/**************************************************
 * dom-drag.js
 * 09.25.2001
 * www.youngpup.net
 **************************************************
 * 10.28.2001 - fixed minor bug where events
 * sometimes fired off the bannertop, not the banner.
 **************************************************/
var Drag = {
obj : null,
        init : function(o, obanner, minX, maxX, minY, maxY, bSwapHorzRef, bSwapVertRef, fXMapper, fYMapper)
        {
                o.onmousedown = Drag.start;
                o.hmode       = bSwapHorzRef ? false : true ;
                o.vmode       = bSwapVertRef ? false : true ;
                o.banner = obanner && obanner != null ? obanner : o ;
                if (o.hmode  && isNaN(parseInt(o.banner.style.left  ))) o.banner.style.left   = "0px";
                if (o.vmode  && isNaN(parseInt(o.banner.style.top   ))) o.banner.style.top    = "0px";
                if (!o.hmode && isNaN(parseInt(o.banner.style.right ))) o.banner.style.right  = "0px";
                if (!o.vmode && isNaN(parseInt(o.banner.style.bottom))) o.banner.style.bottom = "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.banner.onDragStart = new Function();
                o.banner.onDragEnd   = new Function();
                o.banner.onDrag      = new Function();
        },
        start : function(e)
        {
                var o = Drag.obj = this;
                e = Drag.fixE(e);
                var y = parseInt(o.vmode ? o.banner.style.top  : o.banner.style.bottom);
                var x = parseInt(o.hmode ? o.banner.style.left : o.banner.style.right );
                o.banner.onDragStart(x, y);
                o.lastMouseX = e.clientX;
                o.lastMouseY = e.clientY;
                if (o.hmode) {
                        if (o.minX != null) o.minMouseX = e.clientX - x + o.minX;
                        if (o.maxX != null) o.maxMouseX = o.minMouseX + o.maxX - o.minX;
                } else {
                        if (o.minX != null) o.maxMouseX = -o.minX + e.clientX + x;
                        if (o.maxX != null) o.minMouseX = -o.maxX + e.clientX + x;
                }
                if (o.vmode) {
                        if (o.minY != null) o.minMouseY = e.clientY - y + o.minY;
                        if (o.maxY != null) o.maxMouseY = o.minMouseY + o.maxY - o.minY;
                } else {
                        if (o.minY != null) o.maxMouseY = -o.minY + e.clientY + y;
                        if (o.maxY != null) o.minMouseY = -o.maxY + e.clientY + y;
                }
                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.vmode ? o.banner.style.top  : o.banner.style.bottom);
                var x = parseInt(o.hmode ? o.banner.style.left : o.banner.style.right );
                var nx, ny;
                if (o.minX != null) ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex, o.maxMouseX);
                if (o.maxX != null) ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex, o.minMouseX);
                if (o.minY != null) ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey, o.maxMouseY);
                if (o.maxY != null) ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey, o.minMouseY);
                nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1));
                ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1));
                if (o.xMapper)      nx = o.xMapper(y)
                else if (o.yMapper) ny = o.yMapper(x)
                Drag.obj.banner.style[o.hmode ? "left" : "right"] = nx + "px";
                Drag.obj.banner.style[o.vmode ? "top" : "bottom"] = ny + "px";
                Drag.obj.lastMouseX = ex;
                Drag.obj.lastMouseY = ey;
                Drag.obj.banner.onDrag(nx, ny);
                return false;
        },
        end : function()
        {
                document.onmousemove = null;
                document.onmouseup   = null;
                Drag.obj.banner.onDragEnd(parseInt(Drag.obj.banner.style[Drag.obj.hmode ? "left" : "right"]),
                                        parseInt(Drag.obj.banner.style[Drag.obj.vmode ? "top" : "bottom"]));
                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;
        }
};