void PaintLayerClipper::calculateClipRects(const ClipRectsContext& context, ClipRects& clipRects) const
{
bool rootLayerScrolls = m_layoutObject.document().settings() && m_layoutObject.document().settings()->rootLayerScrolls();
if (!m_layoutObject.layer()->parent() && !rootLayerScrolls) {
// The root layer's clip rect is always infinite.
clipRects.reset(LayoutRect(LayoutRect::infiniteIntRect()));
return;
}
bool isClippingRoot = m_layoutObject.layer() == context.rootLayer;
// 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.
PaintLayer* parentLayer = !isClippingRoot ? m_layoutObject.layer()->parent() : 0;
// Ensure that our parent's clip has been calculated so that we can examine the values.
if (parentLayer) {
// FIXME: Why don't we just call getClipRects here?
if (context.usesCache() && parentLayer->clipper().cachedClipRects(context)) {
clipRects = *parentLayer->clipper().cachedClipRects(context);
} else {
parentLayer->clipper().calculateClipRects(context, clipRects);
}
} else {
clipRects.reset(LayoutRect(LayoutRect::infiniteIntRect()));
}
adjustClipRectsForChildren(m_layoutObject, clipRects);
if ((m_layoutObject.hasOverflowClip() && shouldRespectOverflowClip(context)) || m_layoutObject.hasClip()) {
// This offset cannot use convertToLayerCoords, because sometimes our rootLayer may be across
// some transformed layer boundary, for example, in the PaintLayerCompositor overlapMap, where
// clipRects are needed in view space.
applyClipRects(context, m_layoutObject, roundedLayoutPoint(m_layoutObject.localToContainerPoint(FloatPoint(), context.rootLayer->layoutObject())), clipRects);
}
}
TEST_F(PaintLayerClipperTest, NestedContainPaintClip) {
setBodyInnerHTML(
"<div style='contain: paint; width: 200px; height: 200px; overflow: "
"auto'>"
" <div id='target' style='contain: paint; height: 400px'>"
" </div>"
"</div>");
LayoutRect infiniteRect(LayoutRect::infiniteIntRect());
PaintLayer* layer =
toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
ClipRectsContext context(layer->parent(),
PaintingClipRectsIgnoringOverflowClip);
LayoutRect layerBounds;
ClipRect backgroundRect, foregroundRect;
layer->clipper().calculateRects(context, infiniteRect, layerBounds,
backgroundRect, foregroundRect);
EXPECT_EQ(LayoutRect(0, 0, 200, 400), backgroundRect.rect());
EXPECT_EQ(LayoutRect(0, 0, 200, 400), foregroundRect.rect());
EXPECT_EQ(LayoutRect(0, 0, 200, 400), layerBounds);
ClipRectsContext contextClip(layer->parent(), PaintingClipRects);
layer->clipper().calculateRects(contextClip, infiniteRect, layerBounds,
backgroundRect, foregroundRect);
EXPECT_EQ(LayoutRect(0, 0, 200, 200), backgroundRect.rect());
EXPECT_EQ(LayoutRect(0, 0, 200, 200), foregroundRect.rect());
EXPECT_EQ(LayoutRect(0, 0, 200, 400), layerBounds);
}
static bool shouldRepaintSubsequence(PaintLayer& paintLayer, const PaintLayerPaintingInfo& paintingInfo, ShouldRespectOverflowClip respectOverflowClip, const LayoutSize& subpixelAccumulation)
{
bool needsRepaint = false;
// Repaint subsequence if the layer is marked for needing repaint.
if (paintLayer.needsRepaint())
needsRepaint = true;
// Repaint if layer's clip changes.
ClipRects& clipRects = paintLayer.clipper().paintingClipRects(paintingInfo.rootLayer, respectOverflowClip, subpixelAccumulation);
ClipRects* previousClipRects = paintLayer.previousPaintingClipRects();
if (!needsRepaint && &clipRects != previousClipRects && (!previousClipRects || clipRects != *previousClipRects))
needsRepaint = true;
paintLayer.setPreviousPaintingClipRects(clipRects);
// Repaint if previously the layer might be clipped by paintDirtyRect and paintDirtyRect changes.
if (!needsRepaint && paintLayer.previousPaintResult() == PaintLayerPainter::MayBeClippedByPaintDirtyRect && paintLayer.previousPaintDirtyRect() != paintingInfo.paintDirtyRect)
needsRepaint = true;
paintLayer.setPreviousPaintDirtyRect(paintingInfo.paintDirtyRect);
// Repaint if scroll offset accumulation changes.
if (!needsRepaint && paintingInfo.scrollOffsetAccumulation != paintLayer.previousScrollOffsetAccumulationForPainting())
needsRepaint = true;
paintLayer.setPreviousScrollOffsetAccumulationForPainting(paintingInfo.scrollOffsetAccumulation);
return needsRepaint;
}
void PaintLayerClipper::clearClipRectsIncludingDescendants()
{
m_cache = nullptr;
for (PaintLayer* layer = m_layoutObject.layer()->firstChild(); layer; layer = layer->nextSibling()) {
layer->clipper().clearClipRectsIncludingDescendants();
}
}
void PaintLayerClipper::clearClipRectsIncludingDescendants(ClipRectsCacheSlot cacheSlot)
{
if (m_cache)
m_cache->clear(cacheSlot);
for (PaintLayer* layer = m_layoutObject.layer()->firstChild(); layer; layer = layer->nextSibling()) {
layer->clipper().clearClipRectsIncludingDescendants(cacheSlot);
}
}
void PaintLayerClipper::clearClipRectsIncludingDescendants() {
if (m_geometryMapper)
m_geometryMapper.reset(new GeometryMapper);
m_layer.clearClipRectsCache();
for (PaintLayer* layer = m_layer.firstChild(); layer;
layer = layer->nextSibling()) {
layer->clipper().clearClipRectsIncludingDescendants();
}
}
TEST_F(PaintLayerClipperTest, LocalClipRectFixedUnderTransform) {
setBodyInnerHTML(
"<div id='transformed'"
" style='will-change: transform; width: 100px; height: 100px;"
" overflow: hidden'>"
" <div id='fixed' "
" style='position: fixed; width: 100px; height: 100px;"
" top: -50px'>"
" </div>"
"</div>");
LayoutRect infiniteRect(LayoutRect::infiniteIntRect());
PaintLayer* transformed =
toLayoutBoxModelObject(getLayoutObjectByElementId("transformed"))
->layer();
PaintLayer* fixed =
toLayoutBoxModelObject(getLayoutObjectByElementId("fixed"))->layer();
EXPECT_EQ(LayoutRect(0, 0, 100, 100),
transformed->clipper().localClipRect(transformed));
EXPECT_EQ(LayoutRect(0, 50, 100, 100),
fixed->clipper().localClipRect(transformed));
}
TEST_F(PaintLayerClipperTest, LayoutSVGRoot) {
setBodyInnerHTML(
"<!DOCTYPE html>"
"<svg id=target width=200 height=300 style='position: relative'>"
" <rect width=400 height=500 fill='blue'/>"
"</svg>");
Element* target = document().getElementById("target");
PaintLayer* targetPaintLayer =
toLayoutBoxModelObject(target->layoutObject())->layer();
ClipRectsContext context(document().layoutView()->layer(), UncachedClipRects);
LayoutRect layerBounds;
ClipRect backgroundRect, foregroundRect;
targetPaintLayer->clipper().calculateRects(
context, LayoutRect(LayoutRect::infiniteIntRect()), layerBounds,
backgroundRect, foregroundRect);
EXPECT_EQ(LayoutRect(LayoutRect::infiniteIntRect()), backgroundRect.rect());
EXPECT_EQ(LayoutRect(LayoutRect::infiniteIntRect()), foregroundRect.rect());
EXPECT_EQ(LayoutRect(8, 8, 200, 300), layerBounds);
}
TEST_F(PaintLayerClipperTest, LayoutSVGRootChild) {
setBodyInnerHTML(
"<svg width=200 height=300 style='position: relative'>"
" <foreignObject width=400 height=500>"
" <div id=target xmlns='http://www.w3.org/1999/xhtml' "
"style='position: relative'></div>"
" </foreignObject>"
"</svg>");
Element* target = document().getElementById("target");
PaintLayer* targetPaintLayer =
toLayoutBoxModelObject(target->layoutObject())->layer();
ClipRectsContext context(document().layoutView()->layer(), UncachedClipRects);
LayoutRect layerBounds;
ClipRect backgroundRect, foregroundRect;
targetPaintLayer->clipper().calculateRects(
context, LayoutRect(LayoutRect::infiniteIntRect()), layerBounds,
backgroundRect, foregroundRect);
EXPECT_EQ(LayoutRect(8, 8, 200, 300), backgroundRect.rect());
EXPECT_EQ(LayoutRect(8, 8, 200, 300), foregroundRect.rect());
EXPECT_EQ(LayoutRect(8, 8, 400, 0), layerBounds);
}
void PaintLayerClipper::calculateClipRects(const ClipRectsContext& context,
ClipRects& clipRects) const {
const LayoutBoxModelObject& layoutObject = *m_layer.layoutObject();
if (!m_layer.parent() &&
!RuntimeEnabledFeatures::rootLayerScrollingEnabled()) {
// The root layer's clip rect is always infinite.
clipRects.reset(LayoutRect(LayoutRect::infiniteIntRect()));
return;
}
bool isClippingRoot = &m_layer == context.rootLayer;
// 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.
PaintLayer* parentLayer = !isClippingRoot ? m_layer.parent() : nullptr;
// Ensure that our parent's clip has been calculated so that we can examine
// the values.
if (parentLayer) {
parentLayer->clipper().getOrCalculateClipRects(context, clipRects);
} else {
clipRects.reset(LayoutRect(LayoutRect::infiniteIntRect()));
}
adjustClipRectsForChildren(layoutObject, clipRects);
if (shouldClipOverflow(context) || layoutObject.hasClip() ||
(layoutObject.isSVGRoot() &&
toLayoutSVGRoot(&layoutObject)->shouldApplyViewportClip())) {
// This offset cannot use convertToLayerCoords, because sometimes our
// rootLayer may be across some transformed layer boundary, for example, in
// the PaintLayerCompositor overlapMap, where clipRects are needed in view
// space.
applyClipRects(context, layoutObject,
roundedLayoutPoint(layoutObject.localToAncestorPoint(
FloatPoint(), context.rootLayer->layoutObject())),
clipRects);
}
}