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

#include "config.h"
#include "RenderBoxModelObject.h"

#include "GraphicsContext.h"
#include "HTMLElement.h"
#include "HTMLNames.h"
#include "ImageBuffer.h"
#include "RenderBlock.h"
#include "RenderInline.h"
#include "RenderLayer.h"
#include "RenderView.h"

using namespace std;

namespace WebCore {

using namespace HTMLNames;

bool RenderBoxModelObject::s_wasFloating = false;

RenderBoxModelObject::RenderBoxModelObject(Node* node)
    : RenderObject(node)
    , m_layer(0)
{
}

RenderBoxModelObject::~RenderBoxModelObject()
{
    // Our layer should have been destroyed and cleared by now
    ASSERT(!hasLayer());
    ASSERT(!m_layer);
}

void RenderBoxModelObject::destroyLayer()
{
    ASSERT(hasLayer());
    ASSERT(m_layer);
    m_layer->destroy(renderArena());
    m_layer = 0;
    setHasLayer(false);
}

void RenderBoxModelObject::destroy()
{
    // This must be done before we destroy the RenderObject.
    if (m_layer)
        m_layer->clearClipRects();

    // RenderObject::destroy calls back to destroyLayer() for layer destruction
    RenderObject::destroy();
}

bool RenderBoxModelObject::hasSelfPaintingLayer() const
{
    return m_layer && m_layer->isSelfPaintingLayer();
}

void RenderBoxModelObject::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
{
    s_wasFloating = isFloating();

    // If our z-index changes value or our visibility changes,
    // we need to dirty our stacking context's z-order list.
    if (style() && newStyle) {
        if (hasLayer() && (style()->hasAutoZIndex() != newStyle->hasAutoZIndex() ||
                           style()->zIndex() != newStyle->zIndex() ||
                           style()->visibility() != newStyle->visibility())) {
            layer()->dirtyStackingContextZOrderLists();
            if (style()->hasAutoZIndex() != newStyle->hasAutoZIndex() || style()->visibility() != newStyle->visibility())
                layer()->dirtyZOrderLists();
        }
    }

    RenderObject::styleWillChange(diff, newStyle);
}

void RenderBoxModelObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
    RenderObject::styleDidChange(diff, oldStyle);
    updateBoxModelInfoFromStyle();
    
    if (requiresLayer()) {
        if (!layer()) {
            if (s_wasFloating && isFloating())
                setChildNeedsLayout(true);
            m_layer = new (renderArena()) RenderLayer(this);
            setHasLayer(true);
            m_layer->insertOnlyThisLayer();
            if (parent() && !needsLayout() && containingBlock())
                m_layer->updateLayerPositions();
        }
    } else if (layer() && layer()->parent()) {
        setHasTransform(false); // Either a transform wasn't specified or the object doesn't support transforms, so just null out the bit.
        setHasReflection(false);
        m_layer->removeOnlyThisLayer(); // calls destroyLayer() which clears m_layer
        if (s_wasFloating && isFloating())
            setChildNeedsLayout(true);
    }

    if (m_layer)
        m_layer->styleChanged(diff, oldStyle);
}

void RenderBoxModelObject::updateBoxModelInfoFromStyle()
{
    // Set the appropriate bits for a box model object.  Since all bits are cleared in styleWillChange,
    // we only check for bits that could possibly be set to true.
    setHasBoxDecorations(style()->hasBorder() || style()->hasBackground() || style()->hasAppearance() || style()->boxShadow());
    setInline(style()->isDisplayInlineType());
    setRelPositioned(style()->position() == RelativePosition);
}

int RenderBoxModelObject::relativePositionOffsetX() const
{
    if (!style()->left().isAuto()) {
        if (!style()->right().isAuto() && containingBlock()->style()->direction() == RTL)
            return -style()->right().calcValue(containingBlockWidthForContent());
        return style()->left().calcValue(containingBlockWidthForContent());
    }
    if (!style()->right().isAuto())
        return -style()->right().calcValue(containingBlockWidthForContent());
    return 0;
}

int RenderBoxModelObject::relativePositionOffsetY() const
{
    if (!style()->top().isAuto()) {
        if (!style()->top().isPercent() || containingBlock()->style()->height().isFixed())
            return style()->top().calcValue(containingBlock()->availableHeight());
    } else if (!style()->bottom().isAuto()) {
        if (!style()->bottom().isPercent() || containingBlock()->style()->height().isFixed())
            return -style()->bottom().calcValue(containingBlock()->availableHeight());
    }
    return 0;
}

int RenderBoxModelObject::offsetLeft() const
{
    // If the element is the HTML body element or does not have an associated box
    // return 0 and stop this algorithm.
    if (isBody())
        return 0;
    
    RenderBoxModelObject* offsetPar = offsetParent();
    int xPos = (isBox() ? toRenderBox(this)->x() : 0);
    
    // If the offsetParent of the element is null, or is the HTML body element,
    // return the distance between the canvas origin and the left border edge 
    // of the element and stop this algorithm.
    if (offsetPar) {
        if (offsetPar->isBox() && !offsetPar->isBody())
            xPos -= toRenderBox(offsetPar)->borderLeft();
        if (!isPositioned()) {
            if (isRelPositioned())
                xPos += relativePositionOffsetX();
            RenderObject* curr = parent();
            while (curr && curr != offsetPar) {
                // FIXME: What are we supposed to do inside SVG content?
                if (curr->isBox() && !curr->isTableRow())
                    xPos += toRenderBox(curr)->x();
                curr = curr->parent();
            }
            if (offsetPar->isBox() && offsetPar->isBody() && !offsetPar->isRelPositioned() && !offsetPar->isPositioned())
                xPos += toRenderBox(offsetPar)->x();
        }
    }

    return xPos;
}

int RenderBoxModelObject::offsetTop() const
{
    // If the element is the HTML body element or does not have an associated box
    // return 0 and stop this algorithm.
    if (isBody())
        return 0;
    
    RenderBoxModelObject* offsetPar = offsetParent();
    int yPos = (isBox() ? toRenderBox(this)->y() : 0);
    
    // If the offsetParent of the element is null, or is the HTML body element,
    // return the distance between the canvas origin and the top border edge 
    // of the element and stop this algorithm.
    if (offsetPar) {
        if (offsetPar->isBox() && !offsetPar->isBody())
            yPos -= toRenderBox(offsetPar)->borderTop();
        if (!isPositioned()) {
            if (isRelPositioned())
                yPos += relativePositionOffsetY();
            RenderObject* curr = parent();
            while (curr && curr != offsetPar) {
                // FIXME: What are we supposed to do inside SVG content?
                if (curr->isBox() && !curr->isTableRow())
                    yPos += toRenderBox(curr)->y();
                curr = curr->parent();
            }
            if (offsetPar->isBox() && offsetPar->isBody() && !offsetPar->isRelPositioned() && !offsetPar->isPositioned())
                yPos += toRenderBox(offsetPar)->y();
        }
    }
    return yPos;
}

int RenderBoxModelObject::paddingTop(bool) const
{
    int w = 0;
    Length padding = style()->paddingTop();
    if (padding.isPercent())
        w = containingBlock()->availableWidth();
    return padding.calcMinValue(w);
}

int RenderBoxModelObject::paddingBottom(bool) const
{
    int w = 0;
    Length padding = style()->paddingBottom();
    if (padding.isPercent())
        w = containingBlock()->availableWidth();
    return padding.calcMinValue(w);
}

int RenderBoxModelObject::paddingLeft(bool) const
{
    int w = 0;
    Length padding = style()->paddingLeft();
    if (padding.isPercent())
        w = containingBlock()->availableWidth();
    return padding.calcMinValue(w);
}

int RenderBoxModelObject::paddingRight(bool) const
{
    int w = 0;
    Length padding = style()->paddingRight();
    if (padding.isPercent())
        w = containingBlock()->availableWidth();
    return padding.calcMinValue(w);
}


void RenderBoxModelObject::paintFillLayerExtended(const PaintInfo& paintInfo, const Color& c, const FillLayer* bgLayer, int clipY, int clipH,
                                                  int tx, int ty, int w, int h, InlineFlowBox* box, CompositeOperator op)
{
    GraphicsContext* context = paintInfo.context;
    bool includeLeftEdge = box ? box->includeLeftEdge() : true;
    bool includeRightEdge = box ? box->includeRightEdge() : true;
    int bLeft = includeLeftEdge ? borderLeft() : 0;
    int bRight = includeRightEdge ? borderRight() : 0;
    int pLeft = includeLeftEdge ? paddingLeft() : 0;
    int pRight = includeRightEdge ? paddingRight() : 0;

    bool clippedToBorderRadius = false;
    if (style()->hasBorderRadius() && (includeLeftEdge || includeRightEdge)) {
        context->save();
        context->addRoundedRectClip(IntRect(tx, ty, w, h),
            includeLeftEdge ? style()->borderTopLeftRadius() : IntSize(),
            includeRightEdge ? style()->borderTopRightRadius() : IntSize(),