landscape mode savedInstanceState

Question

I'm working on an Android App and dealing with an issue !!

When I change the screen from the portait mode to the Landscape mode without changing the activity I'm working on android Stop, Destroy and then create and launch my Activity.

To know that, I printed the times OnCreate(),onStart(), onRestart() ... are called.

What I want to do is to stop counting when I'm just changing the screen mode or don't kill and distroy my activity, when I change the screen mode.

Here is my code

public class ActivityX extends Activity {

  
	private static final String RESTART_KEY = "restart";
	private static final String RESUME_KEY = "resume";
	private static final String START_KEY = "start";
	private static final String CREATE_KEY = "create";

	// String for LogCat documentation
	private final static String TAG = "ActivityX";

	// Lifecycle counters
	
	private int mCreate 	= 0;
	private int mRestart 	= 0;
	private int mStart 		= 0;
	private int mResume		= 0;

    //Create variables for each of the TextViews
	private static int mTvCreate	= 0;
	private static int mTvRestart 	= 0;
	private static int mTvStart		= 0;
	private static int mTvResume	= 0;


	
	TextView startTxtView ;
	TextView restartTxtView;
	TextView resumeTxtView;
	TextView createTxtView ;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		setContentView(R.layout.activity_one);
		
		
		startTxtView = (TextView) findViewById(R.id.start);
		restartTxtView = (TextView) findViewById(R.id.restart);
		resumeTxtView = (TextView) findViewById(R.id.resume);
		createTxtView = (TextView) findViewById(R.id.create);
		
		
		Button launchActivityYButton = (Button) findViewById(R.id.bLaunchActivityY);
		launchActivityYButton.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				
	         try{
	        	 Intent intentActivity = new Intent(ActivityX.this, ActivityY.class);

	        	 startActivity(intentActivity);
	        	 

	        	 
	         } catch (Exception e) {
                 // Log any error messages to LogCat using Log.e()
                 Log.e(TAG, "On click X not working");
             }
	         


			}
		});

		// Has previous state been saved?
		if (savedInstanceState != null ) {


			mCreate 	= savedInstanceState.getInt(CREATE_KEY);
			mStart 		= savedInstanceState.getInt(START_KEY);
			mRestart 	= savedInstanceState.getInt(RESTART_KEY);
			mResume 	= savedInstanceState.getInt(RESUME_KEY);

		}

		// Emit LogCat message
		Log.i(TAG, "Entered the onCreate() method");


		
		mTvCreate 	=  mCreate + 1;
		mTvStart 	=  mStart;
		mTvRestart 	=  mRestart;
		mTvResume 	=  mResume;
		
		createTxtView.setText("onCreate()calls: "+mTvCreate);
		startTxtView.setText("onStart()calls: "+mTvStart);
		resumeTxtView.setText("onResume()calls: "+mTvResume);
		restartTxtView.setText("onRestart()calls: "+mTvRestart);

	}



	@Override
	public void onStart() {
		super.onStart();

		// Emit LogCat message
		Log.i(TAG, "Entered the onStart() method");

		mTvStart = mTvStart + 1;
		this.displayCounts();
	}

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

		// Emit LogCat message
		Log.i(TAG, "Entered the onResume() method");
		
		mTvResume = mTvResume + 1;
		this.displayCounts();
	}

	@Override
	public void onPause() {
		super.onPause();

		// Emit LogCat message
		Log.i(TAG, "Entered the onPause() method");
	}

	@Override
	public void onStop() {
		super.onStop();

		// Emit LogCat message
		Log.i(TAG, "Entered the onStop() method");
	}

	@Override
	public void onRestart() {
		super.onRestart();

		// Emit LogCat message
		Log.i(TAG, "Entered the onRestart() method");

		mTvRestart = mTvRestart + 1;
		this.displayCounts();

	}

	@Override
	public void onDestroy() {
		super.onDestroy();

		// Emit LogCat message
		Log.i(TAG, "Entered the onDestroy() method");
	}

	@Override
	public void onSaveInstanceState(Bundle savedInstanceState) {

		savedInstanceState.putInt(CREATE_KEY, mTvCreate);
	    savedInstanceState.putInt(RESTART_KEY, mTvRestart);
	    savedInstanceState.putInt(START_KEY, mTvStart);
	    savedInstanceState.putInt(RESUME_KEY, mTvResume);
	    
	    super.onSaveInstanceState(savedInstanceState);

	}


	public void displayCounts() {
	
		
		createTxtView.setText("onCreate() calls: " + mTvCreate);
		startTxtView.setText("onStart() calls: " + mTvStart);
		resumeTxtView.setText("onResume() calls: " + mTvResume);
		restartTxtView.setText("onRestart() calls: " + mTvRestart);
	
	}
}

Answer 1

I don't have enough reputation to comment, but if I understand you correctly, you can ignore screen orientation if you:

1. Start counting in onResume() method.
2. Stop counting in onPause() method.

This way, you don't have to worry about screen orientation as onPause is called whenever orientation started i.e. the device is physically rotated. While onResume() is called when orientation is finished.

Answer 2

Now a quick fix is to add this line to AndroidManifest.xml where you see your activity

android:configChanges="orientation|screenSize"

And in your Activity override the following method

@Override
public void onConfigurationChanged(Configuration newConfig) {
  super.onConfigurationChanged(newConfig);
}

Now your activity will not be destroyed