render_line.cpp

konqueror3 embedded版本, KDE环境下的当家浏览器的嵌入式版本源码包.

        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
        // see khtmltests/rendering/html_align.html

        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));
        bool isTableCell = object()->isTableCell();
        if (isTableCell) {
            RenderTableCell* tableCell = static_cast<RenderTableCell*>(object());
            setBaseline(tableCell->RenderBlock::baselinePosition(m_firstLine));
        }
        else
            setBaseline(object()->baselinePosition(m_firstLine));
        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.
        // CSS2: 10.8.1 - line-height on the block level element specifies the *minimum*
        // height of the generated line box
        if (hasTextChildren() && maxHeight < object()->lineHeight(m_firstLine))
            maxHeight = object()->lineHeight(m_firstLine);
    }

    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 );
#ifdef APPLE_CHANGES
            newBaseline = fm.ascent();
            newY += curr->baseline() - newBaseline;
            newHeight = newBaseline+fm.descent();
#else
            // only adjust if the leading delta is superior to the font's natural leading
            if ( kAbs(fm.ascent() - curr->baseline()) > fm.leading()/2 ) {
                int ascent = fm.ascent()+fm.leading()/2;
                newBaseline = ascent;
                newY += curr->baseline() - newBaseline;
                newHeight = fm.lineSpacing();
            }
#endif
            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 );
#ifdef APPLE_CHANGES
        setHeight(fm.ascent()+fm.descent());
        setYPos(yPos() + baseline() - fm.ascent());
        setBaseline(fm.ascent());
#else
        if ( kAbs(fm.ascent() - baseline()) > fm.leading()/2 ) {
            int ascent = fm.ascent()+fm.leading()/2;
            setHeight(fm.lineSpacing());
            setYPos(yPos() + baseline() - ascent);
            setBaseline(ascent);
        }
#endif
        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::paintBackgrounds(QPainter* p, const QColor& c, const BackgroundLayer* bgLayer,
                                     int my, int mh, int _tx, int _ty, int w, int h, int xoff)
{
    if (!bgLayer)
        return;
    paintBackgrounds(p, c, bgLayer->next(), my, mh, _tx, _ty, w, h, xoff);
    paintBackground(p, c, bgLayer, my, mh, _tx, _ty, w, h, xoff);
}

void InlineFlowBox::paintBackground(QPainter* p, const QColor& c, const BackgroundLayer* bgLayer,
                                    int my, int mh, int _tx, int _ty, int w, int h, int xOffsetOnLine)
{
    CachedImage* bg = bgLayer->backgroundImage();
    bool hasBackgroundImage = bg && (bg->pixmap_size() == bg->valid_rect().size()) &&
                              !bg->isTransparent() && !bg->isErrorImage();
    if (!hasBackgroundImage || (!prevLineBox() && !nextLineBox()) || !parent())
        object()->paintBackgroundExtended(p, c, bgLayer, my, mh, _tx, _ty, w, h, borderLeft(), borderRight());
    else {
        // We have a background image that spans multiple lines.
        // We need to adjust _tx and _ty by the width of all previous lines.
        // Think of background painting on inlines as though you had one long line, a single continuous
        // strip.  Even though that strip has been broken up across multiple lines, you still paint it
        // as though you had one single line.  This means each line has to pick up the background where
        // the previous line left off.
        int startX = _tx - xOffsetOnLine;
        int totalWidth = xOffsetOnLine;
        for (InlineRunBox* curr = this; curr; curr = curr->nextLineBox())
            totalWidth += curr->width();
        QRect clipRect(_tx, _ty, width(), height());
        clipRect = p->xForm(clipRect);
        p->save();
        p->setClipRect( clipRect );
        object()->paintBackgroundExtended(p, c, bgLayer, my, mh, startX, _ty,
                                          totalWidth, h, borderLeft(), borderRight());
        p->restore();
    }
}

void InlineFlowBox::paintBackgroundAndBorder(RenderObject::PaintInfo& pI, 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, pI.r.y());
    int mh;
    if (_ty<pI.r.y())
        mh= kMax(0,h-(pI.r.y()-_ty));
    else
        mh = kMin(pI.r.height(),h);

    // 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())) {
        QColor c = styleToUse->backgroundColor();
        paintBackgrounds(pI.p, c, styleToUse->backgroundLayers(), my, mh, _tx, _ty, w, h, xOffsetOnLine);

        // :first-line cannot be used to put borders on a line. Always paint borders with our
        // non-first-line style.
        if (parent() && object()->style()->hasBorder())
            object()->paintBorder(pI.p, _tx, _ty, w, h, object()->style(), includeLeftEdge(), includeRightEdge());
    }
}

static bool shouldDrawDecoration(RenderObject* obj)
{
    bool shouldDraw = false;
    for (RenderObject* curr = obj->firstChild();
         curr; curr = curr->nextSibling()) {
        if (curr->isInlineFlow()) {
            shouldDraw = true;
            break;
        }
        else if (curr->isText() && !curr->isBR() && (curr->style()->preserveWS() ||
                 !curr->element() || !curr->element()->containsOnlyWhitespace())) {
            shouldDraw = true;
            break;
        }
    }
    return shouldDraw;
}

void InlineFlowBox::paintDecorations(RenderObject::PaintInfo& pI, int _tx, int _ty)
{
    // Now paint our text decorations. We only do this if we aren't in quirks mode (i.e., in
    // almost-strict mode or strict mode).

    _tx += m_x;
    _ty += m_y;
    RenderStyle* styleToUse = object()->style(m_firstLine);
    int deco = parent() ? styleToUse->textDecoration() : styleToUse->textDecorationsInEffect();
    if (deco != TDNONE && shouldDrawDecoration(object())) {
        // We must have child boxes and have decorations defined.
        _tx += borderLeft() + paddingLeft();
        int w = m_width - (borderLeft() + paddingLeft() + borderRight() + paddingRight());
//    kdDebug() << k_funcinfo << "w: " << w << " deco: " << deco << endl;
        if ( !w )
            return;
        const QFontMetrics &fm = object()->fontMetrics( m_firstLine );
        // thick lines on small fonts look ugly
        int thickness = fm.height() > 20 ? fm.lineWidth() : 1;
        QColor underline, overline, linethrough;
        underline = overline = linethrough = styleToUse->color();
        if (!parent())
            object()->getTextDecorationColors(deco, underline, overline, linethrough);
        if (deco & UNDERLINE) {
            int underlineOffset = ( fm.height() + m_baseline ) / 2;
            if (underlineOffset <= m_baseline) underlineOffset = m_baseline+1;

            pI.p->fillRect(_tx, _ty + underlineOffset, w, thickness, underline );
        }
        if (deco & OVERLINE) {
            pI.p->fillRect(_tx, _ty, w, thickness, overline );
        }
        if (deco & LINE_THROUGH) {
            pI.p->fillRect(_tx, _ty + 2*m_baseline/3, w, thickness, linethrough );
        }
    }
}