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(function(
windowId // integer
) {...})
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
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
Examples
Acknowledgements
This API is based on Chromium's chrome.windows API. This documentation is derived from windows.json in the Chromium code.
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