virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) override {
*aSnap = false;
nsHTMLCanvasFrame* f = static_cast<nsHTMLCanvasFrame*>(Frame());
HTMLCanvasElement* canvas =
HTMLCanvasElement::FromContent(f->GetContent());
nsRegion result;
if (canvas->GetIsOpaque()) {
// OK, the entire region painted by the canvas is opaque. But what is
// that region? It's the canvas's "dest rect" (controlled by the
// object-fit/object-position CSS properties), clipped to the container's
// content box (which is what GetBounds() returns). So, we grab those
// rects and intersect them.
nsRect constraintRect = GetBounds(aBuilder, aSnap);
// Need intrinsic size & ratio, for ComputeObjectDestRect:
nsIntSize canvasSize = f->GetCanvasSize();
IntrinsicSize intrinsicSize = IntrinsicSizeFromCanvasSize(canvasSize);
nsSize intrinsicRatio = IntrinsicRatioFromCanvasSize(canvasSize);
const nsRect destRect =
nsLayoutUtils::ComputeObjectDestRect(constraintRect,
intrinsicSize, intrinsicRatio,
f->StylePosition());
return nsRegion(destRect.Intersect(constraintRect));
}
return result;
}
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) {
*aSnap = false;
nsIFrame* f = GetUnderlyingFrame();
HTMLCanvasElement *canvas =
HTMLCanvasElement::FromContent(f->GetContent());
nsRegion result;
if (canvas->GetIsOpaque()) {
result = GetBounds(aBuilder, aSnap);
}
return result;
}
