mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-05 00:25:27 +00:00
107 lines
3.9 KiB
C++
107 lines
3.9 KiB
C++
/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
|
|
/* ***** BEGIN LICENSE BLOCK *****
|
|
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public License Version
|
|
* 1.1 (the "License"); you may not use this file except in compliance with
|
|
* the License. You may obtain a copy of the License at
|
|
* http://www.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS IS" basis,
|
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
|
* for the specific language governing rights and limitations under the
|
|
* License.
|
|
*
|
|
* The Original Code is nsDOMMediaQueryList.
|
|
*
|
|
* The Initial Developer of the Original Code is the Mozilla Foundation.
|
|
* Portions created by the Initial Developer are Copyright (C) 2011
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* L. David Baron <dbaron@dbaron.org>, Mozilla Corporation (original author)
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of
|
|
* either the GNU General Public License Version 2 or later (the "GPL"), or
|
|
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
|
|
* in which case the provisions of the GPL or the LGPL are applicable instead
|
|
* of those above. If you wish to allow use of your version of this file only
|
|
* under the terms of either the GPL or the LGPL, and not to allow others to
|
|
* use your version of this file under the terms of the MPL, indicate your
|
|
* decision by deleting the provisions above and replace them with the notice
|
|
* and other provisions required by the GPL or the LGPL. If you do not delete
|
|
* the provisions above, a recipient may use your version of this file under
|
|
* the terms of any one of the MPL, the GPL or the LGPL.
|
|
*
|
|
* ***** END LICENSE BLOCK ***** */
|
|
|
|
/* implements DOM interface for querying and observing media queries */
|
|
|
|
#ifndef nsDOMMediaQueryList_h_
|
|
#define nsDOMMediaQueryList_h_
|
|
|
|
#include "nsIDOMMediaQueryList.h"
|
|
#include "nsCycleCollectionParticipant.h"
|
|
#include "nsAutoPtr.h"
|
|
#include "nsCOMPtr.h"
|
|
#include "nsTArray.h"
|
|
#include "prclist.h"
|
|
|
|
class nsPresContext;
|
|
class nsMediaList;
|
|
|
|
class nsDOMMediaQueryList : public nsIDOMMediaQueryList,
|
|
public PRCList
|
|
{
|
|
public:
|
|
// The caller who constructs is responsible for calling Evaluate
|
|
// before calling any other methods.
|
|
nsDOMMediaQueryList(nsPresContext *aPresContext,
|
|
const nsAString &aMediaQueryList);
|
|
private:
|
|
~nsDOMMediaQueryList();
|
|
|
|
public:
|
|
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
|
|
NS_DECL_CYCLE_COLLECTION_CLASS(nsDOMMediaQueryList)
|
|
|
|
NS_DECL_NSIDOMMEDIAQUERYLIST
|
|
|
|
struct HandleChangeData {
|
|
nsRefPtr<nsDOMMediaQueryList> mql;
|
|
nsCOMPtr<nsIDOMMediaQueryListListener> listener;
|
|
};
|
|
|
|
typedef FallibleTArray< nsCOMPtr<nsIDOMMediaQueryListListener> > ListenerList;
|
|
typedef FallibleTArray<HandleChangeData> NotifyList;
|
|
|
|
// Appends listeners that need notification to aListenersToNotify
|
|
void MediumFeaturesChanged(NotifyList &aListenersToNotify);
|
|
|
|
private:
|
|
void RecomputeMatches();
|
|
|
|
// We only need a pointer to the pres context to support lazy
|
|
// reevaluation following dynamic changes. However, this lazy
|
|
// reevaluation is perhaps somewhat important, since some usage
|
|
// patterns may involve the creation of large numbers of
|
|
// MediaQueryList objects which almost immediately become garbage
|
|
// (after a single call to the .matches getter).
|
|
//
|
|
// This pointer does make us a little more dependent on cycle
|
|
// collection.
|
|
//
|
|
// We have a non-null mPresContext for our entire lifetime except
|
|
// after cycle collection unlinking. Having a non-null mPresContext
|
|
// is equivalent to being in that pres context's mDOMMediaQueryLists
|
|
// linked list.
|
|
nsRefPtr<nsPresContext> mPresContext;
|
|
|
|
nsRefPtr<nsMediaList> mMediaList;
|
|
bool mMatches;
|
|
bool mMatchesValid;
|
|
ListenerList mListeners;
|
|
};
|
|
|
|
#endif /* !defined(nsDOMMediaQueryList_h_) */
|