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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "DisplayItemClipChain.h"
#include "nsDisplayList.h"
namespace mozilla {
/* static */ const DisplayItemClip* DisplayItemClipChain::ClipForASR(
const DisplayItemClipChain* aClipChain, const ActiveScrolledRoot* aASR) {
while (aClipChain &&
!ActiveScrolledRoot::IsAncestor(aClipChain->mASR, aASR)) {
aClipChain = aClipChain->mParent;
}
return (aClipChain && aClipChain->mASR == aASR) ? &aClipChain->mClip
: nullptr;
}
bool DisplayItemClipChain::Equal(const DisplayItemClipChain* aClip1,
const DisplayItemClipChain* aClip2) {
if (aClip1 == aClip2) {
return true;
}
if (!aClip1 || !aClip2) {
return false;
}
bool ret = aClip1->mASR == aClip2->mASR && aClip1->mClip == aClip2->mClip &&
Equal(aClip1->mParent, aClip2->mParent);
// Sanity check: if two clip chains are equal they must hash to the same
// thing too, or Bad Things (TM) will happen.
MOZ_ASSERT(!ret || (Hash(aClip1) == Hash(aClip2)));
return ret;
}
uint32_t DisplayItemClipChain::Hash(const DisplayItemClipChain* aClip) {
if (!aClip) {
return 0;
}
// We include the number of rounded rects in the hash but not their contents.
// This is to keep the hash fast, because most clips will not have rounded
// rects and including them will slow down the hash in the common case. Note
// that the ::Equal check still checks the rounded rect contents, so in case
// of hash collisions the clip chains can still be distinguished using that.
uint32_t hash = HashGeneric(aClip->mASR, aClip->mClip.GetRoundedRectCount());
if (aClip->mClip.HasClip()) {
const nsRect& rect = aClip->mClip.GetClipRect();
// empty rects are considered equal in DisplayItemClipChain::Equal, even
// though they may have different x and y coordinates. So make sure they
// hash to the same thing in those cases too.
if (!rect.IsEmpty()) {
hash = AddToHash(hash, rect.x, rect.y, rect.width, rect.height);
}
}
return hash;
}
/* static */
nsCString DisplayItemClipChain::ToString(
const DisplayItemClipChain* aClipChain) {
nsAutoCString str;
for (auto* sc = aClipChain; sc; sc = sc->mParent) {
if (sc->mASR) {
str.AppendPrintf("0x%p <%s> [0x%p]", sc, sc->mClip.ToString().get(),
sc->mASR->mScrollableFrame);
} else {
str.AppendPrintf("0x%p <%s> [root asr]", sc, sc->mClip.ToString().get());
}
if (sc->mParent) {
str.AppendLiteral(", ");
}
}
return std::move(str);
}
bool DisplayItemClipChain::HasRoundedCorners() const {
return mClip.GetRoundedRectCount() > 0 ||
(mParent && mParent->HasRoundedCorners());
}
} // namespace mozilla