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

public class MyUI {
	//定義一組表示界面顯示狀態的數值
	public static final int UI_TITLE 		= 0;	//顯示標題畫面
	public static final int UI_HELP		= 1;	//顯示幫助畫面
	public static final int UI_BUTTON 	= 2;	//只顯示按鈕
	public static final int UI_HIDE 		= 3;	//隱藏界面
	public static final int UI_STATE_NUM	 = 4;	//界面狀態總數
	private int m_nState = UI_TITLE;				//當前的界面類型
	
	private Image 		m_TitleImg;					//標題畫面圖像
	private Image		m_HelpImg;					//幫助畫面圖像
	private MyButton	m_Button;
	
	public MyUI(MyButton button){
		m_Button = button;
		try{				//讀取標題圖像
			m_TitleImg = Image.createImage("/demo/title.png");
		}
		catch (Exception ex){} 
		try{				//讀取幫助圖像
			m_HelpImg = Image.createImage("/demo/help.png");
		}
		catch (Exception ex){} 
	}
	/*****
	 * 獲取當前的界面顯示類型
	 * @返回:當前界面的顯示類型
	 */
	public int getState(){
		return m_nState;
	}
	/*****
	 * 設置當前的界面顯示類型,并進行出錯處理
	 * @參數 nType.........要設置的顯示類型
	 */
	public void setState( int state ){
		if( state < 0 || state >= UI_STATE_NUM )
			return;
		m_nState = state;		
	}
	public MyButton getButton(){
		return m_Button;
	}
	/*****
	 * 處理按鍵的輸入
	 * @參數 keyStates.....當前的按鍵狀態
	 * @返回所選按鈕的類型
	 */
	public int Input( int keyStates ){
		int type = -1;
		switch( m_nState ){
		case UI_TITLE:
		case UI_BUTTON:
			{
				type = m_Button.Input(keyStates);
				switch(type){
				case MyButton.BUTTON_CONTINUE:
				case MyButton.BUTTON_START:
					setState(UI_HIDE);
					break;
				case MyButton.BUTTON_HELP:
					setState(UI_HELP);
				}
			}
			break;
		case UI_HELP:
			if( ( keyStates & GameCanvas.FIRE_PRESSED ) != 0 )
				setState(UI_TITLE);
			break;
		case UI_HIDE:
			break;
		}
		return type;
	}
	/*****
	 * 顯示界面內容
	 * @參數 g.............對應顯示屏幕
	 * @參數 scrWidth......屏幕的寬
	 * @參數 scrHeight.....屏幕的高
	 */
	public void Paint( Graphics g, int scrWidth, int scrHeight ){
		int x = scrWidth;
		int y = scrHeight;
		switch( m_nState ){
		case UI_TITLE:				//顯示標題畫面
			if( m_TitleImg != null ){
				x = ( x - m_TitleImg.getWidth() ) / 2;
				y = ( y - m_TitleImg.getHeight() ) / 2;
				g.drawImage(m_TitleImg, x, y, 0 );
			}
			m_Button.Paint(g, scrWidth, scrHeight);
			break;
		case UI_HELP:				//顯示幫助畫面
			if( m_HelpImg != null ){
				x = ( x - m_HelpImg.getWidth() ) / 2;
				y = ( y - m_HelpImg.getHeight() ) / 2;
				g.drawImage(m_HelpImg, x, y, 0 );
			}
			break;
		case UI_BUTTON:				//只顯示按鈕
			m_Button.Paint(g, scrWidth, scrHeight);
			break;
		case UI_HIDE:				//隱藏界面
			break;
		}
	}
}