1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/smil/nsSMILMilestone.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,78 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 +#ifndef NS_SMILMILESTONE_H_
1.10 +#define NS_SMILMILESTONE_H_
1.11 +
1.12 +/*
1.13 + * A significant moment in an nsSMILTimedElement's lifetime where a sample is
1.14 + * required.
1.15 + *
1.16 + * Animations register the next milestone in their lifetime with the time
1.17 + * container that they belong to. When the animation controller goes to run
1.18 + * a sample it first visits all the animations that have a registered milestone
1.19 + * in order of their milestone times. This allows interdependencies between
1.20 + * animations to be correctly resolved and events to fire in the proper order.
1.21 + *
1.22 + * A distinction is made between a milestone representing the end of an interval
1.23 + * and any other milestone. This is because if animation A ends at time t, and
1.24 + * animation B begins at the same time t (or has some other significant moment
1.25 + * such as firing a repeat event), SMIL's endpoint-exclusive timing model
1.26 + * implies that the interval end occurs first. In fact, interval ends can be
1.27 + * thought of as ending an infinitesimally small time before t. Therefore,
1.28 + * A should be sampled before B.
1.29 + *
1.30 + * Furthermore, this distinction between sampling the end of an interval and
1.31 + * a regular sample is used within the timing model (specifically in
1.32 + * nsSMILTimedElement) to ensure that all intervals ending at time t are sampled
1.33 + * before any new intervals are entered so that we have a fully up-to-date set
1.34 + * of instance times available before committing to a new interval. Once an
1.35 + * interval is entered, the begin time is fixed.
1.36 + */
1.37 +class nsSMILMilestone
1.38 +{
1.39 +public:
1.40 + nsSMILMilestone(nsSMILTime aTime, bool aIsEnd)
1.41 + : mTime(aTime), mIsEnd(aIsEnd)
1.42 + { }
1.43 +
1.44 + nsSMILMilestone()
1.45 + : mTime(0), mIsEnd(false)
1.46 + { }
1.47 +
1.48 + bool operator==(const nsSMILMilestone& aOther) const
1.49 + {
1.50 + return mTime == aOther.mTime && mIsEnd == aOther.mIsEnd;
1.51 + }
1.52 +
1.53 + bool operator!=(const nsSMILMilestone& aOther) const
1.54 + {
1.55 + return !(*this == aOther);
1.56 + }
1.57 +
1.58 + bool operator<(const nsSMILMilestone& aOther) const
1.59 + {
1.60 + // Earlier times sort first, and for equal times end milestones sort first
1.61 + return mTime < aOther.mTime ||
1.62 + (mTime == aOther.mTime && mIsEnd && !aOther.mIsEnd);
1.63 + }
1.64 +
1.65 + bool operator<=(const nsSMILMilestone& aOther) const
1.66 + {
1.67 + return *this == aOther || *this < aOther;
1.68 + }
1.69 +
1.70 + bool operator>=(const nsSMILMilestone& aOther) const
1.71 + {
1.72 + return !(*this < aOther);
1.73 + }
1.74 +
1.75 + nsSMILTime mTime; // The milestone time. This may be in container time or
1.76 + // parent container time depending on where it is used.
1.77 + bool mIsEnd; // true if this milestone corresponds to an interval
1.78 + // end, false otherwise.
1.79 +};
1.80 +
1.81 +#endif // NS_SMILMILESTONE_H_
