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
很简单,
el = document.getElementById("your_id"); var isDown = false; 埃尔。addEventListener('mousedown', function () { isDown = true; }); 埃尔。addEventListener('mouseup', function () { isDown = false; }); 埃尔。addEventListener('鼠标移动',函数(){ if (isDown) { //你的代码在这里 } });
其他回答
纯JS与DeltaX和delay
这个DeltaX和delay是由接受的答案中的评论所建议的,以避免由于鼠标移动一划而试图单击并获得拖动操作时的令人沮丧的体验。
deltaX = deltaY = 2;//px
var element = document.getElementById('divID');
element.addEventListener("mousedown", function(e){
if (typeof InitPageX == 'undefined' && typeof InitPageY == 'undefined') {
InitPageX = e.pageX;
InitPageY = e.pageY;
}
}, false);
element.addEventListener("mousemove", function(e){
if (typeof InitPageX !== 'undefined' && typeof InitPageY !== 'undefined') {
diffX = e.pageX - InitPageX;
diffY = e.pageY - InitPageY;
if ( (diffX > deltaX) || (diffX < -deltaX)
||
(diffY > deltaY) || (diffY < -deltaY)
) {
console.log("dragging");//dragging event or function goes here.
}
else {
console.log("click");//click event or moving back in delta goes here.
}
}
}, false);
element.addEventListener("mouseup", function(){
delete InitPageX;
delete InitPageY;
}, false);
element.addEventListener("click", function(){
console.log("click");
}, false);
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);
}
正如mrjrdnthms在他对接受的答案的评论中指出的那样,这不再适用于Chrome(它总是触发鼠标移动),我已经改编了Gustavo的答案(因为我使用jQuery)来解决Chrome的行为。
var currentPos = [];
$(document).on('mousedown', function (evt) {
currentPos = [evt.pageX, evt.pageY]
$(document).on('mousemove', function handler(evt) {
currentPos=[evt.pageX, evt.pageY];
$(document).off('mousemove', handler);
});
$(document).on('mouseup', function handler(evt) {
if([evt.pageX, evt.pageY].equals(currentPos))
console.log("Click")
else
console.log("Drag")
$(document).off('mouseup', handler);
});
});
Array.prototype.equals函数来自这个答案
基于这个答案,我在React组件中这样做:
export default React.memo(() => {
const containerRef = React.useRef(null);
React.useEffect(() => {
document.addEventListener('mousedown', handleMouseMove);
return () => document.removeEventListener('mousedown', handleMouseMove);
}, []);
const handleMouseMove = React.useCallback(() => {
const drag = (e) => {
console.log('mouse is moving');
};
const lift = (e) => {
console.log('mouse move ended');
window.removeEventListener('mousemove', drag);
window.removeEventListener('mouseup', this);
};
window.addEventListener('mousemove', drag);
window.addEventListener('mouseup', lift);
}, []);
return (
<div style={{ width: '100vw', height: '100vh' }} ref={containerRef} />
);
})
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。