Source for gnu.java.awt.peer.gtk.GtkCheckboxGroupPeer

   1: /* GtkCheckboxGroupPeer.java - Wrap a CheckboxGroup
   2:    Copyright (C) 2002 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.java.awt.peer.gtk;
  40: 
  41: import java.awt.CheckboxGroup;
  42: import java.util.WeakHashMap;
  43: 
  44: // Note that there is no peer interface for a CheckboxGroup.  We
  45: // introduce our own in order to make it easier to keep a piece of
  46: // native state for each one.
  47: public class GtkCheckboxGroupPeer extends GtkGenericPeer
  48: {
  49:   // This maps from a CheckboxGroup to the native peer.
  50:   private static WeakHashMap map = new WeakHashMap ();
  51: 
  52:   // Find the native peer corresponding to a CheckboxGroup.
  53:   public static synchronized GtkCheckboxGroupPeer
  54:       getCheckboxGroupPeer (CheckboxGroup group)
  55:   {
  56:     if (group == null)
  57:       return null;
  58:     GtkCheckboxGroupPeer nat = (GtkCheckboxGroupPeer) map.get (group);
  59:     if (nat == null)
  60:       {
  61:     nat = new GtkCheckboxGroupPeer ();
  62:     map.put (group, nat);
  63:       }
  64:     return nat;
  65:   }
  66: 
  67:   private GtkCheckboxGroupPeer ()
  68:   {
  69:     // We don't need any special state here.  Note that we can't store
  70:     // a reference to the java-side CheckboxGroup.  That would mean
  71:     // they could never be collected.
  72:     super (null);
  73:   }
  74: 
  75:   // Dispose of our native resources.
  76:   public native void dispose ();
  77: 
  78:   // Remove a given checkbox from this group.
  79:   public native void remove (GtkCheckboxPeer box);
  80: 
  81:   // When collected, clean up the native state.
  82:   protected void finalize ()
  83:   {
  84:     dispose ();
  85:   }
  86: }