Clear a TextView when EditText inputs

Question

I have 2 EditText fields set up for numeric inputs, a button to start a calculation on the 2 inputs when pressed, and a TextView to display the result of the calculation. For repeated calculations I want to clear the TextView result as soon as either EditText is changed. Following the reply to "A better way to OnClick for EditText fields" given by 'avalancha', my program clears the result when the first EditText field is changed, but retains the previous answer if only the second EditText field is changed. Yet I have used the same source code for both fields. Can someone explain why, and how to cure this? my code is appended:

public class DoublesActivity extends ActionBarActivity {

private EditText textBox1, textBox2;
private Button calcButton;
private Context context;


@Override
protected void onCreate(Bundle outState) {
    super.onCreate(outState);
    setContentView(R.layout.activity_doubles);    // Sets the layout .xml   file

    context = this.getApplicationContext();

    textBox1 = (EditText) findViewById(R.id.editText1);  //textBox1 holds a reference to the editText1 object in the xml layout
    textBox2 = (EditText) findViewById(R.id.editText2);
    textBox1.setText("");
    textBox2.setText("");

    final TextView textBox3 = (TextView) findViewById(R.id.textView1);

    textBox2.setOnFocusChangeListener(new View.OnFocusChangeListener() {
        @Override
        public void onFocusChange(View v2, boolean hasFocus2) {
            if (hasFocus2) {
                textBox3.setText("");
            }
        }
    });

    textBox1.setOnFocusChangeListener(new View.OnFocusChangeListener() {
        @Override
        public void onFocusChange(View v1, boolean hasFocus1) {
            if (hasFocus1) {
                textBox3.setText("");
            }
        }
    });


    calcButton = (Button) findViewById(R.id.button1);
    calcButton.setBackgroundColor(Color.CYAN);
    calcButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {

            CharSequence userNumber1 = textBox1.getText();                    //userNumber1 is a CharSequence holding the text in textBox1
            CharSequence userNumber2 = textBox2.getText();
            Float handicap1 = Float.parseFloat(userNumber1.toString());     //convert to integer
            Float handicap2 = Float.parseFloat(userNumber2.toString());     //convert to integer
            Float handicapT = calculate(handicap1, handicap2);
            CharSequence userNumber = String.valueOf(handicapT);
            if (handicapT > 98.5) {
                userNumber = "Non-valid h'cap 1!";
            }
            if (handicapT < -98.5) {
                userNumber = "Non-valid h'cap 2!";
            }

            textBox3.setText(userNumber);                    // put result in the TextView
        }
    });
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    TextView textBox3 = (TextView) findViewById(R.id.textView1);
    CharSequence userNumber = textBox3.getText();
    outState.putCharSequence("savedText", userNumber);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    final TextView textBox3 = (TextView) findViewById(R.id.textView1);
    CharSequence userText = savedInstanceState.getCharSequence("savedText");
    textBox3.setText(userText);
}

Float calculate(Float h1, Float h2) {
    float[] handicapArray;
    handicapArray = new float[29];
    handicapArray[0] = 28;
    handicapArray[1] = 26;
    handicapArray[2] = 24;
    handicapArray[3] = 22;
    handicapArray[4] = 20;
    handicapArray[5] = 18;
    handicapArray[6] = 16;
    handicapArray[7] = 14;
    handicapArray[8] = 12;
    handicapArray[9] = 11;
    handicapArray[10] = 10;
    handicapArray[11] = 9;
    handicapArray[12] = 8;
    handicapArray[13] = 7;
    handicapArray[14] = 6;
    handicapArray[15] = 5;
    handicapArray[16] = 4.5F;
    handicapArray[17] = 4;
    handicapArray[18] = 3.5F;
    handicapArray[19] = 3;
    handicapArray[20] = 2.5F;
    handicapArray[21] = 2;
    handicapArray[22] = 1.5F;
    handicapArray[23] = 1;
    handicapArray[24] = 0.5F;
    handicapArray[25] = 0;
    handicapArray[26] = -0.5F;
    handicapArray[27] = -1;
    handicapArray[28] = -1.5F;
    int index1 = -1;
    for (int i = 0; i < 29; i++) {
        if (Math.abs(h1 - handicapArray[i]) < 0.001) {
            index1 = i;
            break;
        }
    }
    if (index1 == -1) {
        EditText textBox1 = (EditText) findViewById(R.id.editText1);
        textBox1.setText("");
    }

    int index2 = -1;
    for (int i = 0; i < 29; i++) {
        if (Math.abs(h2 - handicapArray[i]) < 0.001) {
            index2 = i;
            break;
        }
    }
    if (index2 == -1) {
        EditText textBox2 = (EditText) findViewById(R.id.editText2);
        textBox2.setText("");
    }
    int indexT = (index1 + index2) / 2;   // Correctly rounds indexT halves down.
    Float result = handicapArray[indexT];
    if (index1 == -1) {
        result = 99F;
    }
    ;
    if (index2 == -1) {
        result = -99F;
    }
    ;
    return result;
} 

Answer 1

Use addTextChangedListener to clear textview.

editText.addTextChangedListener(new TextWatcher() {

   public void afterTextChanged(Editable s) {}

   public void beforeTextChanged(CharSequence s, int start,
     int count, int after) {
   }

   public void onTextChanged(CharSequence s, int start,
     int before, int count) {
      resultTextView.setText("");
   }
  });

For example please use below link

android on Text Change Listener