mybutton.java

坦克大战

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.game.Sprite;


public class MyButton {
	//定义一组表示按钮种类的数值
	public static final int BUTTON_START 		= 0;	//开始按钮
	public static final int BUTTON_RESET		= 1;	//复位按钮
	public static final int BUTTON_CONTINUE 	= 2;	//继续按钮
	public static final int BUTTON_HELP		= 3;	//帮助按钮
	public static final int BUTTON_SAVE		= 4;	//保存按钮
	public static final int BUTTON_EXIT		= 5;	//退出按钮
	public static final int BUTTON_TYPE_NUM	 = 6;	//按钮种类
	
	private Sprite		m_ButtonSp;						//按钮精灵图像
	private int		m_aIndex[];						//按钮的种类
	private boolean 	m_abShow[];						//按钮是否显示的标志
	private int		m_nShowNum 	= 0;				//当前显示的按钮数量
	private int		m_nFocusType = -1;				//高亮按钮类型
	//构造方法
    //参数width,height设置按钮精灵的宽和高
	//6个Index参数分别是各类型的按钮在精灵图像中的索引,-1表示没有这种按钮的图像
	public MyButton(int width, int height, int startIndex, int resetIndex, 
			int continueIndex, int helpIndex, int saveIndex, int exitIndex){
		m_aIndex = new int[BUTTON_TYPE_NUM];
		m_abShow = new boolean[BUTTON_TYPE_NUM];
		m_nShowNum = 0;
		for( int n = 0; n < BUTTON_TYPE_NUM; n ++ ){
			m_abShow[n] = false;
			m_aIndex[n] = -1;
		}
		try{
			Image img = Image.createImage("/demo/button.png");
			m_ButtonSp = new Sprite(img, width, height);
			m_ButtonSp.defineReferencePixel(width/2, height/2);
		}
		catch (Exception ex){}
		m_aIndex[BUTTON_START] 		= startIndex;
		m_aIndex[BUTTON_RESET] 		= resetIndex;
		m_aIndex[BUTTON_CONTINUE] 	= continueIndex;
		m_aIndex[BUTTON_HELP] 		= helpIndex;
		m_aIndex[BUTTON_SAVE] 		= saveIndex;
		m_aIndex[BUTTON_EXIT] 		= exitIndex;
	}
	//设置各种按钮的显示标志
	public void setShow( boolean bStart, boolean bReset, boolean bContinue, 
			boolean bHelp, boolean bSave, boolean bExit ){	
		m_abShow[BUTTON_START] 		= bStart;
		m_abShow[BUTTON_RESET] 		= bReset;
		m_abShow[BUTTON_CONTINUE] 	= bContinue;
		m_abShow[BUTTON_HELP] 		= bHelp;
		m_abShow[BUTTON_SAVE] 		= bSave;
		m_abShow[BUTTON_EXIT] 		= bExit;
		
		m_nShowNum = 0;
		m_nFocusType = -1;
		for( int n = 0; n < BUTTON_TYPE_NUM; n ++ ){
			if( m_abShow[n] && m_aIndex[n] >= 0 ){
				//设置第一个显示的按钮为当前高亮的按钮
				if( m_nFocusType < 0 )
					m_nFocusType = n;
				m_nShowNum++;
			}
		}
	}
	//处理按键的输入,返回选择的按键类型
	public int Input(int keyStates){
		if( ( keyStates & GameCanvas.UP_PRESSED ) != 0 ){
			int temp = m_nFocusType - 1;
			while( temp >= 0 ){
				if( m_abShow[temp] && m_aIndex[temp] >= 0 ){
					m_nFocusType = temp;
					break;
				}
				temp --;
			}
		}
		if( ( keyStates & GameCanvas.DOWN_PRESSED ) != 0 ){
			int temp = m_nFocusType + 1;
			while( temp < BUTTON_TYPE_NUM ){
				if( m_abShow[temp] && m_aIndex[temp] >= 0 ){
					m_nFocusType = temp;
					break;
				}
				temp ++;
			}
		}
		if( ( keyStates & GameCanvas.FIRE_PRESSED ) != 0 ){
			return m_nFocusType;
		}
		return -1;			
	}
	//显示按钮
	public void Paint(Graphics g, int scrWidth, int scrHeight){
		if( m_ButtonSp == null )
			return;
		int h = m_ButtonSp.getHeight() + 2;
		int x = 15;
		int y = scrHeight - h * m_nShowNum - 15;
		for( int n = 0; n < BUTTON_TYPE_NUM; n ++ )
		{
			if( m_abShow[n] && m_aIndex[n] >= 0 )
			{//如果需要显示按钮，且该类型按钮的图像存在，则显示
				if( m_nFocusType == n )
				{//显示高亮的按钮
					m_ButtonSp.setFrame(m_aIndex[n]);
					m_ButtonSp.setPosition(x, y);
					m_ButtonSp.paint(g);
				}
				else
				{//显示灰色按钮
					int half = m_ButtonSp.getFrameSequenceLength() / 2;
					m_ButtonSp.setFrame(m_aIndex[n] + half);
					m_ButtonSp.setPosition(x, y);
					m_ButtonSp.paint(g);
				}
				y = y + h;
			}
		}
	}
}