text: /*
   *
   *  Copyright (C) 2000 Silicon Graphics, Inc.  All Rights Reserved. 
   *
   *  This library is free software; you can redistribute it and/or
   *  modify it under the terms of the GNU Lesser General Public
   *  License as published by the Free Software Foundation; either
   *  version 2.1 of the License, or (at your option) any later version.
   *
   *  This library 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
   *  Lesser General Public License for more details.
   *
   *  Further, this software is distributed without any warranty that it is
   *  free of the rightful claim of any third person regarding infringement
   *  or the like.  Any license provided herein, whether implied or
   *  otherwise, applies only to this software file.  Patent licenses, if
   *  any, provided herein do not apply to combinations of this program with
   *  other software, or any other product whatsoever.
   * 
   *  You should have received a copy of the GNU Lesser General Public
   *  License along with this library; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   *  Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
   *  Mountain View, CA  94043, or:
   * 
   *  http://www.sgi.com 
   * 
   *  For further information regarding this notice, see: 
   * 
   *  http://oss.sgi.com/projects/GenInfo/NoticeExplan/
   *
   */
  
  /*--------------------------------------------------------------
   *  This is an example from the Inventor Mentor,
   *  chapter 12, example 2.
   *
   *  Using getTriggerNode/getTriggerField methods of the data
   *  sensor.
   *------------------------------------------------------------*/
  
  #include <Inventor/SoDB.h>
  #include <Inventor/nodes/SoCube.h>
  #include <Inventor/nodes/SoSeparator.h>
  #include <Inventor/nodes/SoSphere.h>
  #include <Inventor/sensors/SoNodeSensor.h>
  
  // Sensor callback function:
  static void
  rootChangedCB(void *, SoSensor *s)
  {
     // We know the sensor is really a data sensor:
     SoDataSensor *mySensor = (SoDataSensor *)s;
      
     SoNode *changedNode = mySensor->getTriggerNode();
     SoField *changedField = mySensor->getTriggerField();
      
     printf("The node named '%s' changed\n",
              changedNode->getName().getString());
  
     if (changedField != NULL) {
        SbName fieldName;
        changedNode->getFieldName(changedField, fieldName);
        printf(" (field %s)\n", fieldName.getString());
     } else {
        printf(" (no fields changed)\n");
     }
  }
  
  int
  main(int , char **)
  {
     SoDB::init();
  
     SoSeparator *root = new SoSeparator;
     root->ref();
     root->setName("Root");
  
     SoCube *myCube = new SoCube;
     root->addChild(myCube);
     myCube->setName("MyCube");
  
     SoSphere *mySphere = new SoSphere;
     root->addChild(mySphere);
     mySphere->setName("MySphere");
  
     SoNodeSensor *mySensor = new SoNodeSensor;
  
     mySensor->setPriority(0);
     mySensor->setFunction(rootChangedCB);
     mySensor->attach(root);
  
     // Now, make a few changes to the scene graph; the sensor's
     // callback function will be called immediately after each
     // change.
     myCube->width = 1.0;
     myCube->height = 2.0;
     mySphere->radius = 3.0;
     root->removeChild(mySphere);
  }
  