michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef NS_SMILTIMEVALUE_H_
michael@0: #define NS_SMILTIMEVALUE_H_
michael@0: 
michael@0: #include "nsSMILTypes.h"
michael@0: #include "nsDebug.h"
michael@0: 
michael@0: /*----------------------------------------------------------------------
michael@0:  * nsSMILTimeValue class
michael@0:  *
michael@0:  * A tri-state time value.
michael@0:  *
michael@0:  * First a quick overview of the SMIL time data types:
michael@0:  *
michael@0:  * nsSMILTime          -- a timestamp in milliseconds.
michael@0:  * nsSMILTimeValue     -- (this class) a timestamp that can take the additional
michael@0:  *                        states 'indefinite' and 'unresolved'
michael@0:  * nsSMILInstanceTime  -- an nsSMILTimeValue used for constructing intervals. It
michael@0:  *                        contains additional fields to govern reset behavior
michael@0:  *                        and track timing dependencies (e.g. syncbase timing).
michael@0:  * nsSMILInterval      -- a pair of nsSMILInstanceTimes that defines a begin and
michael@0:  *                        an end time for animation.
michael@0:  * nsSMILTimeValueSpec -- a component of a begin or end attribute, such as the
michael@0:  *                        '5s' or 'a.end+2m' in begin="5s; a.end+2m". Acts as
michael@0:  *                        a broker between an nsSMILTimedElement and its
michael@0:  *                        nsSMILInstanceTimes by generating new instance times
michael@0:  *                        and handling changes to existing times.
michael@0:  *
michael@0:  * Objects of this class may be in one of three states:
michael@0:  *
michael@0:  * 1) The time is resolved and has a definite millisecond value
michael@0:  * 2) The time is resolved and indefinite
michael@0:  * 3) The time is unresolved
michael@0:  *
michael@0:  * In summary:
michael@0:  *
michael@0:  * State      | GetMillis       | IsDefinite | IsIndefinite | IsResolved
michael@0:  * -----------+-----------------+------------+--------------+------------
michael@0:  * Definite   | nsSMILTimeValue | true       | false        | true
michael@0:  * -----------+-----------------+------------+--------------+------------
michael@0:  * Indefinite | --              | false      | true         | true
michael@0:  * -----------+-----------------+------------+--------------+------------
michael@0:  * Unresolved | --              | false      | false        | false
michael@0:  *
michael@0:  */
michael@0: 
michael@0: class nsSMILTimeValue
michael@0: {
michael@0: public:
michael@0:   // Creates an unresolved time value
michael@0:   nsSMILTimeValue()
michael@0:   : mMilliseconds(kUnresolvedMillis),
michael@0:     mState(STATE_UNRESOLVED)
michael@0:   { }
michael@0: 
michael@0:   // Creates a resolved time value
michael@0:   explicit nsSMILTimeValue(nsSMILTime aMillis)
michael@0:   : mMilliseconds(aMillis),
michael@0:     mState(STATE_DEFINITE)
michael@0:   { }
michael@0: 
michael@0:   // Named constructor to create an indefinite time value
michael@0:   static nsSMILTimeValue Indefinite()
michael@0:   {
michael@0:     nsSMILTimeValue value;
michael@0:     value.SetIndefinite();
michael@0:     return value;
michael@0:   }
michael@0: 
michael@0:   bool IsIndefinite() const { return mState == STATE_INDEFINITE; }
michael@0:   void SetIndefinite()
michael@0:   {
michael@0:     mState = STATE_INDEFINITE;
michael@0:     mMilliseconds = kUnresolvedMillis;
michael@0:   }
michael@0: 
michael@0:   bool IsResolved() const { return mState != STATE_UNRESOLVED; }
michael@0:   void SetUnresolved()
michael@0:   {
michael@0:     mState = STATE_UNRESOLVED;
michael@0:     mMilliseconds = kUnresolvedMillis;
michael@0:   }
michael@0: 
michael@0:   bool IsDefinite() const { return mState == STATE_DEFINITE; }
michael@0:   nsSMILTime GetMillis() const
michael@0:   {
michael@0:     NS_ABORT_IF_FALSE(mState == STATE_DEFINITE,
michael@0:        "GetMillis() called for unresolved or indefinite time");
michael@0: 
michael@0:     return mState == STATE_DEFINITE ? mMilliseconds : kUnresolvedMillis;
michael@0:   }
michael@0: 
michael@0:   void SetMillis(nsSMILTime aMillis)
michael@0:   {
michael@0:     mState = STATE_DEFINITE;
michael@0:     mMilliseconds = aMillis;
michael@0:   }
michael@0: 
michael@0:   int8_t CompareTo(const nsSMILTimeValue& aOther) const;
michael@0: 
michael@0:   bool operator==(const nsSMILTimeValue& aOther) const
michael@0:   { return CompareTo(aOther) == 0; }
michael@0: 
michael@0:   bool operator!=(const nsSMILTimeValue& aOther) const
michael@0:   { return CompareTo(aOther) != 0; }
michael@0: 
michael@0:   bool operator<(const nsSMILTimeValue& aOther) const
michael@0:   { return CompareTo(aOther) < 0; }
michael@0: 
michael@0:   bool operator>(const nsSMILTimeValue& aOther) const
michael@0:   { return CompareTo(aOther) > 0; }
michael@0: 
michael@0:   bool operator<=(const nsSMILTimeValue& aOther) const
michael@0:   { return CompareTo(aOther) <= 0; }
michael@0: 
michael@0:   bool operator>=(const nsSMILTimeValue& aOther) const
michael@0:   { return CompareTo(aOther) >= 0; }
michael@0: 
michael@0: private:
michael@0:   static nsSMILTime kUnresolvedMillis;
michael@0: 
michael@0:   nsSMILTime mMilliseconds;
michael@0:   enum {
michael@0:     STATE_DEFINITE,
michael@0:     STATE_INDEFINITE,
michael@0:     STATE_UNRESOLVED
michael@0:   } mState;
michael@0: };
michael@0: 
michael@0: #endif // NS_SMILTIMEVALUE_H_