title: Change button color all edittext fields filled?
body: <p>I have button and text fields like below in my layout file</p>
  
  <pre><code>&lt;EditText
          android:id="@+id/et_password"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@+id/textView4"
          android:layout_centerHorizontal="true"
          android:ems="10"
          android:inputType="textPassword" /&gt;
  
      &lt;Button
          android:id="@+id/btn_app_signup"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@+id/et_password"
          android:layout_centerHorizontal="true"
          android:layout_marginTop="63dp"
          android:background="@drawable/button"
          android:text="SIGN UP"
          android:textColor="@color/white" /&gt;
  </code></pre>
  
  <p>How can I change this background into <code>@drawable/button_success</code> to if all edit text fields filled my Activity class like below</p>
  
  <pre><code>@Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_signup);
          btn_app_signup.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
  
                  String name = et_name.getText().toString();
                  String email = et_email.getText().toString();
                  String password = et_password.getText().toString();
  
                  registerAccount(name, email, password);
              }
          });
      }
  
      private void registerAccount(String name, String email, String password) {
  
          if(TextUtils.isEmpty(name) || TextUtils.isEmpty(email) || TextUtils.isEmpty(password)) {
              Toast.makeText(SignupActivity.this, "All fields required", Toast.LENGTH_LONG).show();
          }
          else {
  
              //save data in datbase
          }
      }
  </code></pre>
  
  <p>How can I do that if I fill all my edit text fields fill change the button button background</p>