package extensions.awt;
import java.awt.*;
import java.util.*;

/**
 * Delegate List action event.
 *
 * @see java.awt.List
 * @see extensions.awt.ActionProtocol
 * @version 1.0.2
 * @author John Webster Small
 */
public class ListAction
  extends List
  implements ActionProtocol
{
  private ActionProtocol ap;
  private Hashtable items;

  /** Construct a ListAction (i.e. a List) with
    * the action to be performed when this List is
    * clicked. The action is performed automatically
    * only if this ListAction appears within an
    * FrameExtended or DialogExtended window.
    * @param ap action to be performed, i.e. run()
    * @see extensions.awt.FrameExtended
    * @see extensions.awt.DialogExtended
    * @see extensions.awt.ActionProtocol
    */
  public ListAction(ActionProtocol ap)
  {
    super();
    this.ap = ap;
  }

  /** Construct a ListAction, e.g. a list. */
  public ListAction()
    { this(null); }

  /** Construct a ListAction (i.e. a List) with
    * the action to be performed when this List is
    * clicked. The action is performed automatically
    * only if this ListAction appears within an
    * FrameExtended or DialogExtended window.
    * @param rows number of items to show
    * @param multipleSelections if true multiple selections are allowed
    * @param ap action to be performed, i.e. run()
    * @see extensions.awt.FrameExtended
    * @see extensions.awt.DialogExtended
    * @see extensions.awt.ActionProtocol
    */
  public ListAction
    (int rows, boolean multipleSelections, ActionProtocol ap)
  {
    super(rows,multipleSelections);
    this.ap = ap;
  }

  /** Construct a ListAction, e.g. a list.
    * @param rows number of items to show
    * @param multipleSelections if true multiple selections are allowed
    */
  public ListAction(int rows, boolean multipleSelections)
    { this(rows,multipleSelections,null); }

  /** Forward the list clicked action event on to
    * the action for further processing by the application
    * model rather than the GUI. This method is called
    * automatically by FrameExtended and DialogExtended.
    * @param forward the component forwarding action event
    * @param evt the event that caused the action
    * @param what the action
    * @see extensions.awt.ActionProtocol
    * @see extensions.awt.FrameExtended#handleEvent
    * @see extensions.awt.DialogExtended#handleEvent
    */
  public final void action(Component forward, Event evt, Object what)
  {
    if (ap != null)
      ap.action(forward,evt,what);
  }

  /** Reset list from dictionary of items.
    * @param items dictionary of items, keys are strings to be displayed by list
    */
  public void setItems(Hashtable items)
  {
    this.items = items;
    Enumeration itemNames = items.keys();
    clear();
    while (itemNames.hasMoreElements())
      addItem((String)itemNames.nextElement());
  }

  /** Returns a dictionary of selected items. */
  public Hashtable getSelections()
  {
    Hashtable selected = new Hashtable();
    if (items != null)  {
      String[] keys = getSelectedItems();
      String key;
      for (int i = 0; i < keys.length; i++)  {
        key = keys[i];
        selected.put(key,items.get(key));
      }
    }
    return selected;
  }

  /** @return true if any selections outstanding. */
  public boolean anySelected()
  {
    int[] idxs = getSelectedIndexes();
    if (getSelectedIndex() >= 0
      || idxs != null || idxs.length > 0)
      return true;
    return false;
  }
}