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©2011 Google
An Event is an object
that allows you to be notified
when something interesting happens.
Here's an example of using the
chrome.tabs.onCreated event
to be notified whenever there's a new tab:
chrome.tabs.onCreated.addListener(function(tab) {
appendToLog('tabs.onCreated --'
+ ' window: ' + tab.windowId
+ ' tab: ' + tab.id
+ ' index: ' + tab.index
+ ' url: ' + tab.url);
});
As the example shows,
you register for notification using addListener().
The argument to addListener()
is always a function that you define to handle the event,
but the parameters to the function depend on
which event you're handling.
Checking the documentation for
chrome.tabs.onCreated,
you can see that the function has a single parameter:
a Tab object
that has details about the newly created tab.
You can invoke the following methods on any Event object:
void addListener(function callback(...)) void removeListener(function callback(...)) bool hasListener(function callback(...))