From 074785cea106179cb3305637055ab0a009ca74f2 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:42:52 -0500 Subject: initial commit --- .../web/api/element/mouseenter_event/index.html | 314 +++++++++++++++++++++ 1 file changed, 314 insertions(+) create mode 100644 files/pt-br/web/api/element/mouseenter_event/index.html (limited to 'files/pt-br/web/api/element/mouseenter_event') diff --git a/files/pt-br/web/api/element/mouseenter_event/index.html b/files/pt-br/web/api/element/mouseenter_event/index.html new file mode 100644 index 0000000000..881958914b --- /dev/null +++ b/files/pt-br/web/api/element/mouseenter_event/index.html @@ -0,0 +1,314 @@ +--- +title: mouseenter +slug: Web/API/Element/mouseenter_event +translation_of: Web/API/Element/mouseenter_event +--- +
{{APIRef}}
+ +

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

+ +

Similar ao {{event('mouseover')}}, ele se diferencia no fato de que não ocorre a fase bubble e não é disparado quando o cursor / apontador mover-se do espaço físico de um de seus descendentes para o seu próprio espaço físico.

+ +
+
mouseenter.png
+Um evento mouseenter 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. + +
mouseover.png
+Um único evento mouseover 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 handler ou alcance a raíz da árvore.
+ +

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

+ +

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

+ +

Informações Gerais

+ +
+
Especificação
+
DOM L3
+
Interface
+
{{domxref('MouseEvent')}}
+
Sincronismo
+
Síncrono
+
Fase Bubble
+
Não
+
Cancelável
+
Não
+
Target
+
Element
+
Ação Padrão
+
Nenhuma
+
+ +

Propriedades

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
PropertyTypeDescription
target {{readonlyInline}}{{domxref("EventTarget")}}The event target (the topmost target in the DOM tree).
type {{readonlyInline}}{{domxref("DOMString")}}The type of event.
bubbles {{readonlyInline}}BooleanWhether the event normally bubbles or not
cancelable {{readonlyInline}}BooleanWhether the event is cancellable or not?
view {{readonlyInline}}{{domxref("WindowProxy")}}{{domxref("document.defaultView")}} (window of the document)
detail {{readonlyInline}}long (float)0.
currentTarget {{readonlyInline}}{{domxref("EventTarget")}}The node that had the event listener attached.
relatedTarget {{readonlyInline}}{{domxref("EventTarget")}}For mouseover, mouseout, mouseenter and mouseleave events: the target of the complementary event (the mouseleave target in the case of a mouseenter event). null otherwise.
screenX {{readonlyInline}}longThe X coordinate of the mouse pointer in global (screen) coordinates.
screenY {{readonlyInline}}longThe Y coordinate of the mouse pointer in global (screen) coordinates.
clientX {{readonlyInline}}longThe X coordinate of the mouse pointer in local (DOM content) coordinates.
clientY {{readonlyInline}}longThe Y coordinate of the mouse pointer in local (DOM content) coordinates.
button {{readonlyInline}}unsigned shortThe 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.
buttons {{readonlyInline}}unsigned shortThe 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). More info.
mozPressure {{readonlyInline}}floatThe 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).
ctrlKey {{readonlyInline}}booleantrue if the control key was down when the event was fired. false otherwise.
shiftKey {{readonlyInline}}booleantrue if the shift key was down when the event was fired. false otherwise.
altKey {{readonlyInline}}booleantrue if the alt key was down when the event was fired. false otherwise.
metaKey {{readonlyInline}}booleantrue if the meta key was down when the event was fired. false otherwise.
+ +

Examples

+ +

The mouseover documentation has an example illustrating the difference between mouseover and mouseenter.

+ +

The following example illustrates how to use mouseover to simulate the principle of event delegation for the mouseenter event.

+ +
<ul id="test">
+  <li>
+    <ul class="enter-sensitive">
+      <li>item 1-1</li>
+      <li>item 1-2</li>
+    </ul>
+  </li>
+  <li>
+    <ul class="enter-sensitive">
+      <li>item 2-1</li>
+      <li>item 2-2</li>
+    </ul>
+  </li>
+</ul>
+
+<script>
+  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 && 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 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 );
+  };
+</script>
+ +

Browser compatibility

+ +

{{CompatibilityTable}}

+ +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FeatureChromeEdgeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support30[1]{{CompatVersionUnknown}}10[2]5.5{{CompatVersionUnknown}}
+ {{CompatNo}} 15.0
+ 17.0		7[3]
On disabled form elements{{CompatNo}}{{CompatNo}}{{CompatGeckoDesktop("44.0")}}[4]{{CompatNo}}{{CompatNo}}{{CompatUnknown}}
+
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FeatureAndroidChrome for AndroidEdgeFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support{{CompatUnknown}}{{CompatUnknown}}{{CompatVersionUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}
On disabled form elements{{CompatUnknown}}{{CompatUnknown}}{{CompatNo}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}
+
+ +

[1] Implemented in bug 236215.

+ +

[2] Implemented in {{bug("432698")}}.

+ +

[3] Safari 7 fires the event in many situations where it's not allowed to, making the whole event useless. See bug 470258 for the description of the bug (it existed in old Chrome versions as well). Safari 8 has correct behavior

+ +

[4] Implemented in {{bug("218093")}}.

+ +

See also

+ + -- cgit v1.2.3-54-g00ecf