// GetNodeInfo.java:   Applet to control the Get Node Info demo
// inspired by the descent applet ../descent/*
// Daniel.Schneider@tecfa.unige.ch  2/98
// hmm actually this applet doesn't do anything of interest besides
// demoing how to to retrieve information from a VRML node.

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

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


public class GetNodeInfo extends Applet implements ActionListener {

    // The Browser
    Browser browser = null;
  
    // Various UI widgets
    Button getInfoButton;
    TextArea output = null;
  
    // Various stuff in the VRML scene we hang on to
    Node positionAvatar = null;
    EventOutSFVec3f positionCoords = null;
    EventOutSFRotation orientationCoords = null;

    // Variables to store current position and orientation
    float[] currentPosition;
    float[] currentOrientation;
  
    // "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
	browser = Browser.getBrowser(this);
    
	if (browser == null) {
	    die("init: NULL browser!");
	}
	System.out.println("Got the browser: " + browser);
    
	// Add the output pane and the button to the Java Panel
	output = new TextArea("Hello EAI apprentice ...\n", 5, 60);
	add(output);
	add (getInfoButton = new Button("Where Am I ?"));
	// register the button for event handling
	getInfoButton.addActionListener(this);

	// Show the real estate of the applet
	Color c = Color.white;
	setBackground(c);
    
	// Initialize some VRML stuff
	initScene();

	System.out.println("GetNodeInfo.init() done.");
    }
  
    /** Start the applet running */
    public void start(){
	System.out.println("GetNodeInfo Applet: start()...");
    }
  
    /** Stop the applet */
    public void stop(){
	System.out.println("GetNodeInfo Applet: stop()...");
    }
  
    /** This applet is about to be unloaded.  Do final cleanup. */
    public void destroy() {
	System.out.println("GetNodeInfo Applet: destroy()...");
    }	
  
    /** Handle a fatal error condition */
    public void die(String s) {
	System.out.println("GetNodeInfo Applet: FATAL ERROR!");
	System.out.println("--> " + s);
	System.out.println("GetNodeInfo Applet: Aborting...\n");
	aborted = true;   // Causes a warning in the action method
    }


    /** Get reference to stuff in the VRML scene */
    public void initScene() {
	System.out.println("initScene()...");
    
	// Get the ViewPoints
	try {
	    positionAvatar = browser.getNode("Spy");
	    System.out.println("ProxminitySensor Node " + positionAvatar + " found.");
	    positionCoords = (EventOutSFVec3f) positionAvatar.getEventOut("position_changed");
	    orientationCoords = (EventOutSFRotation) positionAvatar.getEventOut("orientation_changed");
	}
	catch(InvalidNodeException e){
	    System.out.println("InvalidNodeException: " + e);
	    die("initScene: \"Spy\" node not found!");
	    return;
	}
	catch (InvalidEventOutException ee) {
	    System.out.println("InvalidEventOutException: " + ee);
	    die("initScene: EventOut Field not found!");
	    return;
	}
    }

    /** Handle actions from AWT widgets */
    public void actionPerformed (ActionEvent event) {
	// System.out.println("K was here\n");
	if (aborted == true) {
	    output.append("Something is badly wrong, check the Java Console");
	    return;
	}
	Object clickedButton = event.getSource();
	if (clickedButton == getInfoButton) {
	    currentPosition = positionCoords.getValue();
	    String outString = "Current Position is at" +
		" x=" + currentPosition [0] +
		" y=" + currentPosition [1] +
		" z=" + currentPosition [2] + "\n";
	    // System.out.println(outString);
	    output.append(outString);
	    currentOrientation = orientationCoords.getValue();
	    output.append("Current Orientation is" +
			      " x=" + currentOrientation [0] +
			      " y=" + currentOrientation [1] +
			      " z=" + currentOrientation [2] +
			      " angle=" + currentOrientation [3] + "\n");
	}
    }
}