import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
/**
 * Check all validators, sets the error text if not
 * <p/>
 * NOTE: this stops at the first validator to report invalid.
 *
 * @return True if all validators pass, false if not
 */
public boolean validate() {

  if (validators == null || validators.size() == 0) {
    return true;
  }

  CharSequence text = getText();
  boolean isEmpty = text.length() == 0;

  boolean isValid = true;
  for (METValidator validator : validators) {
    //noinspection ConstantConditions
    isValid = isValid && validator.isValid(text, isEmpty);
    if (!isValid) {
      setError(validator.getErrorMessage());
      break;
    }
  }

  postInvalidate();
  return isValid;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    final View inflate = inflater.inflate(R.layout.fragment_help_feedback, container, false);
    ButterKnife.bind(this, inflate);

    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            boolean validName = userFeedBackEditText.validateWith(new METValidator(getString(R.string.support_textview_feedback_error)) {
                @Override
                public boolean isValid(@NonNull CharSequence charSequence, boolean b) {
                    return charSequence.length() > 1;
                }
            });

            if (validName) {
                sendComment(userFeedBackEditText.getText().toString());
            }
        }
    });

    return inflate;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
/**
 * Run validation on a single validator instance
 *
 * @param validator Validator to check
 * @return True if valid, false if not
 */
public boolean validateWith(@NonNull METValidator validator) {
  CharSequence text = getText();
  boolean isValid = validator.isValid(text, text.length() == 0);
  if (!isValid) {
    setError(validator.getErrorMessage());
  }
  postInvalidate();
  return isValid;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
@Nullable
public List<METValidator> getValidators() {
  return this.validators;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
public List<METValidator> getValidators() {
  return this.validators;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
/**
 * Adds a new validator to the View's list of validators
 * <p/>
 * This will be checked with the others in {@link #validate()}
 *
 * @param validator Validator to add
 * @return This instance, for easy chaining
 */
public MaterialAutoCompleteTextView addValidator(METValidator validator) {
  if (validators == null) {
    this.validators = new ArrayList<>();
  }
  this.validators.add(validator);
  return this;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
/**
 * Adds a new validator to the View's list of validators
 * <p/>
 * This will be checked with the others in {@link #validate()}
 *
 * @param validator Validator to add
 * @return This instance, for easy chaining
 */
public MaterialMultiAutoCompleteTextView addValidator(METValidator validator) {
  if (validators == null) {
    this.validators = new ArrayList<>();
  }
  this.validators.add(validator);
  return this;
}
 

import com.rengwuxian.materialedittext.validation.METValidator; //导入依赖的package包/类
/**
 * Adds a new validator to the View's list of validators
 * <p/>
 * This will be checked with the others in {@link #validate()}
 *
 * @param validator Validator to add
 * @return This instance, for easy chaining
 */
public MaterialEditText addValidator(METValidator validator) {
  if (validators == null) {
    this.validators = new ArrayList<>();
  }
  this.validators.add(validator);
  return this;
}