jlist.java

gcc的组建

      return new AccessibleJListChild(JList.this, n);
    }
  }

  private static final long serialVersionUID = 4406629526391098046L;

  /** 
   * Constant value used in "layoutOrientation" property. This value means
   * that cells are laid out in a single vertical column. This is the default. 
   */
  public static final int VERTICAL = 0;

  /** 
   * Constant value used in "layoutOrientation" property. This value means
   * that cells are laid out in multiple columns "newspaper style", filling
   * vertically first, then horizontally. 
   */
  public static final int VERTICAL_WRAP = 1;
  
  /** 
   * Constant value used in "layoutOrientation" property. This value means
   * that cells are laid out in multiple columns "newspaper style",
   * filling horizontally first, then vertically. 
   */
  public static final int HORIZONTAL_WRAP = 2;

  /**
   * This property indicates whether "drag and drop" functions are enabled
   * on the list.
   */
  boolean dragEnabled;

  /** This property provides a strategy for rendering cells in the list. */
  ListCellRenderer cellRenderer;

  /**
   * This property indicates an fixed width to assign to all cells in the
   * list. If its value is <code>-1</code>, no width has been
   * assigned. This value can be set explicitly, or implicitly by setting
   * the {@link #prototypeCellValue} property.
   */
  int fixedCellWidth;
  
  /**
   * This property indicates an fixed height to assign to all cells in the
   * list. If its value is <code>-1</code>, no height has been
   * assigned. This value can be set explicitly, or implicitly by setting
   * the {@link #prototypeCellValue} property.
   */
  int fixedCellHeight;

  /** 
   * This property holds the current layout orientation of the list, which
   * is one of the integer constants {@link #VERTICAL}, {@link
   * #VERTICAL_WRAP}, or {@link #HORIZONTAL_WRAP}. 
   */
  int layoutOrientation;
  
  /** This property holds the data elements displayed by the list. */
  ListModel model;

  /**
   * <p>This property holds a reference to a "prototype" data value --
   * typically a String -- which is used to calculate the {@link
   * #fixedCellWidth} and {@link #fixedCellHeight} properties, using the
   * {@link #cellRenderer} property to acquire a component to render the
   * prototype.</p>
   *
   * <p>It is important that you <em>not</em> set this value to a
   * component. It has to be a <em>data value</em> such as the objects you
   * would find in the list's model. Setting it to a component will have
   * undefined (and undesirable) affects. </p>
   */
  Object prototypeCellValue;

  /** 
   * This property specifies a foreground color for the selected cells in
   * the list. When {@link ListCellRenderer#getListCellRendererComponent}
   * is called with a selected cell object, the component returned will
   * have its "foreground" set to this color.
   */
  Color selectionBackground;

  /** 
   * This property specifies a background color for the selected cells in
   * the list. When {@link ListCellRenderer#getListCellRendererComponent}
   * is called with a selected cell object, the component returned will
   * have its "background" property set to this color.
   */
  Color selectionForeground;

  /** 
   * This property holds a description of which data elements in the {@link
   * #model} property should be considered "selected", when displaying and
   * interacting with the list.
   */
  ListSelectionModel selectionModel;


  /**
   * This property indicates that the list's selection is currently
   * "adjusting" -- perhaps due to a user actively dragging the mouse over
   * multiple list elements -- and is therefore likely to change again in
   * the near future. A {@link ListSelectionListener} might choose to delay
   * updating its view of the list's selection until this property is
   * false, meaning that the adjustment has completed.
   */
  boolean valueIsAdjusting;

  /** 
   * This property indicates a <em>preference</em> for the number of rows
   * displayed in the list, and will scale the
   * {@link #getPreferredScrollableViewportSize} property accordingly. The actual
   * number of displayed rows, when the list is placed in a real {@link
   * JViewport} or other component, may be greater or less than this number.
   */
  int visibleRowCount;

  /**
   * Fire a {@link ListSelectionEvent} to all the registered ListSelectionListeners.
   */
  protected void fireSelectionValueChanged(int firstIndex, int lastIndex, boolean isAdjusting) 
  {
    ListSelectionEvent evt = new ListSelectionEvent(this, firstIndex, lastIndex, isAdjusting);
    ListSelectionListener listeners[] = getListSelectionListeners();
    for (int i = 0; i < listeners.length; ++i)
      {
        listeners[i].valueChanged(evt);
      }
  }

  /**
   * This private listener propagates {@link ListSelectionEvent} events
   * from the list's "selectionModel" property to the list's {@link
   * ListSelectionListener} listeners. It also listens to {@link
   * ListDataEvent} events from the list's {@link #model} property. If this
   * class receives either type of event, it triggers repainting of the
   * list.
   */
  private class ListListener 
    implements ListSelectionListener, ListDataListener
  {
    // ListDataListener events
    public void contentsChanged(ListDataEvent event)
    {
      JList.this.revalidate();
      JList.this.repaint();
    }
    public void intervalAdded(ListDataEvent event)
    {
      JList.this.revalidate();
      JList.this.repaint();
    }
    public void intervalRemoved(ListDataEvent event)
    {
      JList.this.revalidate();
      JList.this.repaint();
    }
    // ListSelectionListener events
    public void valueChanged(ListSelectionEvent event)
    {
      JList.this.fireSelectionValueChanged(event.getFirstIndex(),
                                           event.getLastIndex(),
                                           event.getValueIsAdjusting());
      JList.this.repaint();
    }
  }

  /** 
   * Shared ListListener instance, subscribed to both the current {@link
   * #model} and {@link #selectionModel} properties of the list.
   */
  ListListener listListener;


  /**
   * Creates a new JList object.
   */
  public JList()
  {
    init();
  }

  /**
   * Creates a new JList object.
   *
   * @param listData Initial data to populate the list with
   */
  public JList(Object[] listData)
  {
    init();
    setListData(listData);
  }

  /**
   * Creates a new JList object.
   *
   * @param listData Initial data to populate the list with
   */
  public JList(Vector listData)
  {
    init();
    setListData(listData);
  }

  /**
   * Creates a new JList object.
   *
   * @param listData Initial data to populate the list with
   */
  public JList(ListModel listData)
  {
    init();
    setModel(listData);
  }

  void init()
  {
    dragEnabled = false;
    fixedCellHeight = -1;
    fixedCellWidth = -1;
    layoutOrientation = VERTICAL;
    opaque = true;
    valueIsAdjusting = false;
    visibleRowCount = 8;

    cellRenderer = new DefaultListCellRenderer();
    listListener = new ListListener();

    setModel(new DefaultListModel());
    setSelectionModel(createSelectionModel());

    updateUI();
  }

  /**
   * Creates the default <code>ListSelectionModel</code>.
   *
   * @return the <code>ListSelectionModel</code>
   */
  protected ListSelectionModel createSelectionModel()
  {
    return new DefaultListSelectionModel();
  }
  
  /**
   * Gets the value of the {@link #fixedCellHeight} property. This property
   * may be <code>-1</code> to indicate that no cell height has been
   * set. This property is also set implicitly when the
   * {@link #prototypeCellValue} property is set.
   *
   * @return The current value of the property 
   * 
   * @see #fixedCellHeight
   * @see #setFixedCellHeight
   * @see #setPrototypeCellValue
   */
  public int getFixedCellHeight()
  {
    return fixedCellHeight;
  }

  /**
   * Sets the value of the {@link #fixedCellHeight} property. This property
   * may be <code>-1</code> to indicate that no cell height has been
   * set. This property is also set implicitly when the {@link
   * #prototypeCellValue} property is set, but setting it explicitly
   * overrides the height computed from {@link #prototypeCellValue}.
   *
   * @see #getFixedCellHeight
   * @see #getPrototypeCellValue
   */
  public void setFixedCellHeight(int h)
  {
    if (fixedCellHeight == h)
      return;

    int old = fixedCellHeight;
    fixedCellHeight = h;
    firePropertyChange("fixedCellWidth", old, h);
  }


  /**
   * Gets the value of the {@link #fixedCellWidth} property. This property
   * may be <code>-1</code> to indicate that no cell width has been
   * set. This property is also set implicitly when the {@link
   * #prototypeCellValue} property is set.
   *
   * @return The current value of the property 
   * 
   * @see #setFixedCellWidth
   * @see #setPrototypeCellValue
   */
  public int getFixedCellWidth()
  {
    return fixedCellWidth;
  }

  /**
   * Sets the value of the {@link #fixedCellWidth} property. This property
   * may be <code>-1</code> to indicate that no cell width has been
   * set. This property is also set implicitly when the {@link
   * #prototypeCellValue} property is set, but setting it explicitly
   * overrides the width computed from {@link #prototypeCellValue}.
   *
   * @see #getFixedCellHeight
   * @see #getPrototypeCellValue
   */
  public void setFixedCellWidth(int w)
  {
    if (fixedCellWidth == w)
      return;
    
    int old = fixedCellWidth;
    fixedCellWidth = w;
    firePropertyChange("fixedCellWidth", old, w);
  }

  /** 
   * Gets the value of the {@link #visibleRowCount} property. 
   *
   * @return the current value of the property.
   */

  public int getVisibleRowCount()
  {
    return visibleRowCount;
  }

  /**
   * Sets the value of the {@link #visibleRowCount} property. 
   *
   * @param vc The new property value
   */
  public void setVisibleRowCount(int vc)
  {
    visibleRowCount = vc;
    revalidate();
    repaint();
  }

  /**
   * Adds a {@link ListSelectionListener} to the listener list for this
   * list. The listener will be called back with a {@link
   * ListSelectionEvent} any time the list's {@link #selectionModel}
   * property changes. The source of such events will be the JList,
   * not the selection model.
   *
   * @param listener The new listener to add
   */
  public void addListSelectionListener(ListSelectionListener listener)
  {
    listenerList.add (ListSelectionListener.class, listener);
  }

  /**
   * Removes a {@link ListSelectionListener} from the listener list for
   * this list. The listener will no longer be called when the list's
   * {@link #selectionModel} changes.
   *
   * @param listener The listener to remove
   */
  public void removeListSelectionListener(ListSelectionListener listener)
  {
    listenerList.remove(ListSelectionListener.class, listener);
  }

  /**
   * Returns an array of all ListSelectionListeners subscribed to this
   * list. 
   *
   * @return The current subscribed listeners
   *
   * @since 1.4
   */
  public ListSelectionListener[] getListSelectionListeners()
  {
    return (ListSelectionListener[]) getListeners(ListSelectionListener.class);
  }

  public int getSelectionMode()
  {
    return selectionModel.getSelectionMode();
  }
  
  /**
   * Sets the list's "selectionMode" property, which simply mirrors the
   * same property on the list's {@link #selectionModel} property. This
   * property should be one of the integer constants
   * <code>SINGLE_SELECTION</code>, <code>SINGLE_INTERVAL_SELECTION</code>,
   * or <code>MULTIPLE_INTERVAL_SELECTION</code> from the {@link
   * ListSelectionModel} interface.
   *
   * @param a The new selection mode
   */
  public void setSelectionMode(int a)
  {
    selectionModel.setSelectionMode(a);
  }

  /**
   * Adds the interval <code>[a,a]</code> to the set of selections managed
   * by this list's {@link #selectionModel} property. Depending on the
   * selection mode, this may cause existing selections to become invalid,
   * or may simply expand the set of selections. 
   *
   * @param a A number in the half-open range <code>[0, x)</code> where
   * <code>x = getModel.getSize()</code>, indicating the index of an
   * element in the list to select.
   *
   * @see #setSelectionMode
   * @see #selectionModel
   */
  public void setSelectedIndex(int a)
  {
    selectionModel.setSelectionInterval(a, a);
  }

  /**
   * For each element <code>a[i]</code> of the provided array
   * <code>a</code>, calls {@link #setSelectedIndex} on <code>a[i]</code>.
   *
   * @see #setSelectionMode