Counting number of times android app goes into background

Issue

I'm developing an app which counts number of times the app goes to the background. It also retains the values when the orientation is changed. Though I have it working of all use cases, I have one use case which does not work.

Case : When I press the home button, change the phone's orientation and reopen the app, It does open in landscape mode but, the background count does not increase. I have tried setting values in all the life cycle methods. It doesn't work. Hope somebody can help me with this. `

    public class MainActivity extends AppCompatActivity {

    private int clickCount =0, backgroundCount = 0;
    TextView tvClickCountValue, tvBackgroundCountValue;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if( savedInstanceState != null){
            clickCount = savedInstanceState.getInt("COUNT");
            backgroundCount = savedInstanceState.getInt("BGCOUNT");
        }
        setContentView(R.layout.activity_main);
        tvClickCountValue = (TextView) this.findViewById(R.id.tvClickCountValue);
        tvBackgroundCountValue = (TextView) this.findViewById(R.id.tvBackgroundCountValue);
        setView(MainActivity.this);

    }

    public void onClick(View v){

        clickCount += 1;
        tvClickCountValue.setText(Integer.toString(clickCount));

    }

    public void setView(Context ctx){

        tvClickCountValue.setText(Integer.toString(clickCount));
        tvBackgroundCountValue.setText(Integer.toString(backgroundCount));
    }

    @Override
    protected void onStop() {
        super.onStop();
        backgroundCount += 1;

    }


    @Override
    protected void onResume() {
        super.onResume();
        tvClickCountValue.setText(Integer.toString(clickCount));
        tvBackgroundCountValue.setText(Integer.toString(backgroundCount));
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("COUNT", clickCount);
        outState.putInt("BGCOUNT", backgroundCount);
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        clickCount = savedInstanceState.getInt("COUNT");
        backgroundCount = savedInstanceState.getInt("BGCOUNT");
    }
}

Solution

This article contains useful information: https://developer.android.com/guide/topics/resources/runtime-changes.html especially in the section about Handling The Change.

Try handling it on onConfigurationChanged() of you have disabled Activity restarts on orientation changes. Otherwise, probably through this article you will find which case applies to your scenario.

By reading the problem description, I am assuming that if you don't rotate the device the application works as intended.

Answered By - Iakovos