The Tor Browser / file comparison
comparison: layout/style/nsNthIndexCache.h
layout/style/nsNthIndexCache.h
- branch
- TOR_BUG_9701
- changeset 3
- 141e0f1194b1
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| -1:000000000000 | 0:21f3f1be0f20 |
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| 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ | |
| 2 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 #ifndef nsContentIndexCache_h__ | |
| 6 #define nsContentIndexCache_h__ | |
| 7 | |
| 8 #include "js/HashTable.h" | |
| 9 | |
| 10 class nsIContent; | |
| 11 | |
| 12 namespace mozilla { | |
| 13 namespace dom { | |
| 14 class Element; | |
| 15 } // namespace dom | |
| 16 } // namespace mozilla | |
| 17 | |
| 18 /* | |
| 19 * A class that computes and caches the indices used for :nth-* pseudo-class | |
| 20 * matching. | |
| 21 */ | |
| 22 | |
| 23 class nsNthIndexCache { | |
| 24 private: | |
| 25 typedef mozilla::dom::Element Element; | |
| 26 | |
| 27 public: | |
| 28 /** | |
| 29 * Constructor and destructor out of line so that we don't try to | |
| 30 * instantiate the hashtable template all over the place. | |
| 31 */ | |
| 32 nsNthIndexCache(); | |
| 33 ~nsNthIndexCache(); | |
| 34 | |
| 35 // Returns a 1-based index of the child in its parent. If the child | |
| 36 // is not in its parent's child list (i.e., it is anonymous content), | |
| 37 // returns 0. | |
| 38 // If aCheckEdgeOnly is true, the function will return 1 if the result | |
| 39 // is 1, and something other than 1 (maybe or maybe not a valid | |
| 40 // result) otherwise. | |
| 41 // This must only be called on nodes which have a non-null parent. | |
| 42 int32_t GetNthIndex(Element* aChild, bool aIsOfType, bool aIsFromEnd, | |
| 43 bool aCheckEdgeOnly); | |
| 44 | |
| 45 void Reset(); | |
| 46 | |
| 47 private: | |
| 48 /** | |
| 49 * Returns true if aSibling and aElement should be considered in the same | |
| 50 * list for nth-index purposes, taking aIsOfType into account. | |
| 51 */ | |
| 52 inline bool SiblingMatchesElement(nsIContent* aSibling, Element* aElement, | |
| 53 bool aIsOfType); | |
| 54 | |
| 55 // This node's index for this cache. | |
| 56 // If -2, needs to be computed. | |
| 57 // If -1, needs to be computed but known not to be 1. | |
| 58 // If 0, the node is not at any index in its parent. | |
| 59 typedef int32_t CacheEntry; | |
| 60 | |
| 61 class SystemAllocPolicy { | |
| 62 public: | |
| 63 void *malloc_(size_t bytes) { return ::malloc(bytes); } | |
| 64 void *calloc_(size_t bytes) { return ::calloc(bytes, 1); } | |
| 65 void *realloc_(void *p, size_t bytes) { return ::realloc(p, bytes); } | |
| 66 void free_(void *p) { ::free(p); } | |
| 67 void reportAllocOverflow() const {} | |
| 68 }; | |
| 69 | |
| 70 typedef js::HashMap<nsIContent*, CacheEntry, js::DefaultHasher<nsIContent*>, | |
| 71 SystemAllocPolicy> Cache; | |
| 72 | |
| 73 /** | |
| 74 * Returns true if aResult has been set to the correct value for aChild and | |
| 75 * no more work needs to be done. Returns false otherwise. | |
| 76 * | |
| 77 * aResult is an inout parameter. The in value is the number of elements | |
| 78 * that are in the half-open range (aSibling, aChild] (so including aChild | |
| 79 * but not including aSibling) that match aChild. The out value is the | |
| 80 * correct index for aChild if this function returns true and the number of | |
| 81 * elements in the closed range [aSibling, aChild] that match aChild | |
| 82 * otherwise. | |
| 83 */ | |
| 84 inline bool IndexDeterminedFromPreviousSibling(nsIContent* aSibling, | |
| 85 Element* aChild, | |
| 86 bool aIsOfType, | |
| 87 bool aIsFromEnd, | |
| 88 const Cache& aCache, | |
| 89 int32_t& aResult); | |
| 90 | |
| 91 // Caches of indices for :nth-child(), :nth-last-child(), | |
| 92 // :nth-of-type(), :nth-last-of-type(), keyed by Element*. | |
| 93 // | |
| 94 // The first subscript is 0 for -child and 1 for -of-type, the second | |
| 95 // subscript is 0 for nth- and 1 for nth-last-. | |
| 96 Cache mCaches[2][2]; | |
| 97 }; | |
| 98 | |
| 99 #endif /* nsContentIndexCache_h__ */ |
