import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.net.*;
import java.applet.*;
//ResourceLocator.java 演示用資源定位器裝載圖片和音頻文件到應用程序和小應用程序
public class ResourceLocator extends JApplet
    implements ActionListener,ItemListener{
	//圖像畫板演示一個圖片
	private ImagePanel imagePanel =new ImagePanel();
	//Combo box選擇一個國家
	private JComboBox jcboCountry = new JComboBox();
	//Button 用來播放音頻文件
	private JButton jbtPlayAnthem = new JButton("Play Anthem");
	//選擇國家
	private String country = "china";
	/** 初始化applet*/
	public void init(){
		    JPanel p = new JPanel();
		p.add(new JLabel("選擇一個國家"));
		p.add(jcboCountry);
		p.add(jbtPlayAnthem);
		//初始化 combo box
		jcboCountry.addItem("China");
		jcboCountry.addItem("Norway");
		jcboCountry.addItem("America");
		jcboCountry.addItem("India");
		jcboCountry.addItem("Germany");
		jcboCountry.addItem("Denmark");
		//默認中國國旗
		imagePanel.showImage(createImage("china.jpg"));
		imagePanel.setPreferredSize(new Dimension(300,300));
		getContentPane().add(p,BorderLayout.NORTH);
		getContentPane().add(imagePanel,BorderLayout.CENTER);
		imagePanel.setBorder(new LineBorder(Color.black,1));
		//注冊監聽器
		jbtPlayAnthem.addActionListener(this);
		jcboCountry.addItemListener(this);
	}
	    /** 處理響應事件*/
	public void actionPerformed(ActionEvent e){
		//得到文件名
		String filename = null;
		//.wav 音頻文件存放在文件夾anthem下
		if (country.equals("China"))
			filename = "china.wav";
		else if(country.equals("Norway"))
			filename = "norway.wav";
		else if(country.equals("American"))
			filename = "american.wav";
		else if(country.equals("India"))
			filename = "india.wav";
		else if(country.equals("Germany"))
			filename = "germany.wav";
		else if(country.equals("Denmark"))
			filename = "denmark.wav";
		//創建音頻剪輯并播放它
		createAudioClip(filename).play();	
	}
	/**處理ItemEvent*/
	public void itemStateChanged(ItemEvent e){
		//選擇一個國家
		country = (String)jcboCountry.getSelectedItem();
		//得到文件名
		String filename = null;
		//.jpg文件存放在文件夾image中
		if (country.equals("China"))
			filename = "china.jpg";
		else if(country.equals("Norway"))
			filename = "norway.jpg";
		else if(country.equals("American"))
			filename = "american.jpg";
		else if(country.equals("India"))
			filename = "india.jpg";
		else if(country.equals("Germany"))
			filename = "germany.jpg";
		else if(country.equals("Denmark"))
			filename = "denmark.jpg";
		//從文件夾image中裝載圖片，顯示在面板上
		imagePanel.showImage(createImage(filename));	
	}
	/** 從指定的文件中創建一個音頻*/
	public AudioClip createAudioClip(String filename){
		//獲得文件的URL
		URL url = this.getClass().getResource("anthem/"+filename);
		//返回音頻剪輯
		return Applet.newAudioClip(url);
	}
	/** 從指定的文件中創建一個圖片*/
	public Image createImage(String filename){
		//獲得文件的URL
		URL url = this.getClass().getResource("image/"+filename);
		//獲得一個image icon
		ImageIcon imageIcon = new ImageIcon(url);
		//返回圖片
		return imageIcon.getImage();
	 }
	 /** 主函數*/
	public static void main(String []args){
		//創建一個窗體
		JFrame frame = new JFrame("升旗奏國歌");
		//創建一個applet實例
		ResourceLocator applet = new ResourceLocator();
		//添加實例applet到窗體上
		frame.getContentPane().add(applet,BorderLayout.CENTER);
		//激活init() 和start()
		applet.init();
		applet.start();
		//演示窗體
		frame.pack();
		frame.setVisible(true);	
	}
}
class ImagePanel extends JPanel {
       public ImagePanel panel;
       public Image img; 
          //構造方法
	   public ImagePanel() {
		this.setBackground(Color.white);
	   }
	   //顯示圖片
	   public void showImage(Image image){
		   img=image;
		   panel = new ImagePanel();
	   }
	   //繪制圖片
	   public void paint(Graphics g){
		   g.drawImage(img,0,0,this);
	   }
	   //設置窗口大小
	   public void setPreferredSize(Dimension d){
		    setSize(d);
	   } 
	}