// NavigateTour.java:   Applet that shows how to retrieve viewpoints
//
// Daniel.Schneider@tecfa.unige.ch   1/98
// Freeware if you give a line of credit :)
//
// Changes in relation to Navigate.java :
//   - We query the Viewpoints Group for its viewpoints
//   - We use arrays to store things (hey i am learning Java)
//   - We organize a short tour thru the scene

//   inspired by: http://www.tomco.net/~raf/faqs/TestExternal4.html
//                (TestExternal4 applet by Ross A. Finlayson 1997)

// Things have changed since the Late Nite Book !
//    See the initScene method
//    node.getExposedField("children") -> ....
//    MFNode -> EventOutMFNode

import java.awt.*;
import java.applet.*;

import vrml.external.field.*;
import vrml.external.Node;
import vrml.external.Browser;
import vrml.external.exception.*;


public class NavigateTour extends Applet {

  // The Browser
  Browser browser = null;
  
  // Various UI widgets
  Button startTourButton;
  Label tourStatus;

  // Various stuff in the VRML scene we hang on to

  // array for the various View Points found
  Node[] VPList ;
  // array for the handles to the set_bind EventIn Fields
  EventInSFBool[] set_VPList ;
  // array with the buttons generated
  Button[] VPButtons ;
  // The number of Viewpoints found in the scene
  int nVPs = 0;
  
  // "Aborted" state (used to disable some UI or code
  // if we've already had a fatal error)
  boolean aborted = false;
  
  /** Initialize the Applet */
  public void init() {
    
    // Connect to the browser

    for (int count = 0; count < 10; count++) {
      browser = Browser.getBrowser (this);
      if (browser != null) break;
      try {Thread.sleep (200);}
      catch (InterruptedException ignored) {}
      System.out.println ("browser was null, trying again");
    }
    if (browser == null) {
      throw new Error ("Failed to get the browser after 10 tries!");
    }
    System.out.println("Got the browser: " + browser);
    
    // Paint tour button
    add (startTourButton = new Button ("Start Tour")) ;
    add (tourStatus = new Label ("  (OFF)  ")) ;

    // Misc other UI setup
    Color c = Color.white;
    System.out.println("Setting bg color to: " + c);
    setBackground(c);
    
    System.out.println("Navigate.init() done.");

    // Initialize some VRML stuff and paint buttons
    initScene();
  }
  
  /** Start the applet running */
  public void start(){
    System.out.println("Navigate Applet: start()...");
  }
  
  /** Stop the applet */
  public void stop(){
    System.out.println("Navigate Applet: stop()...");
  }
  
  /**
    * This applet is about to be unloaded.  Do final cleanup.
    */
  public void destroy() {
    System.out.println("Navigate Applet: destroy()...");
  }	
  
  
  /** Handle a fatal error condition */
  public void die(String s) {
    System.out.println("Navigate Applet: FATAL ERROR!");
    System.out.println("-->; " + s);
    System.out.println("Navigate Applet: Aborting...\n");
    
    aborted = true;   // Causes update() to display a warning
  }

 
  /** Set up some stuff in the VRML scene */
  public void initScene() {
    System.out.println("initScene()...");
    
    int i;

    // Get the ViewPoints
    try {

      // Get the Group node called Viewpoints
      Node Viewpoints = browser.getNode("Viewpoints");

      // Extract the list of children
      VPList = ((EventOutMFNode) (Viewpoints.getEventOut("children_changed"))).getValue();

      // Initalize arrays for storing handles and Button strings
      nVPs = VPList.length;
      set_VPList = new EventInSFBool[nVPs];
      VPButtons = new Button[nVPs];

      for (i=0; i < nVPs ; i++) {

	// Get the handles for the Viewpoint set_bind Event fields

	System.out.println
	  ("initScene: node '" + VPList[i] + "')...");
	set_VPList[i] = (EventInSFBool)VPList[i].getEventIn("set_bind");
	System.out.println
	  ("initScene: got the EventIn: " + set_VPList[i]);

	// Insert push buttons into the Java applet

	String buttonLabel = "VP-" + i;
	add (VPButtons[i] = new Button(buttonLabel));
    	System.out.println
	  ("initScene: Generated Button + string: " + VPButtons[i]);
      }
    }
    catch(InvalidNodeException e){
      System.out.println("InvalidNodeException: " + e);
      die("initScene: VP node not found!");
      return;
    }
    // or should I move this into the inner loop ?
    catch(InvalidEventInException e) {
      die("bindToViewpoint: InvalidEventInException: " + e);
      return;
    }
  }


  /** Organise a tour thru the various viewpoints */
  public void doVPTour () {

    //hmm don't know if this is the right (easy) way to do it
    tourStatus.setText("Touring..");
    for (int i=0; i < nVPs ; i++) {
      set_VPList[i].setValue(true);
      // wait for 2000 ms
      try {Thread.sleep (2000);}
      catch (InterruptedException ignored) {}
    }
    set_VPList[0].setValue(true);
    tourStatus.setText("  (OFF)  ");
  }


  /** Handle actions from AWT widgets */
  public boolean action(Event event, Object what) {
    
    if (event.target instanceof Button) {
      Button b = (Button) event.target;

      if (b == startTourButton) {
	doVPTour();
      }
      else {
	for (int i=0; i < nVPs ; i++) {
	  if (b == VPButtons[i]) {
	    // get the corresponding VP
	    EventInSFBool set_bindVP = set_VPList[i];
	    set_bindVP.setValue(true);
	    System.out.println("action(): set_bound " + set_bindVP);
	  }
	}
      } // end else
    } // end button handling

    return true;
  }

}