// TreasureWorld: a computer game.
// Collect the treasure before running out of strength

// Note: the code assumes an applet window 400 pixels wide, and 300 high

// sbj May 1998; updated to Java 1.1 May 1999

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

public class TreasureWorld extends Applet
  implements ActionListener, MouseListener, MouseMotionListener, ItemListener {
        
  private final int windowWidth = 400;
  private final int windowHeight = 300;
  
  private final int clickSep = 5;        // How close the cursor has to be to player icon 
                                         // for a click to start dragging
  
  private final int displayFrequency = 10;   // Once in every this many repaints (on average)
  private final int displayTime = 200;       // show treasure for this many milliseconds
  
  private final int initialStrength = 200;

  private TreasureCollection theTreasure;
  private int collected;                 // How many items collected so far
  private Label collectedIndicator;
  private Panel controls, info;          // To hold controls buttons & information widgets
  private Button restart;                // To reset the game to the start
  private Choice icon;                   // For choosing the player icon  
  private int strength;                  // Reduced by 1 per mouse event
  private Label strengthIndicator;
  private int currentX, currentY;        // Current player position
  private boolean trackingNow;           // True when mouse is dragging the player                
  
  public void init() {    
    int noOfTreasures = (int)(Math.random()*11+5);  // Random from 5 - 15
    theTreasure = new TreasureCollection(noOfTreasures);
    collected = 0;
    currentX = 200;
    currentY = 200;
    trackingNow = false;
    strength = initialStrength;
   
    setLayout(new BorderLayout());       // Alter the applet's layout manager
    
    info = new Panel();                  // info panel holds title, remaining 'strength' and collection 'score'
    Label title = new Label("Treasure World.");
    title.setFont(new Font("TimesRoman", Font.BOLD, 14));
    info.add(title);
    
    strengthIndicator = new Label("Remaining strength:       ");
    info.add(strengthIndicator);
    
    collectedIndicator = new Label("Collected so far:       ");
    info.add(collectedIndicator);
    
    add("North", info);                  // info panel is across top of window
    
    controls = new Panel();              // controls panel for restart button and icon choice
    
    restart = new Button("Restart game");
    controls.add(restart);
    restart.addActionListener(this);
    
    icon = new Choice();
    icon.addItem("Cross");
    icon.addItem("Fido");
    controls.add(icon);
    icon.addItemListener(this);
    
    add("South", controls);              // controls panel is across bottom of window

    addMouseListener(this);
    addMouseMotionListener(this);
  }
    
  public void paint(Graphics g) {
    strengthIndicator.setText("Remaining strength: "+strength);
    collectedIndicator.setText("Collected so far: "+collected);
    if (collected == theTreasure.maxItems)   // All treasure collected?
      g.drawString("Well done! You have won!", 100, 150);
    else if (strength <= 0)                  // No strength left?
      g.drawString("Bad luck! You are dead!", 100, 150);
    else {                                   // Still playing...
      if ((int) (Math.random()*displayFrequency) == 0) {   // One in so many repaints,
        theTreasure.display(g);              // display the treasure...
        drawIcon(g);
        try {
          Thread.sleep(displayTime);         // for while...
        } 
        catch (InterruptedException e) { }   // (Ignore it!)
        g.clearRect(0, 0, windowWidth, windowHeight);  // then hide the treasure again
      }
      drawIcon(g);                           // Draw the player
    }
  }
    
  private void drawIcon(Graphics g) {
    if (icon.getSelectedItem().equals("Cross")) 
      drawCross(g);
    if (icon.getSelectedItem().equals("Fido"))
      drawFido(g);
  }
  
  private void drawCross(Graphics g) {  
    // A large cross centred at currentX, currentY
    g.setColor(Color.black);
    g.drawLine(currentX-10, currentY-10, currentX+10, currentY+10);
    g.drawLine(currentX-10, currentY+10, currentX+10, currentY-10);
  }

  private void drawFido(Graphics g) {  
    // Fido the dog roughly centred at currentX, currentY
    g.setColor(Color.black);
    g.fillOval(currentX-7, currentY-3, 15, 7);                   // Body
    g.drawLine(currentX-5, currentY, currentX-5, currentY+7);    // Back leg
    g.drawLine(currentX+5, currentY, currentX+5, currentY+7);    // Front leg
    g.fillOval(currentX+4, currentY-7, 8, 6);                    // Head
    g.drawLine(currentX+6, currentY-6, currentX+6, currentY-9);  // Ear
    g.drawLine(currentX-10, currentY-4, currentX-6, currentY);   // Tail
  }
  
  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == restart) {
      // Reset game to initial state
      int noOfTreasures = (int)(Math.random()*11+5);  // Random from 5 - 15
      theTreasure = new TreasureCollection(noOfTreasures);
      collected = 0;
      currentX = 200;
      currentY = 200;
      strength = initialStrength;
      trackingNow = false;
      repaint();
    }
  }
  
  public void itemStateChanged(ItemEvent e) {
  // User has selected an icon in the choice list
    if (e.getSource() == icon)
      repaint();
  }
  
  public void mousePressed(MouseEvent e) {
    // The mouseDown event only starts player icon dragging if
    // quite close to the current player position
    int x = e.getX();
    int y = e.getY();
    int distance = (x-currentX)*(x-currentX)+(y-currentY)*(y-currentY);  // Pythagoras
    if (distance<=clickSep*clickSep) {       // No more than clickSep pixels from current player position?
      strength--;                            // Use up some strength
      currentX = x;                          // Record current position
      currentY = y;
      collected += theTreasure.check(x, y);  // Collect any treasure here
      trackingNow = true;                    // Mouse down, so now tracking
      repaint();
    }
  } 

  public void mouseReleased(MouseEvent e) {
    // Stop tracking, if we have been
    int x = e.getX();
    int y = e.getY();
    if (trackingNow) {
      strength--;                            // Use up some strength
      currentX = x;
      currentY = y;
      collected += theTreasure.check(x, y);  // Collect any treasure here
      trackingNow = false;                   // Mouse released, so stop tracking
      repaint();
    }
  } 
        
  public void mouseClicked(MouseEvent e) { }
  
  public void mouseEntered(MouseEvent e) { }
  
  public void mouseExited(MouseEvent e) { }
  
  public void mouseDragged(MouseEvent e) {
    // Only drag player icon if we are actually tracking the mouse
    int x = e.getX();
    int y = e.getY();
    if (trackingNow) {
      strength--;                            // Use up some strength
      currentX = x;
      currentY = y;
      collected += theTreasure.check(x, y);  // Collect any treasure here
      repaint();
    }
  } 
  
  public void mouseMoved(MouseEvent e) { }
  
} // End of TreasureWorld