How user app can get call when user press user button on android device?

[tvnaidu]

I have one question, if I keep one user button next to power button on android running device, this "user button" for user action, will android sends a message to application layer when user press that button? thanks


Basically I want to take some action like "packageManager .getLaunchInten tForPackage("co m.android.brows er"))" should get called when somebody press that "user button". Is Android can send event when somebody press "user button" to me, then I can call getLaunchIntent ForPackage call?.

Thanks in advance.