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

public class Logistic extends Applet {
    double a=4;
    double x0=0.618;
    
    Chronicle chronicle=new Chronicle();
    Plot plot=new Plot();
    Tree tree=new Tree();
    
    CardLayout layout=new CardLayout();
    Panel main=new Panel(layout);
    {
        main.add(chronicle,chronicle.toString());
        main.add(plot,plot.toString());
        main.add(tree,tree.toString());
    }

    Choice choice=new Choice();
    {
        choice.add(chronicle.toString());
        choice.add(plot.toString());
        choice.add(tree.toString());
        choice.addItemListener(new ItemListener() {
            public void itemStateChanged(ItemEvent e) {
                layout.show(main,choice.getSelectedItem());
            }
        });
    }
    Panel head=new Panel(new FlowLayout());
    {
        head.add(choice);
    }
    
    public void init() {
        setLayout(new BorderLayout());
        add(head,BorderLayout.NORTH);
        add(main,BorderLayout.CENTER);
    }
    
    double f(double x) {
        return f(a,x);
    }
    
    static double f(double a,double x) {
        return a*x*(1-x);
    }
    
    void setX0(double x0) {
        if (x0<0) this.x0=0;
        else if (x0>1) this.x0=1;
        else this.x0=x0;
    }
    
    void setA(double a) {
        if (a<0) this.a=0;
        else if (a>4) this.a=4;
        else this.a=a;
    }
    
    abstract class Canvas2 extends Canvas 
    implements MouseListener,MouseMotionListener,KeyListener {
        int width,height;
        Image image;
        Thread daemon;
        public Canvas2() {
            setBackground(Color.white);
            addMouseListener(this);
            addMouseMotionListener(this);
            addKeyListener(this);
        }
        public void update(Graphics g) {
            paint(g);
        }
        public void paint(Graphics g) {
            if (image==null) {
                width=getSize().width;
                height=getSize().height;
                image=createImage(width,height);
            }
            Graphics og=image.getGraphics();
            og.clearRect(0,0,width,height);
            paint2(og);
            og.dispose();
            g.drawImage(image,0,0,this);
        }
        public void paint2(Graphics g) {}
        void drawString(Graphics g,String string,int x,int y) {
            FontMetrics metrics=g.getFontMetrics();
            int width=g.getFontMetrics().stringWidth(string);
            int height=g.getFont().getSize();
            if (y-height<0) y+=height;
            if (x+width>this.width) x-=width;
            g.clearRect(x,y-height,width,height);
            g.drawString(string,x,y);
        }
        int plotX(double x) {
            return (int)((width-1)*x);
        }
        int plotY(double x) {
            return (int)((height-1)*(1-x));
        }
        public void mouseEntered(MouseEvent e) {}
        public void mouseExited(MouseEvent e) {}
        public void mousePressed(MouseEvent e) {}
        public void mouseReleased(MouseEvent e) {}
        public void mouseClicked(MouseEvent e) {}
        public void mouseMoved(MouseEvent e) {}
        public void mouseDragged(MouseEvent e) {}
        public void keyPressed(KeyEvent e) {}
        public void keyReleased(KeyEvent e) {}
        public void keyTyped(KeyEvent e) {}
    }
    
    class Chronicle extends Canvas2 {
        boolean dragging;
        public void paint2(Graphics g) {
            double x=x0;
            for (int t=0;t<width;t+=8) {
                double x_next=f(x);
                g.drawLine(t,plotY(x),t+8,plotY(x_next));
                x=x_next;
            }
            g.setColor(Color.red);
            drawString(g,"X(0)="+(float)x0,width,plotY(x0));
            g.drawLine(0,plotY(x0),width,plotY(x0));
        }
        public void mousePressed(MouseEvent e) {
            dragging=Math.abs((1-x0)*height-e.getY())<8;
        }
        public void mouseDragged(MouseEvent e) {
            if (dragging) {
                setX0(1-(double)e.getY()/height);
                repaint();
            }
        }
        public String toString() {
            return "時系列";
        }
    }
    
    class Plot extends Canvas2 {
        char dragging;
        public void paint2(Graphics g) {
            g.setColor(Color.lightGray);
            double x=x0;
            for (int i=0;i<(dragging==0?1000:10);i++) {
                double x_next=f(x);
                g.drawLine(plotX(x),plotY(x_next),plotX(x_next),plotY(x_next));
                g.drawLine(plotX(x_next),plotY(x_next),plotX(x_next),plotY(f(x_next)));
                x=x_next;
            }
            g.setColor(Color.green.darker());
            drawString(g,(float)(a/4)+" (a="+(float)a+")",0,plotY(a/4));
            g.drawLine(0,plotY(a/4),width,plotY(a/4));
            g.setColor(Color.black);
            for (int i=0;i<=width;i+=4) 
                g.drawLine(i,plotY(f((double)i/width)),i+4,plotY(f((double)(i+4)/width)));
            g.drawLine(0,height,width,0);
            g.setColor(Color.red);
            if (dragging==0) for (int i=0;i<32;i++) {
                double x_next=f(x);
                g.drawLine(plotX(x),plotY(x_next),plotX(x_next),plotY(x_next));
                g.drawLine(plotX(x_next),plotY(x_next),plotX(x_next),plotY(f(x_next)));
                x=x_next;
            }
            g.setColor(Color.gray);
            drawString(g," X(0)="+(float)x0,plotX(x0),height);
            g.drawLine(plotX(x0),plotY(0),plotX(x0),plotY(f(x0)));
        }
        public void mousePressed(MouseEvent e) {
            if (Math.abs((1-a/4)*height-e.getY())<8)
                dragging='a';
            else if (Math.abs(x0*width-e.getX())<8)
                dragging='x';
            else
                dragging=0;
        }
        public void mouseDragged(MouseEvent e) {
            if (dragging=='a') {
                setA(4-4.0*e.getY()/height);
                repaint();
            } else if (dragging=='x') {
                setX0((double)e.getX()/width);
                repaint();
            }
        }
        public void mouseReleased(MouseEvent e) {
            if (dragging!=0) {
                dragging=0;
                repaint();
            }
        }
        public String toString() {
            return "プロット";
        }
    }
    
    class Tree extends Canvas2 implements Runnable {
        int[] pix;
        MemoryImageSource mit;
        Image image;
        boolean dragging;
        public void paint2(Graphics g) {
            if (image==null) {
                pix=new int[width*height];
                mit=new MemoryImageSource(width,height,pix,0,width);
                mit.setAnimated(true);
                image=createImage(mit);
                new Thread(this).start();
            }
            g.drawImage(image,0,0,this);
            g.setColor(Color.green.darker());
            drawString(g," a="+(float)a,plotX(a/4),0);
            g.drawLine(plotX(a/4),0,plotX(a/4),height);
        }
        public void run() {
            double[] x=new double[height];
            for (int i=0;i<width;i++) {
                double a=4.0*i/width;
                for (int j=0;j<height;j++)
                    x[j]=(j+Math.PI/100)/height;
                for (int t=0;t<100;t++)
                    for (int j=0;j<height;j++)
                        x[j]=f(a,x[j]);
                for (int j=0;j<height;j++)
                    pix[i+j*width]=0xffffffff;
                for (int j=0;j<height;j++)
                    pix[i+width*plotY(x[j])]=0xff000000;
                if (i%16==0) {
                    mit.newPixels();
                    repaint();
                }
            }
            mit.newPixels();
            repaint();
        }
        public void mousePressed(MouseEvent e) {
            dragging=Math.abs(a/4*width-e.getX())<8;
        }
        public void mouseDragged(MouseEvent e) {
            if (dragging) {
                setA(4.0*e.getX()/width);
                repaint();
            }
        }
        public String toString() {
            return "分岐図";
        }
    }
}