package vgp.tutor.lsystem;

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

import jv.object.PsConfig;
import jv.object.PsViewerIf;
import jv.project.PvCameraIf;
import jv.project.PvDisplayIf;
import jv.viewer.PvViewer;

/**
 * Generate a tree with an L-system and display using turtle graphics.
 * Additionally, this subclass implements the interface PsUpdateIf
 * to catch events from a parameter slider.
 * 
 * @author		Konrad Polthier
 * @version		30.10.01, 2.00 revised (kp) L-System converted into a project.<br>
 *					17.02.00, 1.10 revised (kp) Slider added.<br>
 *					16.02.00, 1.00 created (kp)
 */
public class PaLSystem extends Applet implements Runnable {
	/** Frame to allow applet to run as application too. */
	protected		Frame			m_frame;
	/** 3D-viewer window for graphics output and which is embedded into the applet */
	protected	PvViewer			m_viewer;
	/** Message string drawn in applet while loading. Modify string with drawMessage(). */
	private		String			m_drawString	= "Initializing ...";

	/**
	 * Create thread that configures and initializes the viewer, loads system and user projects.
	 */
	public void init() {
		Thread thread = new Thread(this, "JavaView: inititialize applet");
		thread.setPriority(Thread.NORM_PRIORITY);
		thread.start();
	}
	/**
	 * Configure and initialize the viewer, load system and user projects.
	 * One of the user projects may be selected here.
	 */
	public void run() {
		drawMessage("Loading viewer ...");
		m_viewer = new PvViewer(this, m_frame);	// at first initalize the viewer

		drawMessage("Loading project ...");

		// Create and load a project
		// PjHeight prj = new PjHeight(PsConfig.getCodeBase()+scalar);
		PjLSystem prj = new PjLSystem();
		m_viewer.addProject(prj);
		m_viewer.selectProject(prj);

		// Get 3d display from viewer and add it to applet
		setLayout(new BorderLayout());
		PvDisplayIf disp = m_viewer.getDisplay();
		disp.selectCamera(PvCameraIf.CAMERA_ORTHO_XY);		// project onto xy-plane
		add((Component)disp, BorderLayout.CENTER);
		add(m_viewer.getPanel(PsViewerIf.PROJECT), BorderLayout.EAST);
		validate();

		// Choose initial panel in control window (must press F1 inside the applet)
		m_viewer.showPanel(PsViewerIf.MATERIAL);

		// Explicitly start the applet
		startFromThread();
	}
	/**
	 * Standalone application support. The main() method acts as the applet's
	 * entry point when it is run as a standalone application. It is ignored
	 * if the applet is run from within an HTML page.
	 */
	public static void main(String args[]) {
		PaLSystem va	= new PaLSystem();
		// Create toplevel window of application containing the applet
		Frame frame	= new jv.object.PsMainFrame(va, args);
		frame.pack();
		va.m_frame = frame;
		va.init();
		frame.setBounds(new Rectangle(220, 5, 800, 550));
		frame.setVisible(true);
	}

	/** Set message string to be drawn in apllet while loading. */
	private void drawMessage(String message) {
		m_drawString = message;
		repaint();
	}
	/** Print info while initializing applet and viewer. */
	public void paint(Graphics g) {
		g.setColor(Color.blue);
		g.drawString(PsConfig.getProgramAndVersion(), 20, 40);
		g.drawString(m_drawString, 20, 60);
	}
	/**
	 * Does clean-up when applet is destroyed by the browser.
	 * Here we just close and dispose all our control windows.
	 */
	public void destroy()	{ if (m_viewer != null) m_viewer.destroy(); }

	/** Stop viewer, e.g. stop animation if requested */
	public void stop()		{ if (m_viewer != null) m_viewer.stop(); }
	/**
	 * Start viewer, e.g. start animation if requested.
	 * Necessary, if initialization is done in a separate thread. In this case the original
	 * applet.start() has no effect.
	 */
	public void startFromThread()	{ if (m_viewer!=null) m_viewer.start(); }
}