/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* 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 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "nsTreeStyleCache.h" #include "nsStyleSet.h" #include "mozilla/dom/Element.h" #include "mozilla/StyleSetHandle.h" #include "mozilla/StyleSetHandleInlines.h" nsTreeStyleCache::Transition::Transition(DFAState aState, nsIAtom* 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 style context cache impl nsStyleContext* nsTreeStyleCache::GetStyleContext(nsICSSPseudoComparator* aComparator, nsPresContext* aPresContext, nsIContent* aContent, nsStyleContext* aContext, nsIAtom* aPseudoElement, const AtomArray & aInputWord) { uint32_t count = aInputWord.Length(); // Go ahead and init the transition table. if (!mTransitionTable) { // Automatic miss. Build the table mTransitionTable = new 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->Put(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->Put(transition, currState); } } // We're in a final state. // Look up our style context for this state. nsStyleContext* result = nullptr; if (mCache) { result = mCache->GetWeak(currState); } if (!result) { // We missed the cache. Resolve this pseudo-style. // XXXheycam ServoStyleSets do not support XUL tree styles. if (aPresContext->StyleSet()->IsServo()) { MOZ_CRASH("stylo: ServoStyleSets should not support XUL tree styles yet"); } RefPtr<nsStyleContext> newResult = aPresContext->StyleSet()->AsGecko()-> ResolveXULTreePseudoStyle(aContent->AsElement(), aPseudoElement, aContext, aComparator); // Put the style context in our table, transferring the owning reference to the table. if (!mCache) { mCache = new StyleContextCache(); } result = newResult.get(); mCache->Put(currState, newResult.forget()); } return result; }