How can I tell if my Application is resumed from background?

Question

I want to lock my application when it goes in background and when it resumes I want to display my own lock screen. The lock screen is an Activity of my application.

Aft

Answer 1

You can achieve that if you have a global Activity "MyActivity" and all the activities extend from it.

Then you override onPause and onStop methods on "MyActivity"

@Override
public void onPause()
{
    super.onPause();
    setLockStatus(false);
}

@Override
public void onStop()
{
    super.onStop();
    setLockStatus(true);
}

and:

@Override
public void onResume()
{
    super.onResume();
    checkLockScreen();
}

EDIT: Obviously you need to create the methods setLockStatus and checkLockScreen and do whatever you want (like save the status on sharedPreferences).