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

   1: /* GtkCheckboxPeer.java -- Implements CheckboxPeer with GTK
   2:    Copyright (C) 1998, 1999, 2002, 2003 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.Checkbox;
  42: import java.awt.CheckboxGroup;
  43: import java.awt.peer.CheckboxPeer;
  44: 
  45: public class GtkCheckboxPeer extends GtkComponentPeer
  46:   implements CheckboxPeer
  47: {
  48:   // Group from last time it was set.
  49:   public GtkCheckboxGroupPeer old_group;
  50:   // The current state of the GTK checkbox.
  51:   private boolean currentState;  
  52:   private boolean changing = false;
  53: 
  54:   public native void create (GtkCheckboxGroupPeer group);
  55:   public native void nativeSetCheckboxGroup (GtkCheckboxGroupPeer group);
  56:   public native void connectSignals ();
  57:   native void gtkWidgetModifyFont (String name, int style, int size);
  58:   native void gtkButtonSetLabel (String label);
  59:   native void gtkToggleButtonSetActive (boolean is_active);
  60: 
  61:   public GtkCheckboxPeer (Checkbox c)
  62:   {
  63:     super (c);
  64:   }
  65: 
  66:   // FIXME: we must be able to switch between a checkbutton and a
  67:   // radiobutton dynamically.
  68:   public void create ()
  69:   {
  70:     Checkbox checkbox = (Checkbox) awtComponent;
  71:     CheckboxGroup g = checkbox.getCheckboxGroup ();
  72:     old_group = GtkCheckboxGroupPeer.getCheckboxGroupPeer (g);
  73:     create (old_group);
  74:     gtkToggleButtonSetActive (checkbox.getState ());
  75:     gtkButtonSetLabel (checkbox.getLabel ());
  76:   }
  77: 
  78:   public void setState (boolean state)
  79:   {
  80:     // prevent item_toggled_cb -> postItemEvent ->
  81:     // awtComponent.setState -> this.setState ->
  82:     // gtkToggleButtonSetActive self-deadlock on the GDK lock.
  83:     if (changing && Thread.currentThread() == GtkToolkit.mainThread)
  84:       {
  85:         changing = false;
  86:         return;
  87:       }
  88: 
  89:     if (currentState != state)
  90:       gtkToggleButtonSetActive (state);
  91:   }
  92: 
  93:   public void setLabel (String label)
  94:   {
  95:     gtkButtonSetLabel (label);
  96:   }
  97: 
  98:   public void setCheckboxGroup (CheckboxGroup group)
  99:   {
 100:     GtkCheckboxGroupPeer gp
 101:       = GtkCheckboxGroupPeer.getCheckboxGroupPeer (group);
 102:     if (gp != old_group)
 103:       {
 104:     if (old_group != null)
 105:       old_group.remove (this);
 106:     nativeSetCheckboxGroup (gp);
 107:     old_group = gp;
 108:       }
 109:   }
 110: 
 111:   // Override the superclass postItemEvent so that the peer doesn't
 112:   // need information that we have.
 113:   // called back by native side: item_toggled_cb
 114:   public void postItemEvent (Object item, int stateChange)
 115:   {
 116:     Checkbox currentCheckBox = ((Checkbox)awtComponent);
 117:     // A firing of the event is only desired if the state has changed due to a 
 118:     // button press. The currentCheckBox's state must be different from the 
 119:     // one that the stateChange is changing to. 
 120:     // stateChange = 1 if it goes from false -> true
 121:     // stateChange = 2 if it goes from true -> false
 122:     if (( !currentCheckBox.getState() && stateChange == 1)
 123:         || (currentCheckBox.getState() && stateChange == 2))
 124:     {
 125:       super.postItemEvent (awtComponent, stateChange);
 126:       currentState = !currentCheckBox.getState();
 127:       changing = true;
 128:       currentCheckBox.setState(currentState);
 129:     }
 130:   }
 131: 
 132:   public void dispose ()
 133:   {
 134:     // Notify the group so that the native state can be cleaned up
 135:     // appropriately.
 136:     if (old_group != null)
 137:       old_group.remove (this);
 138:     super.dispose ();
 139:   }
 140: }