C++ contentBoxRect函数代码示例

void RenderImage::paintInvalidationOrMarkForLayout(const IntRect* rect)
{
    ASSERT(isRooted());

    LayoutSize oldIntrinsicSize = intrinsicSize();
    LayoutSize newIntrinsicSize = m_imageResource->intrinsicSize();
    updateIntrinsicSizeIfNeeded(newIntrinsicSize);

    bool imageSourceHasChangedSize = oldIntrinsicSize != newIntrinsicSize;
    if (imageSourceHasChangedSize)
        setPreferredLogicalWidthsDirty();

    // If the actual area occupied by the image has changed and it is not constrained by style then a layout is required.
    bool imageSizeIsConstrained = style()->logicalWidth().isSpecified() && style()->logicalHeight().isSpecified();

    // FIXME: We only need to recompute the containing block's preferred size if the containing block's size
    // depends on the image's size (i.e., the container uses shrink-to-fit sizing).
    // There's no easy way to detect that shrink-to-fit is needed, always force a layout.
    bool containingBlockNeedsToRecomputePreferredSize = style()->logicalWidth().isPercent() || style()->logicalMaxWidth().isPercent()  || style()->logicalMinWidth().isPercent();

    if (imageSourceHasChangedSize && (!imageSizeIsConstrained || containingBlockNeedsToRecomputePreferredSize)) {
        setNeedsLayoutAndFullPaintInvalidation();
        return;
    }

    // The image hasn't changed in size or its style constrains its size, so a paint invalidation will suffice.
    if (everHadLayout() && !selfNeedsLayout()) {
        // The inner content rectangle is calculated during layout, but may need an update now
        // (unless the box has already been scheduled for layout). In order to calculate it, we
        // may need values from the containing block, though, so make sure that we're not too
        // early. It may be that layout hasn't even taken place once yet.
        updateInnerContentRect();
    }

    LayoutRect paintInvalidationRect;
    if (rect) {
        // The image changed rect is in source image coordinates,
        // so map from the bounds of the image to the contentsBox.
        paintInvalidationRect = enclosingIntRect(mapRect(*rect, FloatRect(FloatPoint(), m_imageResource->imageSize()), contentBoxRect()));
        // Guard against too-large changed rects.
        paintInvalidationRect.intersect(contentBoxRect());
    } else {
        paintInvalidationRect = contentBoxRect();
    }

    {
        // FIXME: We should not be allowing paint invalidations during layout. crbug.com/339584
        AllowPaintInvalidationScope scoper(frameView());
        DisableCompositingQueryAsserts disabler;
        invalidatePaintRectangle(paintInvalidationRect);
    }

    // Tell any potential compositing layers that the image needs updating.
    contentChanged(ImageChanged);
}

void RenderSnapshottedPlugIn::layout()
{
    StackStats::LayoutCheckPoint layoutCheckPoint;
    LayoutSize oldSize = contentBoxRect().size();

    RenderEmbeddedObject::layout();

    LayoutSize newSize = contentBoxRect().size();
    if (newSize == oldSize)
        return;

    view().frameView().addEmbeddedObjectToUpdate(*this);
}

void RenderWidget::paintContents(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    IntPoint contentPaintOffset = roundedIntPoint(paintOffset + location() + contentBoxRect().location());
    // Tell the widget to paint now. This is the only time the widget is allowed
    // to paint itself. That way it will composite properly with z-indexed layers.
    LayoutRect paintRect = paintInfo.rect;

    IntPoint widgetLocation = m_widget->frameRect().location();
    IntSize widgetPaintOffset = contentPaintOffset - widgetLocation;
    // When painting widgets into compositing layers, tx and ty are relative to the enclosing compositing layer,
    // not the root. In this case, shift the CTM and adjust the paintRect to be root-relative to fix plug-in drawing.
    if (!widgetPaintOffset.isZero()) {
        paintInfo.context().translate(widgetPaintOffset);
        paintRect.move(-widgetPaintOffset);
    }
    // FIXME: Remove repaintrect encolsing/integral snapping when RenderWidget becomes device pixel snapped.
    m_widget->paint(paintInfo.context(), snappedIntRect(paintRect));

    if (!widgetPaintOffset.isZero())
        paintInfo.context().translate(-widgetPaintOffset);

    if (is<FrameView>(*m_widget)) {
        FrameView& frameView = downcast<FrameView>(*m_widget);
        bool runOverlapTests = !frameView.useSlowRepaintsIfNotOverlapped();
        if (paintInfo.overlapTestRequests && runOverlapTests) {
            ASSERT(!paintInfo.overlapTestRequests->contains(this));
            paintInfo.overlapTestRequests->set(this, m_widget->frameRect());
        }
    }
}

bool RenderWidget::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
{
    if (request.allowsChildFrameContent() && widget() && widget()->isFrameView() && toFrameView(widget())->renderView()) {
        FrameView* childFrameView = toFrameView(widget());
        RenderView* childRoot = childFrameView->renderView();

        LayoutPoint adjustedLocation = accumulatedOffset + location();
        LayoutPoint contentOffset = LayoutPoint(borderLeft() + paddingLeft(), borderTop() + paddingTop()) - childFrameView->scrollOffset();
        HitTestLocation newHitTestLocation(locationInContainer, -adjustedLocation - contentOffset);
        HitTestRequest newHitTestRequest(request.type() | HitTestRequest::ChildFrameHitTest);
        HitTestResult childFrameResult(newHitTestLocation);

        bool isInsideChildFrame = childRoot->hitTest(newHitTestRequest, newHitTestLocation, childFrameResult);

        if (newHitTestLocation.isRectBasedTest())
            result.append(childFrameResult);
        else if (isInsideChildFrame)
            result = childFrameResult;

        if (isInsideChildFrame)
            return true;
    }

    bool hadResult = result.innerNode();
    bool inside = RenderReplaced::nodeAtPoint(request, result, locationInContainer, accumulatedOffset, action);

    // Check to see if we are really over the widget itself (and not just in the border/padding area).
    if ((inside || result.isRectBasedTest()) && !hadResult && result.innerNode() == &frameOwnerElement())
        result.setIsOverWidget(contentBoxRect().contains(result.localPoint()));
    return inside;
}

bool RenderImage::foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned) const
{
    if (!m_imageResource->hasImage() || m_imageResource->errorOccurred())
        return false;
    if (m_imageResource->cachedImage() && !m_imageResource->cachedImage()->isLoaded())
        return false;
    if (!contentBoxRect().contains(localRect))
        return false;
    EFillBox backgroundClip = style()->backgroundClip();
    // Background paints under borders.
    if (backgroundClip == BorderFillBox && style()->hasBorder() && !borderObscuresBackground())
        return false;
    // Background shows in padding area.
    if ((backgroundClip == BorderFillBox || backgroundClip == PaddingFillBox) && style()->hasPadding())
        return false;
    // Object-position may leave parts of the content box empty, regardless of the value of object-fit.
    if (style()->objectPosition() != RenderStyle::initialObjectPosition())
        return false;
    // Object-fit may leave parts of the content box empty.
    ObjectFit objectFit = style()->objectFit();
    if (objectFit != ObjectFitFill && objectFit != ObjectFitCover)
        return false;
    // Check for image with alpha.
    return m_imageResource->cachedImage() && m_imageResource->cachedImage()->currentFrameKnownToBeOpaque(this);
}

LayoutRect RenderReplaced::replacedContentRect(const LayoutSize& intrinsicSize) const
{
    LayoutRect contentRect = contentBoxRect();
    if (intrinsicSize.isEmpty())
        return contentRect;

    ObjectFit objectFit = style().objectFit();

    LayoutRect finalRect = contentRect;
    switch (objectFit) {
    case ObjectFitContain:
    case ObjectFitScaleDown:
    case ObjectFitCover:
        finalRect.setSize(finalRect.size().fitToAspectRatio(intrinsicSize, objectFit == ObjectFitCover ? AspectRatioFitGrow : AspectRatioFitShrink));
        if (objectFit != ObjectFitScaleDown || finalRect.width() <= intrinsicSize.width())
            break;
        FALLTHROUGH;
    case ObjectFitNone:
        finalRect.setSize(intrinsicSize);
        break;
    case ObjectFitFill:
        break;
    }

    LengthPoint objectPosition = style().objectPosition();

    LayoutUnit xOffset = minimumValueForLength(objectPosition.x(), contentRect.width() - finalRect.width());
    LayoutUnit yOffset = minimumValueForLength(objectPosition.y(), contentRect.height() - finalRect.height());

    finalRect.move(xOffset, yOffset);

    return finalRect;
}

bool RenderSVGRoot::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int _x, int _y, int _tx, int _ty, HitTestAction hitTestAction)
{
    IntPoint pointInContainer(_x, _y);
    IntSize containerToParentOffset(_tx, _ty);

    IntPoint pointInParent = pointInContainer - containerToParentOffset;
    IntPoint pointInBorderBox = pointInParent - parentOriginToBorderBox();

    // Note: For now, we're ignoring hits to border and padding for <svg>
    IntPoint pointInContentBox = pointInBorderBox - borderOriginToContentBox();
    if (!contentBoxRect().contains(pointInContentBox))
        return false;

    IntPoint localPoint = localToParentTransform().inverse().mapPoint(pointInParent);

    for (RenderObject* child = lastChild(); child; child = child->previousSibling()) {
        if (child->nodeAtFloatPoint(request, result, localPoint, hitTestAction)) {
            // FIXME: CSS/HTML assumes the local point is relative to the border box, right?
            updateHitTestResult(result, pointInBorderBox);
            return true;
        }
    }

    // Spec: Only graphical elements can be targeted by the mouse, so we don't check self here.
    // 16.4: "If there are no graphics elements whose relevant graphics content is under the pointer (i.e., there is no target element), the event is not dispatched."
    return false;
}

void RenderHTMLCanvas::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    GraphicsContext* context = paintInfo.context;

    LayoutRect contentRect = contentBoxRect();
    contentRect.moveBy(paintOffset);
    LayoutRect paintRect = replacedContentRect();
    paintRect.moveBy(paintOffset);

    bool clip = !contentRect.contains(paintRect);
    if (clip) {
        // Not allowed to overflow the content box.
        paintInfo.context->save();
        paintInfo.context->clip(pixelSnappedIntRect(contentRect));
    }

    // FIXME: InterpolationNone should be used if ImageRenderingOptimizeContrast is set.
    // See bug for more details: crbug.com/353716.
    InterpolationQuality interpolationQuality = style()->imageRendering() == ImageRenderingOptimizeContrast ? InterpolationLow : CanvasDefaultInterpolationQuality;

    HTMLCanvasElement* canvas = toHTMLCanvasElement(node());
    LayoutSize layoutSize = contentRect.size();
    if (style()->imageRendering() == ImageRenderingPixelated
        && (layoutSize.width() > canvas->width() || layoutSize.height() > canvas->height() || layoutSize == canvas->size())) {
        interpolationQuality = InterpolationNone;
    }

    InterpolationQuality previousInterpolationQuality = context->imageInterpolationQuality();
    context->setImageInterpolationQuality(interpolationQuality);
    canvas->paint(context, paintRect);
    context->setImageInterpolationQuality(previousInterpolationQuality);

    if (clip)
        context->restore();
}

LayoutRect RenderReplaced::replacedContentRect(const LayoutSize& intrinsicSize) const
{
    LayoutRect contentRect = contentBoxRect();
    ObjectFit objectFit = style().objectFit();
    if (objectFit == ObjectFitFill)
        return contentRect;

    if (!intrinsicSize.width() || !intrinsicSize.height())
        return contentRect;

    LayoutRect finalRect = contentRect;
    switch (objectFit) {
    case ObjectFitContain:
    case ObjectFitScaleDown:
    case ObjectFitCover:
        finalRect.setSize(finalRect.size().fitToAspectRatio(intrinsicSize, objectFit == ObjectFitCover ? AspectRatioFitGrow : AspectRatioFitShrink));
        if (objectFit != ObjectFitScaleDown || finalRect.width() <= intrinsicSize.width())
            break;
        // fall through
    case ObjectFitNone:
        finalRect.setSize(intrinsicSize);
        break;
    case ObjectFitFill:
        ASSERT_NOT_REACHED();
    }

    // FIXME: This is where object-position should be taken into account, but since it's not
    // implemented yet, assume the initial value of "50% 50%".
    LayoutUnit xOffset = (contentRect.width() - finalRect.width()) / 2;
    LayoutUnit yOffset = (contentRect.height() - finalRect.height()) / 2;
    finalRect.move(xOffset, yOffset);

    return finalRect;
}

LayoutSize RenderMultiColumnSet::flowThreadTranslationAtOffset(LayoutUnit blockOffset) const
{
    unsigned columnIndex = columnIndexAtOffset(blockOffset);
    LayoutRect portionRect(flowThreadPortionRectAt(columnIndex));
    flipForWritingMode(portionRect);
    LayoutRect columnRect(columnRectAt(columnIndex));
    flipForWritingMode(columnRect);
    return contentBoxRect().location() + columnRect.location() - portionRect.location();
}

bool RenderWidget::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty, HitTestAction action)
{
    bool hadResult = result.innerNode();
    bool inside = RenderReplaced::nodeAtPoint(request, result, x, y, tx, ty, action);
    
    // Check to see if we are really over the widget itself (and not just in the border/padding area).
    if (inside && !hadResult && result.innerNode() == element())
        result.setIsOverWidget(contentBoxRect().contains(result.localPoint()));
    return inside;
}

bool LayoutPart::nodeAtPointOverWidget(HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
{
    bool hadResult = result.innerNode();
    bool inside = LayoutReplaced::nodeAtPoint(result, locationInContainer, accumulatedOffset, action);

    // Check to see if we are really over the widget itself (and not just in the border/padding area).
    if ((inside || result.isRectBasedTest()) && !hadResult && result.innerNode() == node())
        result.setIsOverWidget(contentBoxRect().contains(result.localPoint()));
    return inside;
}

bool RenderWidget::updateWidgetGeometry()
{
    LayoutRect contentBox = contentBoxRect();
    LayoutRect absoluteContentBox(localToAbsoluteQuad(FloatQuad(contentBox)).boundingBox());
    if (m_widget->isFrameView()) {
        contentBox.setLocation(absoluteContentBox.location());
        return setWidgetGeometry(contentBox);
    }

    return setWidgetGeometry(absoluteContentBox);
}

void RenderMedia::layout()
{
    StackStats::LayoutCheckPoint layoutCheckPoint;
    LayoutSize oldSize = contentBoxRect().size();

    RenderImage::layout();

    RenderBox* controlsRenderer = toRenderBox(m_children.firstChild());
    if (!controlsRenderer)
        return;

    bool controlsNeedLayout = controlsRenderer->needsLayout();
    // If the region chain has changed we also need to relayout the controls to update the region box info.
    // FIXME: We can do better once we compute region box info for RenderReplaced, not only for RenderBlock.
    const RenderFlowThread* flowThread = flowThreadContainingBlock();
    if (flowThread && !controlsNeedLayout) {
        if (flowThread->pageLogicalSizeChanged())
            controlsNeedLayout = true;
    }

    LayoutSize newSize = contentBoxRect().size();
    if (newSize == oldSize && !controlsNeedLayout)
        return;

    // When calling layout() on a child node, a parent must either push a LayoutStateMaintainter, or 
    // instantiate LayoutStateDisabler. Since using a LayoutStateMaintainer is slightly more efficient,
    // and this method will be called many times per second during playback, use a LayoutStateMaintainer:
    LayoutStateMaintainer statePusher(view(), this, locationOffset(), hasTransform() || hasReflection() || style()->isFlippedBlocksWritingMode());

    controlsRenderer->setLocation(LayoutPoint(borderLeft(), borderTop()) + LayoutSize(paddingLeft(), paddingTop()));
    controlsRenderer->style()->setHeight(Length(newSize.height(), Fixed));
    controlsRenderer->style()->setWidth(Length(newSize.width(), Fixed));
    controlsRenderer->setNeedsLayout(true, MarkOnlyThis);
    controlsRenderer->layout();
    setChildNeedsLayout(false);

    statePusher.pop();
}

bool LayoutPart::updateWidgetGeometry()
{
    Widget* widget = this->widget();
    ASSERT(widget);

    LayoutRect contentBox = contentBoxRect();
    LayoutRect absoluteContentBox(localToAbsoluteQuad(FloatQuad(contentBox)).boundingBox());
    if (widget->isFrameView()) {
        contentBox.setLocation(absoluteContentBox.location());
        return setWidgetGeometry(contentBox);
    }

    return setWidgetGeometry(absoluteContentBox);
}