tabs.onActivated

Fires when the active tab in a window changes. Note that the tab's URL may not be set at the time this event fired, but you can listen to tabs.onUpdated events to be notified when a URL is set.

Syntax

browser.tabs.onActivated.addListener(listener)
browser.tabs.onActivated.removeListener(listener)
browser.tabs.onActivated.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 this argument:

activeInfo: object. ID of the tab that was made active, and ID of its window. See the activeInfo section for more details.

Additional objects

activeInfo

previousTabId: integer. The ID of the previous activated tab, if that tab is still open.
tabId: integer. The ID of the tab that has become active.
windowId: integer. The ID of the tab's window.

Examples

Listen for and log tab activation events:

function handleActivated(activeInfo) {
  console.log(`Tab ${activeInfo.tabId} was activated`);
}

browser.tabs.onActivated.addListener(handleActivated);

Example extensions

Browser compatibility

BCD tables only load in the browser

Note: This API is based on Chromium's chrome.tabs API. This documentation is derived from tabs.json in the Chromium code.