import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class MainClass 
{
	public static void main(String[] args) 
	{
		// TODO Auto-generated method stub
		try {
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (InstantiationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (UnsupportedLookAndFeelException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		 SwingUtilities.invokeLater(new Runnable() 
		 {
		        @Override
		        public void run() 
		        {
		        	My_UI mui=new My_UI("");
		        	mui.Show(1024, 768);
		        }
		 });
	}
	
	static class My_UI
	{
		private JFrame main_frame;
		private JMenuBar menuBar;
		private JMenu menu;
		private JMenuItem menuItemOpen,menuItemClose,menuItemExit;
		private Viewer img_view;
		
		private void BuildUI()
		{
			menuBar = new JMenuBar();
	        menu = new JMenu("Файл");
	        menuBar.add(menu);
	        menuItemOpen = new JMenuItem("Загрузити зображення");
	        menuItemOpen.addActionListener(new ActionListener() 
	        {
	            @Override
	            public void actionPerformed(ActionEvent event)
	            {
	            	JFileChooser fc = new JFileChooser();
	            	int returnVal=fc.showOpenDialog(main_frame);
	            	if (returnVal == JFileChooser.APPROVE_OPTION) 
	            	{
	                    File file = fc.getSelectedFile();
	                    img_view.clean();
	                    img_view.setImage(file);
	            	}
	            }
	        });
	        menu.add(menuItemOpen);
	        menu.addSeparator();
	        menuItemClose = new JMenuItem("Очистити");
	        menuItemClose.addActionListener(new ActionListener() 
	        {
	            @Override
	            public void actionPerformed(ActionEvent event)
	            {
	            	img_view.clean();
	            }
	        });
	        menu.add(menuItemClose);
	        menu.addSeparator();
	        menuItemExit = new JMenuItem("Вихід");
	        menuItemExit.addActionListener(new ActionListener() 
	        {
	            @Override
	            public void actionPerformed(ActionEvent event)
	            {
	            	main_frame.dispose();
	            }
	        });
	        menu.add(menuItemExit);
	        main_frame.setJMenuBar(menuBar);
	        img_view = new Viewer();
	        main_frame.add(img_view);
		}
		
		public My_UI(String wnd_title)
		{
			main_frame=new JFrame(wnd_title);
			main_frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		}
		public void Show(int widht,int heigt)
		{
			main_frame.setBounds(0, 0, widht, heigt);
			BuildUI();
			main_frame.setVisible(true);
		}
		
		static class Viewer extends JPanel
		{
			/**
			 * 
			 */
			private static final long serialVersionUID = -1050612360192626088L;
			private BufferedImage image;
			public Viewer()
			{
				image=null;
			}
			public void paint(Graphics g) 
			{
				if(this.image!=null)
				{
					g.drawImage(image, 0, 0,g.getClipBounds().width,g.getClipBounds().height, null);
				}
		    }
			public void setImage(File iFile)
			{
				try 
				{
					this.image=ImageIO.read(iFile);
					this.repaint();
				} 
				catch (IOException e) 
				{
					// TODO Auto-generated catch block
					JOptionPane.showMessageDialog(this.getParent(),e.toString(),"Error",JOptionPane.ERROR_MESSAGE);
					e.printStackTrace();
				}
			}
			public void clean()
			{
				if(this.image!=null)
				{
					this.image.flush();
					this.image=null;
					this.repaint();
				}
			}
		}