if(this.containment) {
            if(position.left < this.containment[0]) position.left = this.containment[0];
            if(position.top < this.containment[1]) position.top = this.containment[1];
            if(position.left > this.containment[2]) position.left = this.containment[2];
            if(position.top > this.containment[3]) position.top = this.containment[3];