forked from mirrors/gecko-dev
265e672179
# ignore-this-changeset --HG-- extra : amend_source : 4d301d3b0b8711c4692392aa76088ba7fd7d1022
83 lines
2.6 KiB
C++
83 lines
2.6 KiB
C++
/* -*- 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
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef nsTreeStyleCache_h__
|
|
#define nsTreeStyleCache_h__
|
|
|
|
#include "mozilla/AtomArray.h"
|
|
#include "mozilla/Attributes.h"
|
|
#include "nsAutoPtr.h"
|
|
#include "nsCOMArray.h"
|
|
#include "nsDataHashtable.h"
|
|
#include "nsRefPtrHashtable.h"
|
|
#include "mozilla/ComputedStyle.h"
|
|
|
|
class nsIContent;
|
|
|
|
class nsTreeStyleCache {
|
|
public:
|
|
nsTreeStyleCache() : mNextState(0) {}
|
|
|
|
~nsTreeStyleCache() { Clear(); }
|
|
|
|
void Clear() {
|
|
mTransitionTable = nullptr;
|
|
mCache = nullptr;
|
|
mNextState = 0;
|
|
}
|
|
|
|
mozilla::ComputedStyle* GetComputedStyle(
|
|
nsPresContext* aPresContext, nsIContent* aContent,
|
|
mozilla::ComputedStyle* aStyle,
|
|
nsCSSAnonBoxPseudoStaticAtom* aPseudoElement,
|
|
const mozilla::AtomArray& aInputWord);
|
|
|
|
protected:
|
|
typedef uint32_t DFAState;
|
|
|
|
class Transition final {
|
|
public:
|
|
Transition(DFAState aState, nsAtom* aSymbol);
|
|
bool operator==(const Transition& aOther) const;
|
|
uint32_t Hash() const;
|
|
|
|
private:
|
|
DFAState mState;
|
|
RefPtr<nsAtom> mInputSymbol;
|
|
};
|
|
|
|
typedef nsDataHashtable<nsGenericHashKey<Transition>, DFAState>
|
|
TransitionTable;
|
|
|
|
// A transition table for a deterministic finite automaton. The DFA
|
|
// takes as its input a single pseudoelement and an ordered set of properties.
|
|
// It transitions on an input word that is the concatenation of the
|
|
// pseudoelement supplied with the properties in the array.
|
|
//
|
|
// It transitions from state to state by looking up entries in the transition
|
|
// table (which is a mapping from (S,i)->S', where S is the current state, i
|
|
// is the next property in the input word, and S' is the state to transition
|
|
// to.
|
|
//
|
|
// If S' is not found, it is constructed and entered into the hashtable
|
|
// under the key (S,i).
|
|
//
|
|
// Once the entire word has been consumed, the final state is used
|
|
// to reference the cache table to locate the ComputedStyle.
|
|
nsAutoPtr<TransitionTable> mTransitionTable;
|
|
|
|
// The cache of all active ComputedStyles. This is a hash from
|
|
// a final state in the DFA, Sf, to the resultant ComputedStyle.
|
|
typedef nsRefPtrHashtable<nsUint32HashKey, mozilla::ComputedStyle>
|
|
ComputedStyleCache;
|
|
nsAutoPtr<ComputedStyleCache> mCache;
|
|
|
|
// An integer counter that is used when we need to make new states in the
|
|
// DFA.
|
|
DFAState mNextState;
|
|
};
|
|
|
|
#endif // nsTreeStyleCache_h__
|