myui.java

J2ME手机游戏50例

package demo;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.GameCanvas;

public class MyUI {
	//定义一组界面的显示状态
	public static final int UI_TITLE 		= 0;	//显示标题画面
	public static final int UI_HIDE 		= 1;	//不显示任何画面
	public static final int UI_STATE_NUM	= 2;	//界面状态总数
	
	private int m_nState = UI_TITLE;				//存储当前的状态
	
	private Image m_TitleImg;						//标题画面图像

	/*****构造方法***********************/
	public MyUI(){
		try{				//读取标题图像
			m_TitleImg = Image.createImage("/demo/title.png");
		}
		catch (Exception ex){} 
	}
	
	/*****获取当前的界面显示状态**********/
	public int getState(){ return m_nState; }
	
	/*****设置当前的界面显示类型**********/
	public void setState( int state ){
		if( state < 0 || state >= UI_STATE_NUM )
			return;
		m_nState = state;		
	}
	
	/*****处理按键的输入
	 * 参数keyStates是按键的状态值*******/
	public void Input( int keyStates ){
		switch( m_nState ){
		case UI_TITLE:								//显示标题画面时
			if( ( keyStates & GameCanvas.FIRE_PRESSED ) != 0 )
				setState(UI_HIDE);
			break;
		case UI_HIDE:								//界面隐藏时
			break;
		}
	}
	
	/*****显示界面图像，参数g对应显示屏幕
	 * 参数scrWidth与scrHeight分别是屏幕的宽与高*/
	public void Paint( Graphics g, int scrWidth, int scrHeight ){
		int x = scrWidth;
		int y = scrHeight;
		switch( m_nState ){
		case UI_TITLE:								//显示标题画面
			if( m_TitleImg != null ){
				x = ( x - m_TitleImg.getWidth() ) / 2;
				y = ( y - m_TitleImg.getHeight() ) / 2;
				g.drawImage(m_TitleImg, x, y, 0 );
			}
			break;
		case UI_HIDE:								//隐藏界面
			break;
		}
	}
}