inlinetextbox.cpp

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    bool useCustomUnderlines = containsComposition && renderer()->document()->frame()->editor()->compositionUsesCustomUnderlines();

    // Set our font.
    RenderStyle* styleToUse = renderer()->style(m_firstLine);
    int d = styleToUse->textDecorationsInEffect();
    const Font& font = styleToUse->font();

    // 1. Paint backgrounds behind text if needed. Examples of such backgrounds include selection
    // and composition underlines.
    if (paintInfo.phase != PaintPhaseSelection && paintInfo.phase != PaintPhaseTextClip && !isPrinting) {
#if PLATFORM(MAC)
        // Custom highlighters go behind everything else.
        if (styleToUse->highlight() != nullAtom && !context->paintingDisabled())
            paintCustomHighlight(tx, ty, styleToUse->highlight());
#endif

        if (containsComposition && !useCustomUnderlines)
            paintCompositionBackground(context, tx, ty, styleToUse, font,
                renderer()->document()->frame()->editor()->compositionStart(),
                renderer()->document()->frame()->editor()->compositionEnd());

        paintDocumentMarkers(context, tx, ty, styleToUse, font, true);

        if (haveSelection && !useCustomUnderlines)
            paintSelection(context, tx, ty, styleToUse, font);
    }

    // 2. Now paint the foreground, including text and decorations like underline/overline (in quirks mode only).
    if (m_len <= 0)
        return;

    Color textFillColor;
    Color textStrokeColor;
    float textStrokeWidth = styleToUse->textStrokeWidth();
    ShadowData* textShadow = paintInfo.forceBlackText ? 0 : styleToUse->textShadow();

    if (paintInfo.forceBlackText) {
        textFillColor = Color::black;
        textStrokeColor = Color::black;
    } else {
        textFillColor = styleToUse->textFillColor();
        if (!textFillColor.isValid())
            textFillColor = styleToUse->color();

        // Make the text fill color legible against a white background
        if (styleToUse->forceBackgroundsToWhite())
            textFillColor = correctedTextColor(textFillColor, Color::white);

        textStrokeColor = styleToUse->textStrokeColor();
        if (!textStrokeColor.isValid())
            textStrokeColor = styleToUse->color();

        // Make the text stroke color legible against a white background
        if (styleToUse->forceBackgroundsToWhite())
            textStrokeColor = correctedTextColor(textStrokeColor, Color::white);
    }

    bool paintSelectedTextOnly = (paintInfo.phase == PaintPhaseSelection);
    bool paintSelectedTextSeparately = false;

    Color selectionFillColor = textFillColor;
    Color selectionStrokeColor = textStrokeColor;
    float selectionStrokeWidth = textStrokeWidth;
    ShadowData* selectionShadow = textShadow;
    if (haveSelection) {
        // Check foreground color first.
        Color foreground = paintInfo.forceBlackText ? Color::black : renderer()->selectionForegroundColor();
        if (foreground.isValid() && foreground != selectionFillColor) {
            if (!paintSelectedTextOnly)
                paintSelectedTextSeparately = true;
            selectionFillColor = foreground;
        }

        if (RenderStyle* pseudoStyle = renderer()->getCachedPseudoStyle(SELECTION)) {
            ShadowData* shadow = paintInfo.forceBlackText ? 0 : pseudoStyle->textShadow();
            if (shadow != selectionShadow) {
                if (!paintSelectedTextOnly)
                    paintSelectedTextSeparately = true;
                selectionShadow = shadow;
            }

            float strokeWidth = pseudoStyle->textStrokeWidth();
            if (strokeWidth != selectionStrokeWidth) {
                if (!paintSelectedTextOnly)
                    paintSelectedTextSeparately = true;
                selectionStrokeWidth = strokeWidth;
            }

            Color stroke = paintInfo.forceBlackText ? Color::black : pseudoStyle->textStrokeColor();
            if (!stroke.isValid())
                stroke = pseudoStyle->color();
            if (stroke != selectionStrokeColor) {
                if (!paintSelectedTextOnly)
                    paintSelectedTextSeparately = true;
                selectionStrokeColor = stroke;
            }
        }
    }

    int baseline = renderer()->style(m_firstLine)->font().ascent();
    IntPoint textOrigin(m_x + tx, m_y + ty + baseline);
    TextRun textRun(textRenderer()->text()->characters() + m_start, m_len, textRenderer()->allowTabs(), textPos(), m_toAdd, direction() == RTL, m_dirOverride || styleToUse->visuallyOrdered());

    int sPos = 0;
    int ePos = 0;
    if (paintSelectedTextOnly || paintSelectedTextSeparately)
        selectionStartEnd(sPos, ePos);

    if (!paintSelectedTextOnly) {
        // For stroked painting, we have to change the text drawing mode.  It's probably dangerous to leave that mutated as a side
        // effect, so only when we know we're stroking, do a save/restore.
        if (textStrokeWidth > 0)
            context->save();

        updateGraphicsContext(context, textFillColor, textStrokeColor, textStrokeWidth);
        if (!paintSelectedTextSeparately || ePos <= sPos) {
            // FIXME: Truncate right-to-left text correctly.
            paintTextWithShadows(context, font, textRun, 0, m_truncation == cNoTruncation ? m_len : m_truncation, textOrigin, m_x + tx, m_y + ty, width(), height(), textShadow, textStrokeWidth > 0);
        } else
            paintTextWithShadows(context, font, textRun, ePos, sPos, textOrigin, m_x + tx, m_y + ty, width(), height(), textShadow, textStrokeWidth > 0);

        if (textStrokeWidth > 0)
            context->restore();
    }

    if ((paintSelectedTextOnly || paintSelectedTextSeparately) && sPos < ePos) {
        // paint only the text that is selected
        if (selectionStrokeWidth > 0)
            context->save();

        updateGraphicsContext(context, selectionFillColor, selectionStrokeColor, selectionStrokeWidth);
        paintTextWithShadows(context, font, textRun, sPos, ePos, textOrigin, m_x + tx, m_y + ty, width(), height(), selectionShadow, selectionStrokeWidth > 0);

        if (selectionStrokeWidth > 0)
            context->restore();
    }

    // Paint decorations
    if (d != TDNONE && paintInfo.phase != PaintPhaseSelection && styleToUse->htmlHacks()) {
        context->setStrokeColor(styleToUse->color());
        paintDecoration(context, tx, ty, d, textShadow);
    }

    if (paintInfo.phase == PaintPhaseForeground) {
        paintDocumentMarkers(context, tx, ty, styleToUse, font, false);

        if (useCustomUnderlines) {
            const Vector<CompositionUnderline>& underlines = renderer()->document()->frame()->editor()->customCompositionUnderlines();
            size_t numUnderlines = underlines.size();

            for (size_t index = 0; index < numUnderlines; ++index) {
                const CompositionUnderline& underline = underlines[index];

                if (underline.endOffset <= start())
                    // underline is completely before this run.  This might be an underline that sits
                    // before the first run we draw, or underlines that were within runs we skipped 
                    // due to truncation.
                    continue;
                
                if (underline.startOffset <= end()) {
                    // underline intersects this run.  Paint it.
                    paintCompositionUnderline(context, tx, ty, underline);
                    if (underline.endOffset > end() + 1)
                        // underline also runs into the next run. Bail now, no more marker advancement.
                        break;
                } else
                    // underline is completely after this run, bail.  A later run will paint it.
                    break;
            }
        }
    }
}

void InlineTextBox::selectionStartEnd(int& sPos, int& ePos)
{
    int startPos, endPos;
    if (renderer()->selectionState() == RenderObject::SelectionInside) {
        startPos = 0;
        endPos = textRenderer()->textLength();
    } else {
        textRenderer()->selectionStartEnd(startPos, endPos);
        if (renderer()->selectionState() == RenderObject::SelectionStart)
            endPos = textRenderer()->textLength();
        else if (renderer()->selectionState() == RenderObject::SelectionEnd)
            startPos = 0;
    }

    sPos = max(startPos - m_start, 0);
    ePos = min(endPos - m_start, (int)m_len);
}

void InlineTextBox::paintSelection(GraphicsContext* context, int tx, int ty, RenderStyle* style, const Font& font)
{
    // See if we have a selection to paint at all.
    int sPos, ePos;
    selectionStartEnd(sPos, ePos);
    if (sPos >= ePos)
        return;

    Color textColor = style->color();
    Color c = renderer()->selectionBackgroundColor();
    if (!c.isValid() || c.alpha() == 0)
        return;

    // If the text color ends up being the same as the selection background, invert the selection
    // background.  This should basically never happen, since the selection has transparency.
    if (textColor == c)
        c = Color(0xff - c.red(), 0xff - c.green(), 0xff - c.blue());

    context->save();
    updateGraphicsContext(context, c, c, 0);  // Don't draw text at all!
    int y = selectionTop();
    int h = selectionHeight();
    context->clip(IntRect(m_x + tx, y + ty, m_width, h));
    context->drawHighlightForText(font, TextRun(textRenderer()->text()->characters() + m_start, m_len, textRenderer()->allowTabs(), textPos(), m_toAdd, 
                                  direction() == RTL, m_dirOverride || style->visuallyOrdered()),
                                  IntPoint(m_x + tx, y + ty), h, c, sPos, ePos);
    context->restore();
}

void InlineTextBox::paintCompositionBackground(GraphicsContext* context, int tx, int ty, RenderStyle* style, const Font& font, int startPos, int endPos)
{
    int offset = m_start;
    int sPos = max(startPos - offset, 0);
    int ePos = min(endPos - offset, (int)m_len);

    if (sPos >= ePos)
        return;

    context->save();

    Color c = Color(225, 221, 85);
    
    updateGraphicsContext(context, c, c, 0); // Don't draw text at all!

    int y = selectionTop();
    int h = selectionHeight();
    context->drawHighlightForText(font, TextRun(textRenderer()->text()->characters() + m_start, m_len, textRenderer()->allowTabs(), textPos(), m_toAdd,
                                  direction() == RTL, m_dirOverride || style->visuallyOrdered()),
                                  IntPoint(m_x + tx, y + ty), h, c, sPos, ePos);
    context->restore();
}

#if PLATFORM(MAC)

void InlineTextBox::paintCustomHighlight(int tx, int ty, const AtomicString& type)
{
    Frame* frame = renderer()->document()->frame();
    if (!frame)
        return;
    Page* page = frame->page();
    if (!page)
        return;

    RootInlineBox* r = root();
    FloatRect rootRect(tx + r->x(), ty + selectionTop(), r->width(), selectionHeight());
    FloatRect textRect(tx + x(), rootRect.y(), width(), rootRect.height());

    page->chrome()->client()->paintCustomHighlight(renderer()->node(), type, textRect, rootRect, true, false);
}

#endif

void InlineTextBox::paintDecoration(GraphicsContext* context, int tx, int ty, int deco, ShadowData* shadow)
{
    tx += m_x;
    ty += m_y;

    if (m_truncation == cFullTruncation)
        return;

    int width = m_width;
    if (m_truncation != cNoTruncation) {
        width = toRenderText(renderer())->width(m_start, m_truncation, textPos(), m_firstLine);
        if (direction() == RTL)
            tx += (m_width - width);
    }
    
    // Get the text decoration colors.
    Color underline, overline, linethrough;
    renderer()->getTextDecorationColors(deco, underline, overline, linethrough, true);
    
    // Use a special function for underlines to get the positioning exactly right.
    bool isPrinting = textRenderer()->document()->printing();
    context->setStrokeThickness(1.0f); // FIXME: We should improve this rule and not always just assume 1.

    bool linesAreOpaque = !isPrinting && (!(deco & UNDERLINE) || underline.alpha() == 255) && (!(deco & OVERLINE) || overline.alpha() == 255) && (!(deco & LINE_THROUGH) || linethrough.alpha() == 255);

    int baseline = renderer()->style(m_firstLine)->font().ascent();

    bool setClip = false;
    int extraOffset = 0;
    if (!linesAreOpaque && shadow && shadow->next) {
        context->save();
        IntRect clipRect(tx, ty, width, baseline + 2);
        for (ShadowData* s = shadow; s; s = s->next) {
            IntRect shadowRect(tx, ty, width, baseline + 2);
            shadowRect.inflate(s->blur);
            shadowRect.move(s->x, s->y);
            clipRect.unite(shadowRect);
            extraOffset = max(extraOffset, max(0, s->y) + s->blur);
        }
        context->save();
        context->clip(clipRect);
        extraOffset += baseline + 2;
        ty += extraOffset;
        setClip = true;
    }

    bool setShadow = false;
    
    do {