import java.applet.*;
import java.awt.*;
import java.net.*;
import java.util.*;
import java.lang.*;

/**
 * A Java applet that simulates the chorded keyboard of
 * Merlin 4.7
 */

public class ChordSim extends Applet {
  protected Image background;
  protected Image bUp, bDown;
  protected boolean bA, bE, bI, bO;

  protected Image chordTips[] = new Image[10];

  protected String codeTab[][] = {
    {"c","m","n","r","s","u","v","w","x","z"},
    {"g","j","p","q","y",",",".",";","[","]"},
    {"b","d","f","h","k","l","t","shift","space","symbol"},
    {"1","2","3","4","5","6","7","8","9","0"},
    {"'","`","/","\\","=","-"," "," "," "," "},
    {"C","M","N","R","S","U","V","W","X","Z"},
    {"G","J","P","Q","Y","<",">",":","{","}"},
    {"B","D","F","H","K","L","T","shift lock","space","shift symbol"},
    {"!","@","#","$","%","^","&","*","(",")"},
    {"\"","~","?","|","+","_"," "," "," "," "}
  };

  protected int chords[] = {0, // none
                            0, // o 
                            0, // i 
                            3, // io
                            0, // e
                            5, // eo
                            2, // ei
                            8, // eio
                            0, // a
                            6, // ao
                            4, // ai 
                            9, // aio
                            1, // ae
                            10, // aeo
                            7, // aei
                            0}; // aeio

  protected int currentCol;
  protected boolean sample;
  protected boolean slock;

  protected String scratch[] = {
     "Welcome to the Chord Simulator!",
     "  by Jecel Assumpcao Junior",
     "",
     "testing:  ",
     "",
     "",
     "",
     "",
     "",
     "",
     "",
     "",
     ""
  };
  protected int currentRow;
  protected String prefix;

  protected boolean redrawAll, redrawKeys, redrawStatus, redrawLine;
  protected boolean loaded;

  public void init() {

    background = this.getImage(this.getDocumentBase(),"merlin4a.gif");
    bUp = this.getImage(this.getDocumentBase(),"buttonUp.gif");
    bDown = this.getImage(this.getDocumentBase(),"buttonDown.gif");
    bA = false;
    bE = false;
    bI = false;
    bO = false;
    currentCol = -1;
    sample = true;
    slock = false;
    currentRow = 3;
    prefix = "";

    redrawAll = true;
    redrawKeys = false;
    redrawStatus = false;
    redrawLine = false;
    loaded = false;
    
    for (int i = 0; i < 10; ++i) {
        chordTips[i] = this.getImage(this.getDocumentBase(),
                                "chord"+Integer.toString(i+1)+".jpeg");
    };
  }

  protected int keys() {
    int k = 0;

    if (bA) k = k + 8;
    if (bE) k = k + 4;
    if (bI) k = k + 2;
    if (bO) k = k + 1;
    return k;
  }

  public void paint(Graphics g) {
    redrawAll =  true;
    update(g);
  };

  public void update(Graphics g) {
    if (!loaded) redrawAll = true;
    if (redrawAll)
      g.drawImage(background, 0, 0, this);
    g.setColor(Color.white);
    if (redrawLine)
      g.fillRect(188, 130+20*currentRow, 235, 20);
    if (redrawStatus)
      g.fillRect(170, 405, 250, 50);
    g.setColor(Color.black);
    if (redrawKeys || redrawAll) {
      g.drawImage(bA?bDown:bUp, 109, 104, this);
      g.drawImage(bE?bDown:bUp, 109, 209, this);
      g.drawImage(bI?bDown:bUp, 109, 319, this);
      g.drawImage(bO?bDown:bUp, 109, 425, this);
    };
    if (redrawLine || redrawAll) {
      for (int i = 0; i < 13; ++i ) {
        if (i == currentRow || redrawAll) g.drawString(scratch[i],
                                                    188, 150+20*i);
        if (i == currentRow) {
          g.setColor(Color.red);
          g.drawString(prefix, 188+g.getFontMetrics().stringWidth(scratch[i]),
                               150+20*i);
          g.setColor(Color.black);
        }
      };
    };
    if (redrawStatus || redrawAll) {
      if ( currentCol >= 0 ) {
        for (int i = 0; i < 10; ++i) {
            g.drawImage(chordTips[i], 180+22*i, 435, this);
            if (codeTab[currentCol][i].length() < 2)
                 g.drawString(codeTab[currentCol][i], 188+22*i, 450);
        }
        if (slock) g.setColor(Color.red);
        switch (currentCol) {
           case 0:
           case 1:
           case 2:
           case 3:
                   g.drawString("           ", 188, 425);
                   break;
           case 4:
                   g.drawString("     symbol", 188, 425);
                   break;
           case 5:
           case 6:
           case 7:
           case 8:
                   g.drawString("shift      ", 188, 425);
                   break;
           case 9:
                   g.drawString("shift symbol", 188, 425);
                   break;
        };
        g.setColor(Color.black);
      }
    };
    redrawAll = false;
    redrawKeys = false;
    redrawStatus = false;
    redrawLine = false;
  }

  public boolean keyDown(Event e, int code) {
  switch (code) {
    case 52 :
    case 55 : bA = true;
              break;
    case 51 :
    case 56 : bE = true;
              break;
    case 50 :
    case 57 : bI = true;
              break;
    case 49 :
    case 48 : bO = true;
              break;
  }
  loaded = true; // just a guess
  redrawKeys = true;
  this.update(this.getGraphics());

  return true;
  }

  protected void addChar (String c) {
    if (this.getGraphics().getFontMetrics().stringWidth(scratch[currentRow]+c)
                > 220) {
      if (currentRow < 12) {
        ++currentRow;
        scratch[currentRow] = scratch[currentRow]+c;
        redrawAll = true;
      }
    } else {
      scratch[currentRow] = scratch[currentRow]+c;
      redrawLine = true;
    }
  };

  protected void doChord (int k) {
    String s;
    int prevCol;

    if (currentCol >= 0) {
      prevCol = currentCol;
      s = codeTab[currentCol][chords[k]-1];
      if (s.length() < 2) addChar(s);
      if (s == "space") addChar(" ");
      if (s == "symbol") currentCol = 4;
      if (currentCol > 4) currentCol -= 5;
      if (s == "shift") currentCol += 5;
      if (s == "shift lock") {
        slock = !slock;
        redrawStatus = true;
      };
      if (slock) currentCol += 5;
      if (s == "shift symbol") currentCol = 9;
      if (prevCol != currentCol) redrawStatus = true;
    };
    prefix = "";
  };

  public boolean keyUp(Event e, int code) {
    int k;

    if (sample) {
      switch(keys()) {
        case 8: addChar(prefix);
                redrawLine = true;
                redrawStatus = true;
                if (slock || (currentCol > 4 && prefix == "")) {
                  currentCol = 5;
                  prefix = "A";
                } else {
                  currentCol = 0;
                  prefix = "a";
                };
                break;
        case 4: addChar(prefix);
                redrawLine = true;
                redrawStatus = true;
                if (slock || (currentCol > 4 && prefix == "")) {
                  currentCol = 6;
                  prefix = "E";
                } else {
                  currentCol = 1;
                  prefix = "e";
                };
                break;
        case 2: addChar(prefix);
                redrawLine = true;
                redrawStatus = true;
                if (slock || (currentCol > 4 && prefix == "")) {
                  currentCol = 7;
                  prefix = "I";
                } else {
                  currentCol = 2;
                  prefix = "i";
                };
                break;
        case 1: addChar(prefix);
                redrawLine = true;
                redrawStatus = true;
                if (slock || (currentCol > 4 && prefix == "")) {
                  currentCol = 8;
                  prefix = "O";
                } else {
                  currentCol = 3;
                  prefix = "o";
                };
                break;
        case 15: currentCol = -1;
                 redrawAll = true;
                 if (prefix != "")
                   prefix = "";
                 else if (scratch[currentRow].length()>0)
                   scratch[currentRow] = scratch[currentRow].substring(0,
                                          scratch[currentRow].length()-1);
                 else if (currentRow > 0) {
                   if(scratch[--currentRow] != "")
                     scratch[currentRow] = scratch[currentRow].substring(0,
                                            scratch[currentRow].length()-1);
                 };
                 break;
        default: doChord(keys());
                 break;
      }
      sample = false;
    }
    switch (code) {
      case 52 :
      case 55 : bA = false;
                break;
      case 51 :
      case 56 : bE = false;
                break;
      case 50 :
      case 57 : bI = false;
                break;
      case 49 :
      case 48 : bO = false;
                break;
    }
    redrawKeys = true;
    this.update(this.getGraphics());
    if (keys() == 0) sample = true;

    return true;
  }
}