让我们从一些事件监听器开始:
window.addEventListener('scroll', function (e) {
console.log('scroll', e);
});
window.addEventListener('touchstart', function (e) {
console.log('touchstart', e);
});
window.addEventListener('touchmove', function (e) {
console.log('touchmove', e);
});
window.addEventListener('touchend', function (e) {
console.log('touchend', e);
});
我需要以编程方式触摸位于位置
{pageX: 0, pageY: 0}
的文档,将其移动到{pageX: 0, pageY: 100}
并结束触摸事件。为此,我将构建一个辅助函数
TouchEvent
,它将在指定元素上触发触摸事件。/**
* @see https://gist.github.com/sstephenson/448808
* @see https://developer.apple.com/library/iad/documentation/UserExperience/Reference/TouchEventClassReference/TouchEvent/TouchEvent.html
* @see https://dev59.com/WmMl5IYBdhLWcg3w3aI-
*/
function touchEvent (element, type, identifier, pageX, pageY) {
var e,
touch,
touches,
targetTouches,
changedTouches;
touch = document.createTouch(window, element, identifier, pageX, pageY, pageX, pageY);
if (type == 'touchend') {
touches = document.createTouchList();
targetTouches = document.createTouchList();
changedTouches = document.createTouchList(touch);
} else {
touches = document.createTouchList(touch);
targetTouches = document.createTouchList(touch);
changedTouches = document.createTouchList(touch);
}
e = document.createEvent('TouchEvent');
e.initTouchEvent(type, true, true, window, null, 0, 0, 0, 0, false, false, false, false, touches, targetTouches, changedTouches, 1, 0);
window.dispatchEvent(e);
};
我会确保文档已经加载并触发先前商定的场景中的触摸事件。
document.addEventListener('DOMContentLoaded', function() {
var identifier = new Date().getTime(),
element = document,
i = 0;
touchEvent(element, 'touchstart', identifier, 0, 0);
while (i++ < 100) {
touchEvent(element, 'touchmove', identifier, 0, i);
}
touchEvent(element, 'touchend', identifier, 0, i);
});
期望的是触发了
touchstart
、touchmove
和touchend
事件。意外的是scroll
事件没有被触发,文档上实际的“触摸”操作没有反映在当前文档中。
window.addEventListener('scroll', function (e) {
console.log('scroll', e);
});
window.addEventListener('resize', function (e) {
console.log('resize', e);
});
window.addEventListener('touchstart', function (e) {
console.log('touchstart', e);
});
window.addEventListener('touchmove', function (e) {
console.log('touchmove', e);
});
window.addEventListener('touchend', function (e) {
console.log('touchend', e);
});
/**
* @see https://gist.github.com/sstephenson/448808
* @see https://developer.apple.com/library/iad/documentation/UserExperience/Reference/TouchEventClassReference/TouchEvent/TouchEvent.html
* @see https://dev59.com/WmMl5IYBdhLWcg3w3aI-
*/
function touchEvent (element, type, identifier, pageX, pageY) {
var e,
touch,
touches,
targetTouches,
changedTouches;
if (!document.createTouch) {
throw new Error('This will work only in Safari browser.');
}
touch = document.createTouch(window, element, identifier, pageX, pageY, pageX, pageY);
if (type == 'touchend') {
touches = document.createTouchList();
targetTouches = document.createTouchList();
changedTouches = document.createTouchList(touch);
} else {
touches = document.createTouchList(touch);
targetTouches = document.createTouchList(touch);
changedTouches = document.createTouchList(touch);
}
e = document.createEvent('TouchEvent');
e.initTouchEvent(type, true, true, window, null, 0, 0, 0, 0, false, false, false, false, touches, targetTouches, changedTouches, 1, 0);
window.dispatchEvent(e);
};
document.addEventListener('DOMContentLoaded', function() {
var identifier = new Date().getTime(),
element = document,
i = 0;
touchEvent(element, 'touchstart', identifier, 0, 0);
while (i++ < 100) {
touchEvent(element, 'touchmove', identifier, 0, i);
}
touchEvent(element, 'touchend', identifier, 0, i);
});
#playground {
background: #999; height: 5000px;
}
<div id="playground"></div>
我的设置缺少什么,以使浏览器将触摸事件解释为用户发出的那样? 实质上,我希望浏览器根据一系列通过编程触发的触摸开始、移动和结束事件滚动。