lib/dojo/dnd/Mover.js

   1 /*
   2         Copyright (c) 2004-2010, 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.Mover"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
   9 dojo._hasResource["dojo.dnd.Mover"] = true;
  10 dojo.provide("dojo.dnd.Mover");
  11
  12 dojo.require("dojo.dnd.common");
  13 dojo.require("dojo.dnd.autoscroll");
  14
  15 dojo.declare("dojo.dnd.Mover", null, {
  16         constructor: function(node, e, host){
  17                 // summary:
  18                 //              an object, which makes a node follow the mouse.
  19                 //              Used as a default mover, and as a base class for custom movers.
  20                 // node: Node
  21                 //              a node (or node's id) to be moved
  22                 // e: Event
  23                 //              a mouse event, which started the move;
  24                 //              only pageX and pageY properties are used
  25                 // host: Object?
  26                 //              object which implements the functionality of the move,
  27                 //              and defines proper events (onMoveStart and onMoveStop)
  28                 this.node = dojo.byId(node);
  29                 this.marginBox = {l: e.pageX, t: e.pageY};
  30                 this.mouseButton = e.button;
  31                 var h = this.host = host, d = node.ownerDocument,
  32                         firstEvent = dojo.connect(d, "onmousemove", this, "onFirstMove");
  33                 this.events = [
  34                         dojo.connect(d, "onmousemove", this, "onMouseMove"),
  35                         dojo.connect(d, "onmouseup",   this, "onMouseUp"),
  36                         // cancel text selection and text dragging
  37                         dojo.connect(d, "ondragstart",   dojo.stopEvent),
  38                         dojo.connect(d.body, "onselectstart", dojo.stopEvent),
  39                         firstEvent
  40                 ];
  41                 // notify that the move has started
  42                 if(h && h.onMoveStart){
  43                         h.onMoveStart(this);
  44                 }
  45         },
  46         // mouse event processors
  47         onMouseMove: function(e){
  48                 // summary:
  49                 //              event processor for onmousemove
  50                 // e: Event
  51                 //              mouse event
  52                 dojo.dnd.autoScroll(e);
  53                 var m = this.marginBox;
  54                 this.host.onMove(this, {l: m.l + e.pageX, t: m.t + e.pageY}, e);
  55                 dojo.stopEvent(e);
  56         },
  57         onMouseUp: function(e){
  58                 if(dojo.isWebKit && dojo.isMac && this.mouseButton == 2 ?
  59                                 e.button == 0 : this.mouseButton == e.button){
  60                         this.destroy();
  61                 }
  62                 dojo.stopEvent(e);
  63         },
  64         // utilities
  65         onFirstMove: function(e){
  66                 // summary:
  67                 //              makes the node absolute; it is meant to be called only once.
  68                 //              relative and absolutely positioned nodes are assumed to use pixel units
  69                 var s = this.node.style, l, t, h = this.host;
  70                 switch(s.position){
  71                         case "relative":
  72                         case "absolute":
  73                                 // assume that left and top values are in pixels already
  74                                 l = Math.round(parseFloat(s.left)) || 0;
  75                                 t = Math.round(parseFloat(s.top)) || 0;
  76                                 break;
  77                         default:
  78                                 s.position = "absolute";        // enforcing the absolute mode
  79                                 var m = dojo.marginBox(this.node);
  80                                 // event.pageX/pageY (which we used to generate the initial
  81                                 // margin box) includes padding and margin set on the body.
  82                                 // However, setting the node's position to absolute and then
  83                                 // doing dojo.marginBox on it *doesn't* take that additional
  84                                 // space into account - so we need to subtract the combined
  85                                 // padding and margin.  We use getComputedStyle and
  86                                 // _getMarginBox/_getContentBox to avoid the extra lookup of
  87                                 // the computed style.
  88                                 var b = dojo.doc.body;
  89                                 var bs = dojo.getComputedStyle(b);
  90                                 var bm = dojo._getMarginBox(b, bs);
  91                                 var bc = dojo._getContentBox(b, bs);
  92                                 l = m.l - (bc.l - bm.l);
  93                                 t = m.t - (bc.t - bm.t);
  94                                 break;
  95                 }
  96                 this.marginBox.l = l - this.marginBox.l;
  97                 this.marginBox.t = t - this.marginBox.t;
  98                 if(h && h.onFirstMove){
  99                         h.onFirstMove(this, e);
 100                 }
 101                 dojo.disconnect(this.events.pop());
 102         },
 103         destroy: function(){
 104                 // summary:
 105                 //              stops the move, deletes all references, so the object can be garbage-collected
 106                 dojo.forEach(this.events, dojo.disconnect);
 107                 // undo global settings
 108                 var h = this.host;
 109                 if(h && h.onMoveStop){
 110                         h.onMoveStop(this);
 111                 }
 112                 // destroy objects
 113                 this.events = this.node = this.host = null;
 114         }
 115 });
 116
 117 }