renderobject.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) 2000 Dirk Mueller ([e-mail])
 *           (C) 2004 Allan Sandfeld Jensen ([e-mail])
 * Copyright (C) 2004, 2005, 2006, 2007, 2008 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 "RenderObject.h"

#include "AXObjectCache.h"
#include "CSSStyleSelector.h"
#include "FloatQuad.h"
#include "Frame.h"
#include "FrameView.h"
#include "GraphicsContext.h"
#include "HTMLNames.h"
#include "HitTestResult.h"
#include "Page.h"
#include "RenderArena.h"
#include "RenderCounter.h"
#include "RenderFlexibleBox.h"
#include "RenderImageGeneratedContent.h"
#include "RenderInline.h"
#include "RenderListItem.h"
#include "RenderTableCell.h"
#include "RenderTableCol.h"
#include "RenderTableRow.h"
#include "RenderTheme.h"
#include "RenderView.h"
#include "TransformState.h"
#include <algorithm>
#include <stdio.h>
#include <wtf/RefCountedLeakCounter.h>
#include <wtf/UnusedParam.h>

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

#if ENABLE(WML)
#include "WMLNames.h"
#endif

using namespace std;

namespace WebCore {

using namespace HTMLNames;

#ifndef NDEBUG
static void* baseOfRenderObjectBeingDeleted;
#endif

bool RenderObject::s_affectsParentBlock = false;

void* RenderObject::operator new(size_t sz, RenderArena* renderArena) throw()
{
    return renderArena->allocate(sz);
}

void RenderObject::operator delete(void* ptr, size_t sz)
{
    ASSERT(baseOfRenderObjectBeingDeleted == ptr);

    // Stash size where destroy can find it.
    *(size_t *)ptr = sz;
}

RenderObject* RenderObject::createObject(Node* node, RenderStyle* style)
{
    Document* doc = node->document();
    RenderArena* arena = doc->renderArena();

    // Minimal support for content properties replacing an entire element.
    // Works only if we have exactly one piece of content and it's a URL.
    // Otherwise acts as if we didn't support this feature.
    const ContentData* contentData = style->contentData();
    if (contentData && !contentData->m_next && contentData->m_type == CONTENT_OBJECT && doc != node) {
        RenderImageGeneratedContent* image = new (arena) RenderImageGeneratedContent(node);
        image->setStyle(style);
        if (StyleImage* styleImage = contentData->m_content.m_image)
            image->setStyleImage(styleImage);
        return image;
    }

    RenderObject* o = 0;

    switch (style->display()) {
        case NONE:
            break;
        case INLINE:
            o = new (arena) RenderInline(node);
            break;
        case BLOCK:
            o = new (arena) RenderBlock(node);
            break;
        case INLINE_BLOCK:
            o = new (arena) RenderBlock(node);
            break;
        case LIST_ITEM:
            o = new (arena) RenderListItem(node);
            break;
        case RUN_IN:
        case COMPACT:
            o = new (arena) RenderBlock(node);
            break;
        case TABLE:
        case INLINE_TABLE:
            o = new (arena) RenderTable(node);
            break;
        case TABLE_ROW_GROUP:
        case TABLE_HEADER_GROUP:
        case TABLE_FOOTER_GROUP:
            o = new (arena) RenderTableSection(node);
            break;
        case TABLE_ROW:
            o = new (arena) RenderTableRow(node);
            break;
        case TABLE_COLUMN_GROUP:
        case TABLE_COLUMN:
            o = new (arena) RenderTableCol(node);
            break;
        case TABLE_CELL:
            o = new (arena) RenderTableCell(node);
            break;
        case TABLE_CAPTION:
            o = new (arena) RenderBlock(node);
            break;
        case BOX:
        case INLINE_BOX:
            o = new (arena) RenderFlexibleBox(node);
            break;
    }

    return o;
}

#ifndef NDEBUG 
static WTF::RefCountedLeakCounter renderObjectCounter("RenderObject");
#endif

RenderObject::RenderObject(Node* node)
    : CachedResourceClient()
    , m_style(0)
    , m_node(node)
    , m_parent(0)
    , m_previous(0)
    , m_next(0)
#ifndef NDEBUG
    , m_hasAXObject(false)
    , m_setNeedsLayoutForbidden(false)
#endif
    , m_needsLayout(false)
    , m_needsPositionedMovementLayout(false)
    , m_normalChildNeedsLayout(false)
    , m_posChildNeedsLayout(false)
    , m_prefWidthsDirty(false)
    , m_floating(false)
    , m_positioned(false)
    , m_relPositioned(false)
    , m_paintBackground(false)
    , m_isAnonymous(node == node->document())
    , m_isText(false)
    , m_isBox(false)
    , m_inline(true)
    , m_replaced(false)
    , m_isDragging(false)
    , m_hasLayer(false)
    , m_hasOverflowClip(false)
    , m_hasTransform(false)
    , m_hasReflection(false)
    , m_hasOverrideSize(false)
    , m_hasCounterNodeMap(false)
    , m_everHadLayout(false)
    , m_childrenInline(false)
    , m_topMarginQuirk(false) 
    , m_bottomMarginQuirk(false)
    , m_hasMarkupTruncation(false)
    , m_selectionState(SelectionNone)
    , m_hasColumns(false)
    , m_cellWidthChanged(false)
    , m_replacedHasOverflow(false)
{
#ifndef NDEBUG
    renderObjectCounter.increment();
#endif
    ASSERT(node);
}

RenderObject::~RenderObject()
{
    ASSERT(!node() || documentBeingDestroyed() || !document()->frame()->view() || document()->frame()->view()->layoutRoot() != this);
#ifndef NDEBUG
    ASSERT(!m_hasAXObject);
    renderObjectCounter.decrement();
#endif
}

bool RenderObject::isDescendantOf(const RenderObject* obj) const
{
    for (const RenderObject* r = this; r; r = r->m_parent) {
        if (r == obj)
            return true;
    }
    return false;
}

bool RenderObject::isBody() const
{
    return node() && node()->hasTagName(bodyTag);
}

bool RenderObject::isHR() const
{
    return node() && node()->hasTagName(hrTag);
}

bool RenderObject::isHTMLMarquee() const
{
    return node() && node()->renderer() == this && node()->hasTagName(marqueeTag);
}

static void updateListMarkerNumbers(RenderObject* child)
{
    for (RenderObject* r = child; r; r = r->nextSibling())
        if (r->isListItem())
            static_cast<RenderListItem*>(r)->updateValue();
}

void RenderObject::addChild(RenderObject* newChild, RenderObject* beforeChild)
{
    RenderObjectChildList* children = virtualChildren();
    ASSERT(children);
    if (!children)
        return;

    bool needsTable = false;

    if (newChild->isListItem())
        updateListMarkerNumbers(beforeChild ? beforeChild : children->lastChild());
    else if (newChild->isTableCol() && newChild->style()->display() == TABLE_COLUMN_GROUP)
        needsTable = !isTable();
    else if (newChild->isRenderBlock() && newChild->style()->display() == TABLE_CAPTION)
        needsTable = !isTable();
    else if (newChild->isTableSection())
        needsTable = !isTable();
    else if (newChild->isTableRow())
        needsTable = !isTableSection();
    else if (newChild->isTableCell()) {
        needsTable = !isTableRow();
        // I'm not 100% sure this is the best way to fix this, but without this
        // change we recurse infinitely when trying to render the CSS2 test page:
        // http://www.bath.ac.uk/%7Epy8ieh/internet/eviltests/htmlbodyheadrendering2.html.
        // See Radar 2925291.
        if (needsTable && isTableCell() && !children->firstChild() && !newChild->isTableCell())
            needsTable = false;
    }

    if (needsTable) {
        RenderTable* table;
        RenderObject* afterChild = beforeChild ? beforeChild->previousSibling() : children->lastChild();
        if (afterChild && afterChild->isAnonymous() && afterChild->isTable())
            table = static_cast<RenderTable*>(afterChild);
        else {
            table = new (renderArena()) RenderTable(document() /* is anonymous */);
            RefPtr<RenderStyle> newStyle = RenderStyle::create();
            newStyle->inheritFrom(style());
            newStyle->setDisplay(TABLE);
            table->setStyle(newStyle.release());
            addChild(table, beforeChild);
        }
        table->addChild(newChild);
    } else {
        // Just add it...
        children->insertChildNode(this, newChild, beforeChild);
    }
    
    if (newChild->isText() && newChild->style()->textTransform() == CAPITALIZE) {
        RefPtr<StringImpl> textToTransform = toRenderText(newChild)->originalText();
        if (textToTransform)
            toRenderText(newChild)->setText(textToTransform.release(), true);
    }
}

void RenderObject::removeChild(RenderObject* oldChild)
{
    RenderObjectChildList* children = virtualChildren();
    ASSERT(children);
    if (!children)
        return;

    // We do this here instead of in removeChildNode, since the only extremely low-level uses of remove/appendChildNode
    // cannot affect the positioned object list, and the floating object list is irrelevant (since the list gets cleared on
    // layout anyway).
    if (oldChild->isFloatingOrPositioned())
        toRenderBox(oldChild)->removeFloatingOrPositionedChildFromBlockLists();
        
    children->removeChildNode(this, oldChild);
}

RenderObject* RenderObject::nextInPreOrder() const
{
    if (RenderObject* o = firstChild())
        return o;

    return nextInPreOrderAfterChildren();
}

RenderObject* RenderObject::nextInPreOrderAfterChildren() const
{
    RenderObject* o;
    if (!(o = nextSibling())) {
        o = parent();
        while (o && !o->nextSibling())
            o = o->parent();
        if (o)
            o = o->nextSibling();
    }

    return o;
}

RenderObject* RenderObject::nextInPreOrder(RenderObject* stayWithin) const
{
    if (RenderObject* o = firstChild())
        return o;

    return nextInPreOrderAfterChildren(stayWithin);
}

RenderObject* RenderObject::nextInPreOrderAfterChildren(RenderObject* stayWithin) const
{
    if (this == stayWithin)
        return 0;