pressing = function() {
            var offset;

            state[axis] = that.fixPos(state[axis] + N * ((axis === "y"

                // jQuery bug on firefox: e.offsetY ==> undefined & position().top ==> 0
                // @see: http://bugs.jquery.com/ticket/8523
                // ? e.offsetY > state.$thumbY.position().top
                // : e.offsetX > state.$thumbX.position().left) ? -1 : 1), axis);
                ? e.pageY - $target.offset().top > Math.max(parseFloat(state.$thumbY.css("marginTop")), state.$thumbY.position().top)
                : e.pageX - $target.offset().left > Math.max(parseFloat(state.$thumbX.css("marginLeft")), state.$thumbX.position().left)) ? -1 : 1), axis);

            that.scrollTo(that.$el, {
                x: state.x
                , y: state.y
            });

            pos[axis] = Math.floor(-state[axis] * N / n);
            that.scrollTo($thumb, pos);

            offset = (axis === "x"
                ? e.pageX - $target.offset().left
                : e.pageY - $target.offset().top) - pos[axis];

            offset = offset > 0
            ? offset > (axis === "x"
                ? state._w
                : state._h)
            : offset < 0;

            that.args.onScroll && that.args.onScroll.call(that, e);

            if(!offset) {
                isPressing = !1;
                pressed = 1;
                that.$wrap.removeClass(that.args.activateClass);

                that.args.onEndPress && that.args.onEndPress.call(that);
            }

            isPressing && setTimeout(function() {
                isPressing && pressing();
            }, that.args.pressDelay);
        }
Mouse evnent handle, contains click & drag
@param {[type]} e [description]
@param {[type]} that [description]
@return {[type]} [description]