firefox extension adding button to existing toolbar

I have this add-on bar at the button of my firefox window where several buttons from extensions are shown. How can I 开发者_运维百科add my own button there?

you can open the source code of that bar and add your own button

example (I'm on Windows right now): C:\%AppData%\Roaming\Mozilla\Firefox\Profiles\PROFILEID.default\extensions\EXTENSION-TO-EDIT-FOLDER\chrome\content

A good way to do this is with the Add-on SDK. You can find documentation on adding an Add-on bar button here. An additional benefit of using the SDK is that your add-ons won't require a restart after they are installed.

hey it is called a status bar and u should consider putting a statusbar xul element e.g

<?xml version="1.0"?>
<overlay id="sample"
xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<statusbar id="status-bar">
<statusbarpanel id="my-panel" label="Hello, World"  />
</statusbar>
</overlay>  

For more details check this link statusbar attributes, methods and properties