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BrowserWindow

Crier e controle janelas de navegação.

Process: Main

Este módulo não pode ser usado até que o evento ready do módulo app seja emitido.

// No processo main.
const { BrowserWindow } = require('electron')

const win = new BrowserWindow({ width: 800, height: 600 })

// Load a remote URL
win.loadURL('https://github.com')

// Or load a local HTML file
win.loadFile('index.html')

Window customization​

The BrowserWindow class exposes various ways to modify the look and behavior of your app's windows. For more details, see the Window Customization tutorial.

Showing the window gracefully​

When loading a page in the window directly, users may see the page load incrementally, which is not a good experience for a native app. To make the window display without a visual flash, there are two solutions for different situations.

Using the ready-to-show event​

Enquanto a página é carregada, o evento ready-to-show será disparado quando o processo de renderização estiver renderizado completamente a página pela primeira vez, caso a janela ainda não tenha sido exibida. Exibindo a janela após este evento não resultará em um flash visual:

const { BrowserWindow } = require('electron')

const win = new BrowserWindow({ show: false })
win.once('ready-to-show', () => {
  win.show()
})

Este evento geralmente é emitido depois do evento did-finish-load, porém para páginas com vários recursos remotos, tal evento pode ser emitido antes.

Please note that using this event implies that the renderer will be considered "visible" and paint even though show is false. This event will never fire if you use paintWhenInitiallyHidden: false

Setting the backgroundColor property​

Para um aplicativo complexo, o evento ready-to-show poderia ser emitido tarde demais, fazendo com que o aplicativo aparente lentidão. Neste caso, é recomendado exibir a janela imediatamente e utilizar a propriedade backgroundColor com cor semelhante a cor de fundo do seu aplicativo:

const { BrowserWindow } = require('electron')

const win = new BrowserWindow({ backgroundColor: '#2e2c29' })
win.loadURL('https://github.com')

Note that even for apps that use ready-to-show event, it is still recommended to set backgroundColor to make the app feel more native.

Some examples of valid backgroundColor values include:

const win = new BrowserWindow()
win.setBackgroundColor('hsl(230, 100%, 50%)')
win.setBackgroundColor('rgb(255, 145, 145)')
win.setBackgroundColor('#ff00a3')
win.setBackgroundColor('blueviolet')

For more information about these color types see valid options in win.setBackgroundColor.

Janelas parent e child​

Ao utilizar a opção parent, é possível criar janelas secundarias:

const { BrowserWindow } = require('electron')

const top = new BrowserWindow()
const child = new BrowserWindow({ parent: top })
child.show()
top.show()

A janela secundaria (child) sempre será exibida em frente a janela principal (top).

Janelas Modais​

A modal window is a child window that disables parent window. To create a modal window, you have to set both the parent and modal options:

const { BrowserWindow } = require('electron')

const top = new BrowserWindow()
const child = new BrowserWindow({ parent: top, modal: true, show: false })
child.loadURL('https://github.com')
child.once('ready-to-show', () => {
  child.show()
})

Visibilidade de página​

A API de visibilidade de página funciona da seguinte forma:

  • Em todas as plataformas, o estado de visibilidade verifica quando a janela é ocultada/minimizada ou não.
  • Adicionalmente, no macOS, o estado de visibilidade também verifica o estado de oclusão da janela. Se a janela estive obstruída (ou seja, completamente coberta) por outra janela, o estado de visibilidade será hidden. Em outras plataformas, o estado de visibilidade será hidden somente quando a janela for minimizada ou explicitamente ocultada com o método win.hide().
  • Se um BrowserWindow é criado com a propriedade show: false, a visibilidade inicial será visible independente da janela estar de fato ocultada.
  • Se a propriedade backgroundThrottling estive desativado, o estado de visibilidade continuará visible mesmo que a janela esteja minimizada, ocultada ou escondida.

É recomendado que você pause operações "caras" quando o estado de visibilidadade for hidden com o objetivo de minimizar o consumo de energia.

Avisos de plataformas​

  • No macOS, janelas modal serão exibidas como "folhas" vinculadas a janela principal.
  • No macOS, as janelas secundarias manterão a posição relativa com a janela principal quando a mesma se mover, enquanto que no Windows e Linux as janelas secundarias não se movem.
  • No Linux, o tipo de janelas modais será modificado para dialog.
  • No Linux, vários ambientes desktop não há suporte para esconder uma janela modal.
  • On Wayland (Linux) it is generally not possible to programmatically resize windows after creation, or to position, move, focus, or blur windows without user input. If your app needs these capabilities, run it in Xwayland by appending the flag --ozone-platform=x11.

Class: BrowserWindow extends BaseWindow​

Crier e controle janelas de navegação.

Process: Main

BrowserWindow é um EventEmitter.

O mesmo cria um novo BrowserWindow com propriedades nativas informadas como a opção options.

[!WARNING] Electron's built-in classes cannot be subclassed in user code. For more information, see the FAQ.

new BrowserWindow([options])​

  • options BrowserWindowConstructorOptions (optional)
    • webPreferences WebPreferences (optional) - Settings of web page's features.
      • devTools boolean (optional) - Whether to enable DevTools. If it is set to false, can not use BrowserWindow.webContents.openDevTools() to open DevTools. Por padrão é true.
      • nodeIntegration boolean (optional) - Whether node integration is enabled. Por padrão é false.
      • nodeIntegrationInWorker boolean (optional) - Whether node integration is enabled in web workers. Por padrão é false. More about this can be found in Multithreading.
      • nodeIntegrationInSubFrames boolean (optional) - Experimental option for enabling Node.js support in sub-frames such as iframes and child windows. All your preloads will load for every iframe, you can use process.isMainFrame to determine if you are in the main frame or not.
      • preload string (optional) - Specifies a script that will be loaded before other scripts run in the page. This script will always have access to node APIs no matter whether node integration is turned on or off. The value should be the absolute file path to the script. When node integration is turned off, the preload script can reintroduce Node global symbols back to the global scope. See example here.
      • sandbox boolean (optional) - If set, this will sandbox the renderer associated with the window, making it compatible with the Chromium OS-level sandbox and disabling the Node.js engine. This is not the same as the nodeIntegration option and the APIs available to the preload script are more limited. Default is true since Electron 20. The sandbox will automatically be disabled when nodeIntegration is set to true. Read more about the option here.
      • session Session (optional) - Sets the session used by the page. Instead of passing the Session object directly, you can also choose to use the partition option instead, which accepts a partition string. When both session and partition are provided, session will be preferred. Default is the default session.
      • partition string (optional) - Sets the session used by the page according to the session's partition string. If partition starts with persist:, the page will use a persistent session available to all pages in the app with the same partition. If there is no persist: prefix, the page will use an in-memory session. By assigning the same partition, multiple pages can share the same session. Default is the default session.
      • zoomFactor number (optional) - The default zoom factor of the page, 3.0 represents 300%. Por padrão é 1.0.
      • javascript boolean (optional) - Enables JavaScript support. Por padrão é true.
      • webSecurity boolean (optional) - When false, it will disable the same-origin policy (usually using testing websites by people), and set allowRunningInsecureContent to true if this option has not been set by user. Por padrão é true.
      • allowRunningInsecureContent boolean (optional) - Allow an https page to run JavaScript, CSS or plugins from http URLs. Por padrão é false.
      • images boolean (optional) - Enables image support. Por padrão é true.
      • imageAnimationPolicy string (optional) - Specifies how to run image animations (E.g. GIFs). Can be animate, animateOnce or noAnimation. Por padrão é animate.
      • textAreasAreResizable boolean (optional) - Make TextArea elements resizable. Default is true.
      • webgl boolean (optional) - Enables WebGL support. Por padrão é true.
      • plugins boolean (optional) - Whether plugins should be enabled. Por padrão é false.
      • experimentalFeatures boolean (optional) - Enables Chromium's experimental features. Por padrão é false.
      • scrollBounce boolean (optional) macOS - Enables scroll bounce (rubber banding) effect on macOS. Por padrão é false.
      • enableBlinkFeatures string (optional) - A list of feature strings separated by ,, like CSSVariables,KeyboardEventKey to enable. The full list of supported feature strings can be found in the RuntimeEnabledFeatures.json5 file.
      • disableBlinkFeatures string (optional) - A list of feature strings separated by ,, like CSSVariables,KeyboardEventKey to disable. The full list of supported feature strings can be found in the RuntimeEnabledFeatures.json5 file.
      • defaultFontFamily Object (optional) - Sets the default font for the font-family.
        • standard string (optional) - Defaults to Times New Roman.
        • serif string (optional) - Defaults to Times New Roman.
        • sansSerif string (optional) - Defaults to Arial.
        • monospace string (optional) - Defaults to Courier New.
        • cursive string (optional) - Defaults to Script.
        • fantasy string (optional) - Defaults to Impact.
        • math string (optional) - Defaults to Latin Modern Math.
      • defaultFontSize Integer (optional) - Defaults to 16.
      • defaultMonospaceFontSize Integer (optional) - Defaults to 13.
      • minimumFontSize Integer (optional) - Defaults to 0.
      • defaultEncoding string (optional) - Defaults to ISO-8859-1.
      • backgroundThrottling boolean (optional) - Whether to throttle animations and timers when the page becomes background. This also affects the Page Visibility API. When at least one webContents displayed in a single browserWindow has disabled backgroundThrottling then frames will be drawn and swapped for the whole window and other webContents displayed by it. O padrão é true.
      • offscreen Object | boolean (optional) - Whether to enable offscreen rendering for the browser window. O padrão é false. See the offscreen rendering tutorial for more details.
        • useSharedTexture boolean (optional) Experimental - Whether to use GPU shared texture for accelerated paint event. O padrão é false. See the offscreen rendering tutorial for more details.
        • sharedTexturePixelFormat string (optional) Experimental - The requested output format of the shared texture. O padrão é argb. The name is originated from Chromium media::VideoPixelFormat enum suffix and only subset of them are supported. The actual output pixel format and color space of the texture should refer to OffscreenSharedTexture object in the paint event.
          • argb - The requested output texture format is 8-bit unorm RGBA, with SRGB SDR color space.
          • rgbaf16 - The requested output texture format is 16-bit float RGBA, with scRGB HDR color space.
      • contextIsolation boolean (optional) - Whether to run Electron APIs and the specified preload script in a separate JavaScript context. Defaults to true. The context that the preload script runs in will only have access to its own dedicated document and window globals, as well as its own set of JavaScript builtins (Array, Object, JSON, etc.), which are all invisible to the loaded content. The Electron API will only be available in the preload script and not the loaded page. This option should be used when loading potentially untrusted remote content to ensure the loaded content cannot tamper with the preload script and any Electron APIs being used. This option uses the same technique used by Chrome Content Scripts. You can access this context in the dev tools by selecting the 'Electron Isolated Context' entry in the combo box at the top of the Console tab.
      • webviewTag boolean (optional) - Whether to enable the <webview> tag. O padrão é false. Note: The preload script configured for the <webview> will have node integration enabled when it is executed so you should ensure remote/untrusted content is not able to create a <webview> tag with a possibly malicious preload script. You can use the will-attach-webview event on webContents to strip away the preload script and to validate or alter the <webview>'s initial settings.
      • additionalArguments string[] (optional) - A list of strings that will be appended to process.argv in the renderer process of this app. Useful for passing small bits of data down to renderer process preload scripts.
      • safeDialogs boolean (optional) - Whether to enable browser style consecutive dialog protection. Por padrão é false.
      • safeDialogsMessage string (optional) - The message to display when consecutive dialog protection is triggered. If not defined the default message would be used, note that currently the default message is in English and not localized.
      • disableDialogs boolean (optional) - Whether to disable dialogs completely. Overrides safeDialogs. Por padrão é false.
      • navigateOnDragDrop boolean (optional) - Whether dragging and dropping a file or link onto the page causes a navigation. Por padrão é false.
      • autoplayPolicy string (optional) - Autoplay policy to apply to content in the window, can be no-user-gesture-required, user-gesture-required, document-user-activation-required. Padrão sendo no-user-gesture-required.
      • disableHtmlFullscreenWindowResize boolean (optional) - Whether to prevent the window from resizing when entering HTML Fullscreen. Default is false.
      • accessibleTitle string (optional) - An alternative title string provided only to accessibility tools such as screen readers. This string is not directly visible to users.
      • spellcheck boolean (optional) - Whether to enable the builtin spellchecker. Por padrão é true.
      • enableWebSQL boolean (optional) - Whether to enable the WebSQL api. Por padrão é true.
      • v8CacheOptions string (optional) - Enforces the v8 code caching policy used by blink. Accepted values are
        • none - Disables code caching
        • code - Heuristic based code caching
        • bypassHeatCheck - Bypass code caching heuristics but with lazy compilation
        • bypassHeatCheckAndEagerCompile - Same as above except compilation is eager. Default policy is code.
      • enablePreferredSizeMode boolean (optional) - Whether to enable preferred size mode. The preferred size is the minimum size needed to contain the layout of the document—without requiring scrolling. Enabling this will cause the preferred-size-changed event to be emitted on the WebContents when the preferred size changes. Por padrão é false.
      • transparent boolean (optional) - Whether to enable background transparency for the guest page. Por padrão é true. Note: The guest page's text and background colors are derived from the color scheme of its root element. When transparency is enabled, the text color will still change accordingly but the background will remain transparent.
      • enableDeprecatedPaste boolean (optional) Deprecated - Whether to enable the paste execCommand. Por padrão é false.
      • focusOnNavigation boolean (optional) - Whether to focus the WebContents when navigating. Por padrão é true.
    • paintWhenInitiallyHidden boolean (optional) - Whether the renderer should be active when show is false and it has just been created. In order for document.visibilityState to work correctly on first load with show: false you should set this to false. Setting this to false will cause the ready-to-show event to not fire. Por padrão é true.