C++ RenderObject::everHadLayout方法代码示例

void SVGRenderSupport::layoutChildren(RenderObject* start, bool selfNeedsLayout)
{
    bool layoutSizeChanged = layoutSizeOfNearestViewportChanged(start);
    bool transformChanged = transformToRootChanged(start);
    bool hasSVGShadow = rendererHasSVGShadow(start);
    bool needsBoundariesUpdate = start->needsBoundariesUpdate();
    HashSet<RenderObject*> notlayoutedObjects;

    for (RenderObject* child = start->firstChildSlow(); child; child = child->nextSibling()) {
        bool needsLayout = selfNeedsLayout;
        bool childEverHadLayout = child->everHadLayout();

        if (needsBoundariesUpdate && hasSVGShadow) {
            // If we have a shadow, our shadow is baked into our children's cached boundaries,
            // so they need to update.
            child->setNeedsBoundariesUpdate();
            needsLayout = true;
        }

        if (transformChanged) {
            // If the transform changed we need to update the text metrics (note: this also happens for layoutSizeChanged=true).
            if (child->isSVGText())
                toRenderSVGText(child)->setNeedsTextMetricsUpdate();
            needsLayout = true;
        }

        if (layoutSizeChanged) {
            // When selfNeedsLayout is false and the layout size changed, we have to check whether this child uses relative lengths
            if (SVGElement* element = child->node()->isSVGElement() ? toSVGElement(child->node()) : 0) {
                if (element->hasRelativeLengths()) {
                    // When the layout size changed and when using relative values tell the RenderSVGShape to update its shape object
                    if (child->isSVGShape())
                        toRenderSVGShape(child)->setNeedsShapeUpdate();
                    else if (child->isSVGText()) {
                        toRenderSVGText(child)->setNeedsTextMetricsUpdate();
                        toRenderSVGText(child)->setNeedsPositioningValuesUpdate();
                    }

                    needsLayout = true;
                }
            }
        }

        if (needsLayout)
            child->setNeedsLayout(MarkOnlyThis);

        if (child->needsLayout()) {
            toRenderElement(child)->layout();
            // Renderers are responsible for repainting themselves when changing, except
            // for the initial paint to avoid potential double-painting caused by non-sensical "old" bounds.
            // We could handle this in the individual objects, but for now it's easier to have
            // parent containers call repaint().  (RenderBlock::layout* has similar logic.)
            if (!childEverHadLayout)
                child->repaint();
        } else if (layoutSizeChanged)
            notlayoutedObjects.add(child);

        ASSERT(!child->needsLayout());
    }

    if (!layoutSizeChanged) {
        ASSERT(notlayoutedObjects.isEmpty());
        return;
    }

    // If the layout size changed, invalidate all resources of all children that didn't go through the layout() code path.
    HashSet<RenderObject*>::iterator end = notlayoutedObjects.end();
    for (HashSet<RenderObject*>::iterator it = notlayoutedObjects.begin(); it != end; ++it)
        invalidateResourcesOfChildren(*it);
}

void SVGRenderSupport::layoutChildren(RenderObject* start, bool selfNeedsLayout)
{
    bool layoutSizeChanged = layoutSizeOfNearestViewportChanged(start);
    bool transformChanged = transformToRootChanged(start);
    HashSet<RenderObject*> notlayoutedObjects;

    for (RenderObject* child = start->slowFirstChild(); child; child = child->nextSibling()) {
        bool needsLayout = selfNeedsLayout;
        bool childEverHadLayout = child->everHadLayout();

        if (transformChanged) {
            // If the transform changed we need to update the text metrics (note: this also happens for layoutSizeChanged=true).
            if (child->isSVGText())
                toRenderSVGText(child)->setNeedsTextMetricsUpdate();
            needsLayout = true;
        }

        if (layoutSizeChanged) {
            // When selfNeedsLayout is false and the layout size changed, we have to check whether this child uses relative lengths
            if (SVGElement* element = child->node()->isSVGElement() ? toSVGElement(child->node()) : 0) {
                if (element->hasRelativeLengths()) {
                    // When the layout size changed and when using relative values tell the RenderSVGShape to update its shape object
                    if (child->isSVGShape()) {
                        toRenderSVGShape(child)->setNeedsShapeUpdate();
                    } else if (child->isSVGText()) {
                        toRenderSVGText(child)->setNeedsTextMetricsUpdate();
                        toRenderSVGText(child)->setNeedsPositioningValuesUpdate();
                    }

                    needsLayout = true;
                }
            }
        }

        SubtreeLayoutScope layoutScope(*child);
        // Resource containers are nasty: they can invalidate clients outside the current SubtreeLayoutScope.
        // Since they only care about viewport size changes (to resolve their relative lengths), we trigger
        // their invalidation directly from SVGSVGElement::svgAttributeChange() or at a higher
        // SubtreeLayoutScope (in RenderView::layout()).
        if (needsLayout && !child->isSVGResourceContainer())
            layoutScope.setNeedsLayout(child);

        layoutResourcesIfNeeded(child);

        if (child->needsLayout()) {
            child->layout();
            // Renderers are responsible for repainting themselves when changing, except
            // for the initial paint to avoid potential double-painting caused by non-sensical "old" bounds.
            // We could handle this in the individual objects, but for now it's easier to have
            // parent containers call repaint().  (RenderBlock::layout* has similar logic.)
            if (!childEverHadLayout && !RuntimeEnabledFeatures::repaintAfterLayoutEnabled())
                child->paintInvalidationForWholeRenderer();
        } else if (layoutSizeChanged) {
            notlayoutedObjects.add(child);
        }
    }

    if (!layoutSizeChanged) {
        ASSERT(notlayoutedObjects.isEmpty());
        return;
    }

    // If the layout size changed, invalidate all resources of all children that didn't go through the layout() code path.
    HashSet<RenderObject*>::iterator end = notlayoutedObjects.end();
    for (HashSet<RenderObject*>::iterator it = notlayoutedObjects.begin(); it != end; ++it)
        invalidateResourcesOfChildren(*it);
}

void SVGRenderSupport::layoutChildren(RenderElement& start, bool selfNeedsLayout)
{
    bool layoutSizeChanged = layoutSizeOfNearestViewportChanged(start);
    bool transformChanged = transformToRootChanged(&start);
    bool hasSVGShadow = rendererHasSVGShadow(start);
    bool needsBoundariesUpdate = start.needsBoundariesUpdate();
    HashSet<RenderElement*> elementsThatDidNotReceiveLayout;

    for (RenderObject* child = start.firstChild(); child; child = child->nextSibling()) {
        bool needsLayout = selfNeedsLayout;
        bool childEverHadLayout = child->everHadLayout();

        if (needsBoundariesUpdate && hasSVGShadow) {
            // If we have a shadow, our shadow is baked into our children's cached boundaries,
            // so they need to update.
            child->setNeedsBoundariesUpdate();
            needsLayout = true;
        }

        if (transformChanged) {
            // If the transform changed we need to update the text metrics (note: this also happens for layoutSizeChanged=true).
            if (is<RenderSVGText>(*child))
                downcast<RenderSVGText>(*child).setNeedsTextMetricsUpdate();
            needsLayout = true;
        }

        if (layoutSizeChanged) {
            // When selfNeedsLayout is false and the layout size changed, we have to check whether this child uses relative lengths
            if (SVGElement* element = is<SVGElement>(*child->node()) ? downcast<SVGElement>(child->node()) : nullptr) {
                if (element->hasRelativeLengths()) {
                    // When the layout size changed and when using relative values tell the RenderSVGShape to update its shape object
                    if (is<RenderSVGShape>(*child))
                        downcast<RenderSVGShape>(*child).setNeedsShapeUpdate();
                    else if (is<RenderSVGText>(*child)) {
                        RenderSVGText& svgText = downcast<RenderSVGText>(*child);
                        svgText.setNeedsTextMetricsUpdate();
                        svgText.setNeedsPositioningValuesUpdate();
                    }

                    needsLayout = true;
                }
            }
        }

        if (needsLayout)
            child->setNeedsLayout(MarkOnlyThis);

        if (child->needsLayout()) {
            downcast<RenderElement>(*child).layout();
            // Renderers are responsible for repainting themselves when changing, except
            // for the initial paint to avoid potential double-painting caused by non-sensical "old" bounds.
            // We could handle this in the individual objects, but for now it's easier to have
            // parent containers call repaint().  (RenderBlock::layout* has similar logic.)
            if (!childEverHadLayout)
                child->repaint();
        } else if (layoutSizeChanged && is<RenderElement>(*child))
            elementsThatDidNotReceiveLayout.add(downcast<RenderElement>(child));

        ASSERT(!child->needsLayout());
    }

    if (!layoutSizeChanged) {
        ASSERT(elementsThatDidNotReceiveLayout.isEmpty());
        return;
    }

    // If the layout size changed, invalidate all resources of all children that didn't go through the layout() code path.
    for (auto* element : elementsThatDidNotReceiveLayout)
        invalidateResourcesOfChildren(*element);
}