1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/style/MediaQueryList.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,95 @@
1.4 +/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* implements DOM interface for querying and observing media queries */
1.10 +
1.11 +#ifndef mozilla_dom_MediaQueryList_h
1.12 +#define mozilla_dom_MediaQueryList_h
1.13 +
1.14 +#include "nsISupports.h"
1.15 +#include "nsCycleCollectionParticipant.h"
1.16 +#include "nsAutoPtr.h"
1.17 +#include "nsTArray.h"
1.18 +#include "prclist.h"
1.19 +#include "mozilla/Attributes.h"
1.20 +#include "nsWrapperCache.h"
1.21 +#include "mozilla/dom/MediaQueryListBinding.h"
1.22 +
1.23 +class nsPresContext;
1.24 +class nsMediaList;
1.25 +
1.26 +namespace mozilla {
1.27 +namespace dom {
1.28 +
1.29 +class MediaQueryList MOZ_FINAL : public nsISupports,
1.30 + public nsWrapperCache,
1.31 + public PRCList
1.32 +{
1.33 +public:
1.34 + // The caller who constructs is responsible for calling Evaluate
1.35 + // before calling any other methods.
1.36 + MediaQueryList(nsPresContext *aPresContext,
1.37 + const nsAString &aMediaQueryList);
1.38 +private:
1.39 + ~MediaQueryList();
1.40 +
1.41 +public:
1.42 + NS_DECL_CYCLE_COLLECTING_ISUPPORTS
1.43 + NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaQueryList)
1.44 +
1.45 + nsISupports* GetParentObject() const;
1.46 +
1.47 + struct HandleChangeData {
1.48 + nsRefPtr<MediaQueryList> mql;
1.49 + nsRefPtr<mozilla::dom::MediaQueryListListener> callback;
1.50 + };
1.51 +
1.52 + typedef FallibleTArray< nsRefPtr<mozilla::dom::MediaQueryListListener> > CallbackList;
1.53 + typedef FallibleTArray<HandleChangeData> NotifyList;
1.54 +
1.55 + // Appends listeners that need notification to aListenersToNotify
1.56 + void MediumFeaturesChanged(NotifyList &aListenersToNotify);
1.57 +
1.58 + bool HasListeners() const { return !mCallbacks.IsEmpty(); }
1.59 +
1.60 + void RemoveAllListeners();
1.61 +
1.62 + JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE;
1.63 +
1.64 + // WebIDL methods
1.65 + void GetMedia(nsAString& aMedia);
1.66 + bool Matches();
1.67 + void AddListener(mozilla::dom::MediaQueryListListener& aListener);
1.68 + void RemoveListener(mozilla::dom::MediaQueryListListener& aListener);
1.69 +
1.70 +private:
1.71 + void RecomputeMatches();
1.72 +
1.73 + // We only need a pointer to the pres context to support lazy
1.74 + // reevaluation following dynamic changes. However, this lazy
1.75 + // reevaluation is perhaps somewhat important, since some usage
1.76 + // patterns may involve the creation of large numbers of
1.77 + // MediaQueryList objects which almost immediately become garbage
1.78 + // (after a single call to the .matches getter).
1.79 + //
1.80 + // This pointer does make us a little more dependent on cycle
1.81 + // collection.
1.82 + //
1.83 + // We have a non-null mPresContext for our entire lifetime except
1.84 + // after cycle collection unlinking. Having a non-null mPresContext
1.85 + // is equivalent to being in that pres context's mDOMMediaQueryLists
1.86 + // linked list.
1.87 + nsRefPtr<nsPresContext> mPresContext;
1.88 +
1.89 + nsRefPtr<nsMediaList> mMediaList;
1.90 + bool mMatches;
1.91 + bool mMatchesValid;
1.92 + CallbackList mCallbacks;
1.93 +};
1.94 +
1.95 +} // namespace dom
1.96 +} // namespace mozilla
1.97 +
1.98 +#endif /* !defined(mozilla_dom_MediaQueryList_h) */
