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       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #ifndef NS_SMILMILESTONE_H_
       8             : #define NS_SMILMILESTONE_H_
       9             : 
      10             : /*
      11             :  * A significant moment in an nsSMILTimedElement's lifetime where a sample is
      12             :  * required.
      13             :  *
      14             :  * Animations register the next milestone in their lifetime with the time
      15             :  * container that they belong to. When the animation controller goes to run
      16             :  * a sample it first visits all the animations that have a registered milestone
      17             :  * in order of their milestone times. This allows interdependencies between
      18             :  * animations to be correctly resolved and events to fire in the proper order.
      19             :  *
      20             :  * A distinction is made between a milestone representing the end of an interval
      21             :  * and any other milestone. This is because if animation A ends at time t, and
      22             :  * animation B begins at the same time t (or has some other significant moment
      23             :  * such as firing a repeat event), SMIL's endpoint-exclusive timing model
      24             :  * implies that the interval end occurs first. In fact, interval ends can be
      25             :  * thought of as ending an infinitesimally small time before t. Therefore,
      26             :  * A should be sampled before B.
      27             :  *
      28             :  * Furthermore, this distinction between sampling the end of an interval and
      29             :  * a regular sample is used within the timing model (specifically in
      30             :  * nsSMILTimedElement) to ensure that all intervals ending at time t are sampled
      31             :  * before any new intervals are entered so that we have a fully up-to-date set
      32             :  * of instance times available before committing to a new interval. Once an
      33             :  * interval is entered, the begin time is fixed.
      34             :  */
      35             : class nsSMILMilestone
      36             : {
      37             : public:
      38          61 :   nsSMILMilestone(nsSMILTime aTime, bool aIsEnd)
      39          61 :     : mTime(aTime), mIsEnd(aIsEnd)
      40          61 :   { }
      41             : 
      42          58 :   nsSMILMilestone()
      43          58 :     : mTime(0), mIsEnd(false)
      44          58 :   { }
      45             : 
      46           0 :   bool operator==(const nsSMILMilestone& aOther) const
      47             :   {
      48           0 :     return mTime == aOther.mTime && mIsEnd == aOther.mIsEnd;
      49             :   }
      50             : 
      51             :   bool operator!=(const nsSMILMilestone& aOther) const
      52             :   {
      53             :     return !(*this == aOther);
      54             :   }
      55             : 
      56           0 :   bool operator<(const nsSMILMilestone& aOther) const
      57             :   {
      58             :     // Earlier times sort first, and for equal times end milestones sort first
      59           0 :     return mTime < aOther.mTime ||
      60           0 :           (mTime == aOther.mTime && mIsEnd && !aOther.mIsEnd);
      61             :   }
      62             : 
      63             :   bool operator<=(const nsSMILMilestone& aOther) const
      64             :   {
      65             :     return *this == aOther || *this < aOther;
      66             :   }
      67             : 
      68           0 :   bool operator>=(const nsSMILMilestone& aOther) const
      69             :   {
      70           0 :     return !(*this < aOther);
      71             :   }
      72             : 
      73             :   nsSMILTime   mTime;  // The milestone time. This may be in container time or
      74             :                        // parent container time depending on where it is used.
      75             :   bool mIsEnd; // true if this milestone corresponds to an interval
      76             :                        // end, false otherwise.
      77             : };
      78             : 
      79             : #endif // NS_SMILMILESTONE_H_