operator delete and free the memory.
+renderArena->free(*(size_t *)this, this);
+}
+void RenderLayer::addChild(RenderLayer *child, RenderLayer* beforeChild)
+{
+RenderLayer* prevSibling = beforeChild ? beforeChild->previousSibling() : lastChild();
+if (prevSibling) {
+child->setPreviousSibling(prevSibling);
+prevSibling->setNextSibling(child);
+}
+else
+setFirstChild(child);
+if (beforeChild) {
+beforeChild->setPreviousSibling(child);
+child->setNextSibling(beforeChild);
+}
+else
+setLastChild(child);
+child->setParent(this);
+if (child->isOverflowOnly())
+dirtyOverflowList();
+else {
+// Dirty the z-order list in which we are contained.  The stackingContext() can be null in the
+// case where we're building up generated content layers.  This is ok, since the lists will start
+// off dirty in that case anyway.
+RenderLayer* stackingContext = child->stackingContext();
+if (stackingContext)
+stackingContext->dirtyZOrderLists();
+}
+child->updateVisibilityStatus();
+if (child->m_hasVisibleContent || child->m_hasVisibleDescendant)
+childVisibilityChanged(true);
+}
+RenderLayer* RenderLayer::removeChild(RenderLayer* oldChild)
+{
+// remove the child
+if (oldChild->previousSibling())
+oldChild->previousSibling()->setNextSibling(oldChild->nextSibling());
+if (oldChild->nextSibling())
+oldChild->nextSibling()->setPreviousSibling(oldChild->previousSibling());
+if (m_first == oldChild)
+m_first = oldChild->nextSibling();
+if (m_last == oldChild)
+m_last = oldChild->previousSibling();
+if (oldChild->isOverflowOnly())
+dirtyOverflowList();
+else {
+// Dirty the z-order list in which we are contained.  When called via the
+// reattachment process in removeOnlyThisLayer, the layer may already be disconnected
+// from the main layer tree, so we need to null-check the |stackingContext| value.
+RenderLayer* stackingContext = oldChild->stackingContext();
+if (stackingContext)
+stackingContext->dirtyZOrderLists();
+}
+oldChild->setPreviousSibling(0);
+oldChild->setNextSibling(0);
+oldChild->setParent(0);
+oldChild->updateVisibilityStatus();
+if (oldChild->m_hasVisibleContent || oldChild->m_hasVisibleDescendant)
+childVisibilityChanged(false);
+return oldChild;
+}
+void RenderLayer::removeOnlyThisLayer()
+{
+if (!m_parent)
+return;
+// Dirty the clip rects.
+clearClipRects();
+// Remove us from the parent.
+RenderLayer* parent = m_parent;
+RenderLayer* nextSib = nextSibling();
+parent->removeChild(this);
+// Now walk our kids and reattach them to our parent.
+RenderLayer* current = m_first;
+while (current) {
+RenderLayer* next = current->nextSibling();
+removeChild(current);
+parent->addChild(current, nextSib);
+current->updateLayerPositions();
+current = next;
+}
+destroy(renderer()->renderArena());
+}
+void RenderLayer::insertOnlyThisLayer()
+{
+if (!m_parent && renderer()->parent()) {
+// We need to connect ourselves when our renderer() has a parent.
+// Find our enclosingLayer and add ourselves.
+RenderLayer* parentLayer = renderer()->parent()->enclosingLayer();
+if (parentLayer)
+parentLayer->addChild(this,
+renderer()->parent()->findNextLayer(parentLayer, renderer()));
+}
+// Remove all descendant layers from the hierarchy and add them to the new position.
+for (RenderObject* curr = renderer()->firstChild(); curr; curr = curr->nextSibling())
+curr->moveLayers(m_parent, this);
+// Clear out all the clip rects.
+clearClipRects();
+}
+void
+RenderLayer::convertToLayerCoords(const RenderLayer* ancestorLayer, int& x, int& y) const
+{
+if (ancestorLayer == this)
+return;
+if (m_object->style()->position() == FixedPosition) {
+// Add in the offset of the view.  We can obtain this by calling
+// absolutePosition() on the RenderView.
+int xOff, yOff;
+m_object->absolutePosition(xOff, yOff, true);
+x += xOff;
+y += yOff;
+return;
+}
+RenderLayer* parentLayer;
+if (m_object->style()->position() == AbsolutePosition)
+parentLayer = enclosingPositionedAncestor();
+else
+parentLayer = parent();
+if (!parentLayer) return;
+parentLayer->convertToLayerCoords(ancestorLayer, x, y);
+x += xPos();
+y += yPos();
+}
+void
+RenderLayer::scrollOffset(int& x, int& y)
+{
+x += scrollXOffset() + m_scrollLeftOverflow;
+y += scrollYOffset();
+}
+void
+RenderLayer::subtractScrollOffset(int& x, int& y)
+{
+x -= scrollXOffset() + m_scrollLeftOverflow;
+y -= scrollYOffset();
+}
+void RenderLayer::scrollToOffset(int x, int y, bool updateScrollbars, bool repaint)
+{
+if (renderer()->style()->overflowX() != OMARQUEE) {
+if (x < 0) x = 0;
+if (y < 0) y = 0;
+// Call the scrollWidth/Height functions so that the dimensions will be computed if they need
+// to be (for overflow:hidden blocks).
+int maxX = scrollWidth() - m_object->clientWidth();
+int maxY = scrollHeight() - m_object->clientHeight();
+if (x > maxX) x = maxX;
+if (y > maxY) y = maxY;
+}
+// FIXME: Eventually, we will want to perform a blit.  For now never
+// blit, since the check for blitting is going to be very
+// complicated (since it will involve testing whether our layer
+// is either occluded by another layer or clipped by an enclosing
+// layer or contains fixed backgrounds, etc.).
+m_scrollX = x - m_scrollOriginX;
+m_scrollY = y;
+// Update the positions of our child layers.
+for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
+child->updateLayerPositions(false, false);
+RenderView* view = renderer()->view();
+// We should have a RenderView if we're trying to scroll.
+ASSERT(view);
+if (view) {
+// Update dashboard regions, scrolling may change the clip of a
+// particular region.
+view->frameView()->updateDashboardRegions();
+view->updateWidgetPositions();
+}
+// Just schedule a full repaint of our object.
+if (repaint)
+m_object->repaint();
+if (updateScrollbars) {
+if (m_hBar)
+m_hBar->setValue(scrollXOffset());
+if (m_vBar)
+m_vBar->setValue(m_scrollY);
+}
+// Schedule the scroll DOM event.
+if (view)
+if (FrameView* frameView = view->frameView())
+frameView->scheduleEvent(new Event(scrollEvent, true, false), EventTargetNodeCast(renderer()->element()), true);
+}
+void RenderLayer::scrollRectToVisible(const IntRect &rect, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
+{
+RenderLayer* parentLayer = 0;
+IntRect newRect = rect;
+int xOffset = 0, yOffset = 0;
+// We may end up propagating a scroll event. It is important that we suspend events until
+// the end of the function since they could delete the layer or the layer's m_object.
+FrameView* frameView = m_object->document()->view();
+if (frameView)
+frameView->pauseScheduledEvents();
+bool restrictedByLineClamp = false;
+if (m_object->parent()) {
+parentLayer = m_object->parent()->enclosingLayer();
+restrictedByLineClamp = m_object->parent()->style()->lineClamp() >= 0;
+}
+if (m_object->hasOverflowClip() && !restrictedByLineClamp) {
+// Don't scroll to reveal an overflow layer that is restricted by the -webkit-line-clamp property.
+// This will prevent us from revealing text hidden by the slider in Safari RSS.
+int x, y;
+m_object->absolutePosition(x, y);
+x += m_object->borderLeft();
+y += m_object->borderTop();
+IntRect layerBounds = IntRect(x + scrollXOffset(), y + scrollYOffset(), m_object->clientWidth(), m_object->clientHeight());
+IntRect exposeRect = IntRect(rect.x() + scrollXOffset(), rect.y() + scrollYOffset(), rect.width(), rect.height());
+IntRect r = getRectToExpose(layerBounds, exposeRect, alignX, alignY);
+xOffset = r.x() - x;
+yOffset = r.y() - y;
+// Adjust offsets if they're outside of the allowable range.
+xOffset = max(0, min(scrollWidth() - layerBounds.width(), xOffset));
+yOffset = max(0, min(scrollHeight() - layerBounds.height(), yOffset));
+if (xOffset != scrollXOffset() || yOffset != scrollYOffset()) {
+int diffX = scrollXOffset();
+int diffY = scrollYOffset();
+scrollToOffset(xOffset, yOffset);
+diffX = scrollXOffset() - diffX;
+diffY = scrollYOffset() - diffY;
+newRect.setX(rect.x() - diffX);
+newRect.setY(rect.y() - diffY);
+}
+} else if (!parentLayer) {
+if (frameView) {
+if (m_object->document() && m_object->document()->ownerElement() && m_object->document()->ownerElement()->renderer()) {
+IntRect viewRect = enclosingIntRect(frameView->visibleContentRect());
+IntRect r = getRectToExpose(viewRect, rect, alignX, alignY);
+xOffset = r.x();
+yOffset = r.y();
+// Adjust offsets if they're outside of the allowable range.
+xOffset = max(0, min(frameView->contentsWidth(), xOffset));
+yOffset = max(0, min(frameView->contentsHeight(), yOffset));
+frameView->setContentsPos(xOffset, yOffset);
+parentLayer = m_object->document()->ownerElement()->renderer()->enclosingLayer();
+newRect.setX(rect.x() - frameView->contentsX() + frameView->x());
+newRect.setY(rect.y() - frameView->contentsY() + frameView->y());
+} else {
+IntRect viewRect = enclosingIntRect(frameView->visibleContentRectConsideringExternalScrollers());
+IntRect r = getRectToExpose(viewRect, rect, alignX, alignY);
+// If this is the outermost view that RenderLayer needs to scroll, then we should scroll the view recursively
+// Other apps, like Mail, rely on this feature.
+frameView->scrollRectIntoViewRecursively(r);
+}
+}
+}
+if (parentLayer)
+parentLayer->scrollRectToVisible(newRect, alignX, alignY);
+if (frameView)
+frameView->resumeScheduledEvents();
+}
+IntRect RenderLayer::getRectToExpose(const IntRect &visibleRect, const IntRect &exposeRect, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
+{
+// Determine the appropriate X behavior.
+ScrollBehavior scrollX;
+IntRect exposeRectX(exposeRect.x(), visibleRect.y(), exposeRect.width(), visibleRect.height());
+int intersectWidth = intersection(visibleRect, exposeRectX).width();
+if (intersectWidth == exposeRect.width() || intersectWidth >= MIN_INTERSECT_FOR_REVEAL)
+// If the rectangle is fully visible, use the specified visible behavior.
+// If the rectangle is partially visible, but over a certain threshold,
+// then treat it as fully visible to avoid unnecessary horizontal scrolling
+scrollX = getVisibleBehavior(alignX);
+else if (intersectWidth == visibleRect.width()) {
+// If the rect is bigger than the visible area, don't bother trying to center. Other alignments will work.
+scrollX = getVisibleBehavior(alignX);
+if (scrollX == alignCenter)
+scrollX = noScroll;
+} else if (intersectWidth > 0)
+// If the rectangle is partially visible, but not above the minimum threshold, use the specified partial behavior
+scrollX = getPartialBehavior(alignX);
+else
+scrollX = getHiddenBehavior(alignX);
+// If we're trying to align to the closest edge, and the exposeRect is further right
+// than the visibleRect, and not bigger than the visible area, then align with the right.
+if (scrollX == alignToClosestEdge && exposeRect.right() > visibleRect.right() && exposeRect.width() < visibleRect.width())
+scrollX = alignRight;
+// Given the X behavior, compute the X coordinate.
+int x;
+if (scrollX == noScroll)
+x = visibleRect.x();
+else if (scrollX == alignRight)
+x = exposeRect.right() - visibleRect.width();
+else if (scrollX == alignCenter)
+x = exposeRect.x() + (exposeRect.width() - visibleRect.width()) / 2;
+else
+x = exposeRect.x();
+// Determine the appropriate Y behavior.
+ScrollBehavior scrollY;
+IntRect exposeRectY(visibleRect.x(), exposeRect.y(), visibleRect.width(), exposeRect.height());
+int intersectHeight = intersection(visibleRect, exposeRectY).height();
+if (intersectHeight == exposeRect.height())
+// If the rectangle is fully visible, use the specified visible behavior.
+scrollY = getVisibleBehavior(alignY);
+else if (intersectHeight == visibleRect.height()) {
+// If the rect is bigger than the visible area, don't bother trying to center. Other alignments will work.
+scrollY = getVisibleBehavior(alignY);
+if (scrollY == alignCenter)
+scrollY = noScroll;
+} else if (intersectHeight > 0)
+// If the rectangle is partially visible, use the specified partial behavior
+scrollY = getPartialBehavior(alignY);
+else
+scrollY = getHiddenBehavior(alignY);
+// If we're trying to align to the closest edge, and the exposeRect is further down
+// than the visibleRect, and not bigger than the visible area, then align with the bottom.
+if (scrollY == alignToClosestEdge && exposeRect.bottom() > visibleRect.bottom() && exposeRect.height() < visibleRect.height())
+scrollY = alignBottom;
+// Given the Y behavior, compute the Y coordinate.
+int y;
+if (scrollY == noScroll)
+y = visibleRect.y();
+else if (scrollY == alignBottom)
+y = exposeRect.bottom() - visibleRect.height();
+else if (scrollY == alignCenter)
+y = exposeRect.y() + (exposeRect.height() - visibleRect.height()) / 2;
+else
+y = exposeRect.y();
+return IntRect(IntPoint(x, y), visibleRect.size());
+}
+void RenderLayer::autoscroll()
+{
+Frame* frame = renderer()->document()->frame();
+if (!frame)
+return;
+FrameView* frameView = frame->view();
+if (!frameView)
+return;
+frame->eventHandler()->updateSelectionForMouseDrag();
+IntPoint currentDocumentPosition = frameView->windowToContents(frame->eventHandler()->currentMousePosition());
+scrollRectToVisible(IntRect(currentDocumentPosition, IntSize(1, 1)), gAlignToEdgeIfNeeded, gAlignToEdgeIfNeeded);
+}
+void RenderLayer::resize(const PlatformMouseEvent& evt, const IntSize& oldOffset)
+{
+if (!inResizeMode() || !m_object->hasOverflowClip())
+return;
+// Set the width and height of the shadow ancestor node if there is one.
+// This is necessary for textarea elements since the resizable layer is in the shadow content.
+Element* element = static_cast<Element*>(m_object->node()->shadowAncestorNode());
+RenderBox* renderer = static_cast<RenderBox*>(element->renderer());
+EResize resize = renderer->style()->resize();
+if (resize == RESIZE_NONE)
+return;
+Document* document = element->document();
+if (!document->frame()->eventHandler()->mousePressed())
+return;
+IntSize newOffset = offsetFromResizeCorner(document->view()->windowToContents(evt.pos()));
+IntSize currentSize = IntSize(renderer->width(), renderer->height());
+IntSize minimumSize = element->minimumSizeForResizing().shrunkTo(currentSize);
+element->setMinimumSizeForResizing(minimumSize);
+IntSize difference = (currentSize + newOffset - oldOffset).expandedTo(minimumSize) - currentSize;
+CSSStyleDeclaration* style = element->style();
+bool isBoxSizingBorder = renderer->style()->boxSizing() == BORDER_BOX;
+ExceptionCode ec;
+if (difference.width()) {
+if (element && element->isControl()) {
+// Make implicit margins from the theme explicit (see <http://bugs.webkit.org/show_bug.cgi?id=9547>).
+style->setProperty(CSS_PROP_MARGIN_LEFT, String::number(renderer->marginLeft()) + "px", false, ec);
+style->setProperty(CSS_PROP_MARGIN_RIGHT, String::number(renderer->marginRight()) + "px", false, ec);
+}
+int baseWidth = renderer->width() - (isBoxSizingBorder ? 0
+: renderer->borderLeft() + renderer->paddingLeft() + renderer->borderRight() + renderer->paddingRight());
+style->setProperty(CSS_PROP_WIDTH, String::number(baseWidth + difference.width()) + "px", false, ec);
+}
+if (difference.height()) {
+if (element && element->isControl()) {
+// Make implicit margins from the theme explicit (see <http://bugs.webkit.org/show_bug.cgi?id=9547>).
+style->setProperty(CSS_PROP_MARGIN_TOP, String::number(renderer->marginTop()) + "px", false, ec);
+style->setProperty(CSS_PROP_MARGIN_BOTTOM, String::number(renderer->marginBottom()) + "px", false, ec);
+}
+int baseHeight = renderer->height() - (isBoxSizingBorder ? 0
+: renderer->borderTop() + renderer->paddingTop() + renderer->borderBottom() + renderer->paddingBottom());
+style->setProperty(CSS_PROP_HEIGHT, String::number(baseHeight + difference.height()) + "px", false, ec);
+}
+document->updateLayout();
+// FIXME (Radar 4118564): We should also autoscroll the window as necessary to keep the point under the cursor in view.
+}
+PlatformScrollbar* RenderLayer::horizontalScrollbarWidget() const
+{
+if (m_hBar && m_hBar->isWidget())
+return static_cast<PlatformScrollbar*>(m_hBar.get());
+return 0;
+}
+PlatformScrollbar* RenderLayer::verticalScrollbarWidget() const
+{
+if (m_vBar && m_vBar->isWidget())
+return static_cast<PlatformScrollbar*>(m_vBar.get());
+return 0;
+}
+void RenderLayer::valueChanged(Scrollbar*)
+{
+// Update scroll position from scrollbars.
+bool needUpdate = false;
+int newX = scrollXOffset();
+int newY = m_scrollY;
+if (m_hBar) {
+newX = m_hBar->value();
+if (newX != scrollXOffset())
+needUpdate = true;
+}
+if (m_vBar) {
+newY = m_vBar->value();
+if (newY != m_scrollY)
+needUpdate = true;
+}
+if (needUpdate)
+scrollToOffset(newX, newY, false);
+}
+IntRect RenderLayer::windowClipRect() const
+{
+RenderView* view = renderer()->view();
+ASSERT(view);
+FrameView* frameView = view->frameView();
+if (!frameView)
+return IntRect();
+return frameView->windowClipRectForLayer(this, false);
+}
+PassRefPtr<Scrollbar> RenderLayer::createScrollbar(ScrollbarOrientation orientation)
+{
+if (Scrollbar::hasPlatformScrollbars()) {
+RefPtr<PlatformScrollbar> widget = new PlatformScrollbar(this, orientation, RegularScrollbar);
+m_object->document()->view()->addChild(widget.get());
+return widget.release();
+}
+// FIXME: Create scrollbars using the engine.
+return 0;
+}
+void RenderLayer::destroyScrollbar(ScrollbarOrientation orientation)
+{
+RefPtr<Scrollbar>& scrollbar = orientation == HorizontalScrollbar ? m_hBar : m_vBar;
+if (scrollbar) {
+if (scrollbar->isWidget())
+static_cast<PlatformScrollbar*>(scrollbar.get())->removeFromParent();
+// FIXME: Destroy the engine scrollbar.
+scrollbar = 0;
+}
+}
+void RenderLayer::setHasHorizontalScrollbar(bool hasScrollbar)
+{
+if (hasScrollbar == (m_hBar != 0))
+return;
+if (hasScrollbar)
+m_hBar = createScrollbar(HorizontalScrollbar);
+else
+destroyScrollbar(HorizontalScrollbar);
+// Force an update since we know the scrollbars have changed things.
+if (m_object->document()->hasDashboardRegions())
+m_object->document()->setDashboardRegionsDirty(true);
+}
+void RenderLayer::setHasVerticalScrollbar(bool hasScrollbar)
+{
+if (hasScrollbar == (m_vBar != 0))
+return;
+if (hasScrollbar)
+m_vBar = createScrollbar(VerticalScrollbar);
+else
+destroyScrollbar(VerticalScrollbar);
+// Force an update since we know the scrollbars have changed things.
+if (m_object->document()->hasDashboardRegions())
+m_object->document()->setDashboardRegionsDirty(true);
+}
+int RenderLayer::verticalScrollbarWidth() const
+{
+if (!m_vBar)
+return 0;
+return m_vBar->width();
+}
+int RenderLayer::horizontalScrollbarHeight() const
+{
+if (!m_hBar)
+return 0;
+return m_hBar->height();
+}
+IntSize RenderLayer::offsetFromResizeCorner(const IntPoint& p) const
+{
+// Currently the resize corner is always the bottom right corner
+int x = width();
+int y = height();
+convertToLayerCoords(root(), x, y);
+return p - IntPoint(x, y);
+}
+static IntRect scrollCornerRect(RenderObject* renderer, const IntRect& absBounds)
+{
+int resizerWidth = PlatformScrollbar::verticalScrollbarWidth();
+int resizerHeight = PlatformScrollbar::horizontalScrollbarHeight();
+return IntRect(absBounds.right() - resizerWidth - renderer->style()->borderRightWidth(),
+absBounds.bottom() - resizerHeight - renderer->style()->borderBottomWidth(), resizerWidth, resizerHeight);
+}
+void RenderLayer::positionOverflowControls()
+{
+if (!m_hBar && !m_vBar && (!m_object->hasOverflowClip() || m_object->style()->resize() == RESIZE_NONE))
+return;
+int x = 0;
+int y = 0;
+convertToLayerCoords(root(), x, y);
+IntRect absBounds(x, y, m_object->width(), m_object->height());
+IntRect resizeControlRect;
+if (m_object->style()->resize() != RESIZE_NONE)
+resizeControlRect = scrollCornerRect(m_object, absBounds);
+int resizeControlSize = max(resizeControlRect.height(), 0);
+if (m_vBar)
+m_vBar->setRect(IntRect(absBounds.right() - m_object->borderRight() - m_vBar->width(),
+absBounds.y() + m_object->borderTop(),
+m_vBar->width(),
+absBounds.height() - (m_object->borderTop() + m_object->borderBottom()) - (m_hBar ? m_hBar->height() : resizeControlSize)));
+resizeControlSize = max(resizeControlRect.width(), 0);
+if (m_hBar)
+m_hBar->setRect(IntRect(absBounds.x() + m_object->borderLeft(),
+absBounds.bottom() - m_object->borderBottom() - m_hBar->height(),
+absBounds.width() - (m_object->borderLeft() + m_object->borderRight()) - (m_vBar ? m_vBar->width() : resizeControlSize),
+m_hBar->height()));
+}
+int RenderLayer::scrollWidth()
+{
+if (m_scrollDimensionsDirty)
+computeScrollDimensions();
+return m_scrollWidth;
+}
+int RenderLayer::scrollHeight()
+{
+if (m_scrollDimensionsDirty)
+computeScrollDimensions();
+return m_scrollHeight;
+}
+void RenderLayer::computeScrollDimensions(bool* needHBar, bool* needVBar)
+{
+m_scrollDimensionsDirty = false;
+bool ltr = m_object->style()->direction() == LTR;
+int clientWidth = m_object->clientWidth();
+int clientHeight = m_object->clientHeight();
+m_scrollLeftOverflow = ltr ? 0 : min(0, m_object->leftmostPosition(true, false) - m_object->borderLeft());
+int rightPos = ltr ?
+m_object->rightmostPosition(true, false) - m_object->borderLeft() :
+clientWidth - m_scrollLeftOverflow;
+int bottomPos = m_object->lowestPosition(true, false) - m_object->borderTop();
+m_scrollWidth = max(rightPos, clientWidth);
+m_scrollHeight = max(bottomPos, clientHeight);
+m_scrollOriginX = ltr ? 0 : m_scrollWidth - clientWidth;
+if (needHBar)
+*needHBar = rightPos > clientWidth;
+if (needVBar)
+*needVBar = bottomPos > clientHeight;
+}
+void RenderLayer::updateOverflowStatus(bool horizontalOverflow, bool verticalOverflow)
+{
+if (m_overflowStatusDirty) {
+m_horizontalOverflow = horizontalOverflow;
+m_verticalOverflow = verticalOverflow;
+m_overflowStatusDirty = false;
+return;
+}
+bool horizontalOverflowChanged = (m_horizontalOverflow != horizontalOverflow);
+bool verticalOverflowChanged = (m_verticalOverflow != verticalOverflow);
+if (horizontalOverflowChanged || verticalOverflowChanged) {
+m_horizontalOverflow = horizontalOverflow;
+m_verticalOverflow = verticalOverflow;
+if (FrameView* frameView = m_object->document()->view())
+frameView->scheduleEvent(new OverflowEvent(horizontalOverflowChanged, horizontalOverflow, verticalOverflowChanged, verticalOverflow),
+EventTargetNodeCast(m_object->element()), true);
+}
+}
+void
+RenderLayer::updateScrollInfoAfterLayout()
+{
+m_scrollDimensionsDirty = true;
+bool horizontalOverflow, verticalOverflow;
+computeScrollDimensions(&horizontalOverflow, &verticalOverflow);
+if (m_object->style()->overflowX() != OMARQUEE) {
+// Layout may cause us to be in an invalid scroll position.  In this case we need
+// to pull our scroll offsets back to the max (or push them up to the min).
+int newX = max(0, min(scrollXOffset(), scrollWidth() - m_object->clientWidth()));
+int newY = max(0, min(m_scrollY, scrollHeight() - m_object->clientHeight()));
+if (newX != scrollXOffset() || newY != m_scrollY) {
+RenderView* view = m_object->view();
+ASSERT(view);
+// scrollToOffset() may call updateLayerPositions(), which doesn't work
+// with LayoutState.
+// FIXME: Remove the disableLayoutState/enableLayoutState if the above changes.
+if (view)
+view->disableLayoutState();
+scrollToOffset(newX, newY);
+if (view)
+view->enableLayoutState();
+}
+}
+bool haveHorizontalBar = m_hBar;
+bool haveVerticalBar = m_vBar;
+// overflow:scroll should just enable/disable.
+if (m_object->style()->overflowX() == OSCROLL)
+m_hBar->setEnabled(horizontalOverflow);
+if (m_object->style()->overflowY() == OSCROLL)
+m_vBar->setEnabled(verticalOverflow);
+// A dynamic change from a scrolling overflow to overflow:hidden means we need to get rid of any
+// scrollbars that may be present.
+if (m_object->style()->overflowX() == OHIDDEN && haveHorizontalBar)
+setHasHorizontalScrollbar(false);
+if (m_object->style()->overflowY() == OHIDDEN && haveVerticalBar)
+setHasVerticalScrollbar(false);
+// overflow:auto may need to lay out again if scrollbars got added/removed.
+bool scrollbarsChanged = (m_object->hasAutoHorizontalScrollbar() && haveHorizontalBar != horizontalOverflow) ||
+(m_object->hasAutoVerticalScrollbar() && haveVerticalBar != verticalOverflow);
+if (scrollbarsChanged) {
+if (m_object->hasAutoHorizontalScrollbar())
+setHasHorizontalScrollbar(horizontalOverflow);
+if (m_object->hasAutoVerticalScrollbar())
+setHasVerticalScrollbar(verticalOverflow);
+// Force an update since we know the scrollbars have changed things.
+if (m_object->document()->hasDashboardRegions())
+m_object->document()->setDashboardRegionsDirty(true);
+m_object->repaint();
+if (m_object->style()->overflowX() == OAUTO || m_object->style()->overflowY() == OAUTO) {
+if (!m_inOverflowRelayout) {
+// Our proprietary overflow: overlay value doesn't trigger a layout.
+m_inOverflowRelayout = true;
+m_object->setNeedsLayout(true);
+if (m_object->isRenderBlock())
+static_cast<RenderBlock*>(m_object)->layoutBlock(true);
+else
+m_object->layout();
+m_inOverflowRelayout = false;
+}
+}
+}
+// If overflow:scroll is turned into overflow:auto a bar might still be disabled (Bug 11985).
+if (m_hBar && m_object->hasAutoHorizontalScrollbar())
+m_hBar->setEnabled(true);
+if (m_vBar && m_object->hasAutoVerticalScrollbar())
+m_vBar->setEnabled(true);
+// Set up the range (and page step/line step).
+if (m_hBar) {
+int clientWidth = m_object->clientWidth();
+int pageStep = (clientWidth-PAGE_KEEP);
+if (pageStep < 0) pageStep = clientWidth;
+m_hBar->setSteps(LINE_STEP, pageStep);
+m_hBar->setProportion(clientWidth, m_scrollWidth);
+m_hBar->setValue(scrollXOffset());
+}
+if (m_vBar) {
+int clientHeight = m_object->clientHeight();
+int pageStep = (clientHeight-PAGE_KEEP);
+if (pageStep < 0) pageStep = clientHeight;
+m_vBar->setSteps(LINE_STEP, pageStep);
+m_vBar->setProportion(clientHeight, m_scrollHeight);
+m_object->repaintRectangle(IntRect(m_object->borderLeft() + m_object->clientWidth(),
+m_object->borderTop(), verticalScrollbarWidth(),
+m_object->height() - m_object->borderTop() - m_object->borderBottom()));
+}
+if (m_object->element() && m_object->document()->hasListenerType(Document::OVERFLOWCHANGED_LISTENER))
+updateOverflowStatus(horizontalOverflow, verticalOverflow);
+}
+void RenderLayer::paintOverflowControls(GraphicsContext* p, int tx, int ty, const IntRect& damageRect)
+{
+// Don't do anything if we have no overflow.
+if (!m_object->hasOverflowClip())
+return;
+// Move the scrollbar widgets if necessary.  We normally move and resize widgets during layout, but sometimes
+// widgets can move without layout occurring (most notably when you scroll a document that
+// contains fixed positioned elements).
+positionOverflowControls();
+// Now that we're sure the scrollbars are in the right place, paint them.
+if (m_hBar)
+m_hBar->paint(p, damageRect);
+if (m_vBar)
+m_vBar->paint(p, damageRect);
+// We fill our scroll corner with white if we have a scrollbar that doesn't run all the way up to the
+// edge of the box.
+IntRect paddingBox(m_object->xPos() + m_object->borderLeft() + tx,
+m_object->yPos() + m_object->borderTop() + ty,
+m_object->width() - m_object->borderLeft() - m_object->borderRight(),
+m_object->height() - m_object->borderTop() - m_object->borderBottom());
+IntRect hCorner;
+if (m_hBar && paddingBox.width() - m_hBar->width() > 0) {
+hCorner = IntRect(paddingBox.x() + m_hBar->width(),
+paddingBox.y() + paddingBox.height() - m_hBar->height(),
+paddingBox.width() - m_hBar->width(),
+m_hBar->height());
+if (hCorner.intersects(damageRect))
+p->fillRect(hCorner, Color::white);
+}
+if (m_vBar && paddingBox.height() - m_vBar->height() > 0) {
+IntRect vCorner(paddingBox.x() + paddingBox.width() - m_vBar->width(),
+paddingBox.y() + m_vBar->height(),
+m_vBar->width(),
+paddingBox.height() - m_vBar->height());
+if (vCorner != hCorner && vCorner.intersects(damageRect))
+p->fillRect(vCorner, Color::white);
+}
+if (m_object->style()->resize() != RESIZE_NONE)  {
+IntRect absBounds(m_object->xPos() + tx, m_object->yPos() + ty, m_object->width(), m_object->height());
+IntRect scrollCorner = scrollCornerRect(m_object, absBounds);
+if (!scrollCorner.intersects(damageRect))
+return;
+// Paint the resizer control.
+static Image* resizeCornerImage;
+if (!resizeCornerImage)
+resizeCornerImage = Image::loadPlatformResource("textAreaResizeCorner");
+IntPoint imagePoint(scrollCorner.right() - resizeCornerImage->width(), scrollCorner.bottom() - resizeCornerImage->height());
+p->drawImage(resizeCornerImage, imagePoint);
+// Draw a frame around the resizer (1px grey line) if there are any scrollbars present.
+// Clipping will exclude the right and bottom edges of this frame.
+if (m_hBar || m_vBar) {
+p->save();
+scrollCorner.setSize(IntSize(scrollCorner.width() + 1, scrollCorner.height() + 1));
+p->setStrokeColor(Color(makeRGB(217, 217, 217)));
+p->setStrokeThickness(1.0f);
+p->setFillColor(Color::transparent);
+p->drawRect(scrollCorner);
+p->restore();
+}
+}
+}
+bool RenderLayer::isPointInResizeControl(const IntPoint& point)
+{
+if (!m_object->hasOverflowClip() || m_object->style()->resize() == RESIZE_NONE)
+return false;
+int x = 0;
+int y = 0;
+convertToLayerCoords(root(), x, y);
+IntRect absBounds(x, y, m_object->width(), m_object->height());
+return scrollCornerRect(m_object, absBounds).contains(point);
+}
+bool RenderLayer::hitTestOverflowControls(HitTestResult& result)
+{
+if (!m_hBar && !m_vBar && (!renderer()->hasOverflowClip() || renderer()->style()->resize() == RESIZE_NONE))
+return false;
+int x = 0;
+int y = 0;
+convertToLayerCoords(root(), x, y);
+IntRect absBounds(x, y, renderer()->width(), renderer()->height());
+IntRect resizeControlRect;
+if (renderer()->style()->resize() != RESIZE_NONE) {
+resizeControlRect = scrollCornerRect(renderer(), absBounds);
+if (resizeControlRect.contains(result.point()))
+return true;
+}
+int resizeControlSize = max(resizeControlRect.height(), 0);
+if (m_vBar) {
+IntRect vBarRect(absBounds.right() - renderer()->borderRight() - m_vBar->width(), absBounds.y() + renderer()->borderTop(), m_vBar->width(), absBounds.height() - (renderer()->borderTop() + renderer()->borderBottom()) - (m_hBar ? m_hBar->height() : resizeControlSize));
+if (vBarRect.contains(result.point())) {
+result.setScrollbar(verticalScrollbarWidget());
+return true;
+}
+}
+resizeControlSize = max(resizeControlRect.width(), 0);
+if (m_hBar) {
+IntRect hBarRect(absBounds.x() + renderer()->borderLeft(), absBounds.bottom() - renderer()->borderBottom() - m_hBar->height(), absBounds.width() - (renderer()->borderLeft() + renderer()->borderRight()) - (m_vBar ? m_vBar->width() : resizeControlSize), m_hBar->height());
+if (hBarRect.contains(result.point())) {
+result.setScrollbar(horizontalScrollbarWidget());
+return true;
+}
+}
+return false;
+}
+bool RenderLayer::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier)
+{
+bool didHorizontalScroll = false;
+bool didVerticalScroll = false;
+if (m_hBar) {
+if (granularity == ScrollByDocument) {
+// Special-case for the ScrollByDocument granularity. A document scroll can only be up
+// or down and in both cases the horizontal bar goes all the way to the left.
+didHorizontalScroll = m_hBar->scroll(ScrollLeft, ScrollByDocument, multiplier);
+} else
+didHorizontalScroll = m_hBar->scroll(direction, granularity, multiplier);
+}
+if (m_vBar)
+didVerticalScroll = m_vBar->scroll(direction, granularity, multiplier);
+return (didHorizontalScroll || didVerticalScroll);
+}
+void
+RenderLayer::paint(GraphicsContext* p, const IntRect& damageRect, PaintRestriction paintRestriction, RenderObject *paintingRoot)
+{
+paintLayer(this, p, damageRect, false, paintRestriction, paintingRoot);
+}
+static void setClip(GraphicsContext* p, const IntRect& paintDirtyRect, const IntRect& clipRect)
+{
+// Work around bugs in focus ring clipping on Mac.
+p->setFocusRingClip(clipRect);
+if (paintDirtyRect == clipRect)
+return;
+p->save();
+p->clip(clipRect);
+}
+static void restoreClip(GraphicsContext* p, const IntRect& paintDirtyRect, const IntRect& clipRect)
+{
+// Work around bugs in focus ring clipping on Mac.
+p->clearFocusRingClip();
+if (paintDirtyRect == clipRect)
+return;
+p->restore();
+}
+void
+RenderLayer::paintLayer(RenderLayer* rootLayer, GraphicsContext* p,
+const IntRect& paintDirtyRect, bool haveTransparency, PaintRestriction paintRestriction,
+RenderObject *paintingRoot)
+{
+// Avoid painting layers when stylesheets haven't loaded.  This eliminates FOUC.
+// It's ok not to draw, because later on, when all the stylesheets do load, updateStyleSelector on the Document
+// will do a full repaint().
+if (renderer()->document()->didLayoutWithPendingStylesheets() && !renderer()->isRenderView() && !renderer()->isRoot())
+return;
+// Calculate the clip rects we should use.
+IntRect layerBounds, damageRect, clipRectToApply, outlineRect;
+calculateRects(rootLayer, paintDirtyRect, layerBounds, damageRect, clipRectToApply, outlineRect);
+int x = layerBounds.x();
+int y = layerBounds.y();
+int tx = x - renderer()->xPos();
+int ty = y - renderer()->yPos() + renderer()->borderTopExtra();
+// Ensure our lists are up-to-date.
+updateZOrderLists();
+updateOverflowList();
+// If this layer is totally invisible then there is nothing to paint.
+if (!m_object->opacity())
+return;
+bool selectionOnly = paintRestriction == PaintRestrictionSelectionOnly || paintRestriction == PaintRestrictionSelectionOnlyBlackText;
+bool forceBlackText = paintRestriction == PaintRestrictionSelectionOnlyBlackText;
+if (isTransparent())
+haveTransparency = true;
+// If this layer's renderer is a child of the paintingRoot, we render unconditionally, which
+// is done by passing a nil paintingRoot down to our renderer (as if no paintingRoot was ever set).
+// Else, our renderer tree may or may not contain the painting root, so we pass that root along
+// so it will be tested against as we decend through the renderers.
+RenderObject *paintingRootForRenderer = 0;
+if (paintingRoot && !m_object->isDescendantOf(paintingRoot))
+paintingRootForRenderer = paintingRoot;
+// We want to paint our layer, but only if we intersect the damage rect.
+bool shouldPaint = intersectsDamageRect(layerBounds, damageRect) && m_hasVisibleContent;
+if (shouldPaint && !selectionOnly && !damageRect.isEmpty()) {
+// Begin transparency layers lazily now that we know we have to paint something.
+if (haveTransparency)
+beginTransparencyLayers(p, paintDirtyRect);
+// Paint our background first, before painting any child layers.
+// Establish the clip used to paint our background.
+setClip(p, paintDirtyRect, damageRect);
+// Paint the background.
+RenderObject::PaintInfo paintInfo(p, damageRect, PaintPhaseBlockBackground, false, paintingRootForRenderer, 0);
+renderer()->paint(paintInfo, tx, ty);
+// Our scrollbar widgets paint exactly when we tell them to, so that they work properly with
+// z-index.  We paint after we painted the background/border, so that the scrollbars will
+// sit above the background/border.
+paintOverflowControls(p, tx, ty, damageRect);
+// Restore the clip.
+restoreClip(p, paintDirtyRect, damageRect);
+}
+// Now walk the sorted list of children with negative z-indices.
+if (m_negZOrderList)
+for (Vector<RenderLayer*>::iterator it = m_negZOrderList->begin(); it != m_negZOrderList->end(); ++it)
+it[0]->paintLayer(rootLayer, p, paintDirtyRect, haveTransparency, paintRestriction, paintingRoot);
+// Now establish the appropriate clip and paint our child RenderObjects.
+if (shouldPaint && !clipRectToApply.isEmpty()) {
+// Begin transparency layers lazily now that we know we have to paint something.
+if (haveTransparency)
+beginTransparencyLayers(p, paintDirtyRect);
+// Set up the clip used when painting our children.
+setClip(p, paintDirtyRect, clipRectToApply);
+RenderObject::PaintInfo paintInfo(p, clipRectToApply,
+selectionOnly ? PaintPhaseSelection : PaintPhaseChildBlockBackgrounds,
+forceBlackText, paintingRootForRenderer, 0);
+renderer()->paint(paintInfo, tx, ty);
+if (!selectionOnly) {
+paintInfo.phase = PaintPhaseFloat;
+renderer()->paint(paintInfo, tx, ty);
+paintInfo.phase = PaintPhaseForeground;
+renderer()->paint(paintInfo, tx, ty);
+paintInfo.phase = PaintPhaseChildOutlines;
+renderer()->paint(paintInfo, tx, ty);
+}
+// Now restore our clip.
+restoreClip(p, paintDirtyRect, clipRectToApply);
+}
+if (!outlineRect.isEmpty()) {
+// Paint our own outline
+RenderObject::PaintInfo paintInfo(p, outlineRect, PaintPhaseSelfOutline, false, paintingRootForRenderer, 0);
+setClip(p, paintDirtyRect, outlineRect);
+renderer()->paint(paintInfo, tx, ty);
+restoreClip(p, paintDirtyRect, outlineRect);
+}
+// Paint any child layers that have overflow.
+if (m_overflowList)
+for (Vector<RenderLayer*>::iterator it = m_overflowList->begin(); it != m_overflowList->end(); ++it)
+it[0]->paintLayer(rootLayer, p, paintDirtyRect, haveTransparency, paintRestriction, paintingRoot);
+// Now walk the sorted list of children with positive z-indices.
+if (m_posZOrderList)
+for (Vector<RenderLayer*>::iterator it = m_posZOrderList->begin(); it != m_posZOrderList->end(); ++it)
+it[0]->paintLayer(rootLayer, p, paintDirtyRect, haveTransparency, paintRestriction, paintingRoot);
+// End our transparency layer
+if (isTransparent() && m_usedTransparency) {
+p->endTransparencyLayer();
+p->restore();
+m_usedTransparency = false;
+}
+}
+static inline IntRect frameVisibleRect(RenderObject* renderer)
+{
+FrameView* frameView = renderer->document()->view();
+if (!frameView)
+return IntRect();
+return enclosingIntRect(frameView->visibleContentRect());
+}
+bool RenderLayer::hitTest(const HitTestRequest& request, HitTestResult& result)
+{
+renderer()->document()->updateLayout();
+IntRect boundsRect(m_x, m_y, width(), height());
+boundsRect.intersect(frameVisibleRect(renderer()));
+RenderLayer* insideLayer = hitTestLayer(this, request, result, boundsRect);
+// Now determine if the result is inside an anchor; make sure an image map wins if
+// it already set URLElement and only use the innermost.
+Node* node = result.innerNode();
+while (node) {
+// for imagemaps, URLElement is the associated area element not the image itself
+if (node->isLink() && !result.URLElement() && !node->hasTagName(imgTag))
+result.setURLElement(static_cast<Element*>(node));
+node = node->parentNode();
+}
+// Next set up the correct :hover/:active state along the new chain.
+updateHoverActiveState(request, result);
+// Now return whether we were inside this layer (this will always be true for the root
+// layer).
+return insideLayer;
+}
+Node* RenderLayer::enclosingElement() const
+{
+for (RenderObject* r = renderer(); r; r = r->parent()) {
+if (Node* e = r->element())
+return e;
+}
+ASSERT_NOT_REACHED();
+return 0;
+}
+RenderLayer* RenderLayer::hitTestLayer(RenderLayer* rootLayer, const HitTestRequest& request,
+HitTestResult& result, const IntRect& hitTestRect)
+{
+// Calculate the clip rects we should use.
+IntRect layerBounds;
+IntRect bgRect;
+IntRect fgRect;
+IntRect outlineRect;
+calculateRects(rootLayer, hitTestRect, layerBounds, bgRect, fgRect, outlineRect);
+// Ensure our lists are up-to-date.
+updateZOrderLists();
+updateOverflowList();
+// This variable tracks which layer the mouse ends up being inside.  The minute we find an insideLayer,
+// we are done and can return it.
+RenderLayer* insideLayer = 0;
+// Begin by walking our list of positive layers from highest z-index down to the lowest
+// z-index.
+if (m_posZOrderList) {
+for (int i = m_posZOrderList->size() - 1; i >= 0; --i) {
+insideLayer = m_posZOrderList->at(i)->hitTestLayer(rootLayer, request, result, hitTestRect);
+if (insideLayer)
+return insideLayer;
+}
+}
+// Now check our overflow objects.
+if (m_overflowList) {
+for (int i = m_overflowList->size() - 1; i >= 0; --i) {
+insideLayer = m_overflowList->at(i)->hitTestLayer(rootLayer, request, result, hitTestRect);
+if (insideLayer)
+return insideLayer;
+}
+}
+// Next we want to see if the mouse pos is inside the child RenderObjects of the layer.
+if (fgRect.contains(result.point()) &&
+renderer()->hitTest(request, result, result.point().x(), result.point().y(),
+layerBounds.x() - renderer()->xPos(),
+layerBounds.y() - renderer()->yPos() + m_object->borderTopExtra(),
+HitTestDescendants)) {
+// For positioned generated content, we might still not have a
+// node by the time we get to the layer level, since none of
+// the content in the layer has an element. So just walk up
+// the tree.
+if (!result.innerNode() || !result.innerNonSharedNode()) {
+Node* e = enclosingElement();
+if (!result.innerNode())
+result.setInnerNode(e);
+if (!result.innerNonSharedNode())
+result.setInnerNonSharedNode(e);
+}
+return this;
+}
+// Now check our negative z-index children.
+if (m_negZOrderList) {
+for (int i = m_negZOrderList->size() - 1; i >= 0; --i) {
+insideLayer = m_negZOrderList->at(i)->hitTestLayer(rootLayer, request, result, hitTestRect);
+if (insideLayer)
+return insideLayer;
+}
+}
+// Next we want to see if the mouse is inside this layer but not any of its children.
+if (bgRect.contains(result.point()) &&
+renderer()->hitTest(request, result, result.point().x(), result.point().y(),
+layerBounds.x() - renderer()->xPos(),
+layerBounds.y() - renderer()->yPos() + m_object->borderTopExtra(),
+HitTestSelf)) {
+if (!result.innerNode() || !result.innerNonSharedNode()) {
+Node* e = enclosingElement();
+if (!result.innerNode())
+result.setInnerNode(e);
+if (!result.innerNonSharedNode())
+result.setInnerNonSharedNode(e);
+}
+return this;
+}
+// We didn't hit any layer. If we are the root layer and the mouse is -- or just was -- down,
+// return ourselves. We do this so mouse events continue getting delivered after a drag has
+// exited the WebView, and so hit testing over a scrollbar hits the content document.
+if ((request.active || request.mouseUp) && renderer()->isRenderView()) {
+renderer()->updateHitTestResult(result, result.point());
+return this;
+}
+return 0;
+}
+void RenderLayer::calculateClipRects(const RenderLayer* rootLayer)
+{
+if (m_clipRects)
+return; // We have the correct cached value.
+if (!parent()) {
+// The root layer's clip rect is always just its dimensions.
+m_clipRects = new (m_object->renderArena()) ClipRects(IntRect(0,0,width(),height()));
+m_clipRects->ref();
+return;
+}
+// Ensure that our parent's clip has been calculated so that we can examine the values.
+parent()->calculateClipRects(rootLayer);
+// Set up our three rects to initially match the parent rects.
+IntRect posClipRect(parent()->clipRects()->posClipRect());
+IntRect overflowClipRect(parent()->clipRects()->overflowClipRect());
+IntRect fixedClipRect(parent()->clipRects()->fixedClipRect());
+bool fixed = parent()->clipRects()->fixed();
+// A fixed object is essentially the root of its containing block hierarchy, so when
+// we encounter such an object, we reset our clip rects to the fixedClipRect.
+if (m_object->style()->position() == FixedPosition) {
+posClipRect = fixedClipRect;
+overflowClipRect = fixedClipRect;
+fixed = true;
+}
+else if (m_object->style()->position() == RelativePosition)
+posClipRect = overflowClipRect;
+else if (m_object->style()->position() == AbsolutePosition)
+overflowClipRect = posClipRect;
+// Update the clip rects that will be passed to child layers.
+if (m_object->hasOverflowClip() || m_object->hasClip()) {
+// This layer establishes a clip of some kind.
+int x = 0;
+int y = 0;
+convertToLayerCoords(rootLayer, x, y);
+RenderView* view = renderer()->view();
+ASSERT(view);
+if (view && fixed) {
+x -= view->frameView()->contentsX();
+y -= view->frameView()->contentsY();
+}
+if (m_object->hasOverflowClip()) {
+IntRect newOverflowClip = m_object->getOverflowClipRect(x,y);
+overflowClipRect.intersect(newOverflowClip);
+if (m_object->isPositioned() || m_object->isRelPositioned())
+posClipRect.intersect(newOverflowClip);
+}
+if (m_object->hasClip()) {
+IntRect newPosClip = m_object->getClipRect(x,y);
+posClipRect.intersect(newPosClip);
+overflowClipRect.intersect(newPosClip);
+fixedClipRect.intersect(newPosClip);
+}
+}
+// If our clip rects match our parent's clip, then we can just share its data structure and
+// ref count.
+if (fixed == parent()->clipRects()->fixed() &&
+posClipRect == parent()->clipRects()->posClipRect() &&
+overflowClipRect == parent()->clipRects()->overflowClipRect() &&
+fixedClipRect == parent()->clipRects()->fixedClipRect())
+m_clipRects = parent()->clipRects();
+else
+m_clipRects = new (m_object->renderArena()) ClipRects(overflowClipRect, fixedClipRect, posClipRect, fixed);
+m_clipRects->ref();
+}
+void RenderLayer::calculateRects(const RenderLayer* rootLayer, const IntRect& paintDirtyRect, IntRect& layerBounds,
+IntRect& backgroundRect, IntRect& foregroundRect, IntRect& outlineRect) const
+{
+if (parent()) {
+parent()->calculateClipRects(rootLayer);
+backgroundRect = m_object->style()->position() == FixedPosition ? parent()->clipRects()->fixedClipRect() :
+(m_object->isPositioned() ? parent()->clipRects()->posClipRect() :
+parent()->clipRects()->overflowClipRect());
+RenderView* view = renderer()->view();
+ASSERT(view);
+if (view && parent()->clipRects()->fixed())
+backgroundRect.move(view->frameView()->contentsX(), view->frameView()->contentsY());
+backgroundRect.intersect(paintDirtyRect);
+} else
+backgroundRect = paintDirtyRect;
+foregroundRect = backgroundRect;
+outlineRect = backgroundRect;
+int x = 0;
+int y = 0;
+convertToLayerCoords(rootLayer, x, y);
+layerBounds = IntRect(x,y,width(),height());
+// Update the clip rects that will be passed to child layers.
+if (m_object->hasOverflowClip() || m_object->hasClip()) {
+// This layer establishes a clip of some kind.
+if (m_object->hasOverflowClip())
+foregroundRect.intersect(m_object->getOverflowClipRect(x,y));
+if (m_object->hasClip()) {
+// Clip applies to *us* as well, so go ahead and update the damageRect.
+IntRect newPosClip = m_object->getClipRect(x,y);
+backgroundRect.intersect(newPosClip);
+foregroundRect.intersect(newPosClip);
+outlineRect.intersect(newPosClip);
+}
+// If we establish a clip at all, then go ahead and make sure our background
+// rect is intersected with our layer's bounds.
+if (ShadowData* boxShadow = renderer()->style()->boxShadow()) {
+IntRect shadowRect = layerBounds;
+shadowRect.move(boxShadow->x, boxShadow->y);
+shadowRect.inflate(boxShadow->blur);
+shadowRect.unite(layerBounds);
+backgroundRect.intersect(shadowRect);
+} else
+backgroundRect.intersect(layerBounds);
+}
+}
+IntRect RenderLayer::childrenClipRect() const
+{
+RenderLayer* rootLayer = renderer()->document()->renderer()->layer();
+IntRect layerBounds, backgroundRect, foregroundRect, outlineRect;
+calculateRects(rootLayer, rootLayer->absoluteBoundingBox(), layerBounds, backgroundRect, foregroundRect, outlineRect);
+return foregroundRect;
+}
+IntRect RenderLayer::selfClipRect() const
+{
+RenderLayer* rootLayer = renderer()->document()->renderer()->layer();
+IntRect layerBounds, backgroundRect, foregroundRect, outlineRect;
+calculateRects(rootLayer, rootLayer->absoluteBoundingBox(), layerBounds, backgroundRect, foregroundRect, outlineRect);
+return backgroundRect;
+}
+bool RenderLayer::intersectsDamageRect(const IntRect& layerBounds, const IntRect& damageRect) const
+{
+// Always examine the canvas and the root.
+// FIXME: Could eliminate the isRoot() check if we fix background painting so that the RenderView
+// paints the root's background.
+if (renderer()->isRenderView() || renderer()->isRoot())
+return true;
+// If we aren't an inline flow, and our layer bounds do intersect the damage rect, then we
+// can go ahead and return true.
+RenderView* view = renderer()->view();
+ASSERT(view);
+if (view && !renderer()->isInlineFlow()) {
+IntRect b = layerBounds;
+b.inflate(view->maximalOutlineSize());
+if (b.intersects(damageRect))
+return true;
+}
+// Otherwise we need to compute the bounding box of this single layer and see if it intersects
+// the damage rect.
+return absoluteBoundingBox().intersects(damageRect);
+}
+IntRect RenderLayer::absoluteBoundingBox() const
+{
+// There are three special cases we need to consider.
+// (1) Inline Flows.  For inline flows we will create a bounding box that fully encompasses all of the lines occupied by the
+// inline.  In other words, if some <span> wraps to three lines, we'll create a bounding box that fully encloses the root
+// line boxes of all three lines (including overflow on those lines).
+// (2) Left/Top Overflow.  The width/height of layers already includes right/bottom overflow.  However, in the case of left/top
+// overflow, we have to create a bounding box that will extend to include this overflow.
+// (3) Floats.  When a layer has overhanging floats that it paints, we need to make sure to include these overhanging floats
+// as part of our bounding box.  We do this because we are the responsible layer for both hit testing and painting those
+// floats.
+IntRect result;
+if (renderer()->isInlineFlow()) {
+// Go from our first line box to our last line box.
+RenderInline* inlineFlow = static_cast<RenderInline*>(renderer());
+InlineFlowBox* firstBox = inlineFlow->firstLineBox();
+if (!firstBox)
+return result;
+int top = firstBox->root()->topOverflow();
+int bottom = inlineFlow->lastLineBox()->root()->bottomOverflow();
+int left = firstBox->xPos();
+for (InlineRunBox* curr = firstBox->nextLineBox(); curr; curr = curr->nextLineBox())
+left = min(left, curr->xPos());
+result = IntRect(m_x + left, m_y + (top - renderer()->yPos()), width(), bottom - top);
+} else if (renderer()->isTableRow()) {
+// Our bounding box is just the union of all of our cells' border/overflow rects.
+for (RenderObject* child = renderer()->firstChild(); child; child = child->nextSibling()) {
+if (child->isTableCell()) {
+IntRect bbox = child->borderBox();
+bbox.move(0, child->borderTopExtra());
+result.unite(bbox);
+IntRect overflowRect = renderer()->overflowRect(false);
+overflowRect.move(0, child->borderTopExtra());
+if (bbox != overflowRect)
+result.unite(overflowRect);
+}
+}
+result.move(m_x, m_y);
+} else {
+IntRect bbox = renderer()->borderBox();
+result = bbox;
+IntRect overflowRect = renderer()->overflowRect(false);
+if (bbox != overflowRect)
+result.unite(overflowRect);
+// We have to adjust the x/y of this result so that it is in the coordinate space of the layer.
+// We also have to add in borderTopExtra here, since borderBox(), in order to play well with methods like
+// floatRect that deal with child content, uses an origin of (0,0) that is at the child content box (so
+// border box returns a y coord of -borderTopExtra().  The layer, however, uses the outer box.  This is all
+// really confusing.
+result.move(m_x, m_y + renderer()->borderTopExtra());
+}
+// Convert the bounding box to an absolute position.  We can do this easily by looking at the delta
+// between the bounding box's xpos and our layer's xpos and then applying that to the absolute layerBounds
+// passed in.
+int absX = 0, absY = 0;
+convertToLayerCoords(root(), absX, absY);
+result.move(absX - m_x, absY - m_y);
+RenderView* view = renderer()->view();
+ASSERT(view);
+if (view)
+result.inflate(view->maximalOutlineSize());
+return result;
+}
+void RenderLayer::clearClipRects()
+{
+if (!m_clipRects)
+return;
+clearClipRect();
+for (RenderLayer* l = firstChild(); l; l = l->nextSibling())
+l->clearClipRects();
+}
+void RenderLayer::clearClipRect()
+{
+if (m_clipRects) {
+m_clipRects->deref(m_object->renderArena());
+m_clipRects = 0;
+}
+}
+static RenderObject* commonAncestor(RenderObject* obj1, RenderObject* obj2)
+{
+if (!obj1 || !obj2)
+return 0;
+for (RenderObject* currObj1 = obj1; currObj1; currObj1 = currObj1->hoverAncestor())
+for (RenderObject* currObj2 = obj2; currObj2; currObj2 = currObj2->hoverAncestor())
+if (currObj1 == currObj2)
+return currObj1;
+return 0;
+}
+void RenderLayer::updateHoverActiveState(const HitTestRequest& request, HitTestResult& result)
+{
+// We don't update :hover/:active state when the result is marked as readonly.
+if (request.readonly)
+return;
+Document* doc = renderer()->document();
+Node* activeNode = doc->activeNode();
+if (activeNode && !request.active) {
+// We are clearing the :active chain because the mouse has been released.
+for (RenderObject* curr = activeNode->renderer(); curr; curr = curr->parent()) {
+if (curr->element() && !curr->isText())
+curr->element()->setInActiveChain(false);
+}
+doc->setActiveNode(0);
+} else {
+Node* newActiveNode = result.innerNode();
+if (!activeNode && newActiveNode && request.active) {
+// We are setting the :active chain and freezing it. If future moves happen, they
+// will need to reference this chain.
+for (RenderObject* curr = newActiveNode->renderer(); curr; curr = curr->parent()) {
+if (curr->element() && !curr->isText()) {
+curr->element()->setInActiveChain(true);
+}
+}
+doc->setActiveNode(newActiveNode);
+}
+}
+// If the mouse is down and if this is a mouse move event, we want to restrict changes in
+// :hover/:active to only apply to elements that are in the :active chain that we froze
+// at the time the mouse went down.
+bool mustBeInActiveChain = request.active && request.mouseMove;
+// Check to see if the hovered node has changed.  If not, then we don't need to
+// do anything.
+RefPtr<Node> oldHoverNode = doc->hoverNode();
+Node* newHoverNode = result.innerNode();
+// Update our current hover node.
+doc->setHoverNode(newHoverNode);
+// We have two different objects.  Fetch their renderers.
+RenderObject* oldHoverObj = oldHoverNode ? oldHoverNode->renderer() : 0;
+RenderObject* newHoverObj = newHoverNode ? newHoverNode->renderer() : 0;
+// Locate the common ancestor render object for the two renderers.
+RenderObject* ancestor = commonAncestor(oldHoverObj, newHoverObj);
+if (oldHoverObj != newHoverObj) {
+// The old hover path only needs to be cleared up to (and not including) the common ancestor;
+for (RenderObject* curr = oldHoverObj; curr && curr != ancestor; curr = curr->hoverAncestor()) {
+if (curr->element() && !curr->isText() && (!mustBeInActiveChain || curr->element()->inActiveChain())) {
+curr->element()->setActive(false);
+curr->element()->setHovered(false);
+}
+}
+}
+// Now set the hover state for our new object up to the root.
+for (RenderObject* curr = newHoverObj; curr; curr = curr->hoverAncestor()) {
+if (curr->element() && !curr->isText() && (!mustBeInActiveChain || curr->element()->inActiveChain())) {
+curr->element()->setActive(request.active);
+curr->element()->setHovered(true);
+}
+}
+}
+// Helper for the sorting of layers by z-index.
+static inline bool compareZIndex(RenderLayer* first, RenderLayer* second)
+{
+return first->zIndex() < second->zIndex();
+}
+void RenderLayer::dirtyZOrderLists()
+{
+if (m_posZOrderList)
+m_posZOrderList->clear();
+if (m_negZOrderList)
+m_negZOrderList->clear();
+m_zOrderListsDirty = true;
+}
+void RenderLayer::dirtyOverflowList()
+{
+if (m_overflowList)
+m_overflowList->clear();
+m_overflowListDirty = true;
+}
+void RenderLayer::updateZOrderLists()
+{
+if (!isStackingContext() || !m_zOrderListsDirty)
+return;
+for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
+child->collectLayers(m_posZOrderList, m_negZOrderList);
+// Sort the two lists.
+if (m_posZOrderList)
+std::stable_sort(m_posZOrderList->begin(), m_posZOrderList->end(), compareZIndex);
+if (m_negZOrderList)
+std::stable_sort(m_negZOrderList->begin(), m_negZOrderList->end(), compareZIndex);
+m_zOrderListsDirty = false;
+}
+void RenderLayer::updateOverflowList()
+{
+if (!m_overflowListDirty)
+return;
+for (RenderLayer* child = firstChild(); child; child = child->nextSibling()) {
+if (child->isOverflowOnly()) {
+if (!m_overflowList)
+m_overflowList = new Vector<RenderLayer*>;
+m_overflowList->append(child);
+}
+}
+m_overflowListDirty = false;
+}
+void RenderLayer::collectLayers(Vector<RenderLayer*>*& posBuffer, Vector<RenderLayer*>*& negBuffer)
+{
+updateVisibilityStatus();
+// Overflow layers are just painted by their enclosing layers, so they don't get put in zorder lists.
+if (m_hasVisibleContent && !isOverflowOnly()) {
+// Determine which buffer the child should be in.
+Vector<RenderLayer*>*& buffer = (zIndex() >= 0) ? posBuffer : negBuffer;
+// Create the buffer if it doesn't exist yet.
+if (!buffer)
+buffer = new Vector<RenderLayer*>;
+// Append ourselves at the end of the appropriate buffer.
+buffer->append(this);
+}
+// Recur into our children to collect more layers, but only if we don't establish
+// a stacking context.
+if (m_hasVisibleDescendant && !isStackingContext())
+for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
+child->collectLayers(posBuffer, negBuffer);
+}
+void RenderLayer::repaintIncludingDescendants()
+{
+m_object->repaint();
+for (RenderLayer* curr = firstChild(); curr; curr = curr->nextSibling())
+curr->repaintIncludingDescendants();
+}
+bool RenderLayer::shouldBeOverflowOnly() const
+{
+return renderer()->hasOverflowClip() &&
+!renderer()->isPositioned() &&
+!renderer()->isRelPositioned() &&
+!isTransparent();
+}
+void RenderLayer::styleChanged()
+{
+bool isOverflowOnly = shouldBeOverflowOnly();
+if (isOverflowOnly != m_isOverflowOnly) {
+m_isOverflowOnly = isOverflowOnly;
+RenderLayer* p = parent();
+RenderLayer* sc = stackingContext();
+if (p)
+p->dirtyOverflowList();
+if (sc)
+sc->dirtyZOrderLists();
+}
+if (m_object->style()->overflowX() == OMARQUEE && m_object->style()->marqueeBehavior() != MNONE) {
+if (!m_marquee)
+m_marquee = new Marquee(this);
+m_marquee->updateMarqueeStyle();
+}
+else if (m_marquee) {
+delete m_marquee;
+m_marquee = 0;
+}
+}
+void RenderLayer::suspendMarquees()
+{
+if (m_marquee)
+m_marquee->suspend();
+for (RenderLayer* curr = firstChild(); curr; curr = curr->nextSibling())
+curr->suspendMarquees();
+}
+// --------------------------------------------------------------------------
+// Marquee implementation
+Marquee::Marquee(RenderLayer* l)
+: m_layer(l), m_currentLoop(0)
+, m_totalLoops(0)
+, m_timer(this, &Marquee::timerFired)
+, m_start(0), m_end(0), m_speed(0), m_reset(false)
+, m_suspended(false), m_stopped(false), m_direction(MAUTO)
+{
+}
+int Marquee::marqueeSpeed() const
+{
+int result = m_layer->renderer()->style()->marqueeSpeed();
+Node* elt = m_layer->renderer()->element();
+if (elt && elt->hasTagName(marqueeTag)) {
+HTMLMarqueeElement* marqueeElt = static_cast<HTMLMarqueeElement*>(elt);
+result = max(result, marqueeElt->minimumDelay());
+}
+return result;
+}
+EMarqueeDirection Marquee::direction() const
+{
+// FIXME: Support the CSS3 "auto" value for determining the direction of the marquee.
+// For now just map MAUTO to MBACKWARD
+EMarqueeDirection result = m_layer->renderer()->style()->marqueeDirection();
+TextDirection dir = m_layer->renderer()->style()->direction();
+if (result == MAUTO)
+result = MBACKWARD;
+if (result == MFORWARD)
+result = (dir == LTR) ? MRIGHT : MLEFT;
+if (result == MBACKWARD)
+result = (dir == LTR) ? MLEFT : MRIGHT;
+// Now we have the real direction.  Next we check to see if the increment is negative.
+// If so, then we reverse the direction.
+Length increment = m_layer->renderer()->style()->marqueeIncrement();
+if (increment.isNegative())
+result = static_cast<EMarqueeDirection>(-result);
+return result;
+}
+bool Marquee::isHorizontal() const
+{
+return direction() == MLEFT || direction() == MRIGHT;
+}
+int Marquee::computePosition(EMarqueeDirection dir, bool stopAtContentEdge)
+{
+RenderObject* o = m_layer->renderer();
+RenderStyle* s = o->style();
+if (isHorizontal()) {
+bool ltr = s->direction() == LTR;
+int clientWidth = o->clientWidth();
+int contentWidth = ltr ? o->rightmostPosition(true, false) : o->leftmostPosition(true, false);
+if (ltr)
+contentWidth += (o->paddingRight() - o->borderLeft());
+else {
+contentWidth = o->width() - contentWidth;
+contentWidth += (o->paddingLeft() - o->borderRight());
+}
+if (dir == MRIGHT) {
+if (stopAtContentEdge)
+return max(0, ltr ? (contentWidth - clientWidth) : (clientWidth - contentWidth));
+else
+return ltr ? contentWidth : clientWidth;
+}
+else {
+if (stopAtContentEdge)
+return min(0, ltr ? (contentWidth - clientWidth) : (clientWidth - contentWidth));
+else
+return ltr ? -clientWidth : -contentWidth;
+}
+}
+else {
+int contentHeight = m_layer->renderer()->lowestPosition(true, false) -
+m_layer->renderer()->borderTop() + m_layer->renderer()->paddingBottom();
+int clientHeight = m_layer->renderer()->clientHeight();
+if (dir == MUP) {
+if (stopAtContentEdge)
+return min(contentHeight - clientHeight, 0);
+else
+return -clientHeight;
+}
+else {
+if (stopAtContentEdge)
+return max(contentHeight - clientHeight, 0);
+else
+return contentHeight;
+}
+}
+}
+void Marquee::start()
+{
+if (m_timer.isActive() || m_layer->renderer()->style()->marqueeIncrement().isZero())
+return;
+// We may end up propagating a scroll event. It is important that we suspend events until
+// the end of the function since they could delete the layer, including the marquee.
+FrameView* frameView = m_layer->renderer()->document()->view();
+if (frameView)
+frameView->pauseScheduledEvents();
+if (!m_suspended && !m_stopped) {
+if (isHorizontal())
+m_layer->scrollToOffset(m_start, 0, false, false);
+else
+m_layer->scrollToOffset(0, m_start, false, false);
+}
+else {
+m_suspended = false;
+m_stopped = false;
+}
+m_timer.startRepeating(speed() * 0.001);
+if (frameView)
+frameView->resumeScheduledEvents();
+}
+void Marquee::suspend()
+{
+m_timer.stop();
+m_suspended = true;
+}
+void Marquee::stop()
+{
+m_timer.stop();
+m_stopped = true;
+}
+void Marquee::updateMarqueePosition()
+{
+bool activate = (m_totalLoops <= 0 || m_currentLoop < m_totalLoops);
+#if PLATFORM(SYMBIAN)
+// wap-marquee requests loop 0 as inactive marquee
+if (m_totalLoops == 0 && m_layer->renderer()->style()->display() == WAP_MARQUEE)
+activate = false;
+#endif
+if (activate) {
+EMarqueeBehavior behavior = m_layer->renderer()->style()->marqueeBehavior();
+m_start = computePosition(direction(), behavior == MALTERNATE);
+m_end = computePosition(reverseDirection(), behavior == MALTERNATE || behavior == MSLIDE);
+if (!m_stopped)
+start();
+}
+}
+void Marquee::updateMarqueeStyle()
+{
+RenderStyle* s = m_layer->renderer()->style();
+if (m_direction != s->marqueeDirection() || (m_totalLoops != s->marqueeLoopCount() && m_currentLoop >= m_totalLoops))
+m_currentLoop = 0; // When direction changes or our loopCount is a smaller number than our current loop, reset our loop.
+m_totalLoops = s->marqueeLoopCount();
+m_direction = s->marqueeDirection();
+if (m_layer->renderer()->isHTMLMarquee()) {
+// Hack for WinIE.  In WinIE, a value of 0 or lower for the loop count for SLIDE means to only do
+// one loop.
+if (m_totalLoops <= 0 && s->marqueeBehavior() == MSLIDE)
+m_totalLoops = 1;
+// Hack alert: Set the white-space value to nowrap for horizontal marquees with inline children, thus ensuring
+// all the text ends up on one line by default.  Limit this hack to the <marquee> element to emulate
+// WinIE's behavior.  Someone using CSS3 can use white-space: nowrap on their own to get this effect.
+// Second hack alert: Set the text-align back to auto.  WinIE completely ignores text-align on the
+// marquee element.
+// FIXME: Bring these up with the CSS WG.
+if (isHorizontal() && m_layer->renderer()->childrenInline()) {
+s->setWhiteSpace(NOWRAP);
+s->setTextAlign(TAAUTO);
+}
+}
+// Marquee height hack!! Make sure that, if it is a horizontal marquee, the height attribute is overridden
+// if it is smaller than the font size. If it is a vertical marquee and height is not specified, we default
+// to a marquee of 200px.
+if (isHorizontal()) {
+if (s->height().isFixed() && s->height().value() < s->fontSize())
+s->setHeight(Length(s->fontSize(),Fixed));
+} else if (s->height().isAuto())  //vertical marquee with no specified height
+s->setHeight(Length(200, Fixed));
+if (speed() != marqueeSpeed()) {
+m_speed = marqueeSpeed();
+if (m_timer.isActive())
+m_timer.startRepeating(speed() * 0.001);
+}
+// Check the loop count to see if we should now stop.
+bool activate = (m_totalLoops <= 0 || m_currentLoop < m_totalLoops);
+if (activate && !m_timer.isActive())
+m_layer->renderer()->setNeedsLayout(true);
+else if (!activate && m_timer.isActive())
+m_timer.stop();
+}
+void Marquee::timerFired(Timer<Marquee>*)
+{
+if (m_layer->renderer()->needsLayout())
+return;
+if (m_reset) {
+m_reset = false;
+if (isHorizontal())
+m_layer->scrollToXOffset(m_start);
+else
+m_layer->scrollToYOffset(m_start);
+return;
+}
+RenderStyle* s = m_layer->renderer()->style();
+int endPoint = m_end;
+int range = m_end - m_start;
+int newPos;
+if (range == 0)
+newPos = m_end;
+else {
+bool addIncrement = direction() == MUP || direction() == MLEFT;
+bool isReversed = s->marqueeBehavior() == MALTERNATE && m_currentLoop % 2;
+if (isReversed) {
+// We're going in the reverse direction.
+endPoint = m_start;
+range = -range;
+addIncrement = !addIncrement;
+}
+bool positive = range > 0;
+int clientSize = (isHorizontal() ? m_layer->renderer()->clientWidth() : m_layer->renderer()->clientHeight());
+int increment = max(1, abs(m_layer->renderer()->style()->marqueeIncrement().calcValue(clientSize)));
+int currentPos = (isHorizontal() ? m_layer->scrollXOffset() : m_layer->scrollYOffset());
+newPos =  currentPos + (addIncrement ? increment : -increment);
+if (positive)
+newPos = min(newPos, endPoint);
+else
+newPos = max(newPos, endPoint);
+}
+if (newPos == endPoint) {
+m_currentLoop++;
+if (m_totalLoops > 0 && m_currentLoop >= m_totalLoops)
+m_timer.stop();
+else if (s->marqueeBehavior() != MALTERNATE)
+m_reset = true;
+}
+if (isHorizontal())
+m_layer->scrollToXOffset(newPos);
+else
+m_layer->scrollToYOffset(newPos);
+/* HLUU-7D3SDH: This special handling here is not compatible with 3.2 and 3.1 behavior.
+#if PLATFORM(SYMBIAN)
+if( m_totalLoops>0 && m_currentLoop >= m_totalLoops ) {
+// -wap-marquee requires "the element MUST be rendered as if the 'display' property was set
+// to block" after looping
+if(s->display() == WAP_MARQUEE) {
+s->setDisplay(BLOCK);
+s->setOverflowX(OVISIBLE);
+m_layer->renderer()->setHasOverflowClip( false );
+m_layer->styleChanged();
+}
+}
+#endif
+*/
+}
+} // namespace WebCore

changeset 0	dd21522fd290
child 62	c711bdda59f4
child 68	92a765b5b3e7