mouseleave

指点设备（通常是鼠标）的指针移出某个元素时，会触发mouseleave事件。

mouseleave  和 mouseout 是相似的，但是两者的不同在于mouseleave 不会冒泡而mouseout 会冒泡。
这意味着当指针离开元素及其所有后代时，会触发mouseleave，而当指针离开元素或离开元素的后代（即使指针仍在元素内）时，会触发mouseout。

当离开它们时，一个mouseleave事件被发送到层次结构的每个元素。当指针从文本移动到这里表示的最外面的div之外的区域时，这里4个事件会发送到层次结构的四个元素。	一个单一的鼠标事件mouseout被发送到DOM树最深的元素，然后它冒泡层次，直到它被处理程序取消或到达根。

规范

DOM L3

接口

MouseEvent

是否冒泡

否

是否可取消

否

对象

Element

默认动作

无

mouseout 文档有一个例子，说明了mouseout和mouseleave之间的区别。

以下示例说明了如何使用mouseout来模拟mouseleave事件的事件委托原则。

<ul id="test">
  <li>
    <ul class="leave-sensitive">
      <li>item 1-1</li>
      <li>item 1-2</li>
    </ul>
  </li>
  <li>
    <ul class="leave-sensitive">
      <li>item 2-1</li>
      <li>item 2-2</li>
    </ul>
  </li>
</ul>

<script>
  var delegationSelector = ".leave-sensitive";

  document.getElementById("test").addEventListener("mouseout", function( event ) {
    var target = event.target,
        related = event.relatedTarget,
        match;

    // search for a parent node matching the delegation selector
    while ( target && target != document && !( match = matches( target, delegationSelector ) ) ) {
        target = target.parentNode;
    }

    // exit if no matching node has been found
    if ( !match ) { return; }

    // loop through the parent of the related target to make sure that it's not a child of the target
    while ( related && related != target && related != document ) {
        related = related.parentNode;
    }

    // exit if this is the case
    if ( related == target ) { return; }

    // the "delegated mouseleave" handler can now be executed
    // change the color of the text
    target.style.color = "orange";
    // reset the color after a small amount of time
    setTimeout(function() {
        target.style.color = "";
    }, 500);


  }, false);


  // function used to check if a DOM element matches a given selector
  // the following code can be replaced by this IE8 compatible function: https://gist.github.com/2851541
  function matches( elem, selector ) {
    if (typeof elem.matchesSelector === "function") {
      // the matchesSelector is prefixed in most (if not all) browsers
      return elem.matchesSelector( selector );
    } else if (typeof elem.matches === "function") {
      return elem.matches( selector );
​​​​​​​    }
  };
</script>

[1] 实现于 bug 236215.

[2] 实现于bug 432698.

[3] Safari 7 会在许多不适当的情形下引发该事件,使得这个事件变得无用.详情参阅bug 470258  (老版Chrome也有类似问题). Safari 8 已修正.

[4] 实现于 bug 218093.

• mousedown
• mouseup
• mousemove
• click
• dblclick
• mouseover
• mouseout
• mouseenter
• mouseleave
• contextmenu