/*---------------------------------------------------------------------------
File:                           AnimClass.java
Package:                        JAWAA Beta Version 0.1
Author:                         Will Pierson (wcp@acpub.duke.edu)
                                
Description of Contents:        Contains applet routines to run animation.
                                
--------------------------------------------------------------------------*/

/* 
 * Susan H. Rodger, Will Pierson
 * Computer Science Department
 * Duke University
 * December 1996
 *
 * Copyright (c) 1996
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the author.  The name of the author may not be used to
 * endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */


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

//main class that "runs" animation
public class AnimClass extends Applet implements Runnable{
    
    boolean stop = false, time_to_die = false;
    String animLoc, animName;	    
    Thread animThread;
    Image offscreen;     
    Animation anim;
    AnimPanel ap;
    public AnimCanvas ac;
    Interpreter i;    
    Dimension r;
    int step, delay;  
    ThreadGroup myGroup;
    
    public AnimClass(){
    }

    public void init(){
	
	animLoc = getParameter("animLoc");	
	animName = getParameter("animName");	
	r = size();

	offscreen = createImage(r.width, r.height);
	anim = new Animation(r,offscreen, this);
	
    	i = new Interpreter(anim, animLoc, animName);
	
	delay = 400;
    	
 	//set up graphical look
	setLayout(new BorderLayout());
	ac = new AnimCanvas(anim, r, offscreen);
	ap = new AnimPanel(this);
	add("Center", ac);
	add("South", ap);
	myGroup = Thread.currentThread().getThreadGroup();
    }
    
    //runs in separate thread, mainly because of Graphic restrictions
    public synchronized void run(){
      //	System.out.println("Running...");	

	i.readLine();
	ac.repaint(10); 

	while(!time_to_die){		// loop until "stop" clicked
	    if (step == 0) stop = true;   // stop if steps done
			    
	    while (stop == true){      //don't keep stepping when applet 
		try{                   //minimized
		    wait();
		} catch (InterruptedException e) { }
	    }

	    if (i.readLine() == false){
	     //		System.out.println("Animation Done...");
		return;
	    }
    
	    ac.repaint(10);
	    try{
		animThread.sleep(delay);
	    }catch(InterruptedException e){
	    }
	    try{
		wait(100);
	    } catch (InterruptedException e) { }

	    step--;
	}
    }
    
    // redraw elements of animation
    public void paint(Graphics g){
//	System.out.println("Repainting...");
	ac.repaint();
    }
    
    // pause animation
    public void stop(){
      //	System.out.println("Stopping...");
	stop = true;
	step = 0;
    }

    //start animation moving when "start" clicked    
    public void start(){	
      //	System.out.println("Starting Animation...");	
	step = -1;
	if (animThread == null){
	    time_to_die = false;
	    stop = true;
	    animThread = new Thread(myGroup, this);
	    animThread.setPriority(1);
	    animThread.start();
	}
    }
    //wake up animation from paused state
    public synchronized void restartAnim(){	
	step = -1;
	//	System.out.println("Restarting...");
	stop = false;
	notify();
    }

    //animate one step 
    public synchronized void stepAnim(){	
	step = 1;

	stop = false;
	notify();
    }

    //remove animation
    public void killAnim(){
	if (animThread != null){
	    time_to_die = true;
	    animThread.stop();
//	    animThread.destroy();
	    animThread = null;
	}

	anim = new Animation(r, offscreen, this);
	i = new Interpreter(anim, animLoc, animName);	

	ac.setNewAnim(anim);
	ac.clear = true;
	ac.repaint(10);
	ap.reset();	

	start();
    }
}

//provides drawing area for animation
class AnimCanvas extends Canvas{
    Animation anim;
    Dimension r;
    Image offscreen;
    public boolean clear = false;            //if true clear canvas
                                             //before redrawing 

    public AnimCanvas(Animation a, Dimension d, Image os){

        offscreen = os;
	r = d;
	resize(r); 
	anim = a;
    }    

    public void setNewAnim(Animation a){
	anim = a;
    }
   
    public void paint(Graphics g){           //all animation graphics come

//	System.out.println("REPAINT");	
	if (clear == true){		     //through this procedure
	    clear = false;
	    g.clearRect(0,0,r.width, r.height);  
	} 
    	anim.redraw();	
	g.drawImage(offscreen,0,0, this);
//    	System.out.println("END REPAINT");	
    }

    public void update(Graphics g){        //don't allow other update to 
	paint(g);			   //clear canvas
    }
}


// presents three buttons to user
class AnimPanel extends Panel{
    AnimClass parent;
    Button pause;
    Button stepButton;
    Scrollbar speedBar;

    static  final String START = "Start";
    static  final String STOP = "Stop";
    static  final String PAUSE = "  Pause  ";
    static  final String RESTART = "Unpause";
    static  final String STEP = "Step";   


    public AnimPanel(AnimClass p){
	parent = p;	

	speedBar = new Scrollbar(Scrollbar.HORIZONTAL, 400, 20, 0, 800);
	pause = new Button(PAUSE);
	stepButton = new Button(STEP);

	setLayout(new BorderLayout());

	add("South", speedBar);
    
	Panel btns = new Panel();
	btns.add(new Button(START));
	btns.add(new Button(STOP));
	btns.add(pause);
	btns.add(stepButton);
	
	add("North", btns);
    }    

    public boolean handleEvent(Event event) {
        if (event.target == speedBar) { 
                parent.delay = 815 - speedBar.getValue();
                return true;
        } else {
                return super.handleEvent(event);
        }
    }    


    //determine what to do when button pushed
    public boolean action(Event ev, Object arg){
	String label = (String)arg;

	if (label.equals(START)){
	    parent.restartAnim();
	    stepButton.hide();
	}
	else if (label.equals(STOP)){
	    parent.killAnim();
	}
	else if (label.equals(PAUSE)){
	    parent.stop();
	    pause.setLabel(RESTART);
	    stepButton.show();
	}
	else if (label.equals(RESTART)){
	    parent.restartAnim();
	    pause.setLabel(PAUSE);
	    stepButton.hide();
	}
	else if (label.equals(STEP)){
	    parent.stepAnim();
	}
	return true;
    }
    
    //return pause button to "pause" state
    public void reset(){
	pause.setLabel(PAUSE);
    }

}