Element: underflow event

The non-standard underflow event, which is specific to Firefox, is fired when an element is no longer overflowed by its content. This only works for elements for which overflow is not set to visible.

The counterpart overflow event is fired when overflow occurs.

Examples

<div id="wrapper">
    <div id="child"></div>
</div>
<br/>
<label><input type="checkbox" id="toggle" checked/> Overflow</label>

<style>
 #wrapper {
    width: 20px;
    height: 20px;
    background: #000;
    padding: 5px;
    overflow: hidden;
  }

  #child {
    width: 40px;
    height: 40px;
    border: 2px solid grey;
    background: #ccc;
  }
</style>

<script>
  var wrapper = document.getElementById("wrapper"),
      child = document.getElementById("child"),
      toggle = document.getElementById("toggle");

  wrapper.addEventListener("overflow", function( event ) {
      console.log( event );
  }, false);

  wrapper.addEventListener("underflow", function( event ) {
      console.log( event );
  }, false);

  toggle.addEventListener("change", function( event ) {
      if ( event.target.checked ) {
          child.style.width = "40px";
          child.style.height = "40px";
      } else {
          child.style.width = "10px";
          child.style.height = "10px";
      }

  }, false);
</script>

Specifications

Not part of any specification.

Browser compatibility

See also

• Related events: overflow