/**************************************************
 * dom-drag.js
 * 09.25.2001
 * www.youngpup.net
 **************************************************
 * 10.28.2001 - fixed minor bug where events
 * sometimes fired off the handle, not the root.
 **************************************************/
var Drag = {

    obj : null,

    init : function(o, oRoot, minX, maxX, minY, maxY, fXMapper, fYMapper)
    {
        o.onmousedown    = Drag.start;
        o.root = oRoot && oRoot != null ? oRoot : o ;

        if (isNaN(parseInt(o.root.style.left  ))) o.root.style.left   = "0px";
        if (isNaN(parseInt(o.root.style.top   ))) o.root.style.top    = "0px";
 
        o.minX    = typeof minX != 'undefined' ? minX : null;
        o.minY    = typeof minY != 'undefined' ? minY : null;
        o.maxX    = typeof maxX != 'undefined' ? maxX : null;
        o.maxY    = typeof maxY != 'undefined' ? maxY : null;

        o.xMapper = fXMapper ? fXMapper : null;
        o.yMapper = fYMapper ? fYMapper : null;

        o.root.onDragStart    = new Function();
        o.root.onDragEnd    = new Function();
        o.root.onDrag        = new Function();
    },

    start : function(e)
    {
        var o = Drag.obj = this;
        e = Drag.fixE(e);
       
        var y = parseInt(o.root.style.top);
        var x = parseInt(o.root.style.left);
        o.root.style.cursor = "move";
       
        
        o.root.onDragStart(x, y,Drag.obj.id);

        o.lastMouseX    = e.clientX;
        o.lastMouseY    = e.clientY;

        if (o.minX != null)    o.minMouseX    = e.clientX - x + o.minX;
        if (o.maxX != null)    o.maxMouseX    = o.minMouseX + o.maxX - o.minX;
        if (o.minY != null)    o.minMouseY    = e.clientY - y + o.minY;
        if (o.maxY != null)    o.maxMouseY    = o.minMouseY + o.maxY - o.minY;

        document.onmousemove    = Drag.drag;
        document.onmouseup        = Drag.end;

        return false;
    },

    drag : function(e)
    {
        e = Drag.fixE(e);
        var o = Drag.obj;

        var ey    = e.clientY;
        var ex    = e.clientX;
        var y = parseInt(o.root.style.top);
        var x = parseInt(o.root.style.left);
        var nx, ny;

        if (o.minX != null) ex = Math.max(ex, o.minMouseX);
        if (o.maxX != null) ex = Math.min(ex, o.maxMouseX);
        if (o.minY != null) ey = Math.max(ey, o.minMouseY);
        if (o.maxY != null) ey = Math.min(ey, o.maxMouseY);

        nx = x + (ex - o.lastMouseX);
        ny = y + (ey - o.lastMouseY);

        if (o.xMapper)        nx = o.xMapper(y)
        else if (o.yMapper)    ny = o.yMapper(x)

        Drag.obj.root.style.left = nx + "px";
        Drag.obj.root.style.top = ny + "px";
        Drag.obj.lastMouseX    = ex;
        Drag.obj.lastMouseY    = ey;

        Drag.obj.root.onDrag(nx, ny,Drag.obj.id);
        return false;
    },

    end : function()
    {
        document.onmousemove = null;
        document.onmouseup   = null;
        Drag.obj.root.onDragEnd(    parseInt(Drag.obj.root.style.left), parseInt(Drag.obj.root.style.top));
		Drag.obj.root.style.cursor = "default";        
			                            
        Drag.obj = null;
    },

    fixE : function(e)
    {
        if (typeof e == 'undefined') e = window.event;
        if (typeof e.layerX == 'undefined') e.layerX = e.offsetX;
        if (typeof e.layerY == 'undefined') e.layerY = e.offsetY;
        return e;
    }
};


	
function drag_drop_item(name,x,y) 
{
	this.x = x;
	this.y = y;
	this.name = name;
	this.curX = x;
	this.curY = y;	
}

function setDropTarget(obj_id) 
{

}