The Tor Browser: dom/smil/nsSMILTimeValue.h@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #ifndef NS_SMILTIMEVALUE_H_

     7 #define NS_SMILTIMEVALUE_H_

     9 #include "nsSMILTypes.h"

    10 #include "nsDebug.h"

    12 /*----------------------------------------------------------------------

    13  * nsSMILTimeValue class

    14  *

    15  * A tri-state time value.

    16  *

    17  * First a quick overview of the SMIL time data types:

    18  *

    19  * nsSMILTime          -- a timestamp in milliseconds.

    20  * nsSMILTimeValue     -- (this class) a timestamp that can take the additional

    21  *                        states 'indefinite' and 'unresolved'

    22  * nsSMILInstanceTime  -- an nsSMILTimeValue used for constructing intervals. It

    23  *                        contains additional fields to govern reset behavior

    24  *                        and track timing dependencies (e.g. syncbase timing).

    25  * nsSMILInterval      -- a pair of nsSMILInstanceTimes that defines a begin and

    26  *                        an end time for animation.

    27  * nsSMILTimeValueSpec -- a component of a begin or end attribute, such as the

    28  *                        '5s' or 'a.end+2m' in begin="5s; a.end+2m". Acts as

    29  *                        a broker between an nsSMILTimedElement and its

    30  *                        nsSMILInstanceTimes by generating new instance times

    31  *                        and handling changes to existing times.

    32  *

    33  * Objects of this class may be in one of three states:

    34  *

    35  * 1) The time is resolved and has a definite millisecond value

    36  * 2) The time is resolved and indefinite

    37  * 3) The time is unresolved

    38  *

    39  * In summary:

    40  *

    41  * State      | GetMillis       | IsDefinite | IsIndefinite | IsResolved

    42  * -----------+-----------------+------------+--------------+------------

    43  * Definite   | nsSMILTimeValue | true       | false        | true

    44  * -----------+-----------------+------------+--------------+------------

    45  * Indefinite | --              | false      | true         | true

    46  * -----------+-----------------+------------+--------------+------------

    47  * Unresolved | --              | false      | false        | false

    48  *

    49  */

    51 class nsSMILTimeValue

    52 {

    53 public:

    54   // Creates an unresolved time value

    55   nsSMILTimeValue()

    56   : mMilliseconds(kUnresolvedMillis),

    57     mState(STATE_UNRESOLVED)

    58   { }

    60   // Creates a resolved time value

    61   explicit nsSMILTimeValue(nsSMILTime aMillis)

    62   : mMilliseconds(aMillis),

    63     mState(STATE_DEFINITE)

    64   { }

    66   // Named constructor to create an indefinite time value

    67   static nsSMILTimeValue Indefinite()

    68   {

    69     nsSMILTimeValue value;

    70     value.SetIndefinite();

    71     return value;

    72   }

    74   bool IsIndefinite() const { return mState == STATE_INDEFINITE; }

    75   void SetIndefinite()

    76   {

    77     mState = STATE_INDEFINITE;

    78     mMilliseconds = kUnresolvedMillis;

    79   }

    81   bool IsResolved() const { return mState != STATE_UNRESOLVED; }

    82   void SetUnresolved()

    83   {

    84     mState = STATE_UNRESOLVED;

    85     mMilliseconds = kUnresolvedMillis;

    86   }

    88   bool IsDefinite() const { return mState == STATE_DEFINITE; }

    89   nsSMILTime GetMillis() const

    90   {

    91     NS_ABORT_IF_FALSE(mState == STATE_DEFINITE,

    92        "GetMillis() called for unresolved or indefinite time");

    94     return mState == STATE_DEFINITE ? mMilliseconds : kUnresolvedMillis;

    95   }

    97   void SetMillis(nsSMILTime aMillis)

    98   {

    99     mState = STATE_DEFINITE;

   100     mMilliseconds = aMillis;

   101   }

   103   int8_t CompareTo(const nsSMILTimeValue& aOther) const;

   105   bool operator==(const nsSMILTimeValue& aOther) const

   106   { return CompareTo(aOther) == 0; }

   108   bool operator!=(const nsSMILTimeValue& aOther) const

   109   { return CompareTo(aOther) != 0; }

   111   bool operator<(const nsSMILTimeValue& aOther) const

   112   { return CompareTo(aOther) < 0; }

   114   bool operator>(const nsSMILTimeValue& aOther) const

   115   { return CompareTo(aOther) > 0; }

   117   bool operator<=(const nsSMILTimeValue& aOther) const

   118   { return CompareTo(aOther) <= 0; }

   120   bool operator>=(const nsSMILTimeValue& aOther) const

   121   { return CompareTo(aOther) >= 0; }

   123 private:

   124   static nsSMILTime kUnresolvedMillis;

   126   nsSMILTime mMilliseconds;

   127   enum {

   128     STATE_DEFINITE,

   129     STATE_INDEFINITE,

   130     STATE_UNRESOLVED

   131   } mState;

   132 };

   134 #endif // NS_SMILTIMEVALUE_H_

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