js/dom-drag.js

   1 /**************************************************
   2  * dom-drag.js
   3  * 09.25.2001
   4  * www.youngpup.net
   5  **************************************************
   6  * Copyright 2001, Aaron Boodman
   7  * This code is public domain. Please use it for good, not evil.
   8  **************************************************
   9  * 10.28.2001 - fixed minor bug where events
  10  * sometimes fired off the handle, not the root.
  11  **************************************************/
  12
  13 var Drag = {
  14
  15     obj : null,
  16
  17     init : function(o, oRoot, minX, maxX, minY, maxY, bSwapHorzRef, bSwapVertRef, fXMapper, fYMapper)
  18     {
  19         o.onmousedown    = Drag.start;
  20
  21         o.hmode            = bSwapHorzRef ? false : true ;
  22         o.vmode            = bSwapVertRef ? false : true ;
  23
  24         o.root = oRoot && oRoot != null ? oRoot : o ;
  25
  26         if (o.hmode  && isNaN(parseInt(o.root.style.left  ))) o.root.style.left   = "0px";
  27         if (o.vmode  && isNaN(parseInt(o.root.style.top   ))) o.root.style.top    = "0px";
  28         if (!o.hmode && isNaN(parseInt(o.root.style.right ))) o.root.style.right  = "0px";
  29         if (!o.vmode && isNaN(parseInt(o.root.style.bottom))) o.root.style.bottom = "0px";
  30
  31         o.minX    = typeof minX != 'undefined' ? minX : null;
  32         o.minY    = typeof minY != 'undefined' ? minY : null;
  33         o.maxX    = typeof maxX != 'undefined' ? maxX : null;
  34         o.maxY    = typeof maxY != 'undefined' ? maxY : null;
  35
  36         o.xMapper = fXMapper ? fXMapper : null;
  37         o.yMapper = fYMapper ? fYMapper : null;
  38
  39         o.root.onDragStart    = new Function();
  40         o.root.onDragEnd    = new Function();
  41         o.root.onDrag        = new Function();
  42     },
  43
  44     start : function(e)
  45     {
  46         var o = Drag.obj = this;
  47         e = Drag.fixE(e);
  48         var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);
  49         var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );
  50         o.root.onDragStart(x, y);
  51
  52         o.lastMouseX    = e.clientX;
  53         o.lastMouseY    = e.clientY;
  54
  55         if (o.hmode) {
  56             if (o.minX != null)    o.minMouseX    = e.clientX - x + o.minX;
  57             if (o.maxX != null)    o.maxMouseX    = o.minMouseX + o.maxX - o.minX;
  58         } else {
  59             if (o.minX != null) o.maxMouseX = -o.minX + e.clientX + x;
  60             if (o.maxX != null) o.minMouseX = -o.maxX + e.clientX + x;
  61         }
  62
  63         if (o.vmode) {
  64             if (o.minY != null)    o.minMouseY    = e.clientY - y + o.minY;
  65             if (o.maxY != null)    o.maxMouseY    = o.minMouseY + o.maxY - o.minY;
  66         } else {
  67             if (o.minY != null) o.maxMouseY = -o.minY + e.clientY + y;
  68             if (o.maxY != null) o.minMouseY = -o.maxY + e.clientY + y;
  69         }
  70
  71         document.onmousemove    = Drag.drag;
  72         document.onmouseup        = Drag.end;
  73
  74         return false;
  75     },
  76
  77     drag : function(e)
  78     {
  79         e = Drag.fixE(e);
  80         var o = Drag.obj;
  81
  82         var ey    = e.clientY;
  83         var ex    = e.clientX;
  84         var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);
  85         var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );
  86         var nx, ny;
  87
  88         if (o.minX != null) ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex, o.maxMouseX);
  89         if (o.maxX != null) ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex, o.minMouseX);
  90         if (o.minY != null) ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey, o.maxMouseY);
  91         if (o.maxY != null) ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey, o.minMouseY);
  92
  93         nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1));
  94         ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1));
  95
  96         if (o.xMapper)        nx = o.xMapper(y)
  97         else if (o.yMapper)    ny = o.yMapper(x)
  98
  99         Drag.obj.root.style[o.hmode ? "left" : "right"] = nx + "px";
 100         Drag.obj.root.style[o.vmode ? "top" : "bottom"] = ny + "px";
 101         Drag.obj.lastMouseX    = ex;
 102         Drag.obj.lastMouseY    = ey;
 103
 104         Drag.obj.root.onDrag(nx, ny);
 105         return false;
 106     },
 107
 108     end : function()
 109     {
 110         document.onmousemove = null;
 111         document.onmouseup   = null;
 112         Drag.obj.root.onDragEnd(    parseInt(Drag.obj.root.style[Drag.obj.hmode ? "left" : "right"]),
 113                                     parseInt(Drag.obj.root.style[Drag.obj.vmode ? "top" : "bottom"]));
 114         Drag.obj = null;
 115     },
 116
 117     fixE : function(e)
 118     {
 119         if (typeof e == 'undefined') e = window.event;
 120         if (typeof e.layerX == 'undefined') e.layerX = e.offsetX;
 121         if (typeof e.layerY == 'undefined') e.layerY = e.offsetY;
 122         return e;
 123     }
 124 };