render_line.cpp

khtml在gtk上的移植版本

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;

    RenderFlow* flow = static_cast<RenderFlow*>(object());
    
    if (!flow->firstChild())
        includeLeftEdge = includeRightEdge = true; // Empty inlines never split across lines.
    else if (parent()) { // The root inline box never has borders/margins/padding.
        bool ltr = flow->style()->direction() == LTR;
        
        // Check to see if all initial lines are unconstructed.  If so, then
        // we know the inline began on this line.
        if (!flow->firstLineBox()->isConstructed()) {
            if (ltr && flow->firstLineBox() == this)
                includeLeftEdge = true;
            else if (!ltr && flow->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 (!flow->lastLineBox()->isConstructed()) {
            if (ltr) {
                if (!nextLineBox() &&
                    ((lastLine && !object()->continuation()) || nextOnLineExists()
                     || onEndChain(endObject)))
                    includeRightEdge = true;
            }
            else {
                if ((!prevLineBox() || !prevLineBox()->isConstructed()) &&
                    ((lastLine && !object()->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 x)
{
    // Set our x position.
    setXPos(x);

    int startX = x;
    x += borderLeft() + paddingLeft();
    
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->object()->isText()) {
            InlineTextBox* text = static_cast<InlineTextBox*>(curr);
            text->setXPos(x);
            x += text->width();
        }
        else {
            if (curr->object()->isPositioned()) {
                if (curr->object()->parent()->style()->direction() == LTR)
                    curr->setXPos(x);
                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 by walking up to the root line box).
                    InlineBox* root = this;
                    while (!root->isRootInlineBox())
                        root = root->parent();
                    curr->setXPos(root->object()->width()-x);
                }
                continue; // The positioned object has no effect on the width.
            }
            if (curr->object()->isInlineFlow()) {
                InlineFlowBox* flow = static_cast<InlineFlowBox*>(curr);
                if (curr->object()->isCompact()) {
                    int ignoredX = x;
                    flow->placeBoxesHorizontally(ignoredX);
                }
                else {
                    x += flow->marginLeft();
                    x = flow->placeBoxesHorizontally(x);
                    x += flow->marginRight();
                }
            }
            else if (!curr->object()->isCompact()) {
                x += curr->object()->marginLeft();
                curr->setXPos(x);
                x += curr->width() + curr->object()->marginRight();
            }
        }
    }

    x += borderRight() + paddingRight();
    setWidth(x-startX);
    return x;
}

void InlineFlowBox::verticallyAlignBoxes(int& heightOfBlock)
{
    int maxPositionTop = 0;
    int maxPositionBottom = 0;
    int maxAscent = 0;
    int maxDescent = 0;

    // Figure out if we're in strict mode.  Note that we can't simply use !style()->htmlHacks(),
    // because that would match almost strict mode as well.
    RenderObject* curr = object();
    while (curr && !curr->element())
        curr = curr->container();
    bool strictMode = (curr && curr->element()->getDocument()->inStrictMode());
    
    computeLogicalBoxHeights(maxPositionTop, maxPositionBottom, maxAscent, maxDescent, strictMode);

    if (maxAscent + maxDescent < kMax(maxPositionTop, maxPositionBottom))
        adjustMaxAscentAndDescent(maxAscent, maxDescent, maxPositionTop, maxPositionBottom);

    int maxHeight = maxAscent + maxDescent;
    int topPosition = heightOfBlock;
    int bottomPosition = heightOfBlock;
    placeBoxesVertically(heightOfBlock, maxHeight, maxAscent, strictMode, topPosition, bottomPosition);

    setOverflowPositions(topPosition, bottomPosition);

    // Shrink boxes with no text children in quirks and almost strict mode.
    if (!strictMode)
        shrinkBoxesWithNoTextChildren(topPosition, bottomPosition);
    
    heightOfBlock += maxHeight;
}

void InlineFlowBox::adjustMaxAscentAndDescent(int& maxAscent, int& maxDescent,
                                              int maxPositionTop, int maxPositionBottom)
{
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        // The computed lineheight needs to be extended for the
        // positioned elements
        if (curr->object()->isPositioned())
            continue; // Positioned placeholders don't affect calculations.
        if (curr->yPos() == PositionTop || curr->yPos() == PositionBottom) {
            if (curr->yPos() == PositionTop) {
                if (maxAscent + maxDescent < curr->height())
                    maxDescent = curr->height() - maxAscent;
            }
            else {
                if (maxAscent + maxDescent < curr->height())
                    maxAscent = curr->height() - maxDescent;
            }

            if (maxAscent + maxDescent >= kMax(maxPositionTop, maxPositionBottom))
                break;
        }

        if (curr->isInlineFlowBox())
            static_cast<InlineFlowBox*>(curr)->adjustMaxAscentAndDescent(maxAscent, maxDescent, maxPositionTop, maxPositionBottom);
    }
}

void InlineFlowBox::computeLogicalBoxHeights(int& maxPositionTop, int& maxPositionBottom,
                                             int& maxAscent, int& maxDescent, bool strictMode)
{
    if (isRootInlineBox()) {
        // Examine our root box.
        setHeight(object()->lineHeight(m_firstLine, true));
        bool isTableCell = object()->isTableCell();
        if (isTableCell) {
            RenderTableCell* tableCell = static_cast<RenderTableCell*>(object());
            setBaseline(tableCell->RenderBlock::baselinePosition(m_firstLine, true));
        }
        else
            setBaseline(object()->baselinePosition(m_firstLine, true));
        if (hasTextChildren() || strictMode) {
            int ascent = baseline();
            int descent = height() - ascent;
            if (maxAscent < ascent)
                maxAscent = ascent;
            if (maxDescent < descent)
                maxDescent = descent;
        }
    }
    
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->object()->isPositioned())
            continue; // Positioned placeholders don't affect calculations.
        
        curr->setHeight(curr->object()->lineHeight(m_firstLine));
        curr->setBaseline(curr->object()->baselinePosition(m_firstLine));
        curr->setYPos(curr->object()->verticalPositionHint(m_firstLine));
        if (curr->yPos() == PositionTop) {
            if (maxPositionTop < curr->height())
                maxPositionTop = curr->height();
        }
        else if (curr->yPos() == PositionBottom) {
            if (maxPositionBottom < curr->height())
                maxPositionBottom = curr->height();
        }
        else if (curr->hasTextChildren() || strictMode) {
            int ascent = curr->baseline() - curr->yPos();
            int descent = curr->height() - ascent;
            if (maxAscent < ascent)
                maxAscent = ascent;
            if (maxDescent < descent)
                maxDescent = descent;
        }

        if (curr->isInlineFlowBox())
            static_cast<InlineFlowBox*>(curr)->computeLogicalBoxHeights(maxPositionTop, maxPositionBottom, maxAscent, maxDescent, strictMode);
    }
}

void InlineFlowBox::placeBoxesVertically(int y, int maxHeight, int maxAscent, bool strictMode,
                                         int& topPosition, int& bottomPosition)
{
    if (isRootInlineBox())
        setYPos(y + maxAscent - baseline());// Place our root box.
    
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->object()->isPositioned())
            continue; // Positioned placeholders don't affect calculations.
        
        // Adjust boxes to use their real box y/height and not the logical height (as dictated by
        // line-height).
        if (curr->isInlineFlowBox())
            static_cast<InlineFlowBox*>(curr)->placeBoxesVertically(y, maxHeight, maxAscent, strictMode,
                                                                    topPosition, bottomPosition);

        bool childAffectsTopBottomPos = true;
        if (curr->yPos() == PositionTop)
            curr->setYPos(y);
        else if (curr->yPos() == PositionBottom)
            curr->setYPos(y + maxHeight - curr->height());
        else {
            if (!curr->hasTextChildren() && !strictMode)
                childAffectsTopBottomPos = false;
            curr->setYPos(curr->yPos() + y + maxAscent - curr->baseline());
        }
        
        int newY = curr->yPos();
        int newHeight = curr->height();
        int newBaseline = curr->baseline();
        if (curr->isInlineTextBox() || curr->isInlineFlowBox()) {
            const QFontMetrics &fm = curr->object()->fontMetrics( m_firstLine );
            newBaseline = fm.ascent();
            newY += curr->baseline() - newBaseline;
            newHeight = newBaseline+fm.descent();
            if (curr->isInlineFlowBox()) {
                newHeight += curr->object()->borderTop() + curr->object()->paddingTop() +
                            curr->object()->borderBottom() + curr->object()->paddingBottom();
                newY -= curr->object()->borderTop() + curr->object()->paddingTop();
                newBaseline += curr->object()->borderTop() + curr->object()->paddingTop();
            }	
        }
        else {
            newY += curr->object()->marginTop();
            newHeight = curr->height() - (curr->object()->marginTop() + curr->object()->marginBottom());
        }

        curr->setYPos(newY);
        curr->setHeight(newHeight);
        curr->setBaseline(newBaseline);

        if (childAffectsTopBottomPos) {
            if (newY < topPosition)
                topPosition = newY;
            if (newY + newHeight > bottomPosition)
                bottomPosition = newY + newHeight;
        }
    }

    if (isRootInlineBox()) {
        const QFontMetrics &fm = object()->fontMetrics( m_firstLine );
        setHeight(fm.ascent()+fm.descent());
        setYPos(yPos() + baseline() - fm.ascent());
        setBaseline(fm.ascent());
        if (hasTextChildren() || strictMode) {
            if (yPos() < topPosition)
                topPosition = yPos();
            if (yPos() + height() > bottomPosition)
                bottomPosition = yPos() + height();
        }
    }
}

void InlineFlowBox::shrinkBoxesWithNoTextChildren(int topPos, int bottomPos)
{
    // First shrink our kids.
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->object()->isPositioned())
            continue; // Positioned placeholders don't affect calculations.
        
        if (curr->isInlineFlowBox())
            static_cast<InlineFlowBox*>(curr)->shrinkBoxesWithNoTextChildren(topPos, bottomPos);
    }

    // See if we have text children. If not, then we need to shrink ourselves to fit on the line.
    if (!hasTextChildren()) {
        if (yPos() < topPos)
            setYPos(topPos);
        if (yPos() + height() > bottomPos)
            setHeight(bottomPos - yPos());
        if (baseline() > height())
            setBaseline(height());
    }
}

void InlineFlowBox::paintBackgroundAndBorder(RenderObject::PaintInfo& i, int _tx, int _ty, int xOffsetOnLine)
{
    // Move x/y to our coordinates.
    _tx += m_x;
    _ty += m_y;
    
    int w = width();
    int h = height();

    int my = kMax(_ty, i.r.y());
    int mh;
    if (_ty < i.r.y())
        mh= kMax(0, h - (i.r.y() - _ty));
    else
        mh = kMin(i.r.height(), h);

    QPainter* p = i.p;
    
    // You can use p::first-line to specify a background. If so, the root line boxes for
    // a line may actually have to paint a background.
    RenderStyle* styleToUse = object()->style(m_firstLine);
    if ((!parent() && m_firstLine && styleToUse != object()->style()) || 
        (parent() && object()->shouldPaintBackgroundOrBorder())) {
        CachedImage* bg = styleToUse->backgroundImage();
        bool hasBackgroundImage = bg && (bg->pixmap_size() == bg->valid_rect().size()) &&
                                  !bg->isTransparent() && !bg->isErrorImage();
        if (!hasBackgroundImage || (!prevLineBox() && !nextLineBox()) || !parent())
            object()->paintBackgroundExtended(p, styleToUse->backgroundColor(),