wcanvas.java

塞迪网校J2ME移动应用开发教程的所有源代码.

import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;
import java.util.*;
import java.io.*;
import javax.microedition.media.*;
import javax.microedition.media.control.*;

public class WCanvas extends GameCanvas implements Runnable {
  private Display      display;
  private boolean      sleeping;
  private long         frameDelay;
  private int          inputDelay;
  private LayerManager layers;
  private int          xView, yView;
  private TiledLayer   backgroundLayer;
  private TiledLayer   barrierLayer;
  private int          waterDelay, waterTile;
  private Sprite       personSprite;
  private Player       musicPlayer;

  public WCanvas(Display d) {
    super(true);
    display = d;

    // Set the frame rate (30 fps)
    frameDelay = 33;

    // Clear the input delay
    inputDelay = 0;
  }
  
  public void start() {
    // Set the canvas as the current screen
    display.setCurrent(this);

    // Create the background and barrier tiled layers
    try {
      backgroundLayer = new TiledLayer(16, 16, Image.createImage("/Background.png"), 48, 48);
      barrierLayer = new TiledLayer(16, 16, Image.createImage("/Barrier.png"), 48, 48);
    }
    catch (IOException e) {
      System.err.println("Failed loading images!");
    }

    // Setup the background tiled layer map
    int[] backgroundMap = {
      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
      0,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  0,
      0,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  0,
      0,  2,  2,  2,  2,  5, 15, 15, 15, 15, 15, 15,  6,  2,  2,  0,
      0,  2,  2,  2,  2,  7, 10,  1,  1,  1,  1,  1, 16,  2,  2,  0,
      0,  2,  2,  2,  2,  2, 14,  1,  1,  1,  1,  1, 16,  2,  2,  0,
      0,  2,  2,  2,  2,  2,  7, 10,  1,  1,  1,  1, 16,  2,  2,  0,
      0,  2,  2,  2,  2,  2,  2, 14,  1,  1,  1,  1, 16,  2,  2,  0,
      0,  2,  2,  2,  2,  2,  2, 14,  1,  9, 10,  1, 16,  2,  2,  0,
      0,  2,  2,  5, 15,  6,  2, 14,  1, 11, 12,  1, 16,  2,  2,  0,
      0,  2,  2, 14,  1, 16,  2,  7, 13, 13, 13, 13,  8,  2,  2,  0,
      0,  2,  2,  7, 13,  8,  2,  2,  2,  2,  2,  2,  2,  2,  2,  0,
      0,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  0,
      0,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  0,
      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0
    };
    for (int i = 0; i < backgroundMap.length; i++) {
      int column = i % 16;
      int row = (i - column) / 16;
      backgroundLayer.setCell(column, row, backgroundMap[i]);
    }

    // Setup the barrier tiled layer map
    barrierLayer.createAnimatedTile(1);
    int[] barrierMap = {
     -1, -1,  1, -1, -1,  1, -1,  1, -1, -1,  1,  1, -1,  1, -1,  1,
     -1, -1, -1,  1,  1, -1,  1, -1,  1,  1, -1,  1, -1, -1,  1, -1,
      1, 21, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 22,  1,
      1, 18,  0,  5,  5,  5,  5,  8,  0,  0,  8,  0,  0,  0, 20, -1,
      1, 18,  0,  0,  0,  0,  0,  0,  0, 16,  8,  0,  0,  0, 20,  1,
     -1, 18,  7,  7,  7, 11,  7,  8,  0,  0, 10,  5,  0,  0, 20, -1,
      1, 18,  0, 11,  0,  0, 11,  7,  7, 12,  0,  0,  0,  0, 20, -1,
     -1, 18,  0,  7,  7,  7,  0, 11, 12,  8,  0,  0,  0,  0, 20,  1,
      1, 18,  0, 11, 12,  0, 15, 10,  0,  8,  0,  0,  0,  0, 20,  1,
      1, 18,  0,  0, 13,  0, 10,  5,  5,  9,  0,  0,  0,  0, 20, -1,
     -1, 18,  7, 10,  5,  9,  0,  0,  0,  0,  0,  0,  0,  0, 20,  1,
     -1, 18,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 20, -1,
      1, 18,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 20,  1,
      1, 18,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 20,  1,
     -1, 23, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 24, -1,
     -1, -1,  1, -1,  1, -1,  1,  1,  1, -1,  1, -1, -1,  1,  1, -1
    };
    for (int i = 0; i < barrierMap.length; i++) {
      int column = i % 16;
      int row = (i - column) / 16;
      barrierLayer.setCell(column, row, barrierMap[i]);
    }

    // Initialize the animated water delay and tile
    waterDelay = 0;
    waterTile = 1;

    // Initialize the person sprite
    try {
      personSprite = new Sprite(Image.createImage("/Person.png"), 20, 24);
    }
    catch (IOException e) {
      System.err.println("Failed loading images!");
    }

    // Create the layer manager
    layers = new LayerManager();
    layers.append(personSprite);
    layers.append(barrierLayer);
    layers.append(backgroundLayer);
    xView = (backgroundLayer.getWidth() - getWidth()) / 2;
    yView = (backgroundLayer.getHeight() - getHeight()) / 2;
    layers.setViewWindow(xView, yView, getWidth(), getHeight());
    personSprite.setPosition(xView + (getWidth() - personSprite.getWidth()) / 2,
      yView + (getHeight() - personSprite.getHeight()) / 2);

    // Initialize and start the music player
    try {
      InputStream is = getClass().getResourceAsStream("Music.mid");
      musicPlayer = Manager.createPlayer(is, "audio/midi");
      musicPlayer.prefetch();
      musicPlayer.setLoopCount(-1);
      musicPlayer.start();
    }
    catch (IOException ioe) {
    }
    catch (MediaException me) {
    }

    // Start the animation thread
    sleeping = false;
    Thread t = new Thread(this);
    t.start();
  }
  
  public void stop() {
    // Close the music player
    musicPlayer.close();

    // Stop the animation
    sleeping = true;
  }
  
  public void run() {
    Graphics g = getGraphics();
    
    // The main game loop
    while (!sleeping) {
      update();
      draw(g);
      try {
        Thread.sleep(frameDelay);
      }
      catch (InterruptedException ie) {}
    }
  }

  private void update() {
    // Process user input to move the background layer and animate the person
    if (++inputDelay > 2) {
      int keyState = getKeyStates();
      int xMove = 0, yMove = 0;
      if ((keyState & LEFT_PRESSED) != 0)
        xMove = -12;
      else if ((keyState & RIGHT_PRESSED) != 0)
        xMove = 12;
      if ((keyState & UP_PRESSED) != 0)
        yMove = -12;
      else if ((keyState & DOWN_PRESSED) != 0)
        yMove = 12;
      if (xMove != 0 || yMove != 0) {
        layers.setViewWindow(xView + xMove, yView + yMove, getWidth(), getHeight());
        personSprite.move(xMove, yMove);
        personSprite.nextFrame();
      }

      // Check for a collision with the person and the barrier tiled layer
      if (personSprite.collidesWith(barrierLayer, true)) {
        // Play a collision sound
        try {
          Manager.playTone(ToneControl.C4 + 12, 100, 100);
        }
        catch (Exception e) {
        }

        // Restore the original view window and person sprite positions
        layers.setViewWindow(xView, yView, getWidth(), getHeight());
        personSprite.move(-xMove, -yMove);
      }
      else {
        // If there is no collision, commit the changes to the view window position
        xView += xMove;
        yView += yMove;
      }

      // Update the animated water tiles
      if (++waterDelay > 2) {
        if (++waterTile > 4)
          waterTile = 1;
        barrierLayer.setAnimatedTile(-1, waterTile);
        waterDelay = 0;
      }

      // Reset the input delay
      inputDelay = 0;
    }
  }

  private void draw(Graphics g) {
    // Draw the layers
    layers.paint(g, 0, 0);
    
    // Flush the offscreen graphics buffer
    flushGraphics();
  }
}