Window
======

O objeto `window` representa uma janela que contém um elemento DOM; a propriedade `document` aponta para o documento DOM document (en-US) carregado naquela janela. Uma janela para um dado documento pode ser obtido usando a propriedade `document.defaultView`.

Esta seção provê uma breve referência a todos os métodos, propriedades e eventos disponíveis através do objeto DOM `window`. O objeto `window` implementa a interface `Window`, o qual herda da interface `AbstractView`. Algumas funções globais, objeto de namespace, interfaces e construtores, apesar de não tipicamente associados ao objeto em questão, estão disponíveis e estão listados nas referências JavaScript Reference e DOM Reference (en-US).

Em um navegador com suporte a abas, como o Firefox, cada aba contém seu próprio objeto `window` (e, se você estiver escrevendo uma extensão, a janela do navegador é uma janela distinta também - veja Working with windows in chrome code para mais informação). Isto é, o objeto `window` não é compartilhado entre as abas na mesma janela. Alguns métodos, nomeadamente `window.resizeTo` (en-US) e `window.resizeBy` (en-US) aplicam-se à janela toda e não à aba em questão ao que o objeto `window` pertence. Geralmente, qualquer coisa que não pode racionalmente pertencer a uma aba, pertence a uma janela..

Propriedades
------------

*Esta interface herda propriedades da interface `EventTarget` e implementa propriedades de `WindowTimers`, `WindowBase64`, e `WindowEventHandlers`.*

Perceba que propriedades que são objetos (ex.: sobrecarregar o protótipo de elementos built-in) são listados em uma sessão separada abaixo.

`Window.applicationCache` Somente leitura 

Um objeto `OfflineResourceList` fornece acesso aos recursos offline para o window.

`Window.closed` 
Non-standard
Somente leitura 

Esta propriedade indica quando a window atual está fechada ou não.

`Window.Components` 
Non-standard

O ponto de entrada para muitas características XPCOM. Algumas propriedades, por exemplo, classes, estão apenas disponíveis para código suficientemente privilegiado. Código de Web não deve usar essa propriedade.

`Window.console` 
Non-standard
 Somente leitura 

Retorna uma referência para o objeto console fornecendo acesso ao console debugging do navegador.

`Window.content` (en-US) and Window.content 
Non-standard
Somente leitura 

Retorna uma referência para o elemento de conteúdo na janela atual. A variante obsoleta com sublinhado não está disponível a partir do conteúdo da Web.

`Window.controllers`
Non-standard
Somente leitura 

Retorna os objetos de controlador XUL para a janela atual do crome.

`Window.crypto` Somente leitura 

Retorna o objeto de criptografia do navegador.

`Window.defaultStatus`

Obtém/define o texto da barra de status para determinada janela.

`Window.devicePixelRatio` (en-US) 
Non-standard
Somente leitura 

Returns the ratio between physical pixels and device independent pixels in the current display.

`Window.dialogArguments` Somente leitura 

Gets the arguments passed to the window (if it's a dialog box) at the time `window.showModalDialog()` (en-US) was called. This is an `nsIArray`.

`Window.directories`

Synonym of `window.personalbar` (en-US)

`Window.document` Somente leitura 

Retorna a referência à propriedade `document` que a janela contém.

`Window.frameElement` (en-US) Somente leitura 

Returns the element in which the window is embedded, or null if the window is not embedded.

`Window.frames` (en-US) Somente leitura 

Returns an array of the subframes in the current window.

`Window.fullScreen`

This property indicates whether the window is displayed in full screen or not.

`Window.globalStorage`
Non-standard

 Unsupported since Gecko 13 (Firefox 13). Use `Window.localStorage` instead.
 Was: Multiple storage objects that are used for storing data across multiple pages.


`Window.history` Somente leitura 

Retorna a referência ao objeto `history`.

`Window.innerHeight`

Gets the height of the content area of the browser window including, if rendered, the horizontal scrollbar.

`window.innerWidth` (en-US)

Gets the width of the content area of the browser window including, if rendered, the vertical scrollbar.

`Window.length` Somente leitura 

Returns the number of frames in the window. See also `window.frames` (en-US).

`Window.location` Somente leitura 

Gets/sets the location, or current URL, of the window object.

`Window.locationbar` (en-US) Somente leitura 

Returns the locationbar object, whose visibility can be toggled in the window.

`WindowStorage.localStorage` Somente leitura 

Returns a reference to the local storage object used to store data that may only be accessed by the origin that created it.

`Window.menubar` (en-US) Somente leitura 

Returns the menubar object, whose visibility can be toggled in the window.

`Window.messageManager`

Returns the message manager object for this window.

`Window.mozAnimationStartTime` (en-US) Somente leitura 

The time in milliseconds since epoch at which the current animation cycle began.

`Window.mozInnerScreenX` (en-US) Somente leitura 
Non-standard

Returns the horizontal (X) coordinate of the top-left corner of the window's viewport, in screen coordinates. This value is reported in CSS pixels. See `mozScreenPixelsPerCSSPixel` in `nsIDOMWindowUtils` for a conversion factor to adapt to screen pixels if needed.

`Window.mozInnerScreenY` (en-US) Somente leitura  
Non-standard

Returns the vertical (Y) coordinate of the top-left corner of the window's viewport, in screen coordinates. This value is reported in CSS pixels. See `mozScreenPixelsPerCSSPixel` for a conversion factor to adapt to screen pixels if needed.

`Window.mozPaintCount` (en-US) 
Non-standard
Somente leitura 

Returns the number of times the current document has been rendered to the screen in this window. This can be used to compute rendering performance.

`Window.name` (en-US)

Pega/attribui o nome ao objeto `window`.

`Window.navigator` Somente leitura 

Returns a reference to the navigator object.

`Window.opener` (en-US)

Returns a reference to the window that opened this current window.

`Window.outerHeight` (en-US) Somente leitura 

Gets the height of the outside of the browser window.

`Window.outerWidth` (en-US) Somente leitura 

Gets the width of the outside of the browser window.

`Window.pageXOffset` (en-US) Somente leitura 

An alias for `window.scrollX` (en-US).

`Window.pageYOffset`Somente leitura 

An alias for `window.scrollY`

`WindowSession.sessionStorage` Somente leitura 

…

`SpeechSynthesisGetter.speechSynthesis` Somente leitura 

…

`Window.parent` (en-US) Somente leitura 

Returns a reference to the parent of the current window or subframe.

`Window.performance` Somente leitura 

Provides a hosting area for performance related (en-US) attributes.

`Window.personalbar` (en-US) Somente leitura 

Returns the personalbar object, whose visibility can be toggled in the window.

`Window.pkcs11`

Formerly provided access to install and remove PKCS11 modules.

`Window.returnValue`

The return value to be returned to the function that called `window.showModalDialog()` (en-US) to display the window as a modal dialog.

`Window.screen` (en-US) Somente leitura 

Returns a reference to the screen object associated with the window.

`Window.screenX` (en-US) Somente leitura 

Returns the horizontal distance of the left border of the user's browser from the left side of the screen.

`Window.screenY` (en-US) Somente leitura 

Returns the vertical distance of the top border of the user's browser from the top side of the screen.

`Window.scrollbars` (en-US) Somente leitura 

Returns the scrollbars object, whose visibility can be toggled in the window.

`Window.scrollMaxX` (en-US)
Non-standard
Somente leitura 

The maximum offset that the window can be scrolled to horizontally, that is the document width minus the viewport width.

`Window.scrollMaxY` (en-US)
Non-standard
Somente leitura 

The maximum offset that the window can be scrolled to vertically (i.e., the document height minus the viewport height).

`Window.scrollX` (en-US) Somente leitura 

Returns the number of pixels that the document has already been scrolled horizontally.

`Window.scrollY` Somente leitura 

Returns the number of pixels that the document has already been scrolled vertically.

`Window.self` (en-US) Somente leitura 

Returns an object reference to the window object itself.

`Window.sessionStorage`

A storage object for storing data within a single page session.

`Window.sidebar` (en-US) 
Non-standard
Somente leitura 

Returns a reference to the window object of the sidebar.

`Window.status` (en-US)

Gets/sets the text in the statusbar at the bottom of the browser.

`Window.statusbar` (en-US) Somente leitura 

Returns the statusbar object, whose visibility can be toggled in the window.

`Window.toolbar` (en-US) Somente leitura 

Returns the toolbar object, whose visibility can be toggled in the window.

`Window.top` (en-US) Somente leitura 

Returns a reference to the topmost window in the window hierarchy. This property is read only.

`Window.window` (en-US) Somente leitura 

Returns a reference to the current window.

`window[0]`, `window[1]`, etc.

Returns a reference to the `window` object in the frames. See `Window.frames` (en-US) for more details.

Methods
-------

*This interface inherits methods from the `EventTarget` interface and implements methods from `WindowTimers`, `WindowBase64`, and `WindowEventHandlers`.*

`EventTarget.addEventListener()`

Register an event handler to a specific event type on the window.

`Window.alert()`

Displays an alert dialog.

`WindowBase64.atob()`

Decodes a string of data which has been encoded using base-64 encoding.

`Window.back()` (en-US) 
Non-standard

Moves back one in the window history.

`Window.blur()` (en-US)

Sets focus away from the window.

`WindowBase64.btoa()` (en-US)

Creates a base-64 encoded ASCII string from a string of binary data.

`Window.captureEvents()` (en-US) 
Deprecated

Registers the window to capture all events of the specified type.

`Window.clearImmediate()` (en-US)

Cancels the repeated execution set using `setImmediate`.

`WindowTimers.clearInterval()` (en-US)

Cancels the repeated execution set using `WindowTimers.setInterval()` (en-US).

`WindowTimers.clearTimeout()`

Cancels the repeated execution set using `WindowTimers.setTimeout()` (en-US).

`Window.close()` (en-US)

Closes the current window.

`Window.confirm()`

Displays a dialog with a message that the user needs to respond to.

`Window.disableExternalCapture()`
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`Window.dispatchEvent()`

Used to trigger an event.

`Window.dump()` (en-US)

Writes a message to the console.

`Window.enableExternalCapture()`
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`Window.find()` (en-US)

Searches for a given string in a window.

`Window.focus()` (en-US)

Sets focus on the current window.

`Window.forward()` (en-US) 
Non-standard

Moves the window one document forward in the history.

`Window.getAttention()`

Flashes the application icon.

`Window.getAttentionWithCycleCount()`
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`Window.getComputedStyle()` (en-US)

Gets computed style for the specified element. Computed style indicates the computed values of all CSS properties of the element.

`Window.getDefaulComputedStyle()`

Gets default computed style for the specified element, ignoring author stylesheets.

`Window.getSelection()`

Returns the selection object representing the selected item(s).

`Window.home()` 
Non-standard

Returns the browser to the home page.

`Window.matchMedia()`

Returns a `MediaQueryList` (en-US) object representing the specified media query string.

`Window.maximize()`
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`Window.minimize()` (en-US) (top-level XUL windows only)

Minimizes the window.

`Window.moveBy()` (en-US)

Moves the current window by a specified amount.

`Window.moveTo()` (en-US)

Moves the window to the specified coordinates.

`Window.mozRequestAnimationFrame()` (en-US)

Tells the browser that an animation is in progress, requesting that the browser schedule a repaint of the window for the next animation frame. This will cause a `MozBeforePaint` event to fire before that repaint occurs.

`Window.open()` (en-US)

Opens a new window.

`Window.openDialog()`

Opens a new dialog window.

`Window.postMessage()` (en-US)

Provides a secure means for one window to send a string of data to another window, which need not be within the same domain as the first, in a secure manner.

`Window.print()`

Opens the Print Dialog to print the current document.

`Window.prompt()`

Returns the text entered by the user in a prompt dialog.

`Window.releaseEvents()` (en-US) 
Deprecated

Releases the window from trapping events of a specific type.

`Window.removeEventListener()`

Removes an event listener from the window.

`Window.resizeBy()` (en-US)

Resizes the current window by a certain amount.

`Window.resizeTo()` (en-US)

Dynamically resizes window.

`Window.restore()` (en-US)
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`Window.routeEvent()`
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`Window.scroll()`

Scrolls the window to a particular place in the document.

`Window.scrollBy()`

Scrolls the document in the window by the given amount.

`Window.scrollByLines()` (en-US)

Scrolls the document by the given number of lines.

`Window.scrollByPages()`

Scrolls the current document by the specified number of pages.

`Window.scrollTo()`

Scrolls to a particular set of coordinates in the document.

`Window.setCursor()`

Changes the cursor for the current window

`Window.setImmediate()`

Executes a function after the browser has finished other heavy tasks

`WindowTimers.setInterval()` (en-US)

Schedules the execution of a function each X milliseconds.

`Window.setResizable` (en-US)
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`WindowTimers.setTimeout()` (en-US)

Sets a delay for executing a function.

`Window.showModalDialog()` (en-US)

Displays a modal dialog.

`Window.sizeToContent()` (en-US)

Sizes the window according to its content.

`Window.stop()` (en-US)

This method stops window loading.

`Window.updateCommands()` (en-US)

Updates the state of commands of the current chrome window (UI).

Event handlers
--------------

These are properties of the window object that can be set to establish event handlers for the various things that can happen in the window that might be of interest.

*This interface inherits event handlers from the `EventTarget` interface and implements event handlers from `WindowTimers`, `WindowBase64`, and `WindowEventHandlers`.*

**Nota:** Starting in Gecko 9.0, you can now use the syntax `if ("onabort" in window)` to determine whether or not a given event handler property exists. This is because event handler interfaces have been updated to be proper web IDL interfaces. See DOM event handlers (en-US) for details.

`GlobalEventHandlers.onabort`

An event handler property for abort events on the window.

`WindowEventHandlers.onbeforeunload` (en-US)

An event handler property for before-unload events on the window.

`GlobalEventHandlers.onblur`

An event handler property for blur events on the window.

`GlobalEventHandlers.onchange`

An event handler property for change events on the window.

`GlobalEventHandlers.onclick`

An event handler property for click events on the window.

`GlobalEventHandlers.onclose` (en-US)

An event handler property for handling the window close event.

`GlobalEventHandlers.oncontextmenu`

An event handler property for right-click events on the window.

`Window.ondevicelight`

An event handler property for any ambient light levels changes

`Window.ondevicemotion` (en-US)
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`Window.ondeviceorientation` (en-US)

An event handler property for any device orientation changes

`Window.ondeviceproximity`

An event handler property for device proximity event

`GlobalEventHandlers.onerror`

An event handler property for `error (en-US)` events raised on the window.

`GlobalEventHandlers.onfocus`

An event handler property for `focus (en-US)` events on the window.

`WindowEventHandlers.onhashchange`

An event handler property for hash change events on the window; called when the part of the URL after the hash mark ("#") changes.

`GlobalEventHandlers.onkeydown` (en-US)

An event handler property for `keydown (en-US)` events on the window.

`GlobalEventHandlers.onkeypress` (en-US)

An event handler property for `keypress (en-US)` events on the window.

`GlobalEventHandlers.onkeyup`

An event handler property for `keyup (en-US)` events on the window.

`WindowEventHandlers.onlanguagechange` (en-US)

An event handler property for `languagechange (en-US)` events on the window.

`GlobalEventHandlers.onload`

An event handler property for window loading.

`GlobalEventHandlers.onmousedown` (en-US)

An event handler property for mousedown events on the window.

`GlobalEventHandlers.onmousemove` (en-US)

An event handler property for mousemove events on the window.

`GlobalEventHandlers.onmouseout` (en-US)

An event handler property for mouseout events on the window.

`GlobalEventHandlers.onmouseover` (en-US)

An event handler property for mouseover events on the window.

`GlobalEventHandlers.onmouseup` (en-US)

An event handler property for mouseup events on the window.

`Window.onmozbeforepaint`

An event handler property for the `MozBeforePaint` event, which is sent before repainting the window if the event has been requested by a call to the `Window.mozRequestAnimationFrame()` (en-US) method.

`WindowEventHandlers.onpageshow`

An event handler property for pageshow events on the window.

`WindowEventHandlers.onpagehide`

An event handler property for pagehide events on the window.

`Window.onpaint`

An event handler property for paint events on the window.

`WindowEventHandlers.onpopstate`

An event handler property for popstate events, which are fired when navigating to a session history entry representing a state object.

`GlobalEventHandlers.onreset` (en-US)

An event handler property for reset events on the window.

`GlobalEventHandlers.onresize` (en-US)

An event handler property for window resizing.

`GlobalEventHandlers.onscroll`

An event handler property for window scrolling.

`GlobalEventHandlers.onselect` (en-US)

An event handler property for window selection.

`GlobalEventHandlers.onsubmit` (en-US)

An event handler property for submits on window forms.

`Window.onunload` (en-US)

An event handler property for unload events on the window.

`Window.onuserproximity`

An event handler property for user proximity events

Constructors
------------

See also the DOM Interfaces (en-US).

`Window.DOMParser`
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`Window.GeckoActiveXObject`
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`Image` (en-US)

Used for creating an `HTMLImageElement` (en-US).

`Option` (en-US)

Used for creating an `HTMLOptionElement` (en-US)

`Window.QueryInterface`
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`Window.XMLSerializer`
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`Worker`

Used for creating a Web worker (en-US)

`Window.XPCNativeWrapper`
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`Window.XPCSafeJSObjectWrapper`
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Interfaces
----------

See DOM Reference (en-US)

See also
--------

* Working with windows in chrome code