NonEmptyFunction.java

/*
 * *********************************************************************************************************************
 *
 * TheseFoolishThings: Miscellaneous utilities
 * http://tidalwave.it/projects/thesefoolishthings
 *
 * Copyright (C) 2009 - 2023 by Tidalwave s.a.s. (http://tidalwave.it)
 *
 * *********************************************************************************************************************
 *
 * 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.
 *
 * *********************************************************************************************************************
 *
 * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
 * git clone https://github.com/tidalwave-it/thesefoolishthings-src
 *
 * *********************************************************************************************************************
 */
package it.tidalwave.role.ui.function;

import javax.annotation.Nonnull;
import it.tidalwave.role.ui.ChangingSource;

/***********************************************************************************************************************
 *
 * @author  Fabrizio Giudici
 *
 **********************************************************************************************************************/
public class NonEmptyFunction extends UnaryBoundFunctionSupport<String, Boolean>
  {
    @Nonnull
    public static NonEmptyFunction nonEmpty (@Nonnull final ChangingSource<String> source)
      {
        return new NonEmptyFunction(source);
      }

    public NonEmptyFunction (@Nonnull final ChangingSource<String> source)
      {
        super(source);
      }

    @Override
    protected void onSourceChange (@Nonnull final String oldSourceValue, @Nonnull final String newSourceValue)
      {
        final boolean oldValue = function(oldSourceValue);
        value = function(newSourceValue);
        fireValueChanged(oldValue, (boolean)value);
      }

    @Override @Nonnull
    protected Boolean function (final String value)
      {
        return (value != null) && !"".equals(value.trim());
      }
  }