Los objetosKeyboardEvent describen una interacción del usuario con el teclado. Cada evento describe una tecla; el tipo de evento(keydown,keypress, okeyup) identifica el tipo de acción realizada.

Constructor

KeyboardEvent()

Crea un objetoKeyboardEvent.

Métodos

Esta interfaz también hereda métodos de sus padres,UIEvent andEvent.

KeyboardEvent.getModifierState()

Devuelve unBoolean indicando si una tecla modificadora, comoAlt,Shift,Ctrl,Meta, fue pulsada cuando el evento fue creado.

KeyboardEvent.initKeyEvent()Obsoleto

Inicializa un objetoKeyboardEvent. Este método solo ha sido implementado por Gecko (otros usadosKeyboardEvent.initKeyboardEvent()) y nunca más será usado. El modo estándar moderno es usar el constructorKeyboardEvent().

KeyboardEvent.initKeyboardEvent()Obsoleto

Inicializa un objetoKeyboardEvent. Este método nunca fue implementado por Gecko (quien usaKeyboardEvent.initKeyEvent()) y no debe ser utilizado más. El modo estándar moderno es usar el constructorKeyboardEvent().

Propiedades

Esta interfaz también hereda propiedades de sus padresUIEvent yEvent.

KeyboardEvent.altKeyRead only

Devuelve unBoolean que serátrue si la teclaAlt (Option or⌥ on OS X) fue activada cuando el evento fue generado.

KeyboardEvent.charNo estándarObsoletoRead only

Devuelve unDOMString representando el valor del carácter de la tecla. Si la tecla corresponde con un carácter imprimible, este valor es una cadena Unicode no vacía que contiene este carácter. Si la tecla no tiene una representación imprimible, esta es una cadena vacía.

Nota:Si la tecla es usada como una macro que inserta múltiples caracteres, If the key is used as a macro that inserts multiple characters, el valor de este atributo es la cadena completa, no solo el primer carácter.

Advertencia:Esta propiedad ha sido eliminada de los eventos del DOM de nivel 3. Esta es únicamente soportada en IE.

KeyboardEvent.charCodeObsoletoRead only

Returns anunsigned long representing the Unicode reference number of the key; this attribute is used only by thekeypress event. For keys whosechar attribute contains multiple characters, this is the Unicode value of the first character in that attribute. In Firefox 26 this returns codes for printable characters.

Advertencia:This attribute is deprecated; you should usekey instead, if available.

KeyboardEvent.codeRead only

Returns aDOMString with the code value of the key represented by the event.

KeyboardEvent.ctrlKeyRead only

Returns aBoolean that istrue if theCtrl key was active when the key event was generated.

KeyboardEvent.isComposingRead only

Returns aBoolean that istrue if the event is fired between aftercompositionstart and beforecompositionend.

KeyboardEvent.keyRead only

Returns aDOMString representing the key value of the key represented by the event.

KeyboardEvent.keyCodeObsoletoRead only

Returns anunsigned long representing a system and implementation dependent numerical code identifying the unmodified value of the pressed key.

Advertencia:This attribute is deprecated; you should usekey instead, if available.

KeyboardEvent.localeRead only

Returns aDOMString representing a locale string indicating the locale the keyboard is configured for. This may be the empty string if the browser or device doesn't know the keyboard's locale.

Nota:This does not describe the locale of the data being entered. A user may be using one keyboard layout while typing text in a different language.

KeyboardEvent.locationRead only

Returns anunsigned long representing the location of the key on the keyboard or other input device.

KeyboardEvent.metaKeyRead only

Returns aBoolean that istrue if theMeta (orCommand on OS X) key was active when the key event was generated.

KeyboardEvent.repeatRead only

Returns aBoolean that istrue if the key is being held down such that it is automatically repeating.

KeyboardEvent.shiftKeyRead only

Returns aBoolean that istrue if theShift key was active when the key event was generated.

KeyboardEvent.whichObsoletoRead only

Returns anunsigned long representing a system and implementation dependent numeric code identifying the unmodified value of the pressed key; this is usually the same askeyCode.

Advertencia:This attribute is deprecated; you should usekey instead, if available.

Notes

There arekeydown,keypress, andkeyup events. For most keys, Gecko dispatches a sequence of key events like this:

1. When the key is first depressed, thekeydown event is sent.
2. If the key is not a modifier key, thekeypress event is sent.
3. When the user releases the key, thekeyup event is sent.

Special cases

Certain keys toggle the state of an LED indicator, such as Caps Lock, Num Lock, and Scroll Lock. On Windows and Linux, these keys dispatch only thekeydown andkeyup events. Note that on Linux, Firefox 12 and earlier also dispatched thekeypress event for these keys.

On Mac, however, Caps Lock dispatches only thekeydown event due to a platform event model limitation. Num Lock had been supported on old MacBook (2007 model and older) but Mac hasn't supported Num Lock feature even on external keyboards in these days. On the old MacBook which has Num Lock key, Num Lock doesn't cause any key events. And Gecko supports Scroll Lock key if an external keyboard which has F14 is connected. However, it generateskeypress event. This inconsistent behavior is a bug; seeError 602812 en Firefox.

Auto-repeat handling

When a key is pressed and held down, it begins to auto-repeat. This results in a sequence of events similar to the following being dispatched:

1. keydown
2. keypress
3. keydown
4. keypress
5. <<repeating until the user releases the key>>
6. keyup

This is what the DOM Level 3 specification says should happen. There are some caveats, however, as described below.

Auto-repeat on some GTK environments such as Ubuntu 9.4

In some GTK-based environments, auto-repeat dispatches a native key-up event automatically during auto-repeat, and there's no way for Gecko to know the difference between a repeated series of keypresses and an auto-repeat. On those platforms, then, an auto-repeat key will generate the following sequence of events:

1. keydown
2. keypress
3. keyup
4. keydown
5. keypress
6. keyup
7. <<repeating until the user releases the key>>
8. keyup

In these environments, unfortunately, there's no way for web content to tell the difference between auto-repeating keys and keys that are just being pressed repeatedly.

Auto-repeat handling prior to Gecko 4.0

Before Gecko 4.0, keyboard handling was less consistent across platforms.

Windows

Auto-repeat behavior is the same as in Gecko 4.0 and later.

Mac

After the initial keydown event, only keypress events are sent until the keyup event occurs; the inter-spaced keydown events are not sent.

Linux

The event behavior depends on the specific platform. It will either behave like Windows or Mac depending on what the native event model does.

Example

<!DOCTYPE html><html><head><script>var metaChar = false;var exampleKey = 16;function keyEvent(event) {  var key = event.keyCode || event.which;  var keychar = String.fromCharCode(key);  if (key == exampleKey) {    metaChar = true;  }  if (key != exampleKey) {    if (metaChar) {      alert("Combination of metaKey + " + keychar);      metaChar = false;    } else {      alert("Key pressed " + key);    }  }}function metaKeyUp (event) {  var key = event.keyCode || event.which;  if (key == exampleKey) {    metaChar = false;  }}</script></head><body onkeydown="keyEvent(event)" onkeyup="metaKeyUp(event)"></body></html>

Especificaciones

Compatibilidad con navegadores