fishtankcanvas.java

J2ME MIDP_Example_Applications

//
// Copyright 2002 Nokia Corporation.
//
// THIS SOURCE CODE IS PROVIDED 'AS IS', WITH NO WARRANTIES WHATSOEVER,
// EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY, FITNESS
// FOR ANY PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE
// OR TRADE PRACTICE, RELATING TO THE SOURCE CODE OR ANY WARRANTY OTHERWISE
// ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR SAMPLE AND WITH NO
// OBLIGATION OF NOKIA TO PROVIDE THE LICENSEE WITH ANY MAINTENANCE OR
// SUPPORT. FURTHERMORE, NOKIA MAKES NO WARRANTY THAT EXERCISE OF THE
// RIGHTS GRANTED HEREUNDER DOES NOT INFRINGE OR MAY NOT CAUSE INFRINGEMENT
// OF ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OWNED OR CONTROLLED
// BY THIRD PARTIES
//
// Furthermore, information provided in this source code is preliminary,
// and may be changed substantially prior to final release. Nokia Corporation
// retains the right to make changes to this source code at any time,
// without notice. This source code is provided for informational
// purposes only.
//
//
// Nokia and Nokia Connecting People are registered trademarks of Nokia
// Corporation. Java and all Java-based marks are trademarks or registered
// trademarks of Sun Microsystems, Inc. Other product and company names
// mentioned herein may be trademarks or trade names of their respective owners.
//
// A non-exclusive, non-transferable, worldwide, limited license is hereby
// granted to the Licensee to download, print, reproduce and modify the
// source code. The licensee has the right to market, sell, distribute and
// make available the source code in original or modified form only when
// incorporated into the programs developed by the Licensee. No other
// license, express or implied, by estoppel or otherwise, to any other
// intellectual property rights is granted herein.
//


package example.fishtank;

import javax.microedition.lcdui.*;
import java.util.Vector;
import com.nokia.mid.ui.*;

public class FishTankCanvas extends FullCanvas
    implements Runnable
{
    static final int NUM_PLANES = 5;

    private static final int WEEDS_PLANE = 2;
    private static final int MILLIS_PER_TICK = 100;

    static int waterWidth, waterHeight;
    private final FishTankMIDlet parent;
    private final Vector fishes = new Vector();
    private final Weeds weeds;
    private volatile Thread animationThread = null;


    public FishTankCanvas(FishTankMIDlet parent)
    {
        this.parent = parent;
        waterWidth = getWidth();
        waterHeight = (getHeight() * 15) / 16;

        weeds = new Weeds();

        // num = (Tank area in pixels) / (approx area of fish img in pixels)
        int numFishes = (waterWidth * waterHeight) / (35 * 35);
        if (numFishes > 20)
        {
            numFishes = 20; // maximum fishes
        }
        for (int i = 0; i < numFishes; ++i)
        {
            fishes.addElement(new Fish());
        }
    }


    synchronized void start()
    {
        animationThread = new Thread(this);
        animationThread.start();
    }


    synchronized void stop()
    {
        animationThread = null;
    }


    public void run()
    {
        Thread currentThread = Thread.currentThread();

        try
        {
            // This ends when animationThread is set to null, or when
            // it is subsequently set to a new thread; either way, the
            // current thread should terminate
            while (currentThread == animationThread)
            {
                long startTime = System.currentTimeMillis();

                // Only animate when the canvas is visible.
                if (isShown())
                {
                    tick();

                    // Repaint everything above the sand, the fish
                    // never swim at h > waterHeight.
                    repaint(0, 0, waterWidth, waterHeight);
                    serviceRepaints();
                }

                long timeTaken = System.currentTimeMillis() - startTime;
                if (timeTaken < MILLIS_PER_TICK)
                {
                    synchronized (this)
                    {
                        wait(MILLIS_PER_TICK - timeTaken);
                    }
                }
                else
                {
                    currentThread.yield();
                }
            }
        }
        catch (InterruptedException e)
        {
        }
    }


    private synchronized void tick()
    {
        for (int i = 0; i < fishes.size(); ++i)
        {
            Fish fish = (Fish)(fishes.elementAt(i));
            fish.tick();
        }
    }


    public void paint(Graphics g)
    {
        drawFishTank(g);
    }


    private synchronized void drawFishTank(Graphics g)
    {
        // Draw the water
        g.setColor(0, 255, 255);
        g.fillRect(0, 0, waterWidth, waterHeight);

        // Draw the sand
        g.setColor(255, 128, 64);
        g.fillRect(0, waterHeight, waterWidth, getHeight());

        // Draw the weeds and fishes
        for (int plane = 0; plane < NUM_PLANES; plane++)
        {
            if (plane == WEEDS_PLANE)
            {
                weeds.draw(g);
            }

            for (int i = 0; i < fishes.size(); i++)
            {
                Fish fish = (Fish)(fishes.elementAt(i));
                if (fish.getZ() == plane)
                {
                   fish.draw(g);
                }
            }
        }
    }


    public void keyPressed(int keyCode)
    {
        // any softkey key-press exits
        if ((keyCode == KEY_SOFTKEY1) || (keyCode == KEY_SOFTKEY2) ||
            (keyCode == KEY_SOFTKEY3))
        {
            parent.exitRequested();
        }
    }
}