Fired when the currently focused window changes. Will be windows.WINDOW_ID_NONE if all browser windows have lost focus.
Note: On some Linux window managers, WINDOW_ID_NONE will always be sent immediately preceding a switch from one browser window to another.
Syntax
browser.windows.onFocusChanged.addListener(listener) browser.windows.onFocusChanged.removeListener(listener) browser.windows.onFocusChanged.hasListener(listener)
Events have three functions:
addListener(callback)- Adds a listener to this event.
removeListener(listener)- Stop listening to this event. The
listenerargument is the listener to remove. hasListener(listener)- Check whether a
listeneris registered for this event. Returnstrueif it is listening,falseotherwise.
addListener syntax
Parameters
callback-
Function that will be called when this event occurs. The function will be passed the following arguments:
windowIdinteger. ID of the newly focused window.
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Chrome | Edge | Firefox | Firefox for Android | Opera | |
|---|---|---|---|---|---|
| Basic support | Yes | Yes | 45 | No | Yes |
Examples
Log focus changes:
browser.windows.onFocusChanged.addListener((windowId) => {
console.log("Newly focused window: " + windowId);
});
Example extensions
This API is based on Chromium's chrome.windows API. This documentation is derived from windows.json in the Chromium code.
Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.
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