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comparison: layout/style/nsIMediaList.h
layout/style/nsIMediaList.h
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| -1:000000000000 | 0:8d30b16d38d4 |
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| 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- | |
| 2 * | |
| 3 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 /* | |
| 8 * representation of media lists used when linking to style sheets or by | |
| 9 * @media rules | |
| 10 */ | |
| 11 | |
| 12 #ifndef nsIMediaList_h_ | |
| 13 #define nsIMediaList_h_ | |
| 14 | |
| 15 #include "nsIDOMMediaList.h" | |
| 16 #include "nsTArray.h" | |
| 17 #include "nsIAtom.h" | |
| 18 #include "nsCSSValue.h" | |
| 19 #include "nsWrapperCache.h" | |
| 20 #include "mozilla/Attributes.h" | |
| 21 #include "mozilla/ErrorResult.h" | |
| 22 | |
| 23 class nsPresContext; | |
| 24 class nsCSSStyleSheet; | |
| 25 class nsAString; | |
| 26 struct nsMediaFeature; | |
| 27 | |
| 28 struct nsMediaExpression { | |
| 29 enum Range { eMin, eMax, eEqual }; | |
| 30 | |
| 31 const nsMediaFeature *mFeature; | |
| 32 Range mRange; | |
| 33 nsCSSValue mValue; | |
| 34 | |
| 35 // aActualValue must be obtained from mFeature->mGetter | |
| 36 bool Matches(nsPresContext* aPresContext, | |
| 37 const nsCSSValue& aActualValue) const; | |
| 38 }; | |
| 39 | |
| 40 /** | |
| 41 * An nsMediaQueryResultCacheKey records what feature/value combinations | |
| 42 * a set of media query results are valid for. This allows the caller | |
| 43 * to quickly learn whether a prior result of media query evaluation is | |
| 44 * still valid (e.g., due to a window size change) without rerunning all | |
| 45 * of the evaluation and rebuilding the list of rules. | |
| 46 * | |
| 47 * This object may not be used after any media rules in any of the | |
| 48 * sheets it was given to have been modified. However, this is | |
| 49 * generally not a problem since ClearRuleCascades is called on the | |
| 50 * sheet whenever this happens, and these objects are stored inside the | |
| 51 * rule cascades. (FIXME: We're not actually doing this all the time.) | |
| 52 * | |
| 53 * The implementation could be further optimized in the future to store | |
| 54 * ranges (combinations of less-than, less-than-or-equal, greater-than, | |
| 55 * greater-than-or-equal, equal, not-equal, present, not-present) for | |
| 56 * each feature rather than simply storing the list of expressions. | |
| 57 * However, this requires combining any such ranges. | |
| 58 */ | |
| 59 class nsMediaQueryResultCacheKey { | |
| 60 public: | |
| 61 nsMediaQueryResultCacheKey(nsIAtom* aMedium) | |
| 62 : mMedium(aMedium) | |
| 63 {} | |
| 64 | |
| 65 /** | |
| 66 * Record that aExpression was tested while building the cached set | |
| 67 * that this cache key is for, and that aExpressionMatches was whether | |
| 68 * it matched. | |
| 69 */ | |
| 70 void AddExpression(const nsMediaExpression* aExpression, | |
| 71 bool aExpressionMatches); | |
| 72 bool Matches(nsPresContext* aPresContext) const; | |
| 73 private: | |
| 74 struct ExpressionEntry { | |
| 75 // FIXME: if we were better at maintaining invariants about clearing | |
| 76 // rule cascades when media lists change, this could be a |const | |
| 77 // nsMediaExpression*| instead. | |
| 78 nsMediaExpression mExpression; | |
| 79 bool mExpressionMatches; | |
| 80 }; | |
| 81 struct FeatureEntry { | |
| 82 const nsMediaFeature *mFeature; | |
| 83 InfallibleTArray<ExpressionEntry> mExpressions; | |
| 84 }; | |
| 85 nsCOMPtr<nsIAtom> mMedium; | |
| 86 nsTArray<FeatureEntry> mFeatureCache; | |
| 87 }; | |
| 88 | |
| 89 class nsMediaQuery { | |
| 90 public: | |
| 91 nsMediaQuery() | |
| 92 : mNegated(false) | |
| 93 , mHasOnly(false) | |
| 94 , mTypeOmitted(false) | |
| 95 , mHadUnknownExpression(false) | |
| 96 { | |
| 97 } | |
| 98 | |
| 99 private: | |
| 100 // for Clone only | |
| 101 nsMediaQuery(const nsMediaQuery& aOther) | |
| 102 : mNegated(aOther.mNegated) | |
| 103 , mHasOnly(aOther.mHasOnly) | |
| 104 , mTypeOmitted(aOther.mTypeOmitted) | |
| 105 , mHadUnknownExpression(aOther.mHadUnknownExpression) | |
| 106 , mMediaType(aOther.mMediaType) | |
| 107 , mExpressions(aOther.mExpressions) | |
| 108 { | |
| 109 MOZ_ASSERT(mExpressions.Length() == aOther.mExpressions.Length()); | |
| 110 } | |
| 111 | |
| 112 public: | |
| 113 | |
| 114 void SetNegated() { mNegated = true; } | |
| 115 void SetHasOnly() { mHasOnly = true; } | |
| 116 void SetTypeOmitted() { mTypeOmitted = true; } | |
| 117 void SetHadUnknownExpression() { mHadUnknownExpression = true; } | |
| 118 void SetType(nsIAtom* aMediaType) { | |
| 119 NS_ASSERTION(aMediaType, | |
| 120 "expected non-null"); | |
| 121 mMediaType = aMediaType; | |
| 122 } | |
| 123 | |
| 124 // Return a new nsMediaExpression in the array for the caller to fill | |
| 125 // in. The caller must either fill it in completely, or call | |
| 126 // SetHadUnknownExpression on this nsMediaQuery. | |
| 127 // Returns null on out-of-memory. | |
| 128 nsMediaExpression* NewExpression() { return mExpressions.AppendElement(); } | |
| 129 | |
| 130 void AppendToString(nsAString& aString) const; | |
| 131 | |
| 132 nsMediaQuery* Clone() const; | |
| 133 | |
| 134 // Does this query apply to the presentation? | |
| 135 // If |aKey| is non-null, add cache information to it. | |
| 136 bool Matches(nsPresContext* aPresContext, | |
| 137 nsMediaQueryResultCacheKey* aKey) const; | |
| 138 | |
| 139 private: | |
| 140 bool mNegated; | |
| 141 bool mHasOnly; // only needed for serialization | |
| 142 bool mTypeOmitted; // only needed for serialization | |
| 143 bool mHadUnknownExpression; | |
| 144 nsCOMPtr<nsIAtom> mMediaType; | |
| 145 nsTArray<nsMediaExpression> mExpressions; | |
| 146 }; | |
| 147 | |
| 148 class nsMediaList MOZ_FINAL : public nsIDOMMediaList | |
| 149 , public nsWrapperCache | |
| 150 { | |
| 151 public: | |
| 152 typedef mozilla::ErrorResult ErrorResult; | |
| 153 | |
| 154 nsMediaList(); | |
| 155 | |
| 156 virtual JSObject* | |
| 157 WrapObject(JSContext* aCx) MOZ_OVERRIDE; | |
| 158 nsISupports* GetParentObject() const | |
| 159 { | |
| 160 return nullptr; | |
| 161 } | |
| 162 | |
| 163 NS_DECL_CYCLE_COLLECTING_ISUPPORTS | |
| 164 NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsMediaList) | |
| 165 | |
| 166 NS_DECL_NSIDOMMEDIALIST | |
| 167 | |
| 168 void GetText(nsAString& aMediaText); | |
| 169 void SetText(const nsAString& aMediaText); | |
| 170 | |
| 171 // Does this query apply to the presentation? | |
| 172 // If |aKey| is non-null, add cache information to it. | |
| 173 bool Matches(nsPresContext* aPresContext, | |
| 174 nsMediaQueryResultCacheKey* aKey); | |
| 175 | |
| 176 nsresult SetStyleSheet(nsCSSStyleSheet* aSheet); | |
| 177 void AppendQuery(nsAutoPtr<nsMediaQuery>& aQuery) { | |
| 178 // Takes ownership of aQuery | |
| 179 mArray.AppendElement(aQuery.forget()); | |
| 180 } | |
| 181 | |
| 182 already_AddRefed<nsMediaList> Clone(); | |
| 183 | |
| 184 nsMediaQuery* MediumAt(int32_t aIndex) { return mArray[aIndex]; } | |
| 185 void Clear() { mArray.Clear(); } | |
| 186 | |
| 187 // WebIDL | |
| 188 // XPCOM GetMediaText and SetMediaText are fine. | |
| 189 uint32_t Length() { return mArray.Length(); } | |
| 190 void IndexedGetter(uint32_t aIndex, bool& aFound, nsAString& aReturn); | |
| 191 // XPCOM Item is fine. | |
| 192 void DeleteMedium(const nsAString& aMedium, ErrorResult& aRv) | |
| 193 { | |
| 194 aRv = DeleteMedium(aMedium); | |
| 195 } | |
| 196 void AppendMedium(const nsAString& aMedium, ErrorResult& aRv) | |
| 197 { | |
| 198 aRv = AppendMedium(aMedium); | |
| 199 } | |
| 200 | |
| 201 protected: | |
| 202 ~nsMediaList(); | |
| 203 | |
| 204 nsresult Delete(const nsAString & aOldMedium); | |
| 205 nsresult Append(const nsAString & aOldMedium); | |
| 206 | |
| 207 InfallibleTArray<nsAutoPtr<nsMediaQuery> > mArray; | |
| 208 // not refcounted; sheet will let us know when it goes away | |
| 209 // mStyleSheet is the sheet that needs to be dirtied when this medialist | |
| 210 // changes | |
| 211 nsCSSStyleSheet* mStyleSheet; | |
| 212 }; | |
| 213 #endif /* !defined(nsIMediaList_h_) */ |
