path: root/files/pt-br/web/api/element/mouseenter_event/index.html

---
title: mouseenter
slug: Web/API/Element/mouseenter_event
translation_of: Web/API/Element/mouseenter_event
---
<div>{{APIRef}}</div>

<p>O evento <code>mouseenter</code> é disparado quando um dispositivo de apontamento (geralmente um mouse) se move sobre um elemento (para dentro do mesmo).</p>

<p>Similar ao {{event('mouseover')}}, ele se diferencia no fato de que não ocorre a fase <a href="/en-US/docs/Web/API/Event/bubbles">bubble</a> e não é disparado quando o cursor / apontador mover-se do espaço físico de um de seus descendentes para o seu próprio espaço físico.</p>

<div style="-moz-column-width: 455px; -webkit-column-width: 455px; column-width: 455px; border: solid 1px; padding: 5px; margin-bottom: 10px;">
<div style="text-align: center;"><img alt="mouseenter.png" class="default internal" src="/@api/deki/files/5908/=mouseenter.png"></div>
Um evento <code>mouseenter</code> é enviado para cada elemento da hierarquia ao entrar neles. Aqui 4 eventos são enviados aos quatro elementos da hierarquia quando o cursor / apontador chega no Text.

<div style="text-align: center;"><img alt="mouseover.png" class="default internal" src="/@api/deki/files/5909/=mouseover.png"></div>
Um único evento <code>mouseover</code> é enviado ao elemento de maior profundidade na árvore DOM, a partir do qual ocorre a fase bubble e o mesmo percorre subindo na hierarquia dos elementos  até que seja cancelado por um <em>handler</em> ou alcance a raíz da árvore.</div>

<p>De acordo com a profundidade da hierarquia, a quantidade de eventos <code>mouseenter</code> disparados pode se tornar muito grande e causar problemas de performance significativos. Nestes casos é melhor escutar por eventos mouseover.</p>

<p>Combinado ao comportamento do seu evento simétrico, <code>mouseleave</code>, o evento DOM <code>mouseenter</code> age de modo bastante similar à pseudo-classe CSS {{cssxref(':hover')}}.</p>

<h2 id="Informações_Gerais">Informações Gerais</h2>

<dl>
 <dt style="float: left; text-align: right; width: 120px;">Especificação</dt>
 <dd style="margin: 0 0 0 120px;"><a class="external" href="http://www.w3.org/TR/DOM-Level-3-Events/#event-type-mouseenter">DOM L3</a></dd>
 <dt style="float: left; text-align: right; width: 120px;">Interface</dt>
 <dd style="margin: 0 0 0 120px;">{{domxref('MouseEvent')}}</dd>
 <dt style="float: left; text-align: right; width: 120px;">Sincronismo</dt>
 <dd style="margin: 0 0 0 120px;">Síncrono</dd>
 <dt style="float: left; text-align: right; width: 120px;">Fase Bubble</dt>
 <dd style="margin: 0 0 0 120px;">Não</dd>
 <dt style="float: left; text-align: right; width: 120px;">Cancelável</dt>
 <dd style="margin: 0 0 0 120px;">Não</dd>
 <dt style="float: left; text-align: right; width: 120px;">Target</dt>
 <dd style="margin: 0 0 0 120px;">Element</dd>
 <dt style="float: left; text-align: right; width: 120px;">Ação Padrão</dt>
 <dd style="margin: 0 0 0 120px;">Nenhuma</dd>
</dl>

<h2 id="Propriedades">Propriedades</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Property</th>
   <th scope="col">Type</th>
   <th scope="col">Description</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><code>target</code> {{readonlyInline}}</td>
   <td>{{domxref("EventTarget")}}</td>
   <td>The event target (the topmost target in the DOM tree).</td>
  </tr>
  <tr>
   <td><code>type</code> {{readonlyInline}}</td>
   <td>{{domxref("DOMString")}}</td>
   <td>The type of event.</td>
  </tr>
  <tr>
   <td><code>bubbles</code> {{readonlyInline}}</td>
   <td>Boolean</td>
   <td>Whether the event normally bubbles or not</td>
  </tr>
  <tr>
   <td><code>cancelable</code> {{readonlyInline}}</td>
   <td><code>Boolean</code></td>
   <td>Whether the event is cancellable or not?</td>
  </tr>
  <tr>
   <td><code>view</code> {{readonlyInline}}</td>
   <td>{{domxref("WindowProxy")}}</td>
   <td>{{domxref("document.defaultView")}} (<code>window</code> of the document)</td>
  </tr>
  <tr>
   <td><code>detail</code> {{readonlyInline}}</td>
   <td><code>long</code> (<code>float</code>)</td>
   <td>0.</td>
  </tr>
  <tr>
   <td><code>currentTarget</code> {{readonlyInline}}</td>
   <td>{{domxref("EventTarget")}}</td>
   <td>The node that had the event listener attached.</td>
  </tr>
  <tr>
   <td><code>relatedTarget</code> {{readonlyInline}}</td>
   <td>{{domxref("EventTarget")}}</td>
   <td>For <code>mouseover</code>, <code>mouseout</code>, <code>mouseenter</code> and <code>mouseleave</code> events: the target of the complementary event (the <code>mouseleave</code> target in the case of a <code>mouseenter</code> event). <code>null</code> otherwise.</td>
  </tr>
  <tr>
   <td><code>screenX</code> {{readonlyInline}}</td>
   <td>long</td>
   <td>The X coordinate of the mouse pointer in global (screen) coordinates.</td>
  </tr>
  <tr>
   <td><code>screenY</code> {{readonlyInline}}</td>
   <td>long</td>
   <td>The Y coordinate of the mouse pointer in global (screen) coordinates.</td>
  </tr>
  <tr>
   <td><code>clientX</code> {{readonlyInline}}</td>
   <td>long</td>
   <td>The X coordinate of the mouse pointer in local (DOM content) coordinates.</td>
  </tr>
  <tr>
   <td><code>clientY</code> {{readonlyInline}}</td>
   <td>long</td>
   <td>The Y coordinate of the mouse pointer in local (DOM content) coordinates.</td>
  </tr>
  <tr>
   <td><code>button</code> {{readonlyInline}}</td>
   <td>unsigned short</td>
   <td>The button number that was pressed when the mouse event was fired: Left button=0, middle button=1 (if present), right button=2. For mice configured for left handed use in which the button actions are reversed the values are instead read from right to left.</td>
  </tr>
  <tr>
   <td><code>buttons</code> {{readonlyInline}}</td>
   <td>unsigned short</td>
   <td>The buttons being pressed when the mouse event was fired: Left button=1, Right button=2, Middle (wheel) button=4, 4th button (typically, "Browser Back" button)=8, 5th button (typically, "Browser Forward" button)=16. If two or more buttons are pressed, returns the logical sum of the values. E.g., if Left button and Right button are pressed, returns 3 (=1 | 2). <a href="/en-US/docs/Web/API/MouseEvent">More info</a>.</td>
  </tr>
  <tr>
   <td><code>mozPressure</code> {{readonlyInline}}</td>
   <td>float</td>
   <td>The amount of pressure applied to a touch or tabdevice when generating the event; this value ranges between 0.0 (minimum pressure) and 1.0 (maximum pressure).</td>
  </tr>
  <tr>
   <td><code>ctrlKey</code> {{readonlyInline}}</td>
   <td>boolean</td>
   <td><code>true</code> if the control key was down when the event was fired. <code>false</code> otherwise.</td>
  </tr>
  <tr>
   <td><code>shiftKey</code> {{readonlyInline}}</td>
   <td>boolean</td>
   <td><code>true</code> if the shift key was down when the event was fired. <code>false</code> otherwise.</td>
  </tr>
  <tr>
   <td><code>altKey</code> {{readonlyInline}}</td>
   <td>boolean</td>
   <td><code>true</code> if the alt key was down when the event was fired. <code>false</code> otherwise.</td>
  </tr>
  <tr>
   <td><code>metaKey</code> {{readonlyInline}}</td>
   <td>boolean</td>
   <td><code>true</code> if the meta key was down when the event was fired. <code>false</code> otherwise.</td>
  </tr>
 </tbody>
</table>

<h2 id="Examples">Examples</h2>

<p>The <a href="/en-US/docs/Web/Events/mouseover#Example"><code>mouseover</code> </a>documentation has an example illustrating the difference between <code>mouseover</code> and <code>mouseenter</code>.</p>

<p>The following example illustrates how to use <code>mouseover</code> to simulate the principle of event delegation for the mouseenter event.</p>

<pre class="brush: html">&lt;ul id="test"&gt;
  &lt;li&gt;
    &lt;ul class="enter-sensitive"&gt;
      &lt;li&gt;item 1-1&lt;/li&gt;
      &lt;li&gt;item 1-2&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
  &lt;li&gt;
    &lt;ul class="enter-sensitive"&gt;
      &lt;li&gt;item 2-1&lt;/li&gt;
      &lt;li&gt;item 2-2&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
&lt;/ul&gt;

&lt;script&gt;
  var delegationSelector = ".enter-sensitive";

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

    // search for a parent node matching the delegation selector
    while ( target &amp;&amp; target != document &amp;&amp; !( 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 &amp;&amp; related != target &amp;&amp; related != document ) {
        related = related.parentNode;
    }

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

    // the "delegated mouseenter" 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 ){
    // the matchesSelector is prefixed in most (if not all) browsers
    return elem.matchesSelector( selector );
  };
&lt;/script&gt;</pre>

<h2 id="Browser_compatibility">Compatibilidade com navegadores</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>30<sup>[1]</sup></td>
   <td>{{CompatVersionUnknown}}</td>
   <td>10<sup>[2]</sup></td>
   <td>5.5</td>
   <td>{{CompatVersionUnknown}}<br>
    {{CompatNo}} 15.0<br>
    17.0</td>
   <td>7<sup>[3]</sup></td>
  </tr>
  <tr>
   <td>On disabled form elements</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatGeckoDesktop("44.0")}}<sup>[4]</sup></td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td>On disabled form elements</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<p>[1] Implemented in <a href="https://crbug.com/236215">bug 236215</a>.</p>

<p>[2] Implemented in {{bug("432698")}}.</p>

<p>[3] Safari 7 fires the event in many situations where it's not allowed to, making the whole event useless. See <a href="https://crbug.com/470258">bug 470258</a> for the description of the bug (it existed in old Chrome versions as well). Safari 8 has correct behavior</p>

<p>[4] Implemented in {{bug("218093")}}.</p>

<h2 id="See_also">See also</h2>

<ul>
 <li>{{Event("mousedown")}}</li>
 <li>{{Event("mouseup")}}</li>
 <li>{{Event("mousemove")}}</li>
 <li>{{Event("click")}}</li>
 <li>{{Event("dblclick")}}</li>
 <li>{{Event("mouseover")}}</li>
 <li>{{Event("mouseout")}}</li>
 <li>{{Event("mouseenter")}}</li>
 <li>{{Event("mouseleave")}}</li>
 <li>{{Event("contextmenu")}}</li>
</ul>