inlineflowbox.cpp

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/*
 * Copyright (C) 2003, 2004, 2005, 2006, 2007 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 "InlineFlowBox.h"

#include "CachedImage.h"
#include "Document.h"
#include "EllipsisBox.h"
#include "GraphicsContext.h"
#include "InlineTextBox.h"
#include "HitTestResult.h"
#include "RootInlineBox.h"
#include "RenderBlock.h"
#include "RenderInline.h"
#include "RenderListMarker.h"
#include "RenderTableCell.h"
#include "RootInlineBox.h"
#include "Text.h"

#include <math.h>

using namespace std;

namespace WebCore {

#ifndef NDEBUG

InlineFlowBox::~InlineFlowBox()
{
    if (!m_hasBadChildList)
        for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
            child->setHasBadParent();
}

#endif

int InlineFlowBox::height() const
{
    const Font& font = renderer()->style(m_firstLine)->font();
    int result = font.height();
    bool strictMode = renderer()->document()->inStrictMode();
    RenderBoxModelObject* box = boxModelObject();
    result += box->borderTop() + box->paddingTop() + box->borderBottom() + box->paddingBottom();
    if (!strictMode && !hasTextChildren() && !box->hasHorizontalBordersOrPadding()) {
        int bottomOverflow = root()->bottomOverflow();
        if (y() + result > bottomOverflow)
            result = bottomOverflow - y();
    }
    return result;
}

int InlineFlowBox::getFlowSpacingWidth()
{
    int totWidth = marginBorderPaddingLeft() + marginBorderPaddingRight();
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->isInlineFlowBox())
            totWidth += static_cast<InlineFlowBox*>(curr)->getFlowSpacingWidth();
    }
    return totWidth;
}

void InlineFlowBox::addToLine(InlineBox* child) 
{
    ASSERT(!child->parent());
    ASSERT(!child->nextOnLine());
    ASSERT(!child->prevOnLine());
    checkConsistency();

    child->setParent(this);
    if (!m_firstChild) {
        m_firstChild = child;
        m_lastChild = child;
    } else {
        m_lastChild->setNextOnLine(child);
        child->setPrevOnLine(m_lastChild);
        m_lastChild = child;
    }
    child->setFirstLineStyleBit(m_firstLine);
    if (child->isText())
        m_hasTextChildren = true;
    if (child->renderer()->selectionState() != RenderObject::SelectionNone)
        root()->setHasSelectedChildren(true);

    checkConsistency();
}

void InlineFlowBox::removeChild(InlineBox* child)
{
    checkConsistency();

    if (!m_dirty)
        dirtyLineBoxes();

    root()->childRemoved(child);

    if (child == m_firstChild)
        m_firstChild = child->nextOnLine();
    if (child == m_lastChild)
        m_lastChild = child->prevOnLine();
    if (child->nextOnLine())
        child->nextOnLine()->setPrevOnLine(child->prevOnLine());
    if (child->prevOnLine())
        child->prevOnLine()->setNextOnLine(child->nextOnLine());
    
    child->setParent(0);

    checkConsistency();
}

void InlineFlowBox::deleteLine(RenderArena* arena)
{
    InlineBox* child = firstChild();
    InlineBox* next = 0;
    while (child) {
        ASSERT(this == child->parent());
        next = child->nextOnLine();
#ifndef NDEBUG
        child->setParent(0);
#endif
        child->deleteLine(arena);
        child = next;
    }
#ifndef NDEBUG
    m_firstChild = 0;
    m_lastChild = 0;
#endif

    removeLineBoxFromRenderObject();
    destroy(arena);
}

void InlineFlowBox::removeLineBoxFromRenderObject()
{
    toRenderInline(renderer())->lineBoxes()->removeLineBox(this);
}

void InlineFlowBox::extractLine()
{
    if (!m_extracted)
        extractLineBoxFromRenderObject();
    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
        child->extractLine();
}

void InlineFlowBox::extractLineBoxFromRenderObject()
{
    toRenderInline(renderer())->lineBoxes()->extractLineBox(this);
}

void InlineFlowBox::attachLine()
{
    if (m_extracted)
        attachLineBoxToRenderObject();
    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
        child->attachLine();
}

void InlineFlowBox::attachLineBoxToRenderObject()
{
    toRenderInline(renderer())->lineBoxes()->attachLineBox(this);
}

void InlineFlowBox::adjustPosition(int dx, int dy)
{
    InlineRunBox::adjustPosition(dx, dy);
    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
        child->adjustPosition(dx, dy);
}

RenderLineBoxList* InlineFlowBox::rendererLineBoxes() const
{
    return toRenderInline(renderer())->lineBoxes();
}

bool InlineFlowBox::onEndChain(RenderObject* endObject)
{
    if (!endObject)
        return false;
    
    if (endObject == renderer())
        return true;

    RenderObject* curr = endObject;
    RenderObject* parent = curr->parent();
    while (parent && !parent->isRenderBlock()) {
        if (parent->lastChild() != curr || parent == renderer())
            return false;
            
        curr = parent;
        parent = curr->parent();
    }

    return true;
}

void InlineFlowBox::determineSpacingForFlowBoxes(bool lastLine, RenderObject* endObject)
{
    // All boxes start off open.  They will not apply any margins/border/padding on
    // any side.
    bool includeLeftEdge = false;
    bool includeRightEdge = false;

    // The root inline box never has borders/margins/padding.
    if (parent()) {
        bool ltr = renderer()->style()->direction() == LTR;

        // Check to see if all initial lines are unconstructed.  If so, then
        // we know the inline began on this line (unless we are a continuation).
        RenderLineBoxList* lineBoxList = rendererLineBoxes();
        if (!lineBoxList->firstLineBox()->isConstructed() && !renderer()->isInlineContinuation()) {
            if (ltr && lineBoxList->firstLineBox() == this)
                includeLeftEdge = true;
            else if (!ltr && lineBoxList->lastLineBox() == this)
                includeRightEdge = true;
        }
    
        // In order to determine if the inline ends on this line, we check three things:
        // (1) If we are the last line and we don't have a continuation(), then we can
        // close up.
        // (2) If the last line box for the flow has an object following it on the line (ltr,
        // reverse for rtl), then the inline has closed.
        // (3) The line may end on the inline.  If we are the last child (climbing up
        // the end object's chain), then we just closed as well.
        if (!lineBoxList->lastLineBox()->isConstructed()) {
            RenderInline* inlineFlow = toRenderInline(renderer());
            if (ltr) {
                if (!nextLineBox() &&
                    ((lastLine && !inlineFlow->continuation()) || nextOnLineExists() || onEndChain(endObject)))
                    includeRightEdge = true;
            } else {
                if ((!prevLineBox() || prevLineBox()->isConstructed()) &&
                    ((lastLine && !inlineFlow->continuation()) || prevOnLineExists() || onEndChain(endObject)))
                    includeLeftEdge = true;
            }
        }
    }

    setEdges(includeLeftEdge, includeRightEdge);

    // Recur into our children.
    for (InlineBox* currChild = firstChild(); currChild; currChild = currChild->nextOnLine()) {
        if (currChild->isInlineFlowBox()) {
            InlineFlowBox* currFlow = static_cast<InlineFlowBox*>(currChild);
            currFlow->determineSpacingForFlowBoxes(lastLine, endObject);
        }
    }
}

int InlineFlowBox::placeBoxesHorizontally(int xPos, int& leftPosition, int& rightPosition, bool& needsWordSpacing)
{
    // Set our x position.
    setX(xPos);

    int boxShadowLeft = 0;
    int boxShadowRight = 0;
    for (ShadowData* boxShadow = renderer()->style(m_firstLine)->boxShadow(); boxShadow; boxShadow = boxShadow->next) {
        boxShadowLeft = min(boxShadow->x - boxShadow->blur, boxShadowLeft);
        boxShadowRight = max(boxShadow->x + boxShadow->blur, boxShadowRight);
    }
    leftPosition = min(xPos + boxShadowLeft, leftPosition);

    int startX = xPos;
    xPos += borderLeft() + paddingLeft();
    
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer()->isText()) {
            InlineTextBox* text = static_cast<InlineTextBox*>(curr);
            RenderText* rt = toRenderText(text->renderer());
            if (rt->textLength()) {
                if (needsWordSpacing && isSpaceOrNewline(rt->characters()[text->start()]))
                    xPos += rt->style(m_firstLine)->font().wordSpacing();
                needsWordSpacing = !isSpaceOrNewline(rt->characters()[text->end()]);
            }
            text->setX(xPos);
            
            int strokeOverflow = static_cast<int>(ceilf(rt->style()->textStrokeWidth() / 2.0f));
            
            // If letter-spacing is negative, we should factor that into right overflow. (Even in RTL, letter-spacing is
            // applied to the right, so this is not an issue with left overflow.
            int letterSpacing = min(0, (int)rt->style(m_firstLine)->font().letterSpacing());
            
            int leftGlyphOverflow = -strokeOverflow;
            int rightGlyphOverflow = strokeOverflow - letterSpacing;
            
            int visualOverflowLeft = leftGlyphOverflow;
            int visualOverflowRight = rightGlyphOverflow;
            for (ShadowData* shadow = rt->style()->textShadow(); shadow; shadow = shadow->next) {
                visualOverflowLeft = min(visualOverflowLeft, shadow->x - shadow->blur + leftGlyphOverflow);
                visualOverflowRight = max(visualOverflowRight, shadow->x + shadow->blur + rightGlyphOverflow);
            }
            
            leftPosition = min(xPos + visualOverflowLeft, leftPosition);
            rightPosition = max(xPos + text->width() + visualOverflowRight, rightPosition);
            m_maxHorizontalVisualOverflow = max(max(visualOverflowRight, -visualOverflowLeft), (int)m_maxHorizontalVisualOverflow);
            xPos += text->width();
        } else {
            if (curr->renderer()->isPositioned()) {
                if (curr->renderer()->parent()->style()->direction() == LTR)
                    curr->setX(xPos);
                else
                    // Our offset that we cache needs to be from the edge of the right border box and
                    // not the left border box.  We have to subtract |x| from the width of the block
                    // (which can be obtained from the root line box).
                    curr->setX(root()->block()->width() - xPos);
                continue; // The positioned object has no effect on the width.
            }
            if (curr->renderer()->isRenderInline()) {
                InlineFlowBox* flow = static_cast<InlineFlowBox*>(curr);
                xPos += flow->marginLeft();
                xPos = flow->placeBoxesHorizontally(xPos, leftPosition, rightPosition, needsWordSpacing);
                xPos += flow->marginRight();
            } else if (!curr->renderer()->isListMarker() || static_cast<RenderListMarker*>(curr->renderer())->isInside()) {
                xPos += curr->boxModelObject()->marginLeft();
                curr->setX(xPos);
                leftPosition = min(xPos + toRenderBox(curr->renderer())->overflowLeft(false), leftPosition);
                rightPosition = max(xPos + toRenderBox(curr->renderer())->overflowWidth(false), rightPosition);
                xPos += curr->width() + curr->boxModelObject()->marginRight();
            }
        }
    }

    xPos += borderRight() + paddingRight();
    setWidth(xPos - startX);
    rightPosition = max(x() + width() + boxShadowRight, rightPosition);

    return xPos;
}

int InlineFlowBox::verticallyAlignBoxes(int heightOfBlock)