Question

What would be the best way to time how long a user spends in a specific Activity?

Thanks in advance!

Answer 1

I guess I’d start out with something like this:

private static long mTotalTime;
private long mStartTime;

@Override
public void onPause() {
    super.onPause();
    mTotalTime += System.currentTimeMillis() - mStartTime;
}

@Override
public void onResume() {
    super.onResume();
    mStartTime = System.currentTimeMillis();
}

Note that because it’s using onPause/onResume it will also ‘pause’ the timer if the screen turns off, if it re-orients etc. Depending on what your purpose is you may want to use one of the other callbacks like onCreate() or onDestroy(), but note that onDestroy() doesn’t alway get called when a new activity launches from the existing activity.

You may also want to save mTotalTime to SharedPreferences so that it is preserved even if the app is shut down. Maybe something like this:

private long mStartTime;

@Override
public void onPause() {
    super.onPause();
    int totalTime = getPreferences(0).getInt("TotalTime",0);
    getPreferences(0).edit().putInt("TotalTime", totalTime + System.currentTimeMillis() - mStartTime)
}

@Override
public void onResume() {
    super.onResume();
    mStartTime = System.currentTimeMillis();
}