gecko-dev/content/smil/nsSMILInstanceTime.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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 the Mozilla SMIL module.
*
* The Initial Developer of the Original Code is Brian Birtles.
* Portions created by the Initial Developer are Copyright (C) 2005
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Brian Birtles <birtles@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 ***** */
#ifndef NS_SMILINSTANCETIME_H_
#define NS_SMILINSTANCETIME_H_
#include "nsSMILTimeValue.h"
#include "nsAutoPtr.h"
class nsSMILInterval;
class nsSMILTimeContainer;
class nsSMILTimeValueSpec;
//----------------------------------------------------------------------
// nsSMILInstanceTime
//
// An instant in document simple time that may be used in creating a new
// interval.
//
// For an overview of how this class is related to other SMIL time classes see
// the documentation in nsSMILTimeValue.h
//
// These objects are owned by an nsSMILTimedElement but MAY also be referenced
// by:
//
// a) nsSMILIntervals that belong to the same nsSMILTimedElement and which refer
// to the nsSMILInstanceTimes which form the interval endpoints; and/or
// b) nsSMILIntervals that belong to other nsSMILTimedElements but which need to
// update dependent instance times when they change or are deleted.
// E.g. for begin='a.begin', 'a' needs to inform dependent
// nsSMILInstanceTimes if its begin time changes. This notification is
// performed by the nsSMILInterval.
class nsSMILInstanceTime
{
public:
// Instance time source. Times generated by events, syncbase relationships,
// and DOM calls behave differently in some circumstances such as when a timed
// element is reset.
enum nsSMILInstanceTimeSource {
// No particularly significant source, e.g. offset time, 'indefinite'
SOURCE_NONE,
// Generated by a DOM call such as beginElement
SOURCE_DOM,
// Generated by a syncbase relationship
SOURCE_SYNCBASE,
// Generated by an event
SOURCE_EVENT
};
nsSMILInstanceTime(const nsSMILTimeValue& aTime,
nsSMILInstanceTimeSource aSource = SOURCE_NONE,
nsSMILTimeValueSpec* aCreator = nsnull,
nsSMILInterval* aBaseInterval = nsnull);
~nsSMILInstanceTime();
void Unlink();
void HandleChangedInterval(const nsSMILTimeContainer* aSrcContainer,
PRBool aBeginObjectChanged,
PRBool aEndObjectChanged);
void HandleDeletedInterval();
void HandleFilteredInterval();
const nsSMILTimeValue& Time() const { return mTime; }
const nsSMILTimeValueSpec* GetCreator() const { return mCreator; }
PRBool IsDynamic() const { return !!(mFlags & kDynamic); }
PRBool IsFixedTime() const { return !(mFlags & kMayUpdate); }
PRBool FromDOM() const { return !!(mFlags & kFromDOM); }
PRBool ShouldPreserve() const;
void UnmarkShouldPreserve();
void AddRefFixedEndpoint();
void ReleaseFixedEndpoint();
void DependentUpdate(const nsSMILTimeValue& aNewTime)
{
NS_ABORT_IF_FALSE(!IsFixedTime(),
"Updating an instance time that is not expected to be updated");
mTime = aNewTime;
}
PRBool IsDependent() const { return !!mBaseInterval; }
PRBool IsDependentOn(const nsSMILInstanceTime& aOther) const;
const nsSMILInterval* GetBaseInterval() const { return mBaseInterval; }
PRBool SameTimeAndBase(const nsSMILInstanceTime& aOther) const
{
return mTime == aOther.mTime && GetBaseTime() == aOther.GetBaseTime();
}
// Get and set a serial number which may be used by a containing class to
// control the sort order of otherwise similar instance times.
PRUint32 Serial() const { return mSerial; }
void SetSerial(PRUint32 aIndex) { mSerial = aIndex; }
NS_INLINE_DECL_REFCOUNTING(nsSMILInstanceTime)
protected:
void SetBaseInterval(nsSMILInterval* aBaseInterval);
const nsSMILInstanceTime* GetBaseTime() const;
nsSMILTimeValue mTime;
// Internal flags used to represent the behaviour of different instance times
enum {
// Indicates that this instance time was generated by an event or a DOM
// call. Such instance times require special handling when (i) the owning
// element is reset, (ii) when they are to be added as a new end instance
// times (as per SMIL's event sensitivity contraints), and (iii) when
// a backwards seek is performed and the timing model is reconstructed.
kDynamic = 1,
// Indicates that this instance time is referred to by an
// nsSMILTimeValueSpec and as such may be updated. Such instance time should
// not be filtered out by the nsSMILTimedElement even if they appear to be
// in the past as they may be updated to a future time.
kMayUpdate = 2,
// Indicates that this instance time was generated from the DOM as opposed
// to an nsSMILTimeValueSpec. When a 'begin' or 'end' attribute is set or
// reset we should clear all the instance times that have been generated by
// that attribute (and hence an nsSMILTimeValueSpec), but not those from the
// DOM.
kFromDOM = 4,
// Indicates that this instance time was used as the endpoint of an interval
// that has been filtered or removed. However, since it is a dynamic time it
// should be preserved and not filtered.
kWasDynamicEndpoint = 8
};
PRUint8 mFlags; // Combination of kDynamic, kMayUpdate, etc.
PRPackedBool mVisited; // (mutable) Cycle tracking
// Additional reference count to determine if this instance time is currently
// used as a fixed endpoint in any intervals. Instance times that are used in
// this way should not be removed when the owning nsSMILTimedElement removes
// instance times in response to a restart or in an attempt to free up memory
// by filtering out old instance times.
//
// Instance times are only shared in a few cases, namely:
// a) early ends,
// b) zero-duration intervals,
// c) momentarily whilst establishing new intervals and updating the current
// interval, and
// d) trimmed intervals
// Hence the limited range of a PRUint16 should be more than adequate.
PRUint16 mFixedEndpointRefCnt;
PRUint32 mSerial; // A serial number used by the containing class to
// specify the sort order for instance times with the
// same mTime.
nsSMILTimeValueSpec* mCreator; // The nsSMILTimeValueSpec object that created
// us. (currently only needed for syncbase
// instance times.)
nsSMILInterval* mBaseInterval; // Interval from which this time is derived
// (only used for syncbase instance times)
};
#endif // NS_SMILINSTANCETIME_H_