title: Disable Button when Edit Text Fields empty
body: <p>I have two text fields and a Button. I want to disable the Button unless both EditText-Fields are not empty. I tried many solutions here at stackoverflow, but they don't work. Here is my code:</p>
  
  <pre><code>import android.app.Activity;
  import android.content.Intent;
  import android.os.Bundle;
  import android.text.Editable;
  import android.text.TextWatcher;
  import android.view.View;
  import android.widget.Button;
  import android.widget.EditText;
  import android.widget.TextView;
  
  
  public class RegisterActivity extends Activity {
  
      private EditText editText1;
      private EditText editText2;
  
      //TextWatcher
      private TextWatcher textWatcher = new TextWatcher() {
          @Override
          public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3)
         {
  
          }
  
          @Override
          public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
              checkFieldsForEmptyValues();
          }
  
          @Override
          public void afterTextChanged(Editable editable) {
          }
      };
  
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.register_activity);
  
  
          editText1 = (EditText) findViewById(R.id.reg_password);
          editText2 = (EditText) findViewById(R.id.reg_password2);
  
          //set listeners
          editText1.addTextChangedListener(textWatcher);
          editText1.addTextChangedListener(textWatcher);
  
          // run once to disable if empty
          checkFieldsForEmptyValues();
  
  
          TextView loginScreen = (TextView) findViewById(R.id.link_to_login);
          loginScreen.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  startActivity (new Intent(getApplicationContext(), DialogActivity.class));
                  finish();
              }
          });
  
      }
  
      private  void checkFieldsForEmptyValues(){
          Button b = (Button) findViewById(R.id.btnRegister);
  
          String s1 = editText1.getText().toString();
          String s2 = editText2.getText().toString();
  
          if(s1.equals("") &amp;&amp; s2.equals(""))
          {
              b.setEnabled(false);
          }
  
          else if(!s1.equals("")&amp;&amp;s2.equals("")){
              b.setEnabled(false);
          }
  
          else if(!s2.equals("")&amp;&amp;s1.equals(""))
          {
              b.setEnabled(false);
          }
  
          else
          {
              b.setEnabled(true);
          }
      }
  }
  </code></pre>
  
  <p>If I start the activity, it is disabled. But If I type something, it sometimes enables and sometimes doesn't.. I just want to enable the button if both Edit-Text Fields are not empty.</p>