EditText text changed java Android

public class MainActivity extends Activity implements OnClickListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        LinearLayout layout = (LinearLayout) findViewById(R.id.layout);
            RadioGroup radioGroup = new RadioGroup(this);
            
            LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.FILL_PARENT,
                    LinearLayout.LayoutParams.WRAP_CONTENT
            );
            layout.addView(radioGroup, p);

            RadioButton radioButtonView = new RadioButton(this);
            radioButtonView.setText("RadioButton");
            radioButtonView.setOnClickListener(this);
            radioGroup.addView(radioButtonView, p);
            
            RadioButton radioButtonView2 = new RadioButton(this);
            radioButtonView2.setText("RadioButton2");
            radioButtonView2.setOnClickListener(mThisButtonListener);
            radioGroup.addView(radioButtonView2, p);
        
    }
    
    public void onClick(View view) {
    	 try {
    	  String s = ((RadioButton) view).getText().toString();
    	  Toast.makeText(MainActivity.this, "This is: " + s,
    			  Toast.LENGTH_LONG).show();
    	 }
    	 catch (Exception e1) {
    	   e1.printStackTrace();
    	 }
    	}
    
    private OnClickListener mThisButtonListener = new OnClickListener() {
        public void onClick(View v) {
        	String s = ((RadioButton) v).getText().toString();
        	Toast.makeText(MainActivity.this, "Hello from 2!" + s,
        			Toast.LENGTH_LONG).show();
        }
    };

}

   <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:focusable="true" 
        android:focusableInTouchMode="true"
        android:orientation="vertical" >
</LinearLayout>

// Context instead Activity as a parameter
@Override
public void onAttach(Context context) {
    super.onAttach(context);

    Activity a;

    if (context instanceof Activity){
        a=(Activity) context;
    }

}

OnNoteClickedListener listener;
/* old emxample of usage
	@Override
	public void onAttach(Activity activity) {
		super.onAttach(activity);
		try {
			listener = (OnNoteClickedListener) activity;
		} catch (ClassCastException e) {
			throw new ClassCastException(activity.toString()
					+ " must implement OnNoteClickedListener");
		}
	}
*/
// new version of code
	@Override
	public void onAttach(Context context) {
		super.onAttach(context);

		Activity a;

		if (context instanceof Activity){
			a=(Activity) context;
			try {
				listener = (OnNoteClickedListener) a;
			} catch (ClassCastException e) {
				throw new ClassCastException(a.toString()
						+ " must implement OnNoteClickedListener");
			}
		}

	}

private int[] mData = new int[2]; // fill some values into array!!
 @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putBoolean("myBoolean", true);
        outState.putDouble("myDouble", 2.7);
        outState.putInt("myInt", 5);
        outState.putString("myString", "Heloo girls!");
       int[] data = new int[mData.length];
        for (int i = 0; i < data.length; i++) {
            data[i] = mData[i];
        }
        outState.putIntArray("myArray", data);

    }
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  boolean myBoolean = savedInstanceState.getBoolean("myBoolean", false); // false basic value
  double myDouble = savedInstanceState.getDouble("myDouble", 1.5); // 1.5 basic value
  int myInt = savedInstanceState.getInt("myInt", 10);
  String myString = savedInstanceState.getString("myString", "Hello boys!");
  int[] data = savedInstanceState.getIntArray("myArray");
  
  if (data != null && data.length == mData.length) {
            for (int i = 0; i < data.length; i++) {
                mData[i] = data[i];
            }
        }
}
@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  boolean myBoolean =  savedInstanceState != null ? savedInstanceState.getBoolean("myBoolean", false) : true;
// etc.  .......
}

    @Override
	protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
        setContentView(R.layout.main.xml);
        getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title);
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="//schemas.android.com/apk/res/android" android:id="@+id/screen"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:orientation="vertical">
    <TextView android:id="@+id/left_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:text="Some text" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
       
        android:src="@drawable/ic_launcher" />
    
</RelativeLayout>