Fired when the currently focused window changes. Will be
windows.WINDOW_ID_NONE
if all browser windows have lost focus.
注意： In Windows and some Linux window managers, WINDOW_ID_NONE will always be sent immediately preceding a switch from one browser window to another.
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. Returns
true
if it is listening,
false
否则。
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.
BCD tables only load in the browser
Log focus changes:
browser.windows.onFocusChanged.addListener((windowId) => {
console.log("Newly focused window: " + windowId);
});
注意：
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.
最后修改： , 由 MDN 贡献者