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

   1: /* GtkChoicePeer.java -- Implements ChoicePeer with GTK
   2:    Copyright (C) 1998, 1999, 2005  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.Choice;
  42: import java.awt.AWTEvent;
  43: import java.awt.event.ItemEvent;
  44: import java.awt.peer.ChoicePeer;
  45: 
  46: public class GtkChoicePeer extends GtkComponentPeer
  47:   implements ChoicePeer
  48: {
  49:   private int selected;
  50: 
  51:   public GtkChoicePeer (Choice c)
  52:   {
  53:     super (c);
  54: 
  55:     int count = c.getItemCount ();
  56:     if (count > 0)
  57:       {
  58:         for (int i = 0; i < count; i++)
  59:           add(c.getItem(i), i);
  60: 
  61:         selected = c.getSelectedIndex();
  62:         if (selected >= 0)
  63:           select( selected );
  64:       }
  65:     else
  66:       selected = -1;
  67:   }
  68: 
  69:   native void create ();
  70: 
  71:   native int nativeGetSelected ();
  72: 
  73:   native void connectSignals ();
  74: 
  75:   native void selectNative (int position);
  76: 
  77:   native void selectNativeUnlocked (int position);
  78: 
  79:   public native void add (String item, int index);
  80: 
  81:   native void nativeRemove(int index);
  82: 
  83:   native void nativeRemoveAll();
  84: 
  85:   public void select (int position)
  86:   {
  87:     if (Thread.currentThread() == GtkMainThread.mainThread)
  88:       selectNativeUnlocked (position);
  89:     else
  90:       selectNative (position);
  91:   }
  92: 
  93:   public void remove( int index )
  94:   {
  95:     // Ensure the triggering of an event when removing item zero if zero is the
  96:     // selected item, even though the selected index doesn't change.
  97:     if( index == 0 && selected == 0 )
  98:       selected = -1;
  99:     nativeRemove( index );
 100:   }
 101: 
 102:   public void removeAll()
 103:   {
 104:     selected = -1; // we do not want to trigger a select event here.
 105:     nativeRemoveAll();
 106:   }
 107: 
 108:   public void addItem (String item, int position)
 109:   {
 110:     add (item, position);
 111:   }
 112: 
 113:   /**
 114:    * Callback from the native side on an item-select event,
 115:    * which posts an event. The event is only posted if it represents an actual
 116:    * change. Selected is set to the peer's state initially, so that the
 117:    * first call to select(int) from the constructor will not trigger an event.
 118:    * (it should not)
 119:    */
 120:   protected void postChoiceItemEvent ( int index )
 121:   {
 122:     if( selected != index )
 123:       {
 124:         selected = index;
 125:         postItemEvent (((Choice) awtComponent).getItem( selected ),
 126:                        ItemEvent.SELECTED);
 127:       }
 128:   }
 129: 
 130:   /**
 131:    * Catches the event and calls Choice.select() if the component state
 132:    * needs updating.
 133:    */
 134:   public void handleEvent (AWTEvent event)
 135:   {
 136:     super.handleEvent (event);
 137:     if (event instanceof ItemEvent)
 138:       if (((ItemEvent)event).getItemSelectable() == awtComponent
 139:            && ((ItemEvent)event).getStateChange() == ItemEvent.SELECTED)
 140:         ((Choice)awtComponent).select( selected );
 141:   }
 142: }