content: /*
   * Copyright 2015, The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.example.android.testing.unittesting.BasicSample;
  
  import android.text.Editable;
  import android.text.TextWatcher;
  
  import java.util.regex.Pattern;
  
  /**
   * An Email format validator for {@link android.widget.EditText}.
   */
  public class EmailValidator implements TextWatcher {
  
      /**
       * Email validation pattern.
       */
      public static final Pattern EMAIL_PATTERN = Pattern.compile(
              "[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
                      "\\@" +
                      "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
                      "(" +
                      "\\." +
                      "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,25}" +
                      ")+"
      );
  
      private boolean mIsValid = false;
  
      public boolean isValid() {
          return mIsValid;
      }
  
      /**
       * Validates if the given input is a valid email address.
       *
       * @param email        The email to validate.
       * @return {@code true} if the input is a valid email. {@code false} otherwise.
       */
      public static boolean isValidEmail(CharSequence email) {
          return email != null && EMAIL_PATTERN.matcher(email).matches();
      }
  
      @Override
      final public void afterTextChanged(Editable editableText) {
          mIsValid = isValidEmail(editableText);
      }
  
      @Override
      final public void beforeTextChanged(CharSequence s, int start, int count, int after) {/*No-op*/}
  
      @Override
      final public void onTextChanged(CharSequence s, int start, int before, int count) {/*No-op*/}
  }
  