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

public class calculate extends Applet implements ActionListener,
                                                                                                   ItemListener,
                                                                                                    KeyListener {

  AudioClip gong[];
  AudioClip StartAudio,ZeroAudio,BackAudio,ModeChangeAudio,ACAudio;
  Label InputLabel = null;
  Label MemoryLabel = null;
  Checkbox TwoCheckbox;
  Checkbox EightCheckbox;
  Checkbox TenCheckbox;
  Checkbox TenSixCheckbox;
  String NumberButtonName[] = {" 0 "," 1 "," 2 "," 3 "," 4 ",
                               " 5 "," 6 "," 7 "," 8 "," 9 ",
                               " A "," B "," C "," D "," E ",
                               " F "};
  Button NumberButton[] = new Button[16];
  Button PointButton;
  int xy[][] = { {3,4},{3,3},{6,3},{9,3},{3,2},{6,2},{9,2},{3,1},
                 {6,1},{9,1},{0,5},{3,5},{6,5},{9,5},{12,5},{15,5}};

  public void init() {
    super.init();
    setLayout(new GridBagLayout());
    GridBagConstraints gbc = new GridBagConstraints();
    setFont(new Font("DialogInput",Font.PLAIN,20));
    addKeyListener(this);

    Panel TextPanel = new Panel();
    TextPanel.setBackground(Color.green);
    TextPanel.setLayout(new GridBagLayout());
    gbc.fill = GridBagConstraints.BOTH;
    gbc.gridx = 0; gbc.gridy = 0;
    gbc.ipadx = 200; gbc.ipady = 50;
    add(TextPanel,gbc);
    TextPanel.addKeyListener(this);

    InputLabel = new Label();
    InputLabel.setBackground(Color.white);
    InputLabel.setAlignment(Label.RIGHT);
    gbc.fill = GridBagConstraints.BOTH;
    gbc.gridx = 20; gbc.gridy = 10;
    gbc.ipadx = 300; gbc.ipady = 10;
    InputLabel.setText("0");
    TextPanel.add(InputLabel,gbc);
    InputLabel.addKeyListener(this);

    MemoryLabel = new Label("");
    MemoryLabel.setBackground(Color.white);
    MemoryLabel.setAlignment(Label.CENTER);
    gbc.fill = GridBagConstraints.BOTH;
    gbc.gridx = 10; gbc.gridy = 10;
    gbc.ipadx = 10; gbc.ipady = 10;
    TextPanel.add(MemoryLabel,gbc);
    MemoryLabel.addKeyListener(this);

    Panel WholePanel = new Panel();
    WholePanel.setBackground(Color.blue);
    WholePanel.setLayout(new GridBagLayout());
    gbc.gridx = 0; gbc.gridy = 1;
    gbc.ipadx = 200; gbc.ipady = 100;
    gbc.fill = GridBagConstraints.BOTH;
    add(WholePanel,gbc);
    WholePanel.addKeyListener(this);

    gbc.gridwidth = 3; gbc.gridheight = 1;
    gbc.ipadx = 7; gbc.ipady = 5;
    gbc.fill = GridBagConstraints.BOTH;

    CheckboxGroup cbg = new CheckboxGroup();

    gbc.gridx = 0; gbc.gridy = 0;
    TenSixCheckbox = new Checkbox("16", cbg, true);
    WholePanel.add(TenSixCheckbox,gbc);
    TenSixCheckbox.addItemListener(this);
    TenSixCheckbox.setForeground(Color.yellow);

    gbc.gridx = 3; gbc.gridy = 0;
    TenCheckbox = new Checkbox("10", cbg, true);
    WholePanel.add(TenCheckbox,gbc);
    TenCheckbox.addItemListener(this);
    TenCheckbox.setForeground(Color.yellow);

    gbc.gridx = 6; gbc.gridy = 0;
    TwoCheckbox = new Checkbox("2", cbg, false);
    WholePanel.add(TwoCheckbox,gbc);
    TwoCheckbox.addItemListener(this);
    TwoCheckbox.setForeground(Color.yellow);

    gbc.gridx = 9; gbc.gridy = 0;
    EightCheckbox = new Checkbox("8", cbg, false);
    WholePanel.add(EightCheckbox,gbc);
    EightCheckbox.addItemListener(this);
    EightCheckbox.setForeground(Color.yellow);

    Button BackButton = new Button(" <-");
    BackButton.addActionListener(this);
    gbc.gridx = 12; gbc.gridy = 0;
    WholePanel.add(BackButton,gbc);

    Button ClearAllButton = new Button(" AC");
    ClearAllButton.addActionListener(this);
    gbc.gridx = 15;
    WholePanel.add(ClearAllButton,gbc);

    Button MRButton = new Button(" MR");
    MRButton.addActionListener(this);
    gbc.gridx = 0; gbc.gridy = 1;
    WholePanel.add(MRButton,gbc);
    gong = new AudioClip[16];
    for(int i=0;i<16;i++) {
      NumberButton[i] = new Button(NumberButtonName[i]);
      NumberButton[i].addActionListener(this);
      NumberButton[i].setEnabled(i<10);
      gbc.gridx = xy[i][0]; gbc.gridy = xy[i][1];
      WholePanel.add(NumberButton[i],gbc);
      gong[i] = getAudioClip(getDocumentBase(),new Integer(i).toString()+".au");
    }

    Button DivideButton = new Button(" / ");
    DivideButton.addActionListener(this);
    gbc.gridx = 12; gbc.gridy = 1;
    WholePanel.add(DivideButton,gbc);

    Button ClearButton = new Button("_C_");
    ClearButton.addActionListener(this);
    gbc.gridx = 15; gbc.gridy = 1;
    WholePanel.add(ClearButton,gbc);

    Button MCButton = new Button(" MC");
    MCButton.addActionListener(this);
    gbc.gridx = 0; gbc.gridy = 2;
    WholePanel.add(MCButton,gbc);

    Button MutipleButton = new Button(" x ");
    MutipleButton.addActionListener(this);
    gbc.gridx = 12; gbc.gridy = 2;
    WholePanel.add(MutipleButton,gbc);

    Button SqrtButton = new Button("Sqr");
    SqrtButton.addActionListener(this);
    gbc.gridx = 15; gbc.gridy = 2;
    WholePanel.add(SqrtButton,gbc);

    Button MMinusButton = new Button(" M-");
    MMinusButton.addActionListener(this);
    gbc.gridx = 0; gbc.gridy = 3;
    WholePanel.add(MMinusButton,gbc);

    Button MinusButton = new Button(" - ");
    MinusButton.addActionListener(this);
    gbc.gridx = 12; gbc.gridy = 3;
    WholePanel.add(MinusButton,gbc);

    Button ReverseButton = new Button("1/x");
    ReverseButton.addActionListener(this);
    gbc.gridx = 15; gbc.gridy = 3;
    WholePanel.add(ReverseButton,gbc);

    Button MPlusButton = new Button(" M+");
    MPlusButton.addActionListener(this);
    gbc.gridx = 0; gbc.gridy = 4;
    WholePanel.add(MPlusButton,gbc);

    Button SignButton = new Button("+/-");
    SignButton.addActionListener(this);
    gbc.gridx = 6; gbc.gridy = 4;
    WholePanel.add(SignButton,gbc);

    PointButton = new Button(" . ");
    PointButton.addActionListener(this);
    gbc.gridx = 9; gbc.gridy = 4;
    WholePanel.add(PointButton,gbc);

    Button AddButton = new Button(" + ");
    AddButton.addActionListener(this);
    gbc.gridx = 12; gbc.gridy = 4;
    WholePanel.add(AddButton,gbc);

    Button EqualButton = new Button(" = ");
    EqualButton.addActionListener(this);
    gbc.gridx = 15; gbc.gridy = 4;
    WholePanel.add(EqualButton,gbc);

    for(int i=0;i<WholePanel.getComponentCount();i++) {
      WholePanel.getComponents()[i].addKeyListener(this);
    }
    StartAudio = getAudioClip(getDocumentBase(), "gong.au");
    StartAudio.play();
    ZeroAudio = getAudioClip(getDocumentBase(), "adapt-or-die.au");
    BackAudio = getAudioClip(getDocumentBase(), "ip.au");
    ModeChangeAudio = getAudioClip(getDocumentBase(), "drip.au");
    ACAudio = getAudioClip(getDocumentBase(), "return.au");
  }
  public void actionPerformed(ActionEvent e) {
    for(int i=1;i<16;i++) {
      if(e.getActionCommand().equals(NumberButtonName[i])) {
        gong[i].play();
        if(Mode==0) {
          if( !(currentValue.length()==1 &&
               currentValue.equals(NumberButtonName[0].trim())) &&
              !(currentValue.length()==2 &&
               currentValue.charAt(0)=='-'&&currentValue.charAt(1)=='0') )
          currentValue += NumberButtonName[i].trim();
        } else if(Mode==1||Mode==2||Mode==3||currentValue.trim().equals("0")) {
          Mode = 0;
          currentValue = NumberButtonName[i].trim();
        }
        break;
      }
    }

    if(e.getActionCommand().equals(NumberButtonName[0])) {
      gong[0].play();
      if(Mode==0) {
        if(!(currentValue.length()==1 &&
            currentValue.equals(NumberButtonName[0].trim())) &&
            !(currentValue.length()==2 && currentValue.charAt(0)=='-'
             && currentValue.charAt(1)=='0') )
          currentValue += NumberButtonName[0].trim();
      } else if(Mode==1||Mode==2||Mode==3||currentValue.trim().equals("0")) {
        currentValue = "0";
        Mode = 0;
      }
    } else if(e.getActionCommand().equals(" . ")) {
      if( (Mode==0||currentValue.equals("")||currentValue.equals("0")) && Base==10) {
        if(currentValue.indexOf(".")==-1) {
          currentValue += ".";
          Mode = 0;
        }
      } else if(Mode==2||Mode==3) {
        currentValue = ".";
        Mode = 0;
      }
    } else if(e.getActionCommand().equals("_C_")) {
      currentValue = "";
    } else if(e.getActionCommand().equals(" / ")) {
      if(Mode==0||Mode==2) {
        allValue = MyCount(allValue,currentValue,Sign,Base);
        Sign = 4; Mode = 3;
        currentValue = allValue;
      } else if(Mode==3)
        Sign = 4;
    } else if(e.getActionCommand().equals(" x ")) {
      if(Mode==0||Mode==2) {
        allValue = MyCount(allValue,currentValue,Sign,Base);
        Sign = 3; Mode = 3;
        currentValue = allValue;
      } else if(Mode==3)
        Sign = 3;
    } else if(e.getActionCommand().equals(" - ")) {
      if(Mode==0||Mode==2) {
        allValue = MyCount(allValue,currentValue,Sign,Base);
        Sign = 2; Mode = 3;
        currentValue = allValue;
      } else if(Mode==3)
        Sign = 2;
    } else if(e.getActionCommand().equals(" + ")) {
      if(Mode==0||Mode==2) {
        allValue = MyCount(allValue,currentValue,Sign,Base);
        Sign = 1; Mode = 3;
        currentValue = allValue;
      } else if(Mode==3)
        Sign = 1;
    } else if(e.getActionCommand().equals(" M+")) {
      MemoryNumber += Double.valueOf(currentValue).doubleValue();
    } else if(e.getActionCommand().equals(" M-")) {
      MemoryNumber -= Double.valueOf(currentValue).doubleValue();
    } else if(e.getActionCommand().equals(" MC")) {
      MemoryNumber = 0;
    } else if(e.getActionCommand().equals(" MR")) {
        currentValue = Double.toString(MemoryNumber);
        Mode = 2;
    } else if(e.getActionCommand().equals("+/-")) {
      if(currentValue.length()!=0) {
        if(currentValue.charAt(0)=='-')
          currentValue = currentValue.substring(1);
        else
          currentValue = "-" + currentValue;
      }
    } else if(e.getActionCommand().equals(" AC")) {
      ACAudio.play();
      allValue = "";
      currentValue = "";
      Sign = 0;
      Mode = 1;
    } else if(e.getActionCommand().equals("1/x")) {
      temp = Double.valueOf(currentValue).doubleValue();
      if(temp!=0)
        temp = 1 / temp;
      currentValue = Double.toString(temp);
      Mode = 2;
    } else if(e.getActionCommand().equals("Sqr")) {
      temp = Double.valueOf(currentValue).doubleValue();
      temp = Math.sqrt(temp);
      currentValue = Double.toString(temp);
      Mode = 2;
    } else if(e.getActionCommand().equals(" <-")) {
      BackAudio.play();
      if(currentValue.length()>0) {
        currentValue = currentValue.substring(0,currentValue.length()-1);
      if(currentValue.equals("0")||
         currentValue.equals("-0")||
         currentValue.equals(""))
          Mode = 2;
      }
    } else if(e.getActionCommand().equals(" = ")) {
      if(Sign!=0) {
        allValue = MyCount(allValue,currentValue,Sign,Base);
        currentValue = allValue;
        Sign = 0;
        Mode = 2;
      } else {
        ZeroAudio.play();
      }
    }

    if(Math.abs(MemoryNumber)<0.000000000001)
      MemoryLabel.setText("");
    else
      MemoryLabel.setText(" M ");

    if(Base!=10) {
      int use = currentValue.indexOf((int)'.');
      if(use==-1) use = currentValue.length();
      String test = currentValue.substring(0,use);
      if(Base==10)
        currentValue = Integer.toString(Compute(test,Base));
      else if(Base==8)
        currentValue = Integer.toOctalString(Compute(test,Base));
      else if(Base==16)
        currentValue = Integer.toHexString(Compute(test,Base)).toUpperCase();
      else if(Base==2)
        currentValue = Integer.toBinaryString(Compute(test,Base));
    }
    InputLabel.setText(currentValue);
    repaint();
  }

  public void keyTyped(KeyEvent e) {
    /* InputLabel.setText(new Character(e.getKeyChar()).toString()); */
    for(int i=0;i<Base;i++)
      if(e.getKeyChar()==NumberButtonName[i].charAt(1)
       ||e.getKeyChar()==NumberButtonName[i].toLowerCase().charAt(1)) {
        ActionEvent Fake = new ActionEvent(e.getSource(),
                                                                           e.getID(),
                                           NumberButtonName[i]);
        actionPerformed(Fake);
      }
    if(e.getKeyChar()=='+') {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," + ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='-') {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," - ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='*') {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," x ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='x') {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," x ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='/') {
       actionPerformed(new ActionEvent(e.getSource(),e.getID()," / "));
    } else if(e.getKeyChar()==13) {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," = ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='=') {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," = ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()==KeyEvent.VK_BACK_SPACE) {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," <-");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='.') {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," . ");
       actionPerformed(Fake);
    } else if(e.getKeyChar()==27) {
       ActionEvent Fake = new ActionEvent(e.getSource(),e.getID()," AC");
       actionPerformed(Fake);
    } else if(e.getKeyChar()=='!') {
       TenSixCheckbox.setState(true);
       HelperForStateChange(16);
    } else if(e.getKeyChar()=='@') {
       TenCheckbox.setState(true);
       HelperForStateChange(10);
    } else if(e.getKeyChar()=='#') {
       TwoCheckbox.setState(true);
       HelperForStateChange(2);
    } else if(e.getKeyChar()=='$') {
       EightCheckbox.setState(true);
       HelperForStateChange(8);
    }
  }
  public void keyPressed(KeyEvent e) {
  }
  public void keyReleased(KeyEvent e) {
  }

  private int Compute(String Source,int Base) {
    int answer = 0 , num;
    for(int i=0;i<Source.length();i++) {
      if(Source.charAt(i)<='F'&&Source.charAt(i)>='A')
        num = 10 + Source.charAt(i) - 'A';
      else
        num = Source.charAt(i) - '0';
      answer += num *
                (int)Math.pow((double)Base,(double)(Source.length()-i-1));
    }
    return answer;
  }

  private void HelperForStateChange(int temp) {
    ModeChangeAudio.play();
    String test = null;
    int use = 0;
    for(int i=0;i<16;i++)
      NumberButton[i].setEnabled(i<temp);
    if(temp!=10)
      PointButton.setEnabled(false);
    else
      PointButton.setEnabled(true);
    use = currentValue.indexOf((int)'.');
    if(use==-1) use = currentValue.length();
    test = currentValue.substring(0,use);
    if(temp==10&&Base!=10)
      currentValue = Integer.toString(Compute(test,Base));
    else if(temp==8)
      currentValue = Integer.toOctalString(Compute(test,Base));
    else if(temp==16)
      currentValue = Integer.toHexString(Compute(test,Base)).toUpperCase();
    else if(temp==2)
      currentValue = Integer.toBinaryString(Compute(test,Base));
    Base = temp;
    InputLabel.setText(currentValue);
  }
  public void itemStateChanged(ItemEvent e) {
    int temp = Integer.valueOf(e.getItem().toString()).intValue();
    HelperForStateChange(temp);
  }

  private String MyCount(String all,String current,int Type,int Base) {
    if(Type==0) return current;
    String answer = null;
    if(Base==10) {
      double temp1 = Double.valueOf(all).doubleValue(),
             temp2 = Double.valueOf(current).doubleValue();
      switch(Type) {
        case 1:
                  answer = Double.toString(temp1 + temp2);
              break;
        case 2:
          answer = Double.toString(temp1 - temp2);
              break;
        case 3:
          answer = Double.toString(temp1 * temp2);
                  break;
        case 4:
          answer = Double.toString(temp1 / temp2);
          break;

      }
    } else {
      int temp1 = Compute(all,Base);
      int temp2 = Compute(current,Base);
      switch(Type) {
        case 1: if(Base==2)
                  answer = Integer.toBinaryString
                      (new Integer(temp1+temp2).intValue());
                            else if(Base==8)
                  answer = Integer.toOctalString
                                          (new Integer(temp1+temp2).intValue());
                else if(Base==16)
                  answer = Integer.toHexString
                      (new Integer(temp1+temp2).intValue()).toUpperCase();
                            break;
        case 2: if(Base==2)
                  answer = Integer.toBinaryString
                      (new Integer(temp1-temp2).intValue());
                else if(Base==8)
                  answer = Integer.toOctalString
                      (new Integer(temp1-temp2).intValue());
                else if(Base==16)
                  answer = Integer.toHexString
                      (new Integer(temp1-temp2).intValue()).toUpperCase();

                            break;
        case 3: if(Base==2)
                  answer = Integer.toBinaryString
                      (new Integer(temp1*temp2).intValue());
                else if(Base==8)
                  answer = Integer.toOctalString
                      (new Integer(temp1*temp2).intValue());
                else if(Base==16)
                  answer = Integer.toHexString
                      (new Integer(temp1*temp2).intValue()).toUpperCase();
                break;
        case 4: if(Base==2)
                  answer = Integer.toBinaryString
                      (new Integer(temp1/temp2).intValue());
                else if(Base==8)
                  answer = Integer.toOctalString
                      (new Integer(temp1/temp2).intValue());
                else if(Base==16)
                  answer = Integer.toHexString
                      (new Integer(temp1/temp2).intValue()).toUpperCase();
                    break;
      }
    }
    return answer;
  }

  private int Base = 10;
  private String allValue = "";
  private String currentValue = "0";
  private int Sign = 0;  /* 0 empty  1 +  2 -  3 *  4 /     */
  private int Mode = 1;  /* 0 normal  1 right after Sign */
  private double temp = 0.0;
  private double MemoryNumber = 0.0;
}