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.ui.client;
  
  import org.opencms.ui.components.extensions.CmsAutoGrowingTextArea;
  import org.opencms.ui.shared.components.CmsAutoGrowingTextAreaState;
  
  import com.google.gwt.core.client.Scheduler;
  import com.google.gwt.core.client.Scheduler.ScheduledCommand;
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.dom.client.TextAreaElement;
  import com.google.gwt.event.dom.client.KeyUpEvent;
  import com.google.gwt.event.dom.client.KeyUpHandler;
  import com.google.gwt.user.client.ui.Widget;
  import com.vaadin.client.ComponentConnector;
  import com.vaadin.client.ServerConnector;
  import com.vaadin.client.extensions.AbstractExtensionConnector;
  import com.vaadin.shared.ui.Connect;
  
  /**
   * This connector will manipulate the CSS classes of the extended widget depending on the scroll position.<p>
   */
  @Connect(CmsAutoGrowingTextArea.class)
  public class CmsAutoGrowingTextAreaConnector extends AbstractExtensionConnector {
  
      /** The serial version id. */
      private static final long serialVersionUID = -9079215265941920364L;
  
      /** The widget to enhance. */
      private Widget m_widget;
  
      /** The line height. */
      private int m_lineHeight;
  
      /** The padding height. */
      private int m_paddingHeight;
  
      /** The last value. */
      private String m_lastValue = "";
  
      /**
       * @see com.vaadin.client.ui.AbstractConnector#getState()
       */
      @Override
      public CmsAutoGrowingTextAreaState getState() {
  
          return (CmsAutoGrowingTextAreaState)super.getState();
      }
  
      /**
       * @see com.vaadin.client.extensions.AbstractExtensionConnector#extend(com.vaadin.client.ServerConnector)
       */
      @Override
      protected void extend(ServerConnector target) {
  
          // Get the extended widget
          m_widget = ((ComponentConnector)target).getWidget();
          m_widget.addDomHandler(new KeyUpHandler() {
  
              public void onKeyUp(KeyUpEvent event) {
  
                  handle();
  
              }
          }, KeyUpEvent.getType());
  
          Scheduler.get().scheduleDeferred(new ScheduledCommand() {
  
              public void execute() {
  
                  handle();
              }
          });
  
      }
  
      /**
       * Resize the text area.<p>
       */
      protected void handle() {
  
          Element e = m_widget.getElement();
          if (e instanceof TextAreaElement) {
              TextAreaElement elem = (TextAreaElement)e;
              int scrollHeight = elem.getScrollHeight();
              // allow text area to shrink
              if (m_lastValue.length() > elem.getValue().length()) {
                  elem.setRows(getState().getMinRows());
              }
              int currentRows = elem.getRows();
              if (m_lineHeight == 0) {
                  elem.setRows(2);
                  int heightTwo = elem.getClientHeight();
                  elem.setRows(1);
                  int heightOne = elem.getClientHeight();
                  m_lineHeight = heightTwo - heightOne;
                  m_paddingHeight = heightOne - m_lineHeight;
                  elem.setRows(currentRows);
              }
              if (m_lineHeight > 0) {
                  int totalHeight = scrollHeight - m_paddingHeight;
                  int requiredRows = ((scrollHeight - m_paddingHeight) / m_lineHeight);
                  if ((totalHeight % m_lineHeight) > 0) {
                      requiredRows++;
                  }
                  int minRows = getState().getMinRows();
                  int maxRows = getState().getMaxRows();
                  if ((requiredRows <= minRows) && (currentRows != minRows)) {
                      elem.setRows(minRows);
                  } else if ((requiredRows >= maxRows) && (currentRows != maxRows)) {
                      elem.setRows(maxRows);
                  } else if (requiredRows != currentRows) {
                      elem.setRows(requiredRows);
                  }
              }
          }
      }
  }
  