Swingのペイント

import java.awt.*;

import java.awt.event.*;

import java.awt.geom.*;

import java.awt.image.*;

import java.io.*;

import javax.imageio.*;

import javax.swing.*;

import java.awt.image.*;

import java.util.*;

import java.util.List;

import javax.imageio.stream.*;



public class POSE3{

    public static void main(String[] args){

        MyFrame mf = new MyFrame();

        mf.setTitle("PaintOpenSaveEdit");

        mf.setSize(600, 500);

        mf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        mf.show();

    }

}



class MyFrame extends JFrame {

    private JMenuBar menuBar;

    private JFileChooser fileChooser;

//  private JPanel panel;

	

	private BufferedImage[] images;

    private static Set readerSuffixes = getReaderSuffixes();

    private static Set writerFormats = getWriterFormats();

	

	private final JPanel panel; 

	private Point2D.Double p1 = new Point2D.Double(); // 始点 

	private Point2D.Double p2 = new Point2D.Double(); // 終点 

	private Line2D.Double line = new Line2D.Double(); // 直線 

	private BufferedImage image = null; // イメージ 

//Graphics2D imageGraphics; // イメージのGraphics 

	private boolean flag = false; 

	

	public MyFrame(){ 

		panel = new JPanel() { 

			public void paintComponent(Graphics g) { 

			super.paintComponent(g); 

			((Graphics2D)g).drawImage(image, 0, 0, this); 

			} 

		};

		this.getContentPane().add(new JScrollPane(panel), BorderLayout.CENTER); 

		panel.addMouseMotionListener(new MouseMotionAdapter() { 

			public void mouseDragged(MouseEvent e) { 

				p1.setLocation(p2); 

				p2.setLocation((double)e.getX(), (double)e.getY()); 

				if(image==null) { 

					Dimension d = panel.getSize(); 

					int w = d.width; 

					int h = d.height; 

					image = (BufferedImage)panel.createImage(w,h); 

				} 

				Graphics2D imageGraphics = (Graphics2D)image.createGraphics(); 

				imageGraphics.setStroke(new BasicStroke(3.0F)); 

				imageGraphics.setPaint(Color.black); 

				if(flag) { 

					imageGraphics.drawImage(image, 0, 0, null); 

					flag = false; 

				} 

				if(!p1.equals(p2)) { 

					line.setLine(p1,p2); 

					imageGraphics.draw(line); 

					p1.setLocation(p2); 

				} 

				imageGraphics.dispose(); 

				repaint(); 

			} 

		}); 

		

		panel.addMouseListener(new MouseAdapter() { 

			public void mousePressed(MouseEvent e) { 

				p1.setLocation((double)e.getX(), (double)e.getY()); 

				p2.setLocation(p1); 

			} 

		}); 

		

		

        JMenu fileMenu = new JMenu("File");

        JMenuItem openItem = new JMenuItem("Open");

		openItem.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent event) {

               openFile();

            }

         });

        fileMenu.add(openItem);

		

        JMenu saveMenu = new JMenu("Save");

		fileMenu.add(saveMenu);      

        Iterator iter = writerFormats.iterator();

        while (iter.hasNext()) {

            final String formatName = (String)iter.next();

         	JMenuItem formatItem = new JMenuItem(formatName);

	        saveMenu.add(formatItem);

    	    formatItem.addActionListener(new

            ActionListener() {

               public void actionPerformed(ActionEvent event) {

                  saveFile(formatName);

               }

            });         

        }

        JMenuItem exitItem = new JMenuItem("Exit");

        exitItem.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent event) {

               System.exit(0);

            }

         });

        fileMenu.add(exitItem);

		

      JMenu editMenu = new JMenu("Edit");

		JMenuItem clearItem = new JMenuItem("Clear");

		clearItem.addActionListener(new ActionListener() {

			public void actionPerformed(ActionEvent event) {

				panel.repaint();

			}

		});

		editMenu.add(clearItem);

		

		JMenuBar menuBar = new JMenuBar();

    　　　　　    menuBar.add(fileMenu);

		menuBar.add(editMenu);

     　　　　　   setJMenuBar(menuBar);

    }



    public void openFile()

   {  

      JFileChooser chooser = new JFileChooser();

      chooser.setCurrentDirectory(new File("."));



      chooser.setFileFilter(new

         javax.swing.filechooser.FileFilter()

         {  

            public boolean accept(File f)

            {  

               if (f.isDirectory()) return true;

               String name = f.getName();

               int p = name.lastIndexOf('.');

               if (p == -1) return false;

               String suffix 

                  = name.substring(p + 1).toLowerCase();

               return readerSuffixes.contains(suffix);

            }

            public String getDescription()

            {  

               return "Image files";

            }

         });

      int r = chooser.showOpenDialog(this);

      if (r != JFileChooser.APPROVE_OPTION) return;

	  

      File f = chooser.getSelectedFile();

      try{

	  	image = ImageIO.read(f.toURL()); 

		panel.setPreferredSize(new Dimension(image.getWidth(), image.getHeight())); 

		flag = true; 

		}catch(IOException exception) { 

			JOptionPane.showMessageDialog(this, exception); 

		} 

      panel.revalidate();

   }



   public void saveFile(final String formatName)

   {

      JFileChooser chooser = new JFileChooser();

      chooser.setCurrentDirectory(new File("."));

	  

	  Iterator iter = ImageIO.getImageWritersByFormatName(formatName);

	  ImageWriter writer = (ImageWriter)iter.next();



      chooser.setFileFilter(new

         javax.swing.filechooser.FileFilter()

         {  

            public boolean accept(File f)

            {  

               if (f.isDirectory()) return true;

               String name = f.getName();

               int p = name.lastIndexOf('.');

               if (p == -1) return false;

               String suffix 

                  = name.substring(p + 1).toLowerCase();

               return writerFormats.contains(suffix);

            }

            public String getDescription()

            {  

               return "Image files";

            }

         });



      int r = chooser.showSaveDialog(this);

      if (r != JFileChooser.APPROVE_OPTION) return;

  	  File f = chooser.getSelectedFile();

      try

      {

	  	ImageOutputStream imageOut 

            = ImageIO.createImageOutputStream(f);

         writer.setOutput(imageOut);

                   

         writer.write(new IIOImage(images[0], null, null));      

         for (int i = 1; i < images.length; i++)

         {

            IIOImage iioImage 

               = new IIOImage(images[i], null, null);

            if (writer.canInsertImage(i))

               writer.writeInsert(i, iioImage, null); 

         }

      }

      catch (IOException exception)

      {

         JOptionPane.showMessageDialog(this, exception);

      }

   }

   

   public static Set getReaderSuffixes()

   {

      TreeSet readerSuffixes = new TreeSet();

      String[] informalNames = ImageIO.getReaderFormatNames();

      for (int i = 0; i < informalNames.length; i++)

      {

         Iterator iter = ImageIO.getImageReadersByFormatName(

            informalNames[i]);

         while (iter.hasNext())

         {

            ImageReader reader = (ImageReader)iter.next();

            String[] s = reader.getOriginatingProvider()

               .getFileSuffixes();

            readerSuffixes.addAll(Arrays.asList(s));

         }

      }  

      return readerSuffixes;

   }

   

   public static Set getWriterFormats()

   {

      TreeSet writerFormats = new TreeSet();

      TreeSet formatNames = new TreeSet(Arrays.asList(

         ImageIO.getWriterFormatNames()));

      while (formatNames.size() > 0)

      {

         String name = (String)formatNames.iterator().next();

         Iterator iter = ImageIO.getImageWritersByFormatName(

            name);

         ImageWriter writer = (ImageWriter)iter.next();

         String[] names = writer.getOriginatingProvider()

            .getFormatNames();

         writerFormats.add(names[0]);

         formatNames.removeAll(Arrays.asList(names));

      }

      return writerFormats;

   }

}

	

        JMenu saveMenu = new JMenu("Save");

		fileMenu.add(saveMenu);      

        Iterator iter = writerFormats.iterator();

        while (iter.hasNext()) {

            final String formatName = (String)iter.next();

         	JMenuItem formatItem = new JMenuItem(formatName);

	        saveMenu.add(formatItem);

    	    formatItem.addActionListener(new

            ActionListener() {

               public void actionPerformed(ActionEvent event) {

                  saveFile(formatName);

               }

            });         

        }

  JMenu editMenu = new JMenu("Edit");

		JMenuItem clearItem = new JMenuItem("Clear");

		clearItem.addActionListener(new ActionListener() {

			public void actionPerformed(ActionEvent event) {

				panel.repaint();

			}

		});

		editMenu.add(clearItem);