/*
    * Copyright (c) 2005, The JUNG Authors
    * All rights reserved.
    * 
    * This software is open-source under the BSD license; see either "license.txt"
    * or https://github.com/jrtom/jung/blob/master/LICENSE for a description.
    * 
    *
    * Created on Mar 28, 2005
   */
  package edu.uci.ics.jung.visualization.picking;
  
  import java.awt.event.ItemEvent;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Maintains the state of what has been 'picked' in the graph.
   * The <code>Sets</code> are constructed so that their iterators
   * will traverse them in the order in which they are picked.
   * 
   * @author Tom Nelson 
   * @author Joshua O'Madadhain
   * 
   */
  public class MultiPickedState<T> extends AbstractPickedState<T> implements PickedState<T> {
      /**
       * the 'picked' vertices
       */
      protected Set<T> picked = new LinkedHashSet<T>();
      
      public boolean pick(T v, boolean state) {
          boolean prior_state = this.picked.contains(v);
          if (state) {
              picked.add(v);
              if(prior_state == false) {
                  fireItemStateChanged(new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED,
                          v, ItemEvent.SELECTED));
              }
  
          } else {
              picked.remove(v);
              if(prior_state == true) {
                  fireItemStateChanged(new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED,
                      v, ItemEvent.DESELECTED));
              }
  
          }
          return prior_state;
      }
  
      public void clear() {
          Collection<T> unpicks = new ArrayList<T>(picked);
          for(T v : unpicks) {
              pick(v, false);
          }
          picked.clear();
  
      }
  
      public Set<T> getPicked() {
          return Collections.unmodifiableSet(picked);
      }
      
      public boolean isPicked(T e) {
          return picked.contains(e);
      }
  
      /**
       * for the ItemSelectable interface contract
       */
      @SuppressWarnings("unchecked")
      public T[] getSelectedObjects() {
          List<T> list = new ArrayList<T>(picked);
          return (T[])list.toArray();
      }
      
  }