/**
* getScrollTop 获取滚动条距离
* @since 1.0.0
* @returns {Number}
*/
export function getScrollTop() {
return (document.documentElement && document.documentElement.scrollTop) || document.body.scrollTop;
}
/**
* setScrollTop 设置滚动条到顶部的距离
* @since 1.0.0
* @param {Number} value
* @returns {Number}
*/
export function setScrollTop(value) {
window.scrollTo(0, value);
return value;
}
/**
* scrollTo 在${duration}ms时间内,滚动条平滑滚动到${to}指定位置
* @since 1.0.0
* @param {Number} to
* @param {Number} duration
*/
export function scrollTo(to,duration){
if (duration < 0) {
setScrollTop(to);
return
}
let diff = to - getScrollTop();
if (diff === 0) return
let step = diff / duration * 10;
requestAnimFrame(
() => {
if (Math.abs(step) > Math.abs(diff)) {
setScrollTop(getScrollTop() + diff);
return;
}
setScrollTop(getScrollTop() + step);
if (diff > 0 && getScrollTop() >= to || diff < 0 && getScrollTop() <= to) {
return;
}
scrollTo(to, duration - 16);
});
}
const requestAnimFrame = (function () {
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function (callback) {
window.setTimeout(callback, 1000 / 60);
};
})();
/**
* offset 获取元素的距离document的位置
* @since 1.0.0
* @param {HTMLElement} ele
* @returns { {left:Number,top:Number} }
*/
export function offset(ele) {
let pos = {
left: 0,
top: 0
};
while (ele) {
pos.left += ele.offsetLeft;
pos.top += ele.offsetTop;
ele = ele.offsetParent;
};
return pos;
}
/**
* windowResize 软键盘缩回、弹起回调
* 当软件键盘弹起会改变当前 window.innerHeight,监听这个值变化
* @since 1.0.0
* @param {Function} downCb 当软键盘弹起后,缩回的回调
* @returns {Function} upCb 当软键盘弹起的回调
*/
function windowResize(downCb, upCb) {
const clientHeight = window.innerHeight;
downCb = typeof downCb === 'function' ? downCb : function () {}
upCb = typeof upCb === 'function' ? upCb : function () {}
window.addEventListener('resize', () => {
const height = window.innerHeight;
if (height === clientHeight) {
downCb();
}
if (height < clientHeight) {
upCb();
}
});
}
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