gtkcheckboxgrouppeer.java

gcc的JAVA模块的源代码

/* GtkCheckboxGroupPeer.java - Wrap a CheckboxGroup
   Copyright (C) 2002 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package gnu.java.awt.peer.gtk;

import java.awt.CheckboxGroup;
import java.util.WeakHashMap;

// Note that there is no peer interface for a CheckboxGroup.  We
// introduce our own in order to make it easier to keep a piece of
// native state for each one.
public class GtkCheckboxGroupPeer extends GtkGenericPeer
{
  // This maps from a CheckboxGroup to the native peer.
  private static WeakHashMap map = new WeakHashMap ();

  // Find the native peer corresponding to a CheckboxGroup.
  public static synchronized GtkCheckboxGroupPeer
      getCheckboxGroupPeer (CheckboxGroup group)
  {
    if (group == null)
      return null;
    GtkCheckboxGroupPeer nat = (GtkCheckboxGroupPeer) map.get (group);
    if (nat == null)
      {
	nat = new GtkCheckboxGroupPeer ();
	map.put (group, nat);
      }
    return nat;
  }

  private GtkCheckboxGroupPeer ()
  {
    // We don't need any special state here.  Note that we can't store
    // a reference to the java-side CheckboxGroup.  That would mean
    // they could never be collected.
    super (null);
  }

  // Dispose of our native resources.
  public native void dispose ();

  // Remove a given checkbox from this group.
  public native void remove (GtkCheckboxPeer box);

  // When collected, clean up the native state.
  protected void finalize ()
  {
    dispose ();
  }
}