package Drummer;import java.util.*;import java.io.*;import javax.microedition.midlet.*;import javax.microedition.lcdui.*;import javax.microedition.media.*;import javax.microedition.media.control.*;public class DrummerCanvas extends Canvas implements CommandListener {	private static final String TITLE = "Drummer例子";	private static final String LOGO = "/Logo.png";	private Command backCommand = new Command("返回", Command.BACK, 1);	private Command exitCommand = new Command("退出", Command.EXIT, 1);	private Command helpCommand = new Command("幫助", Command.ITEM, 10);	private static int TITLE_TOP = 2;	private static int LOGO_GAP = 2;	private static int CURR_DRUM_GAP = 2;	private static int STATUS_GAP = 2;	private Image logo = null;	private Display parent;	private String status = "";	private String currDrum = "";	private int displayWidth = -1;	private int displayHeight = -1;	private int textHeight = 10;	private int logoTop = 0;	private int currDrumTop = 0;	private int statusTop = 0;	private MIDIControl mc;	//MIDI鼓聲數據	private static final int[] DRUM_NUMBERS = { 0, // not used			0x2A, // 1: closed hihat			0x2E, // 2: open hihat			0x36, // 3: Tambourine			0x32, // 4: hi tom			0x2F, // 5: mid tom			0x2B, // 6: low tom			0x33, // 7: ride cymbal			0x38, // 8: cow bell			0x31, // 9: crash cymbal			0x24, // *: bass drum			0x27, // 0: hand clap			0x28, // #: snare drum	};	//屏幕顯示的當前敲擊的鼓聲名稱	private static final String[] DRUM_NAMES = { "", // not used			"Closed Hi-Hat", // 1			"Open Hi-Hat", // 2			"Tambourine", // 3			"Hi Tom", // 4			"Mid Tom", // 5			"Low Tom", // 6			"Ride Cymbal", // 7			"Cow Bell", // 8			"Crash Cymbal", // 9			"Bass Drum", // *			"Hand Clap", // 0			"Snare Drum", // #	};	private static final String[] SHORT_DRUM_NAMES = { "", "CH", "OH", "TB",			"HT", "MT", "LT", "RC", "CB", "CC", "BD", "HC", "SD", };	private static final int[] DRUM_KEYS = { 0, // not used			KEY_NUM1, KEY_NUM2, KEY_NUM3, KEY_NUM4, KEY_NUM5, KEY_NUM6,			KEY_NUM7, KEY_NUM8, KEY_NUM9, KEY_STAR, KEY_NUM0, KEY_POUND, };	public DrummerCanvas(Display dis) {		super();		this.parent = dis;		show();	}	public void commandAction(Command c, Displayable s) {		if (c == backCommand) {			parent.setCurrent(this);		} else if (c == helpCommand) {			showHelp();		}		if (c ==exitCommand) {		}	}	private void status(String s) {		status = s;		repaint(0, statusTop, displayWidth, textHeight);		serviceRepaints();	}	//提示當前敲鼓聲音	private void setCurrDrum(int num) {		currDrum = DRUM_NAMES[num];		repaint(0, currDrumTop, displayWidth, textHeight);		serviceRepaints();	}	public void updateDisplay() {		repaint();		serviceRepaints();	}	//初始化DrummerDemo	public void show() {		addCommand(exitCommand);		addCommand(helpCommand);		setCommandListener(this);		status("Prefetching and getting MIDIControl");		updateDisplay();		new Thread(new Runnable() {			public void run() {				try {					mc = getMIDIControl();					status("Ready.");				} catch (Exception e) {					//status(Utils.friendlyException(e));					mc = null;				}			}		}).start();	}	protected void keyPressed(int keycode) {		try {			for (int num = 1; num < DRUM_KEYS.length; num++) {				if (keycode == DRUM_KEYS[num]) {					playDrum(num);					return;				}			}					} catch (Throwable t) {		}	}	//播放鼓聲	private void playDrum(int num) {		if (mc == null)			return;		setCurrDrum(num);		mc.shortMidiEvent(0x99, DRUM_NUMBERS[num], 120);		mc.shortMidiEvent(0x99, DRUM_NUMBERS[num], 0);	}	private boolean intersects(int clipY, int clipHeight, int y, int h) {		return (clipY <= y + h && clipY + clipHeight >= y);	}	public void paint(Graphics g) {		try {			if (displayHeight == -1) {				displayWidth = getWidth();				displayHeight = getHeight();				textHeight = g.getFont().getHeight();				logo = getLogo();				int currTop = TITLE_TOP + textHeight;				if (logo != null) {					currTop += LOGO_GAP;					logoTop = currTop;					currTop += logo.getHeight();				}				// curr drum: before-last line				currDrumTop = displayHeight - 2 * textHeight - STATUS_GAP;				// status: last line.				statusTop = displayHeight - textHeight;			}			int clipX = g.getClipX();			int clipY = g.getClipY();			int clipWidth = g.getClipWidth();			int clipHeight = g.getClipHeight();			// 繪畫背景			g.setColor(0);			g.fillRect(clipX, clipY, clipWidth, clipHeight);			// 繪畫標題			if (intersects(clipY, clipHeight, TITLE_TOP, textHeight)) {				g.setColor(0xFF7f00);				g.drawString(TITLE, displayWidth >> 1, TITLE_TOP, Graphics.TOP						| Graphics.HCENTER);			}			// 顯示圖標			if (logo != null					&& intersects(clipY, clipHeight, logoTop, logo.getHeight())) {				g.drawImage(logo, displayWidth / 2, logoTop, Graphics.TOP						| Graphics.HCENTER);			}			// 提示當前鼓聲名稱			if (intersects(clipY, clipHeight, currDrumTop, textHeight)) {				g.setColor(0xE0E0FF);				g.drawString(currDrum, 0, currDrumTop, Graphics.TOP						| Graphics.LEFT);			}			// 狀態			if (intersects(clipY, clipHeight, displayHeight - textHeight,					textHeight)) {				g.setColor(0xFAFAFA);				g.drawString(status, 0, displayHeight, Graphics.BOTTOM						| Graphics.LEFT);			}		} catch (Throwable t) {		}	}	/**	 * 顯示幫組	 */	public void showHelp() {		List list = new List("Drummer Help", Choice.IMPLICIT);		list.append("Use the numeric keys", null);		list.append("to play drums. Each", null);		list.append("Key corresponds to a", null);		list.append("different drum.", null);		list.addCommand(backCommand);		list.setCommandListener(this);		parent.setCurrent(list);	}	private Image getLogo() {		if (logo == null) {			try {				logo = Image.createImage(LOGO);			} catch (Exception ex) {				logo = null;			}			if (logo == null) {			}		}		return logo;	}	MIDIControl getMIDIControl() throws Exception {		Player mp = null;		if (mp == null) {			mp = Manager.createPlayer(Manager.MIDI_DEVICE_LOCATOR);			mp.prefetch();		}		return (MIDIControl) mp				.getControl("javax.microedition.media.control.MIDIControl");	}}