applet1.java

一个自顶向下与自底向上的分析演示

// Decompiled by Jad v1.5.7g. Copyright 2000 Pavel Kouznetsov.
// Jad home page: http://www.geocities.com/SiliconValley/Bridge/8617/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi 
// Source File Name:   Applet1.java

import java.applet.Applet;
import java.awt.Adjustable;
import java.awt.Button;
import java.awt.Canvas;
import java.awt.Checkbox;
import java.awt.CheckboxGroup;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Label;
import java.awt.Panel;
import java.awt.ScrollPane;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.EventObject;

public class Applet1 extends Applet
    implements ActionListener
{

    public ScrollPane lsp;
    public ScrollPane rsp;
    public Button begin;
    public Button next;
    public Button reset;
    public TextField tf1;
    public Adjustable rha;
    public Adjustable rva;
    public Adjustable lha;
    public Adjustable lva;
    public Label la1;
    public Panel pa;
    public int wsize;
    public int hsize;
    public Font f;
    lcanvas4_1 ca1;
    rcanvas4_1 ca2;
    int height;
    int width;
    int sel;
    int lpheight;
    int lpwidth;
    int pheight;
    int pwidth;
    FontMetrics fm;
    int wid;
    int heig;
    int token;
    int tokenp;
    boolean nowldev;
    CheckboxGroup cbg;
    Checkbox ldev;
    Checkbox rdev;
    int bufl[][] = {
        {
            6, 1, 2, 3, 5, 4, 0, 1, 3, 5, 
            3, 5
        }, {
            -1, 5, 3, 5, 3, 1, 5, 3, 0, 4, 
            2, 1
        }
    };
    TextField textField1;
    Button my_description;
    Panel panel1;
    CheckboxGroup Group1;
    Checkbox radioButton3;
    Label label1;
    java.awt.List list1;
    Label label2;
    Label label3;
    final int TNFA = 0;
    final int TDFA = 1;
    final int TMINDFA = 2;
    int FAtype;
    Canvas canvas1;

    public void onclickdesc()
    {
        ca2.state = 1;
        ca2.repaint();
    }

    void drawtoken(Graphics g, int num, int k1, int y)
    {
        int k2 = k1 + width / 2;
        String s2;
        String s3;
        String s1 = s2 = s3 = null;
        switch(num)
        {
        case 0: // '\0'
            s1 = "E";
            s2 = "+";
            s3 = "T";
            break;

        case 2: // '\002'
            s1 = "T";
            s2 = "*";
            s3 = "F";
            break;

        case 4: // '\004'
            s1 = "(";
            s2 = "E";
            s3 = ")";
            break;

        case 1: // '\001'
            s1 = "T";
            break;

        case 3: // '\003'
            s1 = "F";
            break;

        case 5: // '\005'
            s1 = "id";
            break;
        }
        if(num % 2 == 0)
        {
            mydrawnode(g, k2, y, k2 - wid, (y + heig) - height, s1);
            mydrawnode(g, k2, y, k2, (y + heig) - height, s2);
            mydrawnode(g, k2, y, k2 + wid, (y + heig) - height, s3);
        } else
        {
            mydrawnode(g, k2, y, k2, (y + heig) - height, s1);
        }
    }

    void drawconclude(Graphics g)
    {
        int x = 2 * width;
        int y = 7 * height;
        if(nowldev)
            switch(token)
            {
            case 11: // '\013'
                g.drawString("==>id*(id+id)", x, y + 11 * height);
                // fall through

            case 10: // '\n'
                g.drawString("==>id*(id+F)", x, y + 10 * height);
                // fall through

            case 9: // '\t'
                g.drawString("==>id*(id+T)", x, y + 9 * height);
                // fall through

            case 8: // '\b'
                g.drawString("==>id*(F+T)", x, y + 8 * height);
                // fall through

            case 7: // '\007'
                g.drawString("==>id*(T+T)", x, y + 7 * height);
                // fall through

            case 6: // '\006'
                g.drawString("==>id*(E+T)", x, y + 6 * height);
                // fall through

            case 5: // '\005'
                g.drawString("==>id*(E)", x, y + 5 * height);
                // fall through

            case 4: // '\004'
                g.drawString("==>id*F", x, y + 4 * height);
                // fall through

            case 3: // '\003'
                g.drawString("==>F*F", x, y + 3 * height);
                // fall through

            case 2: // '\002'
                g.drawString("==>T*F", x, y + 2 * height);
                // fall through

            case 1: // '\001'
                g.drawString("==>T", x, y + height);
                // fall through

            case 0: // '\0'
                g.drawString("E", x, y);
                break;
            }
        else
            switch(token)
            {
            case 11: // '\013'
                g.drawString("E", x, y);
                // fall through

            case 10: // '\n'
                g.drawString("==>T", x, y + height);
                // fall through

            case 9: // '\t'
                g.drawString("==>T*F", x, y + 2 * height);
                // fall through

            case 8: // '\b'
                g.drawString("==>T*(E)", x, y + 3 * height);
                // fall through

            case 7: // '\007'
                g.drawString("==>T*(E+T)", x, y + 4 * height);
                // fall through

            case 6: // '\006'
                g.drawString("==>T*(E+F)", x, y + 5 * height);
                // fall through

            case 5: // '\005'
                g.drawString("==>T*(E+id)", x, y + 6 * height);
                // fall through

            case 4: // '\004'
                g.drawString("==>T*(T+id)", x, y + 7 * height);
                // fall through

            case 3: // '\003'
                g.drawString("==>T*(F+id)", x, y + 8 * height);
                // fall through

            case 2: // '\002'
                g.drawString("==>T*(id+id)", x, y + 9 * height);
                // fall through

            case 1: // '\001'
                g.drawString("==>F*(id+id)", x, y + 10 * height);
                // fall through

            case 0: // '\0'
                g.drawString("==>id*(id+id)", x, y + 11 * height);
                break;
            }
    }

    void mydrawnode(Graphics g, int x0, int y0, int x1, int y1, String s)
    {
        g.drawLine(x0, y0 + height / 2, x1, y1);
        g.drawOval(((x1 - height) + width / 2) - 2, y1, (height * 3) / 2, (height * 3) / 2);
        Color oldcol = g.getColor();
        g.setColor(Color.green);
        g.fillArc(((x1 - height) + width / 2) - 1, y1 + 1, (height * 3) / 2 - 2, (height * 3) / 2 - 1, 0, 360);
        g.setColor(oldcol);
        g.drawString(s, x1 - width / 2, y1 + height);
    }

    public void repaint()
    {
        ca1.repaint();
        ca2.repaint();
    }

    public Applet1()
    {
        lsp = null;
        rsp = null;
        begin = null;
        next = null;
        reset = null;
        tf1 = null;
        la1 = null;
        pa = null;
        ca1 = null;
        ca2 = null;
        FAtype = 0;
    }

    public void onclicknext()
    {
        ca2.state = 0;
        deal();
        repaint();
    }

    public void lupdate()
    {
        Graphics gg = ca1.getGraphics();
        gg.setFont(f);
        fm = gg.getFontMetrics();
        height = fm.getHeight();
        width = fm.charWidth('E');
        wid = width * 8;
        heig = height * 5;
        Graphics tg = ca1.getGraphics();
        tg.setFont(f);
        tg.clearRect(0, 0, 300, 700);
        int posv = 2 * height;
        int posh = width * 2;
        tg.setColor(Color.black);
        tg.drawString("G[E]", posh - 5, posv);
        tg.drawString("E--> E+T|T", posh, posv += height);
        tg.drawString("T--> T*F|F", posh, posv += height);
        tg.drawString("F--> (E)|id", posh, posv += height);
        posv = 2 * height;
        tg.setColor(Color.red);
        switch(sel)
        {
        case 0: // '\0'
            tg.drawString("E--> E+T", posh, posv += height);
            break;

        case 1: // '\001'
            tg.drawString("E-->", posh, posv += height);
            tg.drawString("T", posh + fm.stringWidth("E--> E+T|"), posv);
            break;

        case 2: // '\002'
            tg.drawString("T--> T*F", posh, posv += 2 * height);
            break;

        case 3: // '\003'
            tg.drawString("T-->", posh, posv += 2 * height);
            tg.drawString("F", posh + fm.stringWidth("T--> T*F|"), posv);
            break;

        case 4: // '\004'
            tg.drawString("F--> (E)", posh, posv += 3 * height);
            break;

        case 5: // '\005'
            tg.drawString("F-->", posh, posv += 3 * height);
            tg.drawString("id", posh + fm.stringWidth("F--> (E)|"), posv);
            break;

        case 6: // '\006'
            tg.drawString("E", posh, posv += height);
            break;
        }
        tg.setColor(Color.black);
        drawconclude(tg);
    }

    public void actionPerformed(ActionEvent ae)
    {
        if(ae.getSource() == begin)
            onclickbegin();
        else
        if(ae.getSource() == next)
            onclicknext();
        else
        if(ae.getSource() == reset)
            onclickreset();
        else
        if(ae.getSource() == my_description)
            onclickdesc();
    }

    void drawtree(Graphics g)
    {
        int k1 = 2 * wid + width / 2;
        int y = width * 2;
        if(nowldev)
            switch(token)
            {
            case 11: // '\013'
                if(token == 11)
                    g.setColor(Color.red);
                drawtoken(g, 5, k1 + 2 * wid, y + 5 * heig);
                if(token == 11)
                    g.setColor(Color.black);
                // fall through

            case 10: // '\n'
                if(token == 10)
                    g.setColor(Color.red);
                drawtoken(g, 3, k1 + 2 * wid, y + 4 * heig);
                if(token == 10)
                    g.setColor(Color.black);
                // fall through

            case 9: // '\t'
                if(token == 9)
                    g.setColor(Color.red);
                drawtoken(g, 5, k1, y + 6 * heig);
                if(token == 9)