electron/docs/api/system-preferences.md
Zeke Sikelianos 6728efe87e Merge pull request #7339 from electron/document-return-values
Document the return values of all methods in the docs
2016-09-27 07:39:25 -07:00

4.4 KiB

systemPreferences

Get system preferences.

const {systemPreferences} = require('electron')
console.log(systemPreferences.isDarkMode())

Events

The systemPreferences object emits the following events:

Event: 'accent-color-changed' Windows

Returns:

  • event Event
  • newColor String - The new RGBA color the user assigned to be there system accent color.

Methods

systemPreferences.isDarkMode() macOS

Returns Boolean - Whether the the system is in Dark Mode.

systemPreferences.isSwipeTrackingFromScrollEventsEnabled() macOS

Returns Boolean - Whether the Swipe between pages setting is on.

systemPreferences.postNotification(event, userInfo) macOS

  • event String
  • userInfo Object

Posts event as native notifications of macOS. The userInfo is an Object that contains the user information dictionary sent along with the notification.

systemPreferences.postLocalNotification(event, userInfo) macOS

  • event String
  • userInfo Object

Posts event as native notifications of macOS. The userInfo is an Object that contains the user information dictionary sent along with the notification.

systemPreferences.subscribeNotification(event, callback) macOS

  • event String
  • callback Function

Subscribes to native notifications of macOS, callback will be called with callback(event, userInfo) when the corresponding event happens. The userInfo is an Object that contains the user information dictionary sent along with the notification.

The id of the subscriber is returned, which can be used to unsubscribe the event.

Under the hood this API subscribes to NSDistributedNotificationCenter, example values of event are:

  • AppleInterfaceThemeChangedNotification
  • AppleAquaColorVariantChanged
  • AppleColorPreferencesChangedNotification
  • AppleShowScrollBarsSettingChanged

systemPreferences.unsubscribeNotification(id) macOS

  • id Integer

Removes the subscriber with id.

systemPreferences.subscribeLocalNotification(event, callback) macOS

  • event String
  • callback Function

Same as subscribeNotification, but uses NSNotificationCenter for local defaults. This is necessary for events such as NSUserDefaultsDidChangeNotification

systemPreferences.unsubscribeLocalNotification(id) macOS

  • id Integer

Same as unsubscribeNotification, but removes the subscriber from NSNotificationCenter.

systemPreferences.getUserDefault(key, type) macOS

  • key String
  • type String - Can be string, boolean, integer, float, double, url, array, dictionary

Get the value of key in system preferences.

This API reads from NSUserDefaults on macOS, some popular key and types are:

  • AppleInterfaceStyle: string
  • AppleAquaColorVariant: integer
  • AppleHighlightColor: string
  • AppleShowScrollBars: string
  • NSNavRecentPlaces: array
  • NSPreferredWebServices: dictionary
  • NSUserDictionaryReplacementItems: array

systemPreferences.isAeroGlassEnabled() Windows

This method returns true if DWM composition (Aero Glass) is enabled, and false otherwise.

An example of using it to determine if you should create a transparent window or not (transparent windows won't work correctly when DWM composition is disabled):

const {BrowserWindow, systemPreferences} = require('electron')
let browserOptions = {width: 1000, height: 800}

// Make the window transparent only if the platform supports it.
if (process.platform !== 'win32' || systemPreferences.isAeroGlassEnabled()) {
  browserOptions.transparent = true
  browserOptions.frame = false
}

// Create the window.
let win = new BrowserWindow(browserOptions)

// Navigate.
if (browserOptions.transparent) {
  win.loadURL(`file://${__dirname}/index.html`)
} else {
  // No transparency, so we load a fallback that uses basic styles.
  win.loadURL(`file://${__dirname}/fallback.html`)
}

systemPreferences.getAccentColor() Windows

Returns the users current system wide color preference in the form of an RGBA hexadecimal string.

const color = systemPreferences.getAccentColor() // `"aabbccdd"`
const red = color.substr(0, 2) // "aa"
const green = color.substr(2, 2) // "bb"
const blue = color.substr(4, 2) // "cc"
const alpha = color.substr(6, 2) // "dd"