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.dnd;
  
  import com.google.common.base.Optional;
  import com.google.gwt.dom.client.Element;
  
  /**
   * Interface defining all methods used by drag and drop on a draggable element.<p>
   *
   * @since 8.0.0
   */
  public interface I_CmsDraggable {
  
      /**
       * Gets an optional pair of integers which are to be used as an "offset delta" for the drag and drop process.<p>
       *
       * @return an optional array containing exactly 2 entries [x,y]
       */
      Optional<int[]> getCursorOffsetDelta();
  
      /**
       * Creates the drag helper element and attaches it into the DOM.<p>
       *
       * @param target the drop target
       *
       * @return the drag helper element
       */
      Element getDragHelper(I_CmsDropTarget target);
  
      /**
       * Returns the draggable element.<p>
       *
       * @return the element
       */
      Element getElement();
  
      /**
       * Returns the draggable id.<p>
       *
       * @return the id
       */
      String getId();
  
      /**
       * Returns the parent drop target or <code>null</code> if there is none.<p>
       *
       * @return the parent drop target
       */
      I_CmsDropTarget getParentTarget();
  
      /**
       * Creates the drag placeholder element.<p>
       *
       * @param target the drop target
       *
       * @return the drag placeholder element
       */
      Element getPlaceholder(I_CmsDropTarget target);
  
      /**
       * Executed on drag cancel.<p>
       */
      void onDragCancel();
  
      /**
       * Executed on drop.<p>
       *
       * @param target the drop target
       */
      void onDrop(I_CmsDropTarget target);
  
      /**
       * Executed on drag start.<p>
       *
       * @param target the current drop target
       */
      void onStartDrag(I_CmsDropTarget target);
  }
  