使用原生js封装webapp滑动效果(惯性滑动、滑动回弹)_javascript技巧

}
/*=====================
* 名称: appTouch
* 功能: web app滑动模拟组件
* 参数: 相关配置
======================*/
var appTouch = function(config, callback) {
this.touchContain = config.tContain;
this.touchMove = config.tMove;
this.touchScroller = config.tScroller;
this.touchScrollerArea = config.tScrollerArea;
this.callbackfn = callback;
this.move();
}

appTouch.prototype = {
move : function(e) {
var monitor = document.getElementById(this.touchContain), //监听容器
target = document.getElementById(this.touchMove), //移动目标
scroller = document.getElementById(this.touchScroller), //自定义滚动条
scrollerArea = document.getElementById(this.touchScrollerArea), //滚动条区域
sheight = monitor.offsetHeight / target.offsetHeight * monitor.offsetHeight, //自定义滚动条的长度
st = (target.offsetHeight - monitor.offsetHeight) / (monitor.offsetHeight - sheight), //移动块对应滚轮单位长度
tslow = 4, //到顶/底减基数
tMove = 0, //滑块到顶top值
tMoveL = tMove + 140, //到顶允许下拉范围
bMove = monitor.offsetHeight - target.offsetHeight, //滑块到底top值
bMoveL = bMove - 140, //到底允许上滑范围
callbackfn = this.callbackfn, //回调函数
flg = false, //标记是否滑动
startY, //标记起始位置
startTop, //标记滑动起始时的高度值
move = 0;
//移动距离
//鼠标事件注册
addEvent(monitor, 'mousedown', moveStart);
addEvent(monitor, 'mousemove', moveIn);
addEvent(monitor, 'mouseup', moveEnd);
addEvent(window, 'mousemove', moveIn);
addEvent(window, 'mouseup', moveEnd);
//移动设备触摸事件注册
addEvent(monitor, 'touchstart', moveStart);
addEvent(monitor, 'touchmove', moveIn);
addEvent(monitor, 'touchend', moveEnd);
/**
*外观/门面模式包装
*/
/*事件监听 */
function addEvent(el, type, fn) {
if (el.addEventListener) {
el.addEventListener(type, fn, false);
} else if (el.attachEvent) {
el.attachEvent('on' + type, fn);
} else {
el['on' + type] = fn;
}
}

//取消浏览器默认行为
function stop(e) {
//Opera/Chrome/FF
if (e.preventDefault)
e.preventDefault();
//IE
e.returnValue = false;
}

//包装结束
/**
*操作函数
*/
//惯性缓动参数
var lastMoveTime = 0;
var lastMoveStart = 0;
var stopInertiaMove = false;
/*移动触发*/
function moveStart(e) {
stop(e);
flg = true;
if (e.touches)
e = e.touches[0];
startY = e.clientY;
startTop = target.style.top || 0;
//惯性缓动
lastMoveStart = startY;
lastMoveTime = new Date().getTime();
stopInertiaMove = true;
scrollerArea.style.visibility = 'visible';

}

/*移动过程中*/
function moveIn(e) {
if (flg) {
stop(e);
if (e.touches)
e = e.touches[0];
move = e.clientY - startY + parseInt(startTop);
if (move > tMove) {
(move - tMove) / tslow + tMove > tMoveL ? move = tMoveL : move = (move - tMove) / tslow + tMove

} else if (move < bMove)
(move - bMove) / tslow + bMove < bMoveL ? move = bMoveL : move = (move - bMove) / tslow + bMove;
target.style.top = move + 'px';
scroller.style.top = -move / st + 'px';
//惯性缓动
var nowTime = new Date().getTime();
stopInertiaMove = true;
if (nowTime - lastMoveTime > 300) {
lastMoveTime = nowTime;
lastMoveStart = e.clientY;
}
}
}

/*移动结束*/
function moveEnd(e) {
stop(e);
if (e.touches)
e = e.touches[0];
//惯性缓动
var contentTop = target.style.top.replace('px', '');
var contentY = (parseInt(contentTop) + e.clientY - lastMoveStart);
var nowTime = new Date().getTime();
var v = (e.clientY - lastMoveStart) / (nowTime - lastMoveTime);
//最后一段时间手指划动速度
stopInertiaMove = false;
(function(v, startTime, contentY) {
var dir = v > 0 ? -1 : 1;
//加速度方向
var deceleration = dir * 0.005;
function inertiaMove() {
if (stopInertiaMove)
return;
var nowTime = new Date().getTime();
var t = nowTime - startTime;
var nowV = v + t * deceleration;
var moveY = (v + nowV) / 2 * t;
// 速度方向变化表示速度达到0了
if (dir * nowV > 0) {
if (move > tMove) {
callbackfn('到顶了');
target.style.top = tMove + 'px';
scroller.style.top = tMove + 'px';
} else if (move < bMove) {
callbackfn('到底了');
target.style.top = bMove + 'px';
scroller.style.top = -bMove / st + 'px';
}
setTimeout(function() {
if (!stopInertiaMove)
scrollerArea.style.visibility = 'hidden';
}, 4000);
return;
}
move = contentY + moveY;
if (move > tMove) {
t /= 20;
move = (move - tMove) / 10 + tMove;
} else if (move < bMove) {
t /= 20;
move = (move - bMove) / 10 + bMove;
}
target.style.top = move + "px";
scroller.style.top = -move / st + 'px';
setTimeout(inertiaMove, 10);
}

inertiaMove();
})(v, nowTime, contentY);
move = 0;
flg = false;
}

//操作结束
/**
*相关初始化
*/
//滚动条长度初始化
scroller.style.height = sheight + 'px';
//初始化结束

},
otherInteract : function() {
//其他功能扩充
}
}