pure javascript to check if something has hover (without setting on mouseover/out)

后端未结

关注

 4  996

I have seen this jQuery syntax:

if($(element).is(\':hover\')) { do something}

Since I am not using jQuery, I am looking for the best way to

相关标签:

4条回答

南笙

2020-11-29 01:26

it occurred to me that one way to check if an element is being hovered over is to set an unused property in css :hover and then check if that property exists in javascript. its not a proper solution to the problem since it is not making use of a dom-native hover property, but it is the closest and most minimal solution i can think of.

<html>
    <head>
        <style type="text/css">
#hover_el
{   
    border: 0px solid blue;
    height: 100px;
    width: 100px;
    background-color: blue;
}   
#hover_el:hover
{   
    border: 0px dashed blue;
}
        </style>
        <script type='text/javascript'>
window.onload = function() {check_for_hover()};
function check_for_hover() {
    var hover_element = document.getElementById('hover_el');
    var hover_status = (getStyle(hover_element, 'border-style') === 'dashed') ? true : false;
    document.getElementById('display').innerHTML = 'you are' + (hover_status ? '' : ' not') + ' hovering';
    setTimeout(check_for_hover, 1000);
};
function getStyle(oElm, strCssRule) {
    var strValue = "";
    if(document.defaultView && document.defaultView.getComputedStyle) {
        strValue = document.defaultView.getComputedStyle(oElm, "").getPropertyValue(strCssRule);
    }
    else if(oElm.currentStyle) {
        strCssRule = strCssRule.replace(/\-(\w)/g, function (strMatch, p1) {
            return p1.toUpperCase();
        });
        strValue = oElm.currentStyle[strCssRule];
    }
    return strValue;
};
        </script>
    </head>
    <body>
        <div id='hover_el'>hover here</div>
        <div id='display'></div>
    </body>
</html>

(function getStyle thanks to JavaScript get Styles)

if anyone can think of a better css property to use as a flag than solid/dashed please let me know. preferably the property would be one which is rarely used and cannot be inherited.

0 讨论(0)

别那么骄傲

2020-11-29 01:28

First you need to keep track of which elements are being hovered on. Here's one way of doing it:

(function() {
    var matchfunc = null, prefixes = ["","ms","moz","webkit","o"], i, m;
    for(i=0; i<prefixes.length; i++) {
        m = prefixes[i]+(prefixes[i] ? "Matches" : "matches");
        if( document.documentElement[m]) {matchfunc = m; break;}
        m += "Selector";
        if( document.documentElement[m]) {matchfunc = m; break;}
    }
    if( matchfunc) window.isHover = function(elem) {return elem[matchfunc](":hover");};
    else {
        window.onmouseover = function(e) {
            e = e || window.event;
            var t = e.srcElement || e.target;
            while(t) {
                t.hovering = true;
                t = t.parentNode;
            }
        };
        window.onmouseout = function(e) {
            e = e || window.event;
            var t = e.srcElement || e.target;
            while(t) {
                t.hovering = false;
                t = t.parentNode;
            }
        };
        window.isHover = function(elem) {return elem.hovering;};
   }
})();

0 讨论(0)

迷失自我

2020-11-29 01:28

You can use querySelector for IE>=8:

const isHover = e => e.parentElement.querySelector(':hover') === e;    

const myDiv = document.getElementById('mydiv');
document.addEventListener('mousemove', function checkHover() {
  const hovered = isHover(myDiv);
  if (hovered !== checkHover.hovered) {
    console.log(hovered ? 'hovered' : 'not hovered');
    checkHover.hovered = hovered;
  }
});

.whyToCheckMe {position: absolute;left: 100px;top: 50px;}

<div id="mydiv">HoverMe
  <div class="whyToCheckMe">Do I need to be checked too?</div>
</div>

to fallback I think it is ok @Kolink answer.

0 讨论(0)

死守一世寂寞

2020-11-29 01:37

Simply using element.matches(':hover') seems to work well for me, you can use a comprehensive polyfill for older browsers too: https://developer.mozilla.org/en-US/docs/Web/API/Element/matches

0 讨论(0)
发布评论:

提交评论
- 加载中...