The Tor Browser / file comparison
comparison: layout/style/MediaQueryList.h
layout/style/MediaQueryList.h
- branch
- TOR_BUG_9701
- changeset 11
- deefc01c0e14
equal
deleted
inserted
replaced
| -1:000000000000 | 0:774a0948edee |
|---|---|
| 1 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */ | |
| 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 | |
| 6 /* implements DOM interface for querying and observing media queries */ | |
| 7 | |
| 8 #ifndef mozilla_dom_MediaQueryList_h | |
| 9 #define mozilla_dom_MediaQueryList_h | |
| 10 | |
| 11 #include "nsISupports.h" | |
| 12 #include "nsCycleCollectionParticipant.h" | |
| 13 #include "nsAutoPtr.h" | |
| 14 #include "nsTArray.h" | |
| 15 #include "prclist.h" | |
| 16 #include "mozilla/Attributes.h" | |
| 17 #include "nsWrapperCache.h" | |
| 18 #include "mozilla/dom/MediaQueryListBinding.h" | |
| 19 | |
| 20 class nsPresContext; | |
| 21 class nsMediaList; | |
| 22 | |
| 23 namespace mozilla { | |
| 24 namespace dom { | |
| 25 | |
| 26 class MediaQueryList MOZ_FINAL : public nsISupports, | |
| 27 public nsWrapperCache, | |
| 28 public PRCList | |
| 29 { | |
| 30 public: | |
| 31 // The caller who constructs is responsible for calling Evaluate | |
| 32 // before calling any other methods. | |
| 33 MediaQueryList(nsPresContext *aPresContext, | |
| 34 const nsAString &aMediaQueryList); | |
| 35 private: | |
| 36 ~MediaQueryList(); | |
| 37 | |
| 38 public: | |
| 39 NS_DECL_CYCLE_COLLECTING_ISUPPORTS | |
| 40 NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaQueryList) | |
| 41 | |
| 42 nsISupports* GetParentObject() const; | |
| 43 | |
| 44 struct HandleChangeData { | |
| 45 nsRefPtr<MediaQueryList> mql; | |
| 46 nsRefPtr<mozilla::dom::MediaQueryListListener> callback; | |
| 47 }; | |
| 48 | |
| 49 typedef FallibleTArray< nsRefPtr<mozilla::dom::MediaQueryListListener> > CallbackList; | |
| 50 typedef FallibleTArray<HandleChangeData> NotifyList; | |
| 51 | |
| 52 // Appends listeners that need notification to aListenersToNotify | |
| 53 void MediumFeaturesChanged(NotifyList &aListenersToNotify); | |
| 54 | |
| 55 bool HasListeners() const { return !mCallbacks.IsEmpty(); } | |
| 56 | |
| 57 void RemoveAllListeners(); | |
| 58 | |
| 59 JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE; | |
| 60 | |
| 61 // WebIDL methods | |
| 62 void GetMedia(nsAString& aMedia); | |
| 63 bool Matches(); | |
| 64 void AddListener(mozilla::dom::MediaQueryListListener& aListener); | |
| 65 void RemoveListener(mozilla::dom::MediaQueryListListener& aListener); | |
| 66 | |
| 67 private: | |
| 68 void RecomputeMatches(); | |
| 69 | |
| 70 // We only need a pointer to the pres context to support lazy | |
| 71 // reevaluation following dynamic changes. However, this lazy | |
| 72 // reevaluation is perhaps somewhat important, since some usage | |
| 73 // patterns may involve the creation of large numbers of | |
| 74 // MediaQueryList objects which almost immediately become garbage | |
| 75 // (after a single call to the .matches getter). | |
| 76 // | |
| 77 // This pointer does make us a little more dependent on cycle | |
| 78 // collection. | |
| 79 // | |
| 80 // We have a non-null mPresContext for our entire lifetime except | |
| 81 // after cycle collection unlinking. Having a non-null mPresContext | |
| 82 // is equivalent to being in that pres context's mDOMMediaQueryLists | |
| 83 // linked list. | |
| 84 nsRefPtr<nsPresContext> mPresContext; | |
| 85 | |
| 86 nsRefPtr<nsMediaList> mMediaList; | |
| 87 bool mMatches; | |
| 88 bool mMatchesValid; | |
| 89 CallbackList mCallbacks; | |
| 90 }; | |
| 91 | |
| 92 } // namespace dom | |
| 93 } // namespace mozilla | |
| 94 | |
| 95 #endif /* !defined(mozilla_dom_MediaQueryList_h) */ |
