bool hitTestFlow(const RenderBlockFlow& flow, const Layout& layout, const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
{
    if (hitTestAction != HitTestForeground)
        return false;

    if (!layout.runCount())
        return false;

    RenderStyle& style = flow.style();
    if (style.visibility() != VISIBLE || style.pointerEvents() == PE_NONE)
        return false;

    RenderObject& renderer = *flow.firstChild();
    LayoutRect rangeRect = locationInContainer.boundingBox();
    rangeRect.moveBy(-accumulatedOffset);

    auto resolver = lineResolver(flow, layout);
    for (FloatRect lineRect : resolver.rangeForRect(rangeRect)) {
        lineRect.moveBy(accumulatedOffset);
        if (!locationInContainer.intersects(lineRect))
            continue;
        renderer.updateHitTestResult(result, locationInContainer.point() - toLayoutSize(accumulatedOffset));
        if (!result.addNodeToRectBasedTestResult(renderer.node(), request, locationInContainer, lineRect))
            return true;
    }

    return false;
}
void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (paintInfo.phase != PaintPhaseForeground)
        return;

    RenderStyle& style = flow.style();
    if (style.visibility() != VISIBLE)
        return;

    bool debugBordersEnabled = flow.frame().settings().simpleLineLayoutDebugBordersEnabled();

    TextPainter textPainter(paintInfo.context());
    textPainter.setFont(style.fontCascade());
    textPainter.setTextPaintStyle(computeTextPaintStyle(flow.frame(), style, paintInfo));

    Optional<TextDecorationPainter> textDecorationPainter;
    if (style.textDecorationsInEffect() != TextDecorationNone) {
        const RenderText* textRenderer = childrenOfType<RenderText>(flow).first();
        if (textRenderer) {
            textDecorationPainter = TextDecorationPainter(paintInfo.context(), style.textDecorationsInEffect(), *textRenderer, false);
            textDecorationPainter->setFont(style.fontCascade());
            textDecorationPainter->setBaseline(style.fontMetrics().ascent());
        }
    }

    LayoutRect paintRect = paintInfo.rect;
    paintRect.moveBy(-paintOffset);

    auto resolver = runResolver(flow, layout);
    float strokeOverflow = std::ceil(flow.style().textStrokeWidth());
    float deviceScaleFactor = flow.document().deviceScaleFactor();
    for (auto run : resolver.rangeForRect(paintRect)) {
        if (run.start() == run.end())
            continue;

        FloatRect rect = run.rect();
        FloatRect visualOverflowRect = rect;
        visualOverflowRect.inflate(strokeOverflow);
        if (paintRect.y() > visualOverflowRect.maxY() || paintRect.maxY() < visualOverflowRect.y())
            continue;

        TextRun textRun(run.text());
        textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
        // x position indicates the line offset from the rootbox. It's always 0 in case of simple line layout.
        textRun.setXPos(0);
        FloatPoint textOrigin = FloatPoint(rect.x() + paintOffset.x(), roundToDevicePixel(run.baselinePosition() + paintOffset.y(), deviceScaleFactor));
        textPainter.paintText(textRun, textRun.length(), rect, textOrigin);
        if (textDecorationPainter) {
            textDecorationPainter->setWidth(rect.width());
            textDecorationPainter->paintTextDecoration(textRun, textOrigin, rect.location() + paintOffset);
        }
        if (debugBordersEnabled)
            paintDebugBorders(paintInfo.context(), LayoutRect(run.rect()), paintOffset);
    }
}
void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (paintInfo.phase != PaintPhaseForeground)
        return;

    RenderStyle& style = flow.style();
    if (style.visibility() != VISIBLE)
        return;

    RenderText& textRenderer = toRenderText(*flow.firstChild());
    ASSERT(!textRenderer.firstTextBox());

    bool debugBordersEnabled = flow.frame().settings().simpleLineLayoutDebugBordersEnabled();

    GraphicsContext& context = *paintInfo.context;

    const Font& font = style.font();
    TextPaintStyle textPaintStyle = computeTextPaintStyle(textRenderer, style, paintInfo);
    GraphicsContextStateSaver stateSaver(context, textPaintStyle.strokeWidth > 0);

    updateGraphicsContext(context, textPaintStyle);
    LayoutRect paintRect = paintInfo.rect;
    paintRect.moveBy(-paintOffset);

    auto resolver = runResolver(flow, layout);
    auto range = resolver.rangeForRect(paintRect);
    for (auto it = range.begin(), end = range.end(); it != end; ++it) {
        const auto& run = *it;
        if (!run.rect().intersects(paintRect))
            continue;
        TextRun textRun(run.text());
        textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
        FloatPoint textOrigin = run.baseline() + paintOffset;
        textOrigin.setY(roundToDevicePixel(LayoutUnit(textOrigin.y()), flow.document().deviceScaleFactor()));
        context.drawText(font, textRun, textOrigin);
        if (debugBordersEnabled)
            paintDebugBorders(context, run.rect(), paintOffset);
    }
}
void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (paintInfo.phase != PaintPhaseForeground)
        return;

    RenderStyle& style = flow.style();
    if (style.visibility() != VISIBLE)
        return;

    bool debugBordersEnabled = flow.frame().settings().simpleLineLayoutDebugBordersEnabled();

    GraphicsContext& context = paintInfo.context();
    const FontCascade& font = style.fontCascade();
    TextPaintStyle textPaintStyle = computeTextPaintStyle(flow.frame(), style, paintInfo);
    GraphicsContextStateSaver stateSaver(context, textPaintStyle.strokeWidth > 0);

    updateGraphicsContext(context, textPaintStyle);
    LayoutRect paintRect = paintInfo.rect;
    paintRect.moveBy(-paintOffset);

    auto resolver = runResolver(flow, layout);
    float strokeOverflow = ceilf(flow.style().textStrokeWidth());
    float deviceScaleFactor = flow.document().deviceScaleFactor();
    for (const auto& run : resolver.rangeForRect(paintRect)) {
        FloatRect rect = run.rect();
        rect.inflate(strokeOverflow);
        if (!rect.intersects(paintRect) || run.start() == run.end())
            continue;
        TextRun textRun(run.text());
        textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
        // x position indicates the line offset from the rootbox. It's always 0 in case of simple line layout.
        textRun.setXPos(0);
        FloatPoint textOrigin = FloatPoint(rect.x() + paintOffset.x(), roundToDevicePixel(run.baselinePosition() + paintOffset.y(), deviceScaleFactor));
        context.drawText(font, textRun, textOrigin);
        if (debugBordersEnabled)
            paintDebugBorders(context, LayoutRect(run.rect()), paintOffset);
    }
}