如何检测用户用JavaScript在网页上向某个方向滑动手指?
我想知道是否有一种解决方案可以同时适用于iPhone和Android手机上的网站。
如何检测用户用JavaScript在网页上向某个方向滑动手指?
我想知道是否有一种解决方案可以同时适用于iPhone和Android手机上的网站。
当前回答
再加上这个答案。这个增加了对鼠标事件的支持,用于桌面测试:
<!--scripts-->
class SwipeEventDispatcher {
constructor(element, options = {}) {
this.evtMap = {
SWIPE_LEFT: [],
SWIPE_UP: [],
SWIPE_DOWN: [],
SWIPE_RIGHT: []
};
this.xDown = null;
this.yDown = null;
this.element = element;
this.isMouseDown = false;
this.listenForMouseEvents = true;
this.options = Object.assign({ triggerPercent: 0.3 }, options);
element.addEventListener('touchstart', evt => this.handleTouchStart(evt), false);
element.addEventListener('touchend', evt => this.handleTouchEnd(evt), false);
element.addEventListener('mousedown', evt => this.handleMouseDown(evt), false);
element.addEventListener('mouseup', evt => this.handleMouseUp(evt), false);
}
on(evt, cb) {
this.evtMap[evt].push(cb);
}
off(evt, lcb) {
this.evtMap[evt] = this.evtMap[evt].filter(cb => cb !== lcb);
}
trigger(evt, data) {
this.evtMap[evt].map(handler => handler(data));
}
handleTouchStart(evt) {
this.xDown = evt.touches[0].clientX;
this.yDown = evt.touches[0].clientY;
}
handleMouseDown(evt) {
if (this.listenForMouseEvents==false) return;
this.xDown = evt.clientX;
this.yDown = evt.clientY;
this.isMouseDown = true;
}
handleMouseUp(evt) {
if (this.isMouseDown == false) return;
const deltaX = evt.clientX - this.xDown;
const deltaY = evt.clientY - this.yDown;
const distMoved = Math.abs(Math.abs(deltaX) > Math.abs(deltaY) ? deltaX : deltaY);
const activePct = distMoved / this.element.offsetWidth;
if (activePct > this.options.triggerPercent) {
if (Math.abs(deltaX) > Math.abs(deltaY)) {
deltaX < 0 ? this.trigger('SWIPE_LEFT') : this.trigger('SWIPE_RIGHT');
} else {
deltaY > 0 ? this.trigger('SWIPE_UP') : this.trigger('SWIPE_DOWN');
}
}
}
handleTouchEnd(evt) {
const deltaX = evt.changedTouches[0].clientX - this.xDown;
const deltaY = evt.changedTouches[0].clientY - this.yDown;
const distMoved = Math.abs(Math.abs(deltaX) > Math.abs(deltaY) ? deltaX : deltaY);
const activePct = distMoved / this.element.offsetWidth;
if (activePct > this.options.triggerPercent) {
if (Math.abs(deltaX) > Math.abs(deltaY)) {
deltaX < 0 ? this.trigger('SWIPE_LEFT') : this.trigger('SWIPE_RIGHT');
} else {
deltaY > 0 ? this.trigger('SWIPE_UP') : this.trigger('SWIPE_DOWN');
}
}
}
}
// add a listener on load
window.addEventListener("load", function(event) {
const dispatcher = new SwipeEventDispatcher(document.body);
dispatcher.on('SWIPE_RIGHT', () => { console.log('I swiped right!') })
dispatcher.on('SWIPE_LEFT', () => { console.log('I swiped left!') })
});
其他回答
我将这里的一些答案合并到一个脚本中,该脚本使用CustomEvent在DOM中触发滑动事件。添加0.7k的swiped-events.min.js脚本到你的页面,并监听滑动事件:
刷卡
document.addEventListener('swiped', function(e) {
console.log(e.target); // the element that was swiped
console.log(e.detail.dir); // swiped direction
});
swiped-left
document.addEventListener('swiped-left', function(e) {
console.log(e.target); // the element that was swiped
});
swiped-right
document.addEventListener('swiped-right', function(e) {
console.log(e.target); // the element that was swiped
});
swiped-up
document.addEventListener('swiped-up', function(e) {
console.log(e.target); // the element that was swiped
});
swiped-down
document.addEventListener('swiped-down', function(e) {
console.log(e.target); // the element that was swiped
});
你也可以直接附加到一个元素:
document.getElementById('myBox').addEventListener('swiped-down', function(e) {
console.log(e.target); // the element that was swiped
});
可选配置
您可以指定以下属性来调整页面中的滑动交互功能(这些是可选的)。
<div data-swipe-threshold="10"
data-swipe-timeout="1000"
data-swipe-ignore="false">
Swiper, get swiping!
</div>
要在应用程序范围内设置默认值,请在最顶部的元素上设置配置属性:
<body data-swipe-threshold="100" data-swipe-timeout="250">
<div>Swipe me</div>
<div>or me</div>
</body>
源代码可在Github
我之前使用的方法是,您必须检测mousedown事件,记录其x,y位置(任何相关的位置),然后检测mouseup事件,并减去两个值。
我必须为旋转木马编写一个简单的脚本,以检测向左或向右的滑动。
我使用指针事件代替触摸事件。
我希望这对个人有用,我欢迎任何改进我的代码的见解;我觉得很不好意思加入这个线程与显著优秀的JS开发人员。
function getSwipeX({elementId}) {
this.e = document.getElementsByClassName(elementId)[0];
this.initialPosition = 0;
this.lastPosition = 0;
this.threshold = 200;
this.diffInPosition = null;
this.diffVsThreshold = null;
this.gestureState = 0;
this.getTouchStart = (event) => {
event.preventDefault();
if (window.PointerEvent) {
this.e.setPointerCapture(event.pointerId);
}
return this.initalTouchPos = this.getGesturePoint(event);
}
this.getTouchMove = (event) => {
event.preventDefault();
return this.lastPosition = this.getGesturePoint(event);
}
this.getTouchEnd = (event) => {
event.preventDefault();
if (window.PointerEvent) {
this.e.releasePointerCapture(event.pointerId);
}
this.doSomething();
this.initialPosition = 0;
}
this.getGesturePoint = (event) => {
this.point = event.pageX
return this.point;
}
this.whatGestureDirection = (event) => {
this.diffInPosition = this.initalTouchPos - this.lastPosition;
this.diffVsThreshold = Math.abs(this.diffInPosition) > this.threshold;
(Math.sign(this.diffInPosition) > 0) ? this.gestureState = 'L' : (Math.sign(this.diffInPosition) < 0) ? this.gestureState = 'R' : this.gestureState = 'N';
return [this.diffInPosition, this.diffVsThreshold, this.gestureState];
}
this.doSomething = (event) => {
let [gestureDelta,gestureThreshold,gestureDirection] = this.whatGestureDirection();
// USE THIS TO DEBUG
console.log(gestureDelta,gestureThreshold,gestureDirection);
if (gestureThreshold) {
(gestureDirection == 'L') ? // LEFT ACTION : // RIGHT ACTION
}
}
if (window.PointerEvent) {
this.e.addEventListener('pointerdown', this.getTouchStart, true);
this.e.addEventListener('pointermove', this.getTouchMove, true);
this.e.addEventListener('pointerup', this.getTouchEnd, true);
this.e.addEventListener('pointercancel', this.getTouchEnd, true);
}
}
可以使用new调用该函数。
window.addEventListener('load', () => {
let test = new getSwipeX({
elementId: 'your_div_here'
});
})
首先使用鼠标事件原型实现它可能会更容易一些。
这里有很多答案,包括顶部,应该谨慎使用,因为它们不考虑边界情况,特别是在边界框周围。
See:
触摸事件 鼠标事件
你需要尝试捕捉边缘情况和行为,比如指针在结束前移动到元素之外。
滑动是一种非常基本的手势,它是一种更高级别的界面指针交互处理,大致介于处理原始事件和手写识别之间。
没有一种确切的方法来检测滑动或投掷,尽管几乎所有方法都遵循一个基本原则,即通过距离和速度或速度的阈值来检测元素的运动。你可以简单地说,如果在给定的时间内,在给定的方向上有65%的屏幕大小的移动,那么这就是一次滑动。具体在哪里划定界限以及如何计算取决于你自己。
有些人可能还会从某个方向的动量角度以及元素释放时它被推离屏幕的距离来看待它。这是更清晰的粘滞滑动,元素可以拖动,然后释放,要么反弹,要么飞出屏幕,就像弹性断裂。
最好是找到一个手势库,你可以移植或重用,通常用于一致性。这里的许多例子都过于简单,将滑动记录为任何方向上最轻微的触摸。
Android将是显而易见的选择,尽管它有相反的问题,它过于复杂。
许多人似乎把这个问题误解为某个方向的任何运动。滑动是一种面向单一方向的广泛且相对简短的运动(尽管可能是弧形的并具有一定的加速属性)。抛掷是类似的,但它是指在自身动量的作用下,随意地将物体推离一定距离。
这两者非常相似,以至于一些库可能只提供可以互换使用的fling或swipe。在平面屏幕上,很难真正区分这两种手势,一般来说,人们都在做这两种动作(滑动物理屏幕,但投掷屏幕上显示的UI元素)。
你最好的选择就是不要自己动手。目前已经有大量用于检测简单手势的JavaScript库。
你可以监听touchstart和touchend事件,并根据事件数据计算方向和力(Codepen):
让start = null; 文档。addEventListener('touchstart', e => { const touch = e. changedtouchs[0]; Start = [touch.]clientX touch.clientY); }); 文档。addEventListener('touchend', e => { const touch = e. changedtouchs[0]; Const end = [touch.]clientX touch.clientY); document.body.innerText = " ${结束[0]-[0]开始},${结束[1]-[1]开始}'; }); 点击这里
或者你可以围绕同样的概念构建一个更符合人体工程学的API (Codepen):
const removeListener = addSwipeRightListener(document, (force, e) => {
console.info('Swiped right with force: ' + force);
});
// removeListener()
// swipe.js const { addSwipeLeftListener, addSwipeRightListener, addSwipeUpListener, addSwipeDownListener, } = (function() { // <element, {listeners: [...], handleTouchstart, handleTouchend}> const elements = new WeakMap(); function readTouch(e) { const touch = e.changedTouches[0]; if (touch == undefined) { return null; } return [touch.clientX, touch.clientY]; } function addListener(element, cb) { let elementValues = elements.get(element); if (elementValues === undefined) { const listeners = new Set(); const handleTouchstart = e => { elementValues.start = readTouch(e); }; const handleTouchend = e => { const start = elementValues.start; if (start === null) { return; } const end = readTouch(e); for (const listener of listeners) { listener([end[0] - start[0], end[1] - start[1]], e); } }; element.addEventListener('touchstart', handleTouchstart); element.addEventListener('touchend', handleTouchend); elementValues = { start: null, listeners, handleTouchstart, handleTouchend, }; elements.set(element, elementValues); } elementValues.listeners.add(cb); return () => deleteListener(element, cb); } function deleteListener(element, cb) { const elementValues = elements.get(element); const listeners = elementValues.listeners; listeners.delete(cb); if (listeners.size === 0) { elements.delete(element); element.removeEventListener('touchstart', elementValues.handleTouchstart); element.removeEventListener('touchend', elementValues.handleTouchend); } } function addSwipeLeftListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (x < 0 && -x > Math.abs(y)) { cb(x, e); } }); } function addSwipeRightListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (x > 0 && x > Math.abs(y)) { cb(x, e); } }); } function addSwipeUpListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (y < 0 && -y > Math.abs(x)) { cb(x, e); } }); } function addSwipeDownListener(element, cb) { return addListener(element, (force, e) => { const [x, y] = force; if (y > 0 && y > Math.abs(x)) { cb(x, e); } }); } return { addSwipeLeftListener, addSwipeRightListener, addSwipeUpListener, addSwipeDownListener, } })(); // app.js function print(direction, force) { document.querySelector('#direction').innerText = direction; document.querySelector('#data').innerText = force; } addSwipeLeftListener(document, (force, e) => { print('left', force); }); addSwipeRightListener(document, (force, e) => { print('right', force); }); addSwipeUpListener(document, (force, e) => { print('up', force); }); addSwipeDownListener(document, (force, e) => { print('down', force); }); <h1>Swipe <span id="direction"></span></h1> Force (px): <span id="data"></span>