renderlayer.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
 *
 * Portions are Copyright (C) 1998 Netscape Communications Corporation.
 *
 * Other contributors:
 *   Robert O'Callahan <[e-mail]>
 *   David Baron <[e-mail]>
 *   Christian Biesinger <[e-mail]>
 *   Randall Jesup <[e-mail]>
 *   Roland Mainz <[e-mail]>
 *   Josh Soref <[e-mail]>
 *   Boris Zbarsky <[e-mail]>
 *
 * 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 "CString.h"
#include "CSSPropertyNames.h"
#include "CSSStyleSelector.h"
#include "Document.h"
#include "EventHandler.h"
#include "EventNames.h"
#include "FloatPoint3D.h"
#include "FloatRect.h"
#include "FocusController.h"
#include "Frame.h"
#include "FrameTree.h"
#include "FrameView.h"
#include "Gradient.h"
#include "GraphicsContext.h"
#include "HTMLNames.h"
#include "HitTestRequest.h"
#include "HitTestResult.h"
#include "OverflowEvent.h"
#include "Page.h"
#include "PlatformMouseEvent.h"
#include "RenderArena.h"
#include "RenderInline.h"
#include "RenderMarquee.h"
#include "RenderReplica.h"
#include "RenderScrollbar.h"
#include "RenderScrollbarPart.h"
#include "RenderTheme.h"
#include "RenderView.h"
#include "ScaleTransformOperation.h"
#include "Scrollbar.h"
#include "ScrollbarTheme.h"
#include "SelectionController.h"
#include "TransformationMatrix.h"
#include "TransformState.h"
#include "TranslateTransformOperation.h"
#include <wtf/StdLibExtras.h>
#include <wtf/UnusedParam.h>

#if USE(ACCELERATED_COMPOSITING)
#include "RenderLayerBacking.h"
#include "RenderLayerCompositor.h"
#endif

#if ENABLE(SVG)
#include "SVGNames.h"
#endif

#define MIN_INTERSECT_FOR_REVEAL 32

using namespace std;

namespace WebCore {

using namespace HTMLNames;

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(RenderBoxModelObject* renderer)
    : m_renderer(renderer)
    , 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_normalFlowList(0)
    , m_clipRects(0) 
#ifndef NDEBUG    
    , m_clipRectsRoot(0)
#endif
    , m_scrollDimensionsDirty(true)
    , m_zOrderListsDirty(true)
    , m_normalFlowListDirty(true)
    , m_isNormalFlowOnly(shouldBeNormalFlowOnly())
    , m_usedTransparency(false)
    , m_paintingInsideReflection(false)
    , m_inOverflowRelayout(false)
    , m_needsFullRepaint(false)
    , m_overflowStatusDirty(true)
    , m_visibleContentStatusDirty(true)
    , m_hasVisibleContent(false)
    , m_visibleDescendantStatusDirty(false)
    , m_hasVisibleDescendant(false)
    , m_3DTransformedDescendantStatusDirty(true)
    , m_has3DTransformedDescendant(false)
#if USE(ACCELERATED_COMPOSITING)
    , m_hasCompositingDescendant(false)
#endif
    , m_marquee(0)
    , m_staticX(0)
    , m_staticY(0)
    , m_reflection(0)
    , m_scrollCorner(0)
    , m_resizer(0)
{
    if (!renderer->firstChild() && renderer->style()) {
        m_visibleContentStatusDirty = false;
        m_hasVisibleContent = renderer->style()->visibility() == VISIBLE;
    }
}

RenderLayer::~RenderLayer()
{
    if (inResizeMode() && !renderer()->documentBeingDestroyed()) {
        if (Frame* frame = renderer()->document()->frame())
            frame->eventHandler()->resizeLayerDestroyed();
    }

    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_normalFlowList;
    delete m_marquee;

#if USE(ACCELERATED_COMPOSITING)
    clearBacking();
#endif
    
    // Make sure we have no lingering clip rects.
    ASSERT(!m_clipRects);
    
    if (m_reflection) {
        if (!m_reflection->documentBeingDestroyed())
            m_reflection->removeLayers(this);
        m_reflection->setParent(0);
        m_reflection->destroy();
    }
    
    if (m_scrollCorner)
        m_scrollCorner->destroy();
    if (m_resizer)
        m_resizer->destroy();
}

#if USE(ACCELERATED_COMPOSITING)
RenderLayerCompositor* RenderLayer::compositor() const
{
    ASSERT(renderer()->view());
    return renderer()->view()->compositor();
}
#endif // USE(ACCELERATED_COMPOSITING)

void RenderLayer::setStaticY(int staticY)
{
    if (m_staticY == staticY)
        return;
    m_staticY = staticY;
    renderer()->setChildNeedsLayout(true, false);
}

void RenderLayer::updateLayerPositions(bool doFullRepaint, bool checkForRepaint)
{
    if (doFullRepaint) {
        renderer()->repaint();
#if USE(ACCELERATED_COMPOSITING)
        checkForRepaint = false;
        // We need the full repaint to propagate to child layers if we are hardware compositing.
        if (!compositor()->inCompositingMode())
            doFullRepaint = false;
#else
        checkForRepaint = doFullRepaint = false;
#endif
    }
    
    updateLayerPosition(); // For relpositioned layers or non-positioned layers,
                           // we need to keep in sync, since we may have shifted relative
                           // to our parent layer.

    int x = 0;
    int y = 0;
    convertToLayerCoords(root(), x, y);
    positionOverflowControls(x, y);

    updateVisibilityStatus();

    updateTransform();
     
    if (m_hasVisibleContent) {
        RenderView* view = renderer()->view();
        ASSERT(view);
        // FIXME: Optimize using LayoutState and remove the disableLayoutState() call
        // from updateScrollInfoAfterLayout().
        ASSERT(!view->layoutStateEnabled());

        RenderBoxModelObject* repaintContainer = renderer()->containerForRepaint();
        IntRect newRect = renderer()->clippedOverflowRectForRepaint(repaintContainer);
        IntRect newOutlineBox = renderer()->outlineBoundsForRepaint(repaintContainer);
        if (checkForRepaint) {
            if (view && !view->printing()) {
                if (m_needsFullRepaint) {
                    renderer()->repaintUsingContainer(repaintContainer, m_repaintRect);
                    if (newRect != m_repaintRect)
                        renderer()->repaintUsingContainer(repaintContainer, newRect);
                } else
                    renderer()->repaintAfterLayoutIfNeeded(repaintContainer, m_repaintRect, m_outlineBox);
            }
        }
        m_repaintRect = newRect;
        m_outlineBox = newOutlineBox;
    } else {
        m_repaintRect = IntRect();
        m_outlineBox = IntRect();
    }

    m_needsFullRepaint = false;

    // Go ahead and update the reflection's position and size.
    if (m_reflection)
        m_reflection->layout();

    for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
        child->updateLayerPositions(doFullRepaint, checkForRepaint);

#if USE(ACCELERATED_COMPOSITING)
    if (!parent())
        compositor()->updateRootLayerPosition();

    if (isComposited())
        backing()->updateAfterLayout();
#endif
        
    // With all our children positioned, now update our marquee if we need to.
    if (m_marquee)
        m_marquee->updateMarqueePosition();
}

void RenderLayer::updateTransform()
{
    // hasTransform() on the renderer is also true when there is transform-style: preserve-3d or perspective set,
    // so check style too.
    bool hasTransform = renderer()->hasTransform() && renderer()->style()->hasTransform();
    bool had3DTransform = has3DTransform();

    bool hadTransform = m_transform;
    if (hasTransform != hadTransform) {
        if (hasTransform)
            m_transform.set(new TransformationMatrix);
        else
            m_transform.clear();
    }
    
    if (hasTransform) {
        RenderBox* box = renderBox();
        ASSERT(box);
        m_transform->makeIdentity();
        box->style()->applyTransform(*m_transform, box->borderBoxRect().size(), RenderStyle::IncludeTransformOrigin);
    }

    if (had3DTransform != has3DTransform())
        dirty3DTransformedDescendantStatus();
}

TransformationMatrix RenderLayer::currentTransform() const
{
    if (!m_transform)
        return TransformationMatrix();

#if USE(ACCELERATED_COMPOSITING)
    if (renderer()->style()->isRunningAcceleratedAnimation()) {
        TransformationMatrix currTransform;
        RefPtr<RenderStyle> style = renderer()->animation()->getAnimatedStyleForRenderer(renderer());
        style->applyTransform(currTransform, renderBox()->borderBoxRect().size(), RenderStyle::IncludeTransformOrigin);
        return currTransform;
    }
#endif

    return *m_transform;
}

void RenderLayer::setHasVisibleContent(bool b)
{ 
    if (m_hasVisibleContent == b && !m_visibleContentStatusDirty)