CODEWITHSUNDEEP
jquerybindmousemove
didi
didi

Reputation: 287

Make element follows cursor position even while scrolling

I would like an element to follow the cursor position with its center. The code works as long as there is no scrolling. Once the page gets scrolled, the element "jumps away" on mouse move. Can anybody help me?

https://jsfiddle.net/L7qshr4z/3/

 $(document).bind('mousemove', function(e){
   $("div").css({
     top: e.pageY - $("div").height()/2, // just minus by half the height
     left:  e.pageX - $("div").width()/2 // just minus by half the width
   });
 });

Upvotes: 1

Views: 130

Answers (1)

Rory McCrossan
Rory McCrossan

Reputation: 337570

Instead of pageX and pageY, which are calculated based on the top/left of the document, use clientX and clientY, which are calculated on the top/left of the browser chrome.

In addition, note that updating the DOM within event handlers which fire very rapidly, such as scroll and mousemove, can lead to slow performance and stuttering in the UI. As such you need to take care to make sure the code is as performant as possible. In this case you can cache the div holding the cursor outside of the event handler so that you are not accessing the DOM every time the event fires. Similarly, you can also cache the cursor width and height, assuming it's not dynamically updated.

Finally, use on() instead of bind() as the latter has been deprecated for a long time, and will be removed from the latest versions of jQuery.

let $cursor = $('.cursor');
let cHeight = $cursor.height() / 2;
let cWidth = $cursor.width() / 2;

$(document).on('mousemove', function(e) {
  $cursor.css({
    top: e.clientY - cHeight,
    left: e.clientX - cWidth
  });
});
body {
  cursor: none;
}

p {
  width: 500px;
  line-height: 1.5em;
}

div {
  position: fixed;
  top: 50px;
  left: 50px;
  padding: 5px;
  background: #eae2e2;
  pointer-events: none;
  mix-blend-mode: difference;
  z-index: 999999 !important;
  font-size: 2.0em;
  color: #141313;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
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<div class="cursor">cursor</div>

With all that said, it should also be noted that it's possible to set a custom cursor using CSS alone, if that meets your needs: https://css-tricks.com/using-css-cursors/#using-a-custom-cursor-to-enhance-an-element

Upvotes: 1

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