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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 "nsTreeStyleCache.h"
#include "mozilla/ComputedStyleInlines.h"
#include "mozilla/dom/Element.h"
#include "mozilla/ServoStyleSet.h"
#include "nsPresContextInlines.h"
using namespace mozilla;
nsTreeStyleCache::Transition::Transition(DFAState aState, nsAtom* aSymbol)
: mState(aState), mInputSymbol(aSymbol) {}
bool nsTreeStyleCache::Transition::operator==(const Transition& aOther) const {
return aOther.mState == mState && aOther.mInputSymbol == mInputSymbol;
}
uint32_t nsTreeStyleCache::Transition::Hash() const {
// Make a 32-bit integer that combines the low-order 16 bits of the state and
// the input symbol.
uint32_t hb = mState << 16;
uint32_t lb = (NS_PTR_TO_UINT32(mInputSymbol.get()) << 16) >> 16;
return hb + lb;
}
// The ComputedStyle cache impl
ComputedStyle* nsTreeStyleCache::GetComputedStyle(
nsPresContext* aPresContext, nsIContent* aContent, ComputedStyle* aStyle,
nsCSSAnonBoxPseudoStaticAtom* aPseudoElement, const AtomArray& aInputWord) {
MOZ_ASSERT(nsCSSAnonBoxes::IsTreePseudoElement(aPseudoElement));
uint32_t count = aInputWord.Length();
// Go ahead and init the transition table.
if (!mTransitionTable) {
// Automatic miss. Build the table
mTransitionTable = MakeUnique<TransitionTable>();
}
// The first transition is always made off the supplied pseudo-element.
Transition transition(0, aPseudoElement);
DFAState currState = mTransitionTable->Get(transition);
if (!currState) {
// We had a miss. Make a new state and add it to our hash.
currState = mNextState;
mNextState++;
mTransitionTable->InsertOrUpdate(transition, currState);
}
for (uint32_t i = 0; i < count; i++) {
Transition transition(currState, aInputWord[i]);
currState = mTransitionTable->Get(transition);
if (!currState) {
// We had a miss. Make a new state and add it to our hash.
currState = mNextState;
mNextState++;
mTransitionTable->InsertOrUpdate(transition, currState);
}
}
// We're in a final state.
// Look up our ComputedStyle for this state.
ComputedStyle* result = nullptr;
if (mCache) {
result = mCache->GetWeak(currState);
}
if (!result) {
// We missed the cache. Resolve this pseudo-style.
RefPtr<ComputedStyle> newResult =
aPresContext->StyleSet()->ResolveXULTreePseudoStyle(
aContent->AsElement(), aPseudoElement, aStyle, aInputWord);
// Normally we rely on nsIFrame::Init / RestyleManager to call this, but
// these are weird and don't use a frame, yet ::-moz-tree-twisty definitely
// pokes at list-style-image.
newResult->StartImageLoads(*aPresContext->Document());
// Even though xul-tree pseudos are defined in nsCSSAnonBoxList, nothing has
// ever treated them as an anon box, and they don't ever get boxes anyway.
//
// This is really weird, and probably nothing really relies on the result of
// these assert, but it's here just to avoid changing them accidentally.
MOZ_ASSERT(newResult->GetPseudoType() == PseudoStyleType::XULTree);
MOZ_ASSERT(!newResult->IsAnonBox());
MOZ_ASSERT(!newResult->IsPseudoElement());
// Put the ComputedStyle in our table, transferring the owning reference to
// the table.
if (!mCache) {
mCache = MakeUnique<ComputedStyleCache>();
}
result = newResult.get();
mCache->InsertOrUpdate(currState, std::move(newResult));
}
return result;
}