Java/J2ME/2D — различия между версиями
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Текущая версия на 06:37, 1 июня 2010
Содержание
Box Text Canvas
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
public class BoxTextCanvas extends Canvas {
private Font mFont;
public BoxTextCanvas() {
mFont = Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_PLAIN, Font.SIZE_LARGE);
}
public void paint(Graphics g) {
int w = getWidth();
int h = getHeight();
g.setColor(0xffffff);
g.fillRect(0, 0, w, h);
g.setColor(0x000000);
String s = "dolce";
int stringWidth = mFont.stringWidth(s);
int stringHeight = mFont.getHeight();
int x = (w - stringWidth) / 2;
int y = h / 2;
g.setFont(mFont);
g.drawString(s, x, y, Graphics.TOP | Graphics.LEFT);
g.drawRect(x, y, stringWidth, stringHeight);
}
}
Illustrate Graphics MIDlet
/*
J2ME in a Nutshell
By Kim Topley
ISBN: 0-596-00253-X
*/
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.List;
import javax.microedition.midlet.MIDlet;
public class GraphicsMIDlet extends MIDlet implements CommandListener {
// The MIDlet"s Display object
private Display display;
// Flag indicating first call of startApp
protected boolean started;
// Exit command
private Command exitCommand;
// Back to examples list command
private Command backCommand;
// The example selection list
private List examplesList;
// The Canvases used to demonstrate different Items
private Canvas[] canvases;
// The example names. Used to populate the list.
private String[] examples = {
"Lines", "Rectangles", "RectangleFills",
"Arcs", "FilledArcs", "Text"
};
protected void startApp() {
if (!started) {
started = true;
display = Display.getDisplay(this);
// Create the common commands
createCommands();
// Create the canvases
createCanvases();
// Create the list of examples
createList();
// Start with the List
display.setCurrent(examplesList);
}
}
protected void pauseApp() {
}
protected void destroyApp(boolean unconditional) {
}
public void commandAction(Command c, Displayable d) {
if (d == examplesList) {
// New example selected
int index = examplesList.getSelectedIndex();
display.setCurrent(canvases[index]);
} else if (c == exitCommand) {
// Exit. No need to call destroyApp
// because it is empty.
notifyDestroyed();
} else if (c == backCommand) {
// Go back to main selection list
display.setCurrent(examplesList);
}
}
private void createCommands() {
exitCommand = new Command("Exit", Command.EXIT, 0);
backCommand = new Command("Back", Command.BACK, 1);
}
private void createList() {
examplesList = new List("Select Example", List.IMPLICIT);
for (int i = 0; i < examples.length; i++) {
examplesList.append(examples[i], null);
}
examplesList.setCommandListener(this);
}
private void createCanvases() {
canvases = new Canvas[examples.length];
canvases[0] = createLinesCanvas();
canvases[1] = createRectanglesCanvas();
canvases[2] = createRectangleFillsCanvas();
canvases[3] = createArcsCanvas();
canvases[4] = createFilledArcsCanvas();
canvases[5] = createTextCanvas();
}
private void addCommands(Displayable d) {
d.addCommand(exitCommand);
d.addCommand(backCommand);
d.setCommandListener(this);
}
// Create the Canvas for the line drawing example
private Canvas createLinesCanvas() {
Canvas canvas = new LineCanvas();
addCommands(canvas);
return canvas;
}
// Create the Canvas for the rectangles example
private Canvas createRectanglesCanvas() {
Canvas canvas = new RectanglesCanvas();
addCommands(canvas);
return canvas;
}
// Create the Canvas for the filled rectangles example
private Canvas createRectangleFillsCanvas() {
Canvas canvas = new RectangleFillsCanvas();
addCommands(canvas);
return canvas;
}
// Create the Canvas for the arcs example
private Canvas createArcsCanvas() {
Canvas canvas = new ArcsCanvas();
addCommands(canvas);
return canvas;
}
// Create the Canvas for the filled arcs example
private Canvas createFilledArcsCanvas() {
Canvas canvas = new FilledArcsCanvas();
addCommands(canvas);
return canvas;
}
// Create the Canvas for the text example
private Canvas createTextCanvas() {
Canvas canvas = new TextCanvas();
addCommands(canvas);
return canvas;
}
}
// A canvas that illustrates line drawing
class LineCanvas extends Canvas {
public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();
// Fill the background using black
g.setColor(0);
g.fillRect(0, 0, width, height);
// White horizontal line
g.setColor(0xFFFFFF);
g.drawLine(0, height/2, width - 1, height/2);
// Yellow dotted horizontal line
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xFFFF00);
g.drawLine(0, height/4, width - 1, height/4);
// Solid diagonal line in brightest gray
g.setGrayScale(255);
g.setStrokeStyle(Graphics.SOLID);
g.drawLine(0, 0, width - 1, height - 1);
}
}
// A canvas that illustrates rectangles
class RectanglesCanvas extends Canvas {
public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();
// Create a white background
g.setColor(0xffffff);
g.fillRect(0, 0, width, height);
// Draw a solid rectangle
g.setColor(0);
g.drawRect(width/4, 0, width/2, height/4);
// Draw a dotted rectangle inside
// the solid rectangle.
g.setStrokeStyle(Graphics.DOTTED);
g.drawRect(width/4 + 4, 4, width/2 - 8, height/4 - 8);
// Draw a rounded rectangle
g.setStrokeStyle(Graphics.SOLID);
g.drawRoundRect(width/4, height/2, width/2, height/4, 16, 8);
}
}
// A canvas that illustrates filled rectangles
class RectangleFillsCanvas extends Canvas {
public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();
// Create a black background
g.setColor(0);
g.fillRect(0, 0, width, height);
// Draw a filled rectangle with
// a dotted rectangle around it
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0x00ff00);
g.fillRect(width/4, height/4, width/2, height/2);
g.setColor(0xffff00);
g.drawRect(width/4, height/4, width/2, height/2);
}
}
// A canvas that illustrates arcs
class ArcsCanvas extends Canvas {
public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();
// Create a black background
g.setColor(0);
g.fillRect(0, 0, width, height);
// A quarter circle, clockwise 90 degrees
// from the 3 o"clock position. Show the
// bounding rectangle as well.
g.setColor(0xffffff);
g.drawArc(0, 0, width/2, height/2, 0, 90);
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xffff00);
g.drawRect(0, 0, width/2, height/2);
// A quarter circle, anticlockwise 90 degrees
// from the 3 o"clock position.
g.setStrokeStyle(Graphics.SOLID);
g.setColor(0xffffff);
g.drawArc(width/2, 0, width/2, height/2, 0, -90);
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xffff00);
g.drawRect(width/2, 0, width/2, height/2);
// An elliptical arc from the six o"clock
// position, counterclockwise 180 degrees
g.setStrokeStyle(Graphics.SOLID);
g.setColor(0xffffff);
g.drawArc(0, height/2, width, height/2, -90, -180);
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xffff00);
g.drawRect(0, height/2, width, height/2);
}
}
// A canvas that illustrates filled arcs
class FilledArcsCanvas extends Canvas {
public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();
// Create a black background
g.setColor(0);
g.fillRect(0, 0, width, height);
// A quarter circle, clockwise 90 degrees
// from the 3 o"clock position. Show the
// bounding rectangle as well.
g.setColor(0xffffff);
g.fillArc(0, 0, width/2, height/2, 0, 90);
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xffff00);
g.drawRect(0, 0, width/2, height/2);
// A quarter circle, anticlockwise 90 degrees
// from the 3 o"clock position.
g.setStrokeStyle(Graphics.SOLID);
g.setColor(0xffffff);
g.fillArc(width/2, 0, width/2, height/2, 0, -90);
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xffff00);
g.drawRect(width/2, 0, width/2, height/2);
// An elliptical arc from the six o"clock
// position, counterclockwise 180 degrees
g.setStrokeStyle(Graphics.SOLID);
g.setColor(0xffffff);
g.fillArc(0, height/2, width, height/2, -90, -180);
g.setStrokeStyle(Graphics.DOTTED);
g.setColor(0xffff00);
g.drawRect(0, height/2, width, height/2);
}
}
// A canvas that illustrates text rendering
class TextCanvas extends Canvas {
public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();
// Create a black background
g.setColor(0);
g.fillRect(0, 0, width, height);
// Top-left of canvas
g.setColor(0xffffff);
g.drawString("Top left", 0, 0, Graphics.TOP | Graphics.LEFT);
// Draw another string one line below
Font font = g.getFont();
g.drawString("Below top left", 0, font.getHeight(), Graphics.TOP | Graphics.LEFT);
// Bottom-right of canvas
g.drawString("Bottom right", width, height, Graphics.BOTTOM | Graphics.RIGHT);
// Mixed fonts and colors
String str = "Multi-font ";
font = Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_UNDERLINED, Font.SIZE_LARGE);
g.setFont(font);
g.drawString(str, 0, height/2, Graphics.LEFT | Graphics.BASELINE);
int x = font.stringWidth(str);
g.setColor(0x00ff00);
g.setFont(Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD | Font.STYLE_ITALIC, Font.SIZE_MEDIUM));
g.drawString("and multi-color", x, height/2, Graphics.LEFT | Graphics.BASELINE);
}
}
Key Canvas
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
public class KeyCanvas extends Canvas {
private Font mFont;
private String mMessage = "[Press keys]";
public KeyCanvas() {
mFont = Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_PLAIN, Font.SIZE_MEDIUM);
}
public void paint(Graphics g) {
int w = getWidth();
int h = getHeight();
// Clear the Canvas.
g.setGrayScale(255);
g.fillRect(0, 0, w - 1, h - 1);
g.setGrayScale(0);
g.drawRect(0, 0, w - 1, h - 1);
g.setFont(mFont);
int x = w / 2;
int y = h / 2;
g.drawString(mMessage, x, y, Graphics.BASELINE | Graphics.HCENTER);
}
protected void keyPressed(int keyCode) {
int gameAction = getGameAction(keyCode);
switch (gameAction) {
case UP:
mMessage = "UP";
break;
case DOWN:
mMessage = "DOWN";
break;
case LEFT:
mMessage = "LEFT";
break;
case RIGHT:
mMessage = "RIGHT";
break;
case FIRE:
mMessage = "FIRE";
break;
case GAME_A:
mMessage = "GAME_A";
break;
case GAME_B:
mMessage = "GAME_B";
break;
case GAME_C:
mMessage = "GAME_C";
break;
case GAME_D:
mMessage = "GAME_D";
break;
default:
mMessage = "";
break;
}
repaint();
}
}
Offscreen MIDlet
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.midlet.MIDlet;
public class OffscreenMIDlet extends MIDlet {
public void startApp() {
Displayable d = new OffscreenCanvas();
d.addCommand(new Command("Exit", Command.EXIT, 0));
d.setCommandListener(new CommandListener() {
public void commandAction(Command c, Displayable s) {
notifyDestroyed();
}
});
Display.getDisplay(this).setCurrent(d);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
}
class OffscreenCanvas extends Canvas {
private Image mImage;
public void paint(Graphics g) {
if (mImage == null)
initialize();
g.drawImage(mImage, 0, 0, Graphics.TOP | Graphics.LEFT);
}
private void initialize() {
int w = getWidth();
int h = getHeight();
mImage = Image.createImage(w, h);
Graphics g = mImage.getGraphics();
g.drawRect(0, 0, w - 1, h - 1);
g.drawLine(0, 0, w - 1, h - 1);
g.drawLine(w - 1, 0, 0, h - 1);
}
}
Pacer
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
public class Pacer extends MIDlet{
public void startApp() {
Displayable d = new PacerCanvas();
d.addCommand(new Command("Exit", Command.EXIT, 0));
d.setCommandListener(new CommandListener() {
public void commandAction(Command c, Displayable s) {
notifyDestroyed();
}
} );
Display.getDisplay(this).setCurrent(d);
}
public void pauseApp() { }
public void destroyApp(boolean unconditional) { }
}
class PacerCanvas extends Canvas {
public void paint(Graphics g) {
int w = getWidth();
int h = getHeight();
g.setColor(0xffffff);
g.fillRect(0, 0, w, h);
g.setColor(0x000000);
for (int x = 0; x < w; x += 10)
g.drawLine(0, w - x, x, 0);
int z = 50;
g.drawRect(z, z, 20, 20);
z += 20;
g.fillRoundRect(z, z, 20, 20, 5, 5);
z += 20;
g.drawArc(z, z, 20, 20, 0, 360);
}
}
Pointer Example
/*
J2ME: The Complete Reference
James Keogh
Publisher: McGraw-Hill
ISBN 0072227109
*/
//jad file (please verify the jar size)
/*
MIDlet-Name: PointerExample
MIDlet-Version: 1.0
MIDlet-Vendor: MyCompany
MIDlet-Jar-URL: PointerExample.jar
MIDlet-1: PointerExample, , PointerExample
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-1.0
MIDlet-JAR-SIZE: 100
*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class PointerExample extends MIDlet
{
private Display display;
private MyClass canvas;
public PointerExample()
{
display = Display.getDisplay(this);
canvas = new MyClass (this);
}
protected void startApp()
{
display.setCurrent( canvas );
}
protected void pauseApp()
{
}
protected void destroyApp( boolean unconditional )
{
}
public void exitMIDlet()
{
destroyApp(true);
notifyDestroyed();
}
}
class MyClass extends Canvas implements CommandListener
{
private Command exit;
private Command erase;
private boolean eraseFlag = false;
private boolean isFirstPaint;
private int sX = 0,sY = 0, cX = 0, cY = 0;
private PointerExample pointerExample;
public MyClass (PointerExample pointerExample)
{
this.pointerExample = pointerExample;
exit = new Command("Exit", Command.EXIT, 1);
erase = new Command("Erase", Command.SCREEN, 1);
addCommand(exit);
addCommand(erase);
setCommandListener(this);
isFirstPaint = true;
}
protected void paint(Graphics graphics)
{
if (eraseFlag || isFirstPaint)
{
graphics.setColor(255, 255, 255);
graphics.fillRect(0, 0, getWidth(), getHeight());
eraseFlag = isFirstPaint = false;
sX = 0;
sY = 0;
cX = 0;
cY = 0;
return;
}
graphics.setColor(0, 0, 0);
graphics.drawLine(sX, sY, cX, cY);
sX = cX;
sY = cY;
}
public void commandAction(Command command, Displayable displayable)
{
if (command == exit)
pointerExample.exitMIDlet();
else if (command == erase)
{
eraseFlag = true;
repaint();
}
}
protected void pointerPressed(int x, int y)
{
sX = x;
sY = y;
}
protected void pointerDragged(int x, int y)
{
cX = x;
cY = y;
repaint();
}
}
Quatsch MIDlet
/*
Wireless Java 2nd edition
Jonathan Knudsen
Publisher: Apress
ISBN: 1590590775
*/
import java.io.IOException;
import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;
import javax.microedition.midlet.MIDlet;
public class QuatschMIDlet extends MIDlet
implements CommandListener {
private Display mDisplay;
private QuatschCanvas mQuatschCanvas;
private Form mShowForm;
private Command mExitCommand, mShowCommand, mOkCommand;
public void startApp() {
if (mQuatschCanvas == null) {
try {
mQuatschCanvas = new QuatschCanvas("/quatsch.png",
"/atmosphere.png", "/background_tiles.png");
mQuatschCanvas.start();
mExitCommand = new Command("Exit", Command.EXIT, 0);
mShowCommand = new Command("Show/Hide", Command.SCREEN, 0);
mOkCommand = new Command("OK", Command.OK, 0);
mQuatschCanvas.addCommand(mExitCommand);
mQuatschCanvas.addCommand(mShowCommand);
mQuatschCanvas.setCommandListener(this);
}
catch (IOException ioe) {
System.out.println(ioe);
}
}
mDisplay = Display.getDisplay(this);
mDisplay.setCurrent(mQuatschCanvas);
}
public void pauseApp() {}
public void destroyApp(boolean unconditional) {
mQuatschCanvas.stop();
}
public void commandAction(Command c, Displayable s) {
if (c.getCommandType() == Command.EXIT) {
destroyApp(true);
notifyDestroyed();
}
else if (c == mShowCommand) {
if (mShowForm == null) {
mShowForm = new Form("Show/Hide");
ChoiceGroup cg = new ChoiceGroup("Layers", Choice.MULTIPLE);
cg.append("Fog", null);
cg.append("Dr. Quatsch", null);
cg.append("Background", null);
mShowForm.append(cg);
mShowForm.addCommand(mOkCommand);
mShowForm.setCommandListener(this);
}
ChoiceGroup cg = (ChoiceGroup)mShowForm.get(0);
cg.setSelectedIndex(0, mQuatschCanvas.isVisible(0));
cg.setSelectedIndex(1, mQuatschCanvas.isVisible(1));
cg.setSelectedIndex(2, mQuatschCanvas.isVisible(2));
mDisplay.setCurrent(mShowForm);
}
else if (c == mOkCommand) {
ChoiceGroup cg = (ChoiceGroup)mShowForm.get(0);
mQuatschCanvas.setVisible(0, cg.isSelected(0));
mQuatschCanvas.setVisible(1, cg.isSelected(1));
mQuatschCanvas.setVisible(2, cg.isSelected(2));
mDisplay.setCurrent(mQuatschCanvas);
}
}
}
class QuatschCanvas extends GameCanvas implements Runnable {
private boolean mTrucking;
private LayerManager mLayerManager;
private TiledLayer mAtmosphere;
private TiledLayer mBackground;
private int mAnimatedIndex;
private Sprite mQuatsch;
private int mState, mDirection;
private static final int kStanding = 1;
private static final int kRunning = 2;
private static final int kLeft = 1;
private static final int kRight = 2;
private static final int[] kRunningSequence = { 0, 1, 2 };
private static final int[] kStandingSequence = { 3 };
public QuatschCanvas(String quatschImageName,
String atmosphereImageName, String backgroundImageName)
throws IOException {
super(true);
// Create a LayerManager.
mLayerManager = new LayerManager();
int w = getWidth();
int h = getHeight();
mLayerManager.setViewWindow(96, 0, w, h);
createBackground(backgroundImageName);
createAtmosphere(atmosphereImageName);
createQuatsch(quatschImageName);
}
private void createBackground(String backgroundImageName)
throws IOException {
// Create the tiled layer.
Image backgroundImage = Image.createImage(backgroundImageName);
int[] map = {
1, 2, 0, 0, 0, 0, 0, 0,
3, 3, 2, 0, 0, 0, 5, 0,
3, 3, 3, 2, 4, 1, 3, 2,
6, 6, 6, 6, 6, 6, 6, 6
};
mBackground = new TiledLayer(8, 4, backgroundImage, 48, 48);
mBackground.setPosition(12, 0);
for (int i = 0; i < map.length; i++) {
int column = i % 8;
int row = (i - column) / 8;
mBackground.setCell(column, row, map[i]);
}
mAnimatedIndex = mBackground.createAnimatedTile(8);
mBackground.setCell(3, 0, mAnimatedIndex);
mBackground.setCell(5, 0, mAnimatedIndex);
mLayerManager.append(mBackground);
}
private void createAtmosphere(String atmosphereImageName)
throws IOException {
// Create the atmosphere layer
Image atmosphereImage = Image.createImage(atmosphereImageName);
mAtmosphere = new TiledLayer(8, 1, atmosphereImage,
atmosphereImage.getWidth(), atmosphereImage.getHeight());
mAtmosphere.fillCells(0, 0, 8, 1, 1);
mAtmosphere.setPosition(0, 96);
mLayerManager.insert(mAtmosphere, 0);
}
private void createQuatsch(String quatschImageName)
throws IOException {
// Create the sprite.
Image quatschImage = Image.createImage(quatschImageName);
mQuatsch = new Sprite(quatschImage, 48, 48);
mQuatsch.setPosition(96 + (getWidth() - 48) / 2, 96);
mQuatsch.defineReferencePixel(24, 24);
setDirection(kLeft);
setState(kStanding);
mLayerManager.insert(mQuatsch, 1);
}
public void start() {
mTrucking = true;
Thread t = new Thread(this);
t.start();
}
public void run() {
int w = getWidth();
int h = getHeight();
Graphics g = getGraphics();
int frameCount = 0;
int factor = 2;
int animatedDelta = 0;
while (mTrucking) {
if (isShown()) {
int keyStates = getKeyStates();
if ((keyStates & LEFT_PRESSED) != 0) {
setDirection(kLeft);
setState(kRunning);
mBackground.move(3, 0);
mAtmosphere.move(3, 0);
mQuatsch.nextFrame();
}
else if ((keyStates & RIGHT_PRESSED) != 0) {
setDirection(kRight);
setState(kRunning);
mBackground.move(-3, 0);
mAtmosphere.move(-3, 0);
mQuatsch.nextFrame();
}
else {
setState(kStanding);
}
frameCount++;
if (frameCount % factor == 0) {
int delta = 1;
if (frameCount / factor < 10) delta = -1;
mAtmosphere.move(delta, 0);
if (frameCount / factor == 20) frameCount = 0;
mBackground.setAnimatedTile(mAnimatedIndex,
8 + animatedDelta++);
if (animatedDelta == 3) animatedDelta = 0;
}
g.setColor(0x5b1793);
g.fillRect(0, 0, w, h);
mLayerManager.paint(g, 0, 0);
flushGraphics();
}
try { Thread.sleep(80); }
catch (InterruptedException ie) {}
}
}
public void stop() {
mTrucking = false;
}
public void setVisible(int layerIndex, boolean show) {
Layer layer = mLayerManager.getLayerAt(layerIndex);
layer.setVisible(show);
}
public boolean isVisible(int layerIndex) {
Layer layer = mLayerManager.getLayerAt(layerIndex);
return layer.isVisible();
}
private void setDirection(int newDirection) {
if (newDirection == mDirection) return;
if (mDirection == kLeft)
mQuatsch.setTransform(Sprite.TRANS_MIRROR);
else if (mDirection == kRight)
mQuatsch.setTransform(Sprite.TRANS_NONE);
mDirection = newDirection;
}
private void setState(int newState) {
if (newState == mState) return;
switch (newState) {
case kStanding:
mQuatsch.setFrameSequence(kStandingSequence);
mQuatsch.setFrame(0);
break;
case kRunning:
mQuatsch.setFrameSequence(kRunningSequence);
break;
default:
break;
}
mState = newState;
}
}
Show various anchor points
/*--------------------------------------------------
* Text.java
*
* Show various anchor points
*
* Example from the book: Core J2ME Technology
* Copyright John W. Muchow http://www.CoreJ2ME.ru
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class Text extends MIDlet
{
private Display display; // The display
private TextCanvas canvas; // Canvas to display text
private AnchorPtList anchorPt; // List to query for anchor point
private int anchorPoint = Graphics.BASELINE | Graphics.HCENTER;
public Text()
{
display = Display.getDisplay(this);
canvas = new TextCanvas(this);
anchorPt = new AnchorPtList("Anchor point", List.IMPLICIT, this);
}
protected void startApp()
{
showCanvas();
}
protected void pauseApp()
{ }
protected void destroyApp( boolean unconditional )
{ }
public void showCanvas()
{
display.setCurrent(canvas);
}
public void showList()
{
display.setCurrent(anchorPt);
}
public int getAnchorPoint()
{
return anchorPoint;
}
public void setAnchorPoint(int anchorPoint)
{
this.anchorPoint = anchorPoint;
}
public void exitMIDlet()
{
destroyApp(true);
notifyDestroyed();
}
}
/*--------------------------------------------------
* Class TextCanvas
*
* Draw text at specified anchor point
*-------------------------------------------------*/
class TextCanvas extends Canvas implements CommandListener
{
private Command cmExit; // Exit midlet
private Command cmGetAnchorPt;
private Text midlet;
public TextCanvas(Text midlet)
{
this.midlet = midlet;
// Create commands & listen for events
cmExit = new Command("Exit", Command.EXIT, 1);
cmGetAnchorPt = new Command("Anchor", Command.SCREEN, 2);
addCommand(cmExit);
addCommand(cmGetAnchorPt);
setCommandListener(this);
}
/*--------------------------------------------------
* Draw text
*-------------------------------------------------*/
protected void paint(Graphics g)
{
int xcenter = getWidth() / 2,
ycenter = getHeight() / 2;
// Due to a bug in MIDP 1.0.3 we need to
// force a clear of the display
g.setColor(255, 255, 255); // White pen
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(0, 0, 0); // Black pen
// Choose a font
g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN, Font.SIZE_MEDIUM));
// Draw a dot at the center of the display
g.drawLine(xcenter, ycenter, xcenter, ycenter);
// x and y are always at the center of the display
// Move the text around x and y based on the anchor point
g.drawString("go j2me!", xcenter, ycenter, midlet.getAnchorPoint());
}
/*--------------------------------------------------
* Exit midlet or show anchor point selection list
*-------------------------------------------------*/
public void commandAction(Command c, Displayable d)
{
if (c == cmExit)
midlet.exitMIDlet();
else if (c == cmGetAnchorPt)
{
midlet.showList();
}
}
}
/*--------------------------------------------------
* Class AnchorPtList
*
* List to query for an anchor point
*-------------------------------------------------*/
class AnchorPtList extends List implements CommandListener
{
private Text midlet;
public AnchorPtList(String title, int listType, Text midlet)
{
// Call list constructor
super(title, listType);
this.midlet = midlet;
append("Top/Left", null);
append("Top/HCenter", null);
append("Top/Right", null);
append("Baseline/Left", null);
append("Baseline/HCenter", null);
append("Baseline/Right", null);
append("Bottom/Left", null);
append("Bottom/HCenter", null);
append("Bottom/Right", null);
setCommandListener(this);
}
/*--------------------------------------------------
* Commands to set anchor point
*-------------------------------------------------*/
public void commandAction(Command c, Displayable s)
{
switch (getSelectedIndex())
{
case 0:
midlet.setAnchorPoint(Graphics.TOP | Graphics.LEFT);
break;
case 1:
midlet.setAnchorPoint(Graphics.TOP | Graphics.HCENTER);
break;
case 2:
midlet.setAnchorPoint(Graphics.TOP | Graphics.RIGHT);
break;
case 3:
midlet.setAnchorPoint(Graphics.BASELINE | Graphics.LEFT);
break;
case 4:
midlet.setAnchorPoint(Graphics.BASELINE | Graphics.HCENTER);
break;
case 5:
midlet.setAnchorPoint(Graphics.BASELINE | Graphics.RIGHT);
break;
case 6:
midlet.setAnchorPoint(Graphics.BOTTOM | Graphics.LEFT);
break;
case 7:
midlet.setAnchorPoint(Graphics.BOTTOM | Graphics.HCENTER);
break;
case 8:
midlet.setAnchorPoint(Graphics.BOTTOM | Graphics.RIGHT);
break;
default:
midlet.setAnchorPoint(Graphics.BASELINE | Graphics.HCENTER);
}
midlet.showCanvas();
}
}
Simple Canvas
/*
Title: J2ME Games With MIDP2
Authors: Carol Hamer
Publisher: Apress
ISBN: 1590593820
*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
/**
* This is the main class of the hello world demo.
*
* @author Carol Hamer
*/
public class Hello extends MIDlet implements CommandListener {
/**
* The canvas is the region of the screen that has been allotted
* to the game.
*/
HelloCanvas myCanvas;
/**
* The Command objects appear as buttons in this example.
*/
private Command exitCommand = new Command("Exit", Command.EXIT, 99);
/**
* The Command objects appear as buttons in this example.
*/
private Command toggleCommand = new Command("Toggle Msg", Command.SCREEN, 1);
/**
* Initialize the canvas and the commands.
*/
public Hello() {
myCanvas = new HelloCanvas();
myCanvas.addCommand(exitCommand);
myCanvas.addCommand(toggleCommand);
// we set one command listener to listen to all
// of the commands on the canvas:
myCanvas.setCommandListener(this);
}
//----------------------------------------------------------------
// implementation of MIDlet
/**
* Start the application.
*/
public void startApp() throws MIDletStateChangeException {
// display my canvas on the screen:
Display.getDisplay(this).setCurrent(myCanvas);
myCanvas.repaint();
}
/**
* If the MIDlet was using resources, it should release
* them in this method.
*/
public void destroyApp(boolean unconditional)
throws MIDletStateChangeException {
}
/**
* This method is called to notify the MIDlet to enter a paused
* state. The MIDlet should use this opportunity to release
* shared resources.
*/
public void pauseApp() {
}
//----------------------------------------------------------------
// implementation of CommandListener
/*
* Respond to a command issued on the Canvas.
* (either reset or exit).
*/
public void commandAction(Command c, Displayable s) {
if(c == toggleCommand) {
myCanvas.toggleHello();
} else if(c == exitCommand) {
try {
destroyApp(false);
notifyDestroyed();
} catch (MIDletStateChangeException ex) {
}
}
}
}
/**
* This class represents the region of the screen that has been allotted
* to the game.
*
* @author Carol Hamer
*/
class HelloCanvas extends Canvas {
//---------------------------------------------------------
// fields
/**
* whether or not the screen should currently display the
* "hello world" message.
*/
boolean mySayHello = true;
//-----------------------------------------------------
// initialization and game state changes
/**
* toggle the hello message.
*/
void toggleHello() {
mySayHello = !mySayHello;
repaint();
}
//-------------------------------------------------------
// graphics methods
/**
* clear the screen and display the hello world message if appropriate.
*/
public void paint(Graphics g) {
// get the dimensions of the screen:
int width = getWidth();
int height = getHeight();
// clear the screen (paint it white):
g.setColor(0xffffff);
// The first two args give the coordinates of the top
// left corner of the rectangle. (0,0) corresponds
// to the top left corner of the screen.
g.fillRect(0, 0, width, height);
// display the hello world message if appropriate:.
if(mySayHello) {
Font font = g.getFont();
int fontHeight = font.getHeight();
int fontWidth = font.stringWidth("Hello World!");
// set the text color to red:
g.setColor(255, 0, 0);
g.setFont(font);
// write the string in the center of the screen
g.drawString("Hello World!", (width - fontWidth)/2,
(height - fontHeight)/2,
g.TOP|g.LEFT);
}
}
}
Text Example
//jad file (please verify the jar size)
/*
MIDlet-Name: TextExample
MIDlet-Version: 1.0
MIDlet-Vendor: MyCompany
MIDlet-Jar-URL: TextExample.jar
MIDlet-1: TextExample, , TextExample
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-1.0
MIDlet-JAR-SIZE: 100
*/
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.midlet.MIDlet;
public class TextExampleMIDlet extends MIDlet {
private Display display;
private MyCanvas canvas;
public TextExampleMIDlet() {
display = Display.getDisplay(this);
canvas = new MyCanvas(this);
}
protected void startApp() {
display.setCurrent(canvas);
}
protected void pauseApp() {
}
protected void destroyApp(boolean unconditional) {
}
public void exitMIDlet() {
destroyApp(true);
notifyDestroyed();
}
}
class MyCanvas extends Canvas implements CommandListener {
private Command exit;
private TextExampleMIDlet textExample;
public MyCanvas(TextExampleMIDlet textExample) {
this.textExample = textExample;
exit = new Command("Exit", Command.EXIT, 1);
addCommand(exit);
setCommandListener(this);
}
protected void paint(Graphics graphics) {
graphics.setColor(255, 255, 255);
graphics.fillRect(0, 0, getWidth(), getHeight());
graphics.setColor(255, 0, 0);
graphics.setFont(Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD, Font.SIZE_SMALL));
graphics.drawString("Profound statement.", 50, 10, Graphics.HCENTER | Graphics.BASELINE);
}
public void commandAction(Command command, Displayable displayable) {
if (command == exit) {
textExample.exitMIDlet();
}
}
}
Text MIDlet
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.midlet.MIDlet;
public class TextMIDlet extends MIDlet {
public void startApp() {
Displayable d = new TextCanvas();
d.addCommand(new Command("Exit", Command.EXIT, 0));
d.setCommandListener(new CommandListener() {
public void commandAction(Command c, Displayable s) {
notifyDestroyed();
}
});
Display.getDisplay(this).setCurrent(d);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
}
class TextCanvas extends Canvas {
public void paint(Graphics g) {
int w = getWidth();
int h = getHeight();
g.setColor(0xffffff);
g.fillRect(0, 0, w, h);
g.setColor(0x000000);
g.drawString("corner", 0, 0, Graphics.TOP | Graphics.LEFT);
g.drawString("corner", w, 0, Graphics.TOP | Graphics.RIGHT);
g.drawString("corner", 0, h, Graphics.BOTTOM | Graphics.LEFT);
g.drawString("corner", w, h, Graphics.BOTTOM | Graphics.RIGHT);
g.drawString("Sin Wagon", w / 2, h / 2, Graphics.BASELINE | Graphics.HCENTER);
}
}
Translate Coordinates
/*
J2ME: The Complete Reference
James Keogh
Publisher: McGraw-Hill
ISBN 0072227109
*/
//jad file (please verify the jar size)
/*
MIDlet-Name: TranslateCoordinates
MIDlet-Version: 1.0
MIDlet-Vendor: MyCompany
MIDlet-Jar-URL: TranslateCoordinates.jar
MIDlet-1: TranslateCoordinates, , TranslateCoordinates
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-1.0
MIDlet-JAR-SIZE: 100
*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class TranslateCoordinates extends MIDlet
{
private Display display;
private MyCanvas canvas;
public TranslateCoordinates ()
{
display = Display.getDisplay(this);
canvas = new MyCanvas (this);
}
protected void startApp()
{
display.setCurrent( canvas );
}
protected void pauseApp()
{
}
protected void destroyApp( boolean unconditional )
{
}
public void exitMIDlet()
{
destroyApp(true);
notifyDestroyed();
}
class MyCanvas extends Canvas implements CommandListener
{
private Command exit;
private TranslateCoordinates translateCoordinates;
private Image image = null;
public MyCanvas(TranslateCoordinates translateCoordinates)
{
this. translateCoordinates = translateCoordinates;
exit = new Command("Exit", Command.EXIT, 1);
addCommand(exit);
setCommandListener(this);
try
{
image = Image.createImage(70, 70);
Graphics graphics = image.getGraphics();
graphics.setColor(255,0,0);
graphics.fillArc(10, 10, 60, 50, 180, 180);
}
catch (Exception error)
{
Alert alert = new Alert("Failure",
"Creating Image", null, null);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}
}
protected void paint(Graphics graphics)
{
if (image != null)
{
graphics.setColor(255,255,255);
graphics.fillRect(0, 0, getWidth(), getHeight());
graphics.translate(45, 45);
graphics.drawImage(image, 0, 0,
Graphics.VCENTER | Graphics.HCENTER); }
}
public void commandAction(Command command, Displayable display)
{
if (command == exit)
{
translateCoordinates.exitMIDlet();
}
}
}
}
Translate coordinate system
/*--------------------------------------------------
* Translate.java
*
* Translate coordinate system
*
* Example from the book: Core J2ME Technology
* Copyright John W. Muchow http://www.CoreJ2ME.ru
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class Translate extends MIDlet
{
private Display display; // The display
private TranslateCanvas canvas; // Canvas
public Translate()
{
display = Display.getDisplay(this);
canvas = new TranslateCanvas(this);
}
protected void startApp()
{
display.setCurrent( canvas );
}
protected void pauseApp()
{ }
protected void destroyApp( boolean unconditional )
{ }
public void exitMIDlet()
{
destroyApp(true);
notifyDestroyed();
}
}
/*--------------------------------------------------
* Class Translate
*
* Draw image using translated coordinates
*-------------------------------------------------*/
class TranslateCanvas extends Canvas implements CommandListener
{
private Command cmExit; // Exit midlet
private Translate midlet;
private Image im = null;
private int translatex = 0, translatey = 0;
public TranslateCanvas(Translate midlet)
{
this.midlet = midlet;
// Create exit command & listen for events
cmExit = new Command("Exit", Command.EXIT, 1);
addCommand(cmExit);
setCommandListener(this);
try
{
// Create immutable image
im = Image.createImage("/bolt.png");
}
catch (java.io.IOException e)
{
System.err.println("Unable to locate or read .png file");
}
}
protected void paint(Graphics g)
{
if (im != null)
{
// Clear the background
g.setColor(255, 255, 255);
g.fillRect(0, 0, getWidth(), getHeight());
// Translate coordinates
g.translate(translatex, translatey);
// Always draw at 0,0
g.drawImage(im, 0, 0, Graphics.LEFT | Graphics.TOP);
}
}
public void commandAction(Command c, Displayable d)
{
if (c == cmExit)
midlet.exitMIDlet();
}
protected void keyPressed(int keyCode)
{
switch (getGameAction(keyCode))
{
case UP:
// If scrolling off the top, roll around to bottom
if (translatey - im.getHeight() < 0)
translatey = getHeight() - im.getHeight();
else
translatey -= im.getHeight();
break;
case DOWN:
// If scrolling off the bottom, roll around to top
if ((translatey + im.getHeight() + im.getHeight()) > getHeight())
translatey = 0;
else
translatey += im.getHeight();
break;
case LEFT:
// If scrolling off the left, bring around to right
if (translatex - im.getWidth() < 0)
translatex = getWidth() - im.getWidth();
else
translatex -= im.getWidth();
break;
case RIGHT:
// If scrolling off the right, bring around to left
if ((translatex + im.getWidth() + translatex) > getWidth())
translatex = 0;
else
translatex += im.getWidth();
break;
}
repaint();
}
}
Use pointer events to draw onto the Canvas
/*--------------------------------------------------
* Doodle.java
*
* Use pointer events to draw onto the Canvas
*
* Example from the book: Core J2ME Technology
* Copyright John W. Muchow http://www.CoreJ2ME.ru
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class Doodle extends MIDlet
{
private Display display; // The display
private DoodleCanvas canvas; // Canvas
public Doodle()
{
display = Display.getDisplay(this);
canvas = new DoodleCanvas(this);
}
protected void startApp()
{
display.setCurrent( canvas );
}
protected void pauseApp()
{ }
protected void destroyApp( boolean unconditional )
{ }
public void exitMIDlet()
{
destroyApp(true);
notifyDestroyed();
}
}
/*--------------------------------------------------
* Class DoodleCanvas
*
* Pointer event handling
*-------------------------------------------------*/
class DoodleCanvas extends Canvas implements CommandListener
{
private Command cmExit; // Exit midlet
private Command cmClear; // Clear display
private int startx = 0, // Where pointer was clicked
starty = 0,
currentx = 0, // Current location
currenty = 0;
private Doodle midlet;
private boolean clearDisplay = false;
/*--------------------------------------------------
* Constructor
*-------------------------------------------------*/
public DoodleCanvas(Doodle midlet)
{
this.midlet = midlet;
// Create exit command & listen for events
cmExit = new Command("Exit", Command.EXIT, 1);
cmClear = new Command("Clear", Command.SCREEN, 1);
addCommand(cmExit);
addCommand(cmClear);
setCommandListener(this);
}
/*--------------------------------------------------
* Paint the text representing the key code
*-------------------------------------------------*/
protected void paint(Graphics g)
{
// Clear the background (to white)
if (clearDisplay)
{
g.setColor(255, 255, 255);
g.fillRect(0, 0, getWidth(), getHeight());
clearDisplay = false;
startx = currentx = starty = currenty = 0;
return;
}
// Draw with black pen
g.setColor(0, 0, 0);
// Draw line
g.drawLine(startx, starty, currentx, currenty);
// New starting point is the current position
startx = currentx;
starty = currenty;
}
/*--------------------------------------------------
* Command event handling
*-------------------------------------------------*/
public void commandAction(Command c, Displayable d)
{
if (c == cmExit)
midlet.exitMIDlet();
else if (c == cmClear)
{
clearDisplay = true;
repaint();
}
}
/*--------------------------------------------------
* Pointer pressed
*-------------------------------------------------*/
protected void pointerPressed(int x, int y)
{
startx = x;
starty = y;
}
/*--------------------------------------------------
* Pointer moved
*-------------------------------------------------*/
protected void pointerDragged(int x, int y)
{
currentx = x;
currenty = y;
repaint();
}
}