binarypageitem.java

手机播放交谈实时监控软件

// Copyright (c) 2005 Sony Ericsson Mobile Communications AB
//
// This software is provided "AS IS," without a warranty of any kind. 
// ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, 
// INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A 
// PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. 
//
// THIS SOFTWARE IS COMPLEMENTARY OF JAYWAY AB (www.jayway.se)

package bluegammon.gui.menu;

import javax.microedition.lcdui.Image;

/**
 * An abstract item that can be set to true or false. An image is
 * used to represent each state. 
 * The method <code>getBoolean</code> must be implemented
 * to get the state of the item. The method <code>setBoolean</code> is
 * called with the new state when user selects this item.    
 * @author Peter Andersson
 */
public abstract class BinaryPageItem extends PageItem
	implements ItemAction
{
  /** Image for true flag */
  protected Image m_imgTrue;
  /** Image for false flag */
  protected Image m_imgFalse;
  /** Action that will be called after this action has been executed */
  protected ItemAction m_dispatchAction;

  /**
   * Constructor for <code>BinaryPageItem</code>.
   * @param label		The label of the item or null.
   * @param imageTrue	Image for true value or null.
   * @param imageFalse	Image for false value or null.
   * @param subPage		The page that will be navigated to when activating this item,
   * 					or null of no such page.
   */
  public BinaryPageItem(char[] label, Image imageTrue, Image imageFalse,
      MenuPage subPage)
  {
    super(label, null, null, subPage);
    m_imgTrue = imageTrue;
    m_imgFalse = imageFalse;
    setAction(this);
    setLayout(LAYOUT_ALIGN_RIGHT);
  }
  
  /**
   * Constructor for <code>BinaryPageItem</code>.
   * @param label		The label of the item or null.
   * @param imageTrue	Image for true value or null.
   * @param imageFalse	Image for false value or null.
   * @param subPage		The page that will be navigated to when activating this item,
   * 					or null of no such page.
   * @param dispatchAction
   * 					The action that is called when activating this item,
   * 					or null if no action.
   * @param id			The id of this item.
   */
  public BinaryPageItem(char[] label, Image imageTrue, Image imageFalse,
      MenuPage subPage, ItemAction dispatchAction, int id)
  {
    super(label, null, null, subPage, id);
    m_imgTrue = imageTrue;
    m_imgFalse = imageFalse;
    m_dispatchAction = dispatchAction;
    setAction(this);
    setLayout(LAYOUT_ALIGN_RIGHT);
  }
  
  /**
   * Initializes this item with correct image.
   */
  public void addedToPage()
  {
    setImage(getBoolean() ? m_imgTrue: m_imgFalse);
  }

  /**
   * Toggles the boolean value by calling
   * <code>getBoolean</code> and <code>setBoolean</code>.
   * If a dispatch action is given in constructor, this is
   * called after switching flags.
   * 
   * @param page	The page this action is called from.
   * @param item	The item this action is called from.
   */
  public void itemAction(MenuPage page, PageItem item)
  {
    boolean b = !getBoolean();
    setBoolean(b);
    setImage(b ? m_imgTrue: m_imgFalse);
    if (m_dispatchAction != null)
    {
      m_dispatchAction.itemAction(page, item);
    }
  }
  
  /**
   * Implement this to return the state of the flag.
   * @return	The state of the flag.
   */
  public abstract boolean getBoolean();
  
  /**
   * Implement this to set the state of the flag.
   * @param value	The new boolean value of the flag.
   */
  public abstract void setBoolean(boolean value);
  
}