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.util;
  
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.dom.client.Style;
  import com.google.gwt.dom.client.Style.Unit;
  import com.google.gwt.user.client.Command;
  
  /**
   * Changes the elements height until the target height is reached.<p>
   *
   * @since 8.0.0
   */
  public class CmsChangeHeightAnimation extends A_CmsAnimation {
  
      /** The element style. */
      private Style m_elementStyle;
  
      /** The height of the fully visible element. */
      private int m_height;
  
      /** The difference between the target height and the original height. */
      private int m_heightDiff;
  
      /** The height when the animation should stop. */
      private int m_targetHeight;
  
      /**
       * Constructor.<p>
       *
       * @param element the element to animate
       * @param targetHeight the height when the animation should stop
       * @param callback the callback executed after the animation is completed
       */
      public CmsChangeHeightAnimation(Element element, int targetHeight, Command callback) {
  
          super(callback);
  
          m_elementStyle = element.getStyle();
  
          m_height = CmsDomUtil.getCurrentStyleInt(element, CmsDomUtil.Style.height);
          m_targetHeight = targetHeight;
          m_heightDiff = m_targetHeight - m_height;
      }
  
      /**
       * Slides the given element into view executing the callback afterwards.<p>
       *
       * @param element the element to slide in
       * @param targetHeight the height when the animation should stop
       * @param callback the callback executed after the animation is completed
       * @param duration the animation duration
       *
       * @return the running animation object
       */
      public static CmsChangeHeightAnimation change(Element element, int targetHeight, Command callback, int duration) {
  
          CmsChangeHeightAnimation animation = new CmsChangeHeightAnimation(element, targetHeight, callback);
          animation.run(duration);
          return animation;
      }
  
      /**
       * @see com.google.gwt.animation.client.Animation#onComplete()
       */
      @Override
      protected void onComplete() {
  
          m_elementStyle.setHeight(m_targetHeight, Unit.PX);
          if (m_callback != null) {
              m_callback.execute();
          }
      }
  
      /**
       * @see com.google.gwt.animation.client.Animation#onUpdate(double)
       */
      @Override
      protected void onUpdate(double progress) {
  
          m_elementStyle.setHeight((m_heightDiff * progress * progress) + m_height, Unit.PX);
      }
  }
  