MultiTextWatcher.java

/* We create an interface with one method  */

  public interface TextWatcherWithInstance {
      void onTextChanged(EditText editText, CharSequence s, int start, int before, int count);
  }
  
  
  /* We create a custom class called MultiTextWatcher. 
   * And pass the interface here  
   */            
  public class MultiTextWatcher {
      private TextWatcherWithInstance callback;

      public MultiTextWatcher setCallback(TextWatcherWithInstance callback) {
          this.callback = callback;
          return this;
      }

      public MultiTextWatcher registerEditText(final EditText editText) {
          editText.addTextChangedListener(new TextWatcher() {
              @Override
              public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

              @Override
              public void onTextChanged(CharSequence s, int start, int before, int count) {
                  callback.onTextChanged(editText, s, start, before, count);
              }

              @Override
              public void afterTextChanged(Editable editable) {}
          });

          return this;
   }
   
   
   /*  
    * We can call this class from our Activity/Fragment like this:
    * This only has one method, which we are using in the app
    */
    new MultiTextWatcher()
    .registerEditText(editText)
    .setCallback(new MultiTextWatcher.TextWatcherWithInstance() {
          @Override
          public void onTextChanged(EditText editText, CharSequence s, int start, int before, int count) {

          }
      });