theme.onUpdated

Fires when a theme supplied as a browser extension is applied or removed. Specifically:

when a static theme is installed
when a dynamic theme calls theme.update() or theme.reset()
when a theme gets uninstalled.

This event is not fired for changes to the built-in themes.

Syntax

browser.theme.onUpdated.addListener(listener)
browser.theme.onUpdated.removeListener(listener)
browser.theme.onUpdated.hasListener(listener)

Events have three functions:

addListener(listener): Adds a listener to this event.
removeListener(listener): Stop listening to this event. The listener argument is the listener to remove.
hasListener(listener): Check whether listener is registered for this event. Returns true if it is listening, false otherwise.

addListener syntax

Parameters

listener

The function called when this event occurs. The function is passed these arguments:

updateInfo

object. An object containing two properties:

theme: object. If the event fired because an extension-supplied theme was removed, this is an empty object. If it fired because an extension-supplied theme was applied, then it is a theme.Theme object representing the theme that was applied.
windowId Optional: integer. The ID of the window in which the theme was updated. If this property is not present, the theme was updated in all windows.

Examples

function handleUpdated(updateInfo) {
  if (updateInfo.theme.colors) {
    console.log(`Theme was applied: ${updateInfo.theme}`);
  } else {
    console.log(`Theme was removed`);
  }
}

browser.theme.onUpdated.addListener(handleUpdated);

Example extensions

theme-integrated-sidebar

Browser compatibility

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