我使用jQuery。点击来处理Raphael图形上的鼠标点击事件,同时,我需要处理鼠标拖动事件,鼠标拖动在Raphael中由鼠标下拉,鼠标上拉和鼠标移动组成。
很难区分点击和拖动,因为点击也包含鼠标下拉和鼠标上拉,我怎么能区分鼠标“点击”和鼠标“拖动”然后在Javascript?
我使用jQuery。点击来处理Raphael图形上的鼠标点击事件,同时,我需要处理鼠标拖动事件,鼠标拖动在Raphael中由鼠标下拉,鼠标上拉和鼠标移动组成。
很难区分点击和拖动,因为点击也包含鼠标下拉和鼠标上拉,我怎么能区分鼠标“点击”和鼠标“拖动”然后在Javascript?
当前回答
来自@Przemek的回答,
函数listenClickOnly(元素,回调,阈值=10){ 让拖动= 0; 元素。addEventListener('mousedown', () => drag = 0); 元素。addEventListener('mousemove', () => drag++); 元素。addEventListener('mouseup', e => { 如果(拖动<阈值)回调(e); }); } listenClickOnly ( 文档, () => console.log('click'), 10 );
其他回答
我认为区别在于,在拖拽中,mousedown和mouseup之间有一个鼠标移动,但在点击中没有。
你可以这样做:
const element = document.createElement('div') element.innerHTML = 'test' document.body.appendChild(element) let moved let downListener = () => { moved = false } element.addEventListener('mousedown', downListener) let moveListener = () => { moved = true } element.addEventListener('mousemove', moveListener) let upListener = () => { if (moved) { console.log('moved') } else { console.log('not moved') } } element.addEventListener('mouseup', upListener) // release memory element.removeEventListener('mousedown', downListener) element.removeEventListener('mousemove', moveListener) element.removeEventListener('mouseup', upListener)
另一个基于类的香草JS使用距离阈值的解决方案
private initDetectDrag(element) {
let clickOrigin = { x: 0, y: 0 };
const dragDistanceThreshhold = 20;
element.addEventListener('mousedown', (event) => {
this.isDragged = false
clickOrigin = { x: event.clientX, y: event.clientY };
});
element.addEventListener('mousemove', (event) => {
if (Math.sqrt(Math.pow(clickOrigin.y - event.clientY, 2) + Math.pow(clickOrigin.x - event.clientX, 2)) > dragDistanceThreshhold) {
this.isDragged = true
}
});
}
在类内部添加(SOMESLIDER_ELEMENT也可以是document为global):
private isDragged: boolean;
constructor() {
this.initDetectDrag(SOMESLIDER_ELEMENT);
this.doSomeSlideStuff(SOMESLIDER_ELEMENT);
element.addEventListener('click', (event) => {
if (!this.sliderIsDragged) {
console.log('was clicked');
} else {
console.log('was dragged, ignore click or handle this');
}
}, false);
}
下面的编码是检测鼠标的移动。
它适用于大多数情况。这也取决于 关于如何将mouseevent处理为单击。 在JavaScript中,检测非常简单。它不关心如何 在鼠标下拉和鼠标上拉之间按住或移动。 Event.detail不会重置为1当你的鼠标移动 鼠标下拉和鼠标上拉。 如果你需要区分点击和长按,你需要 检查事件的差异。时间戳。
// ==== add the code at the begining of your coding ==== let clickStatus = 0; (() => { let screenX, screenY; document.addEventListener('mousedown', (event) => ({screenX, screenY} = event), true); document.addEventListener('mouseup', (event) => (clickStatus = Math.abs(event.screenX - screenX) + Math.abs(event.screenY - screenY) < 3), true); })(); // ==== add the code at the begining of your coding ==== $("#draggable").click(function(event) { if (clickStatus) { console.log(`click event is valid, click count: ${event.detail}`) } else { console.log(`click event is invalid`) } }) <!doctype html> <html lang="en"> <!-- coding example from https://jqueryui.com/draggable/ --> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>jQuery UI Draggable - Default functionality</title> <link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css"> <link rel="stylesheet" href="/resources/demos/style.css"> <style> #draggable { width: 150px; height: 150px; padding: 0.5em; } </style> <script src="https://code.jquery.com/jquery-1.12.4.js"></script> <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script> <script> $( function() { $( "#draggable" ).draggable(); } ); </script> </head> <body> <div id="draggable" class="ui-widget-content"> <p>Drag me around</p> </div> </body> </html>
如果你想使用Rxjs:
var element = document; Rx.Observable .merge( Rx.Observable.fromEvent(element, 'mousedown').mapTo(0), Rx.Observable.fromEvent(element, 'mousemove').mapTo(1) ) .sample(Rx.Observable.fromEvent(element, 'mouseup')) .subscribe(flag => { console.clear(); console.log(flag ? "drag" : "click"); }); <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <script src="https://unpkg.com/@reactivex/rxjs@5.4.1/dist/global/Rx.js"></script>
这是@wong2在他的回答中所做的直接克隆,但转换为RxJs。
样本的使用也很有趣。示例操作符将从源(mousedown和mousemove的合并)中获取最新的值,并在内部观察对象(mouseup)发出时发出它。
有同样的问题,最近在一个树列表中,用户可以点击项目或拖动它,使这个小指针类,并把它放在我的utils.js
function Pointer(threshold = 10) {
let x = 0;
let y = 0;
return {
start(e) {
x = e.clientX;
y = e.clientY;
},
isClick(e) {
const deltaX = Math.abs(e.clientX - x);
const deltaY = Math.abs(e.clientY - y);
return deltaX < threshold && deltaY < threshold;
}
}
}
下面你可以看到它的工作原理:
function Pointer(threshold = 10) { let x = 0; let y = 0; return { start(e) { x = e.clientX; y = e.clientY; }, isClick(e) { const deltaX = Math.abs(e.clientX - x); const deltaY = Math.abs(e.clientY - y); return deltaX < threshold && deltaY < threshold; } } } const pointer = new Pointer(); window.addEventListener('mousedown', (e) => pointer.start(e)) //window.addEventListener('mousemove', (e) => pointer.last(e)) window.addEventListener('mouseup', (e) => { const operation = pointer.isClick(e) ? "Click" : "Drag" console.log(operation) })