content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.gwt.client.ui.input;
  
  import com.google.common.base.Objects;
  import com.google.gwt.event.logical.shared.ValueChangeEvent;
  import com.google.gwt.event.logical.shared.ValueChangeHandler;
  import com.google.gwt.event.shared.EventBus;
  import com.google.gwt.event.shared.GwtEvent;
  import com.google.gwt.event.shared.HandlerRegistration;
  import com.google.gwt.event.shared.SimpleEventBus;
  
  /**
   * The default string model implementation.<p>
   *
   * @since 8.0.0
   */
  public class CmsDefaultStringModel implements I_CmsStringModel {
  
      /** The event bus for this class. */
      EventBus m_eventBus = new SimpleEventBus();
  
      /**
       * A flag which indicates that the model is currently being updated, which is used to prevent infinite recursion.<p>
       */
      private boolean m_active;
  
      /** The id. */
      private String m_id;
  
      /** The model value. */
      private String m_value;
  
      /**
       * Creates a new string model.<p>
       *
       * @param id the model id
       */
      public CmsDefaultStringModel(String id) {
  
          m_id = id;
          m_value = "";
      }
  
      /**
       * @see com.google.gwt.event.logical.shared.HasValueChangeHandlers#addValueChangeHandler(com.google.gwt.event.logical.shared.ValueChangeHandler)
       */
      public HandlerRegistration addValueChangeHandler(ValueChangeHandler<String> handler) {
  
          return m_eventBus.addHandler(ValueChangeEvent.getType(), handler);
      }
  
      /**
       * @see com.google.gwt.event.shared.HasHandlers#fireEvent(com.google.gwt.event.shared.GwtEvent)
       */
      public void fireEvent(GwtEvent<?> event) {
  
          m_eventBus.fireEvent(event);
      }
  
      /**
       * @see org.opencms.gwt.client.ui.input.I_CmsStringModel#getId()
       */
      public String getId() {
  
          return m_id;
      }
  
      /**
       * @see org.opencms.gwt.client.ui.input.I_CmsStringModel#getValue()
       */
      public String getValue() {
  
          return m_value;
      }
  
      /**
       * @see org.opencms.gwt.client.ui.input.I_CmsStringModel#setValue(java.lang.String, boolean)
       */
      public void setValue(String value, boolean notify) {
  
          if (!m_active) {
              m_active = true;
              try {
  
                  boolean changed = !Objects.equal(value, m_value);
                  m_value = value;
                  if (notify && changed) {
                      ValueChangeEvent.fire(this, value);
                  }
              } finally {
                  m_active = false;
              }
          }
  
      }
  
  }
  