Switching tab in the Firefox extension

I want to know a tab event fo开发者_StackOverflow中文版r Firefox extension to capture the event of switching from new tab to the older tab. I want to know event for switching from the new tab to the old tab.

You can add an event listener:

gBrowser.addEventListener("select", function(event)
{
  // Tab switched, do something
}, false);

You are searching for the TabSelect event.