windows.onFocusChanged
Fired when the currently focused window changes. Will be windows.WINDOW_ID_NONE
if all browser windows have lost focus.
Note: In Windows and 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
listener
argument is the listener to remove. hasListener(listener)
-
Check whether a
listener
is registered for this event. Returnstrue
if it is listening,false
otherwise.
addListener syntax
Parameters
callback
-
Function that will be called when this event occurs. The function will be passed the following arguments:
windowId
-
integer
. ID of the newly focused window.
Browser compatibility
BCD tables only load in the browser
Examples
Log focus changes:
browser.windows.onFocusChanged.addListener((windowId) => {
console.log("Newly focused window: " + windowId);
});
Example extensions
Note: 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.