layout/style/nsCSSPropertySet.h@141e0f1194b1 (annotated)
layout/style/nsCSSPropertySet.h
Wed, 31 Dec 2014 07:16:47 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 07:16:47 +0100
- branch
- TOR_BUG_9701
- changeset 3
- 141e0f1194b1
- permissions
- -rw-r--r--
Revert simplistic fix pending revisit of Mozilla integration attempt.
| michael@0 | 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 4 | |
| michael@0 | 5 | /* bit vectors for sets of CSS properties */ |
| michael@0 | 6 | |
| michael@0 | 7 | #ifndef nsCSSPropertySet_h__ |
| michael@0 | 8 | #define nsCSSPropertySet_h__ |
| michael@0 | 9 | |
| michael@0 | 10 | #include "mozilla/ArrayUtils.h" |
| michael@0 | 11 | |
| michael@0 | 12 | #include "nsCSSProperty.h" |
| michael@0 | 13 | #include <limits.h> // for CHAR_BIT |
| michael@0 | 14 | |
| michael@0 | 15 | /** |
| michael@0 | 16 | * nsCSSPropertySet maintains a set of non-shorthand CSS properties. In |
| michael@0 | 17 | * other words, for each longhand CSS property we support, it has a bit |
| michael@0 | 18 | * for whether that property is in the set. |
| michael@0 | 19 | */ |
| michael@0 | 20 | class nsCSSPropertySet { |
| michael@0 | 21 | public: |
| michael@0 | 22 | nsCSSPropertySet() { Empty(); } |
| michael@0 | 23 | // auto-generated copy-constructor OK |
| michael@0 | 24 | |
| michael@0 | 25 | void AssertInSetRange(nsCSSProperty aProperty) const { |
| michael@0 | 26 | NS_ASSERTION(0 <= aProperty && |
| michael@0 | 27 | aProperty < eCSSProperty_COUNT_no_shorthands, |
| michael@0 | 28 | "out of bounds"); |
| michael@0 | 29 | } |
| michael@0 | 30 | |
| michael@0 | 31 | // Conversion of aProperty to |size_t| after AssertInSetRange |
| michael@0 | 32 | // lets the compiler generate significantly tighter code. |
| michael@0 | 33 | |
| michael@0 | 34 | void AddProperty(nsCSSProperty aProperty) { |
| michael@0 | 35 | AssertInSetRange(aProperty); |
| michael@0 | 36 | size_t p = aProperty; |
| michael@0 | 37 | mProperties[p / kBitsInChunk] |= |
| michael@0 | 38 | property_set_type(1) << (p % kBitsInChunk); |
| michael@0 | 39 | } |
| michael@0 | 40 | |
| michael@0 | 41 | void RemoveProperty(nsCSSProperty aProperty) { |
| michael@0 | 42 | AssertInSetRange(aProperty); |
| michael@0 | 43 | size_t p = aProperty; |
| michael@0 | 44 | mProperties[p / kBitsInChunk] &= |
| michael@0 | 45 | ~(property_set_type(1) << (p % kBitsInChunk)); |
| michael@0 | 46 | } |
| michael@0 | 47 | |
| michael@0 | 48 | bool HasProperty(nsCSSProperty aProperty) const { |
| michael@0 | 49 | AssertInSetRange(aProperty); |
| michael@0 | 50 | size_t p = aProperty; |
| michael@0 | 51 | return (mProperties[p / kBitsInChunk] & |
| michael@0 | 52 | (property_set_type(1) << (p % kBitsInChunk))) != 0; |
| michael@0 | 53 | } |
| michael@0 | 54 | |
| michael@0 | 55 | void Empty() { |
| michael@0 | 56 | memset(mProperties, 0, sizeof(mProperties)); |
| michael@0 | 57 | } |
| michael@0 | 58 | |
| michael@0 | 59 | void AssertIsEmpty(const char* aText) const { |
| michael@0 | 60 | for (size_t i = 0; i < mozilla::ArrayLength(mProperties); ++i) { |
| michael@0 | 61 | NS_ASSERTION(mProperties[i] == 0, aText); |
| michael@0 | 62 | } |
| michael@0 | 63 | } |
| michael@0 | 64 | |
| michael@0 | 65 | private: |
| michael@0 | 66 | typedef unsigned long property_set_type; |
| michael@0 | 67 | public: |
| michael@0 | 68 | // number of bits in |property_set_type|. |
| michael@0 | 69 | static const size_t kBitsInChunk = sizeof(property_set_type)*CHAR_BIT; |
| michael@0 | 70 | // number of |property_set_type|s in the set |
| michael@0 | 71 | static const size_t kChunkCount = |
| michael@0 | 72 | (eCSSProperty_COUNT_no_shorthands + kBitsInChunk - 1) / kBitsInChunk; |
| michael@0 | 73 | |
| michael@0 | 74 | /* |
| michael@0 | 75 | * For fast enumeration of all the bits that are set, callers can |
| michael@0 | 76 | * check each chunk against zero (since in normal cases few bits are |
| michael@0 | 77 | * likely to be set). |
| michael@0 | 78 | */ |
| michael@0 | 79 | bool HasPropertyInChunk(size_t aChunk) const { |
| michael@0 | 80 | return mProperties[aChunk] != 0; |
| michael@0 | 81 | } |
| michael@0 | 82 | bool HasPropertyAt(size_t aChunk, size_t aBit) const { |
| michael@0 | 83 | return (mProperties[aChunk] & (property_set_type(1) << aBit)) != 0; |
| michael@0 | 84 | } |
| michael@0 | 85 | static nsCSSProperty CSSPropertyAt(size_t aChunk, size_t aBit) { |
| michael@0 | 86 | return nsCSSProperty(aChunk * kBitsInChunk + aBit); |
| michael@0 | 87 | } |
| michael@0 | 88 | |
| michael@0 | 89 | private: |
| michael@0 | 90 | property_set_type mProperties[kChunkCount]; |
| michael@0 | 91 | }; |
| michael@0 | 92 | |
| michael@0 | 93 | #endif /* !defined(nsCSSPropertySet_h__) */ |
