如何触发触摸事件？

Question

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文档的位置{pageX: 0, pageY: 0},移动它{pageX: 0, pageY: 100}并结束触摸事件.

为此,我将构建一个辅助函数TouchEvent,它将触发指定元素上的触摸事件.

/**
 * @see https://gist.github.com/sstephenson/448808
 * @see https://developer.apple.com/library/iad/documentation/UserExperience/Reference/TouchEventClassReference/TouchEvent/TouchEvent.html
 * @see http://stackoverflow.com/questions/18059860/manually-trigger-touch-event
 */
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);
};

我将确保加载文档并发送代表先前商定的方案的触摸事件.

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);
});

预期的是touchstart,touchmove和touchend事件被触发.出乎意料的是,scroll事件尚未触发,文档的实际"触摸"未反映在当前文档中.

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 http://stackoverflow.com/questions/18059860/manually-trigger-touch-event
 */
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>

我的设置缺少什么使浏览器将触摸事件解释为最终用户发布的触摸事件？本质上,我期待浏览器滚动以响应一系列以编程方式触发的触摸开始,移动和结束事件.

Answer 1

我不确定我是否正确理解了您的问题，但是如果您开始触摸页面顶部并向下拖动，您将尝试将页面滚动到顶部，并且它已经在那里，所以为什么要触发滚动。也许从位置开始{pageX: 0, pageY: 100}，结束于{pageX: 0, pageY: 0}，然后看看它是否仍然不起作用。