/*******************************************************************************
 * Copyright (c) 2008 Innoopract Informationssysteme GmbH.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Innoopract Informationssysteme GmbH - initial API and implementation
 ******************************************************************************/
package org.eclipse.swt.events;

import org.eclipse.rwt.Adaptable;
import org.eclipse.swt.SWT;
import org.eclipse.swt.internal.widgets.EventUtil;
import org.eclipse.swt.widgets.*;

/**
 * Instances of this class are sent as a result of expand item being expanded
 * and collapsed.
 * <p>
 * <strong>IMPORTANT:</strong> All <code>public static</code> members of this
 * class are <em>not</em> part of the RWT public API. They are marked public
 * only so that they can be shared within the packages provided by RWT. They
 * should never be accessed from application code.
 * </p>
 *
 * @see ExpandListener
 * @since 1.2
 */
public class ExpandEvent extends SelectionEvent {

  private static final long serialVersionUID = 1L;

  public static final int EXPAND = SWT.Expand;
  public static final int COLLAPSE = SWT.Collapse;
  
  private static final Class LISTENER = ExpandListener.class;

  /**
   * Constructs a new instance of this class based on the information in the
   * given untyped event.
   *
   * @param event the untyped event containing the information
   */
  public ExpandEvent( final Event event ) {
    this( event.widget, event.item, event.type );
  }

  /**
   * Constructs a new instance of this class.
   * <p>
   * <strong>IMPORTANT:</strong> This method is <em>not</em> part of the RWT
   * public API. It is marked public only so that it can be shared within the
   * packages provided by RWT. It should never be accessed from application
   * code.
   * </p>
   */
  public ExpandEvent( final Widget widget, final Widget item, final int id ) {
    super( widget, item, id );
  }

  protected void dispatchToObserver( final Object listener ) {
    switch( getID() ) {
      case EXPAND:
        ( ( ExpandListener )listener ).itemExpanded( this );
      break;
      case COLLAPSE:
        ( ( ExpandListener )listener ).itemCollapsed( this );
      break;
      default:
        throw new IllegalStateException( "Invalid event handler type." );
    }
  }

  protected Class getListenerType() {
    return LISTENER;
  }

  protected boolean allowProcessing() {
    return EventUtil.isAccessible( widget );
  }

  public static boolean hasListener( final Adaptable adaptable ) {
    return hasListener( adaptable, LISTENER );
  }

  public static void addListener( final Adaptable adaptable,
                                  final ExpandListener listener )
  {
    addListener( adaptable, LISTENER, listener );
  }

  public static void removeListener( final Adaptable adaptable,
                                     final ExpandListener listener )
  {
    removeListener( adaptable, LISTENER, listener );
  }

  public static Object[] getListeners( final Adaptable adaptable ) {
    return getListener( adaptable, LISTENER );
  }

  public String toString() {
    String string = super.toString();
    return string.substring( 0, string.length() - 1 ) // remove trailing '}'
           + " item="
           + item
           + " doit="
           + doit
           + " x="
           + x
           + " y="
           + y
           + " width="
           + width
           + " height="
           + height
           + "}";
  }
}