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Diffstat (limited to 'dom/smil/nsSMILInstanceTime.h')
| -rw-r--r-- | dom/smil/nsSMILInstanceTime.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/dom/smil/nsSMILInstanceTime.h b/dom/smil/nsSMILInstanceTime.h new file mode 100644 index 000000000..d5a5807e3 --- /dev/null +++ b/dom/smil/nsSMILInstanceTime.h @@ -0,0 +1,166 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef NS_SMILINSTANCETIME_H_ +#define NS_SMILINSTANCETIME_H_ + +#include "nsSMILTimeValue.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 final +{ +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 + }; + + explicit nsSMILInstanceTime(const nsSMILTimeValue& aTime, + nsSMILInstanceTimeSource aSource = SOURCE_NONE, + nsSMILTimeValueSpec* aCreator = nullptr, + nsSMILInterval* aBaseInterval = nullptr); + + void Unlink(); + void HandleChangedInterval(const nsSMILTimeContainer* aSrcContainer, + bool aBeginObjectChanged, + bool aEndObjectChanged); + void HandleDeletedInterval(); + void HandleFilteredInterval(); + + const nsSMILTimeValue& Time() const { return mTime; } + const nsSMILTimeValueSpec* GetCreator() const { return mCreator; } + + bool IsDynamic() const { return !!(mFlags & kDynamic); } + bool IsFixedTime() const { return !(mFlags & kMayUpdate); } + bool FromDOM() const { return !!(mFlags & kFromDOM); } + + bool ShouldPreserve() const; + void UnmarkShouldPreserve(); + + void AddRefFixedEndpoint(); + void ReleaseFixedEndpoint(); + + void DependentUpdate(const nsSMILTimeValue& aNewTime) + { + MOZ_ASSERT(!IsFixedTime(), + "Updating an instance time that is not expected to be updated"); + mTime = aNewTime; + } + + bool IsDependent() const { return !!mBaseInterval; } + bool IsDependentOn(const nsSMILInstanceTime& aOther) const; + const nsSMILInterval* GetBaseInterval() const { return mBaseInterval; } + const nsSMILInstanceTime* GetBaseTime() const; + + bool 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. + uint32_t Serial() const { return mSerial; } + void SetSerial(uint32_t aIndex) { mSerial = aIndex; } + + NS_INLINE_DECL_REFCOUNTING(nsSMILInstanceTime) + +private: + // Private destructor, to discourage deletion outside of Release(): + ~nsSMILInstanceTime(); + + void SetBaseInterval(nsSMILInterval* aBaseInterval); + + 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 + }; + uint8_t mFlags; // Combination of kDynamic, kMayUpdate, etc. + mutable bool mVisited; // 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 uint16_t should be more than adequate. + uint16_t mFixedEndpointRefCnt; + + uint32_t 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_ |