lib/dojo/dnd/TimedMoveable.js

   1 /*
   2         Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
   3         Available via Academic Free License >= 2.1 OR the modified BSD license.
   4         see: http://dojotoolkit.org/license for details
   5 */
   6
   7
   8 if(!dojo._hasResource["dojo.dnd.TimedMoveable"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
   9 dojo._hasResource["dojo.dnd.TimedMoveable"] = true;
  10 dojo.provide("dojo.dnd.TimedMoveable");
  11 dojo.require("dojo.dnd.Moveable");
  12
  13
  14 /*=====
  15 dojo.declare("dojo.dnd.__TimedMoveableArgs", [dojo.dnd.__MoveableArgs], {
  16         // timeout: Number
  17         //              delay move by this number of ms,
  18         //              accumulating position changes during the timeout
  19         timeout: 0
  20 });
  21 =====*/
  22
  23 (function(){
  24         // precalculate long expressions
  25         var oldOnMove = dojo.dnd.Moveable.prototype.onMove;
  26
  27         dojo.declare("dojo.dnd.TimedMoveable", dojo.dnd.Moveable, {
  28                 // summary:
  29                 //              A specialized version of Moveable to support an FPS throttling.
  30                 //              This class puts an upper restriction on FPS, which may reduce
  31                 //              the CPU load. The additional parameter "timeout" regulates
  32                 //              the delay before actually moving the moveable object.
  33
  34                 // object attributes (for markup)
  35                 timeout: 40,    // in ms, 40ms corresponds to 25 fps
  36
  37                 constructor: function(node, params){
  38                         // summary:
  39                         //              an object that makes a node moveable with a timer
  40                         // node: Node||String
  41                         //              a node (or node's id) to be moved
  42                         // params: dojo.dnd.__TimedMoveableArgs
  43                         //              object with additional parameters.
  44
  45                         // sanitize parameters
  46                         if(!params){ params = {}; }
  47                         if(params.timeout && typeof params.timeout == "number" && params.timeout >= 0){
  48                                 this.timeout = params.timeout;
  49                         }
  50                 },
  51
  52                 // markup methods
  53                 markupFactory: function(params, node){
  54                         return new dojo.dnd.TimedMoveable(node, params);
  55                 },
  56
  57                 onMoveStop: function(/* dojo.dnd.Mover */ mover){
  58                         if(mover._timer){
  59                                 // stop timer
  60                                 clearTimeout(mover._timer)
  61                                 // reflect the last received position
  62                                 oldOnMove.call(this, mover, mover._leftTop)
  63                         }
  64                         dojo.dnd.Moveable.prototype.onMoveStop.apply(this, arguments);
  65                 },
  66                 onMove: function(/* dojo.dnd.Mover */ mover, /* Object */ leftTop){
  67                         mover._leftTop = leftTop;
  68                         if(!mover._timer){
  69                                 var _t = this;  // to avoid using dojo.hitch()
  70                                 mover._timer = setTimeout(function(){
  71                                         // we don't have any pending requests
  72                                         mover._timer = null;
  73                                         // reflect the last received position
  74                                         oldOnMove.call(_t, mover, mover._leftTop);
  75                                 }, this.timeout);
  76                         }
  77                 }
  78         });
  79 })();
  80
  81 }