third_party/web-animations-js/sources/src/effect-callback.js

   1 // Copyright 2014 Google Inc. All rights reserved.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 //     You may obtain a copy of the License at
   6 //
   7 // http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 //     See the License for the specific language governing permissions and
  13 // limitations under the License.
  14 (function(shared, scope, testing) {
  15
  16   var nullTarget = document.createElementNS('http://www.w3.org/1999/xhtml', 'div');
  17
  18   var sequenceNumber = 0;
  19   scope.bindPlayerForCustomEffect = function(player) {
  20     var target = player.source.target;
  21     var effect = player.source.effect;
  22     var timing = player.source.timing;
  23     var last = undefined;
  24     timing = shared.normalizeTimingInput(timing);
  25     var callback = function() {
  26       var t = callback._player ? callback._player.currentTime : null;
  27       if (t !== null) {
  28         t = shared.calculateTimeFraction(shared.calculateActiveDuration(timing), t, timing);
  29         if (isNaN(t))
  30           t = null;
  31       }
  32       // FIXME: There are actually more conditions under which the effect
  33       // should be called.
  34       if (t !== last)
  35         effect(t, target, player.source);
  36       last = t;
  37     };
  38
  39     callback._player = player;
  40     callback._registered = false;
  41     callback._sequenceNumber = sequenceNumber++;
  42     player._callback = callback;
  43     register(callback);
  44   };
  45
  46   var callbacks = [];
  47   var ticking = false;
  48   function register(callback) {
  49     if (callback._registered)
  50       return;
  51     callback._registered = true;
  52     callbacks.push(callback);
  53     if (!ticking) {
  54       ticking = true;
  55       requestAnimationFrame(tick);
  56     }
  57   }
  58
  59   function tick(t) {
  60     var updating = callbacks;
  61     callbacks = [];
  62     updating.sort(function(left, right) {
  63       return left._sequenceNumber - right._sequenceNumber;
  64     });
  65     updating.filter(function(callback) {
  66       callback();
  67       if (!callback._player || callback._player.finished || callback._player.paused)
  68         callback._registered = false;
  69       return callback._registered;
  70     });
  71     callbacks.push.apply(callbacks, updating);
  72
  73     if (callbacks.length) {
  74       ticking = true;
  75       requestAnimationFrame(tick);
  76     } else {
  77       ticking = false;
  78     }
  79   }
  80
  81   scope.Player.prototype._register = function() {
  82     if (this._callback)
  83       register(this._callback);
  84   };
  85
  86 })(webAnimationsShared, webAnimationsNext, webAnimationsTesting);