Ejemplo n.º 1
0
static void adjustClipRectsForChildren(const LayoutObject& layoutObject, ClipRects& clipRects)
{
    EPosition position = layoutObject.style()->position();
    // A fixed object is essentially the root of its containing block hierarchy, so when
    // we encounter such an object, we reset our clip rects to the fixedClipRect.
    if (position == FixedPosition) {
        clipRects.setPosClipRect(clipRects.fixedClipRect());
        clipRects.setOverflowClipRect(clipRects.fixedClipRect());
        clipRects.setFixed(true);
    } else if (position == RelativePosition) {
        clipRects.setPosClipRect(clipRects.overflowClipRect());
    } else if (position == AbsolutePosition) {
        clipRects.setOverflowClipRect(clipRects.posClipRect());
    }
}
Ejemplo n.º 2
0
void RenderLayerClipper::calculateClipRects(const ClipRectsContext& clipRectsContext, ClipRects& clipRects) const
{
    if (!m_renderer->layer()->parent()) {
        // The root layer's clip rect is always infinite.
        clipRects.reset(PaintInfo::infiniteRect());
        return;
    }

    ClipRectsType clipRectsType = clipRectsContext.clipRectsType;
    bool useCached = clipRectsType != TemporaryClipRects;

    // For transformed layers, the root layer was shifted to be us, so there is no need to
    // examine the parent. We want to cache clip rects with us as the root.
    RenderLayer* parentLayer = clipRectsContext.rootLayer != m_renderer->layer() ? m_renderer->layer()->parent() : 0;

    // Ensure that our parent's clip has been calculated so that we can examine the values.
    if (parentLayer) {
        if (useCached && parentLayer->clipper().clipRects(clipRectsContext)) {
            clipRects = *parentLayer->clipper().clipRects(clipRectsContext);
        } else {
            ClipRectsContext parentContext(clipRectsContext);
            parentContext.overlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize; // FIXME: why?
            parentLayer->clipper().calculateClipRects(parentContext, clipRects);
        }
    } else {
        clipRects.reset(PaintInfo::infiniteRect());
    }

    // A fixed object is essentially the root of its containing block hierarchy, so when
    // we encounter such an object, we reset our clip rects to the fixedClipRect.
    if (m_renderer->style()->position() == FixedPosition) {
        clipRects.setPosClipRect(clipRects.fixedClipRect());
        clipRects.setOverflowClipRect(clipRects.fixedClipRect());
        clipRects.setFixed(true);
    } else if (m_renderer->style()->hasInFlowPosition()) {
        clipRects.setPosClipRect(clipRects.overflowClipRect());
    } else if (m_renderer->style()->position() == AbsolutePosition) {
        clipRects.setOverflowClipRect(clipRects.posClipRect());
    }

    // Update the clip rects that will be passed to child layers.
    if ((m_renderer->hasOverflowClip() && (clipRectsContext.respectOverflowClip == RespectOverflowClip || m_renderer->layer() != clipRectsContext.rootLayer)) || m_renderer->hasClip()) {
        // This layer establishes a clip of some kind.

        // This offset cannot use convertToLayerCoords, because sometimes our rootLayer may be across
        // some transformed layer boundary, for example, in the RenderLayerCompositor overlapMap, where
        // clipRects are needed in view space.
        LayoutPoint offset;
        offset = roundedLayoutPoint(m_renderer->localToContainerPoint(FloatPoint(), clipRectsContext.rootLayer->renderer()));
        RenderView* view = m_renderer->view();
        ASSERT(view);
        if (view && clipRects.fixed() && clipRectsContext.rootLayer->renderer() == view) {
            offset -= view->frameView()->scrollOffsetForFixedPosition();
        }

        if (m_renderer->hasOverflowClip()) {
            ClipRect newOverflowClip = toRenderBox(m_renderer)->overflowClipRect(offset, clipRectsContext.region, clipRectsContext.overlayScrollbarSizeRelevancy);
            if (m_renderer->style()->hasBorderRadius())
                newOverflowClip.setHasRadius(true);
            clipRects.setOverflowClipRect(intersection(newOverflowClip, clipRects.overflowClipRect()));
            if (m_renderer->isPositioned())
                clipRects.setPosClipRect(intersection(newOverflowClip, clipRects.posClipRect()));
        }
        if (m_renderer->hasClip()) {
            LayoutRect newPosClip = toRenderBox(m_renderer)->clipRect(offset, clipRectsContext.region);
            clipRects.setPosClipRect(intersection(newPosClip, clipRects.posClipRect()));
            clipRects.setOverflowClipRect(intersection(newPosClip, clipRects.overflowClipRect()));
            clipRects.setFixedClipRect(intersection(newPosClip, clipRects.fixedClipRect()));
        }
    }
}