workspace/plasma/scriptengines/webkit/dashboard/AppleClasses/AppleAnimator.js

   1 /*
   2  * Copyright 2008 Stefan Buller <hikingpete@cain.afraid.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) version 3, or any
   8  * later version accepted by the membership of KDE e.V. (or its
   9  * successor approved by the membership of KDE e.V.), which shall
  10  * act as a proxy defined in Section 6 of version 3 of the license.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 function AppleAnimator(duration, interval, start, finish, handler)
  22 {
  23     //properties specified by Apple
  24     this.duration = duration;
  25     this.interval = interval;
  26     this.animations = [];
  27     this.timer = 0;
  28     this.oncomplete; //no documentation exists for this.
  29
  30     //internal members:
  31     this.intervalPointer = undefined;
  32
  33     var that = this;
  34
  35     if (arguments.length === 5) {
  36         var animation = new AppleAnimation(start, finish, handler);
  37         that.addAnimation(animation); //I hope I can use this already
  38     }
  39 };
  40
  41 AppleAnimator.prototype.addAnimation = function (animation) {
  42     //I'm unsure what the behaviour of this function should be if
  43     //AppleAnimator.start() has already been called.
  44     animation.initialize(this.duration, this.interval);
  45     this.animations.push(animation);
  46 };
  47
  48 AppleAnimator.prototype.start = function ()
  49 {
  50     if (this.intervalPointer == undefined) {
  51
  52         var that = this; //for the closure (may not be necessary?)
  53         function intervalHandler() {
  54             //setInterval doesn't pass 'this', so we need a closure instead.
  55             that.timer += that.interval;
  56             if (that.timer > that.duration) {
  57                 that.stop();
  58             } else {
  59                 for (var i=0; i<that.animations.length; i++) {
  60                     var animation = that.animations[i];
  61                     animation.step();
  62                     animation.callback(animation, animation.now,
  63                             animation.from, animation.to);
  64                 }
  65             }
  66         }
  67
  68         this.intervalPointer = setInterval(intervalHandler, this.interval);
  69     }
  70 };
  71
  72 AppleAnimator.prototype.stop = function ()
  73 {
  74     if (this.intervalPointer != undefined) {
  75         clearInterval(this.intervalPointer);
  76         delete this.intervalPointer;
  77         //Maybe this.timer should be set to 0, and animations re-initialized
  78     }
  79 };
  80
  81 function AppleAnimation(start, finish, handler)
  82 {
  83     this.from = start;
  84     this.to = finish;
  85     this.now = undefined;
  86     this.callback = handler;
  87
  88     //internal members:
  89     //prototype.initialize
  90     //this.step
  91 };
  92
  93 AppleAnimation.prototype.initialize = function(duration, interval)
  94 {
  95     this.now = this.from;
  96
  97     var frac = interval / duration;
  98     var diff = this.to - this.from; //Oh memory/speed trade-off (premature optimization?)
  99
 100     this.step = function () {
 101         //This is a closure, and don't forget it.
 102         this.now += diff * frac;
 103     }
 104 };
 105
 106 function AppleRect(left, top, right, bottom)
 107 {
 108     this.left = left;
 109     this.top = top;
 110     this.right = right;
 111     this.bottom = bottom;
 112 };
 113
 114 function AppleRectAnimation(start, finish, handler)
 115 {
 116     this.from = start;
 117     this.to = finish;
 118     this.now = undefined;
 119     this.callback = handler;
 120 };
 121
 122 AppleRectAnimation.prototype.initialize = function(duration, interval)
 123 {
 124     this.now = this.from;
 125
 126     var frac = interval / duration;
 127     var diff = {
 128             left: this.to.left - this.from.left,
 129             top: this.to.top - this.from.top,
 130             right: this.to.right - this.from.right,
 131             bottom: this.to.bottom - this.from.bottom
 132     }
 133
 134     this.step = function () {
 135         //This is a closure, and don't forget it.
 136         this.now = new AppleRect(this.now.left + frac * diff.left,
 137                                  this.now.top + frac * diff.top,
 138                                  this.now.right + frac * diff.right,
 139                                  this.now.bottom + frac * diff.right)
 140     }
 141 };
 142