Ext.lib.Region = function(t, r, b, l) {
		var me = this;
        me.top = t;
        me[1] = t;
        me.right = r;
        me.bottom = b;
        me.left = l;
        me[0] = l;
    };

    Ext.lib.Region.prototype = {
        contains : function(region) {
	        var me = this;
            return ( region.left >= me.left &&
                     region.right <= me.right &&
                     region.top >= me.top &&
                     region.bottom <= me.bottom );

        },

        getArea : function() {
	        var me = this;
            return ( (me.bottom - me.top) * (me.right - me.left) );
        },

        intersect : function(region) {
            var me = this,
            	t = Math.max(me.top, region.top),
            	r = Math.min(me.right, region.right),
            	b = Math.min(me.bottom, region.bottom),
            	l = Math.max(me.left, region.left);

            if (b >= t && r >= l) {
                return new Ext.lib.Region(t, r, b, l);
            }
        },
        
        union : function(region) {
	        var me = this,
            	t = Math.min(me.top, region.top),
            	r = Math.max(me.right, region.right),
            	b = Math.max(me.bottom, region.bottom),
            	l = Math.min(me.left, region.left);

            return new Ext.lib.Region(t, r, b, l);
        },

        constrainTo : function(r) {
	        var me = this;
            me.top = me.top.constrain(r.top, r.bottom);
            me.bottom = me.bottom.constrain(r.top, r.bottom);
            me.left = me.left.constrain(r.left, r.right);
            me.right = me.right.constrain(r.left, r.right);
            return me;
        },

        adjust : function(t, l, b, r) {
	        var me = this;
            me.top += t;
            me.left += l;
            me.right += r;
            me.bottom += b;
            return me;
        }
    };

    Ext.lib.Region.getRegion = function(el) {
        var p = Ext.lib.Dom.getXY(el),
        	t = p[1],
        	r = p[0] + el.offsetWidth,
        	b = p[1] + el.offsetHeight,
        	l = p[0];

        return new Ext.lib.Region(t, r, b, l);
    };