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 {{WebExtAPIRef("theme.Theme")}} object representing the theme that was applied.
        • windowId {{optional_inline}}
          • : 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);

{{WebExtExamples}}

Browser compatibility

{{Compat}}