huatu2.java

画图程序

 import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.awt.event.*;
import java.io.File;
import javax.imageio.ImageIO;
public class HuaTu2 implements MouseMotionListener,ActionListener{
  static final int r=3;
  static int ox, oy;
  static int flag=1;
  static Color [] color = {Color.red,Color.green,Color.blue,Color.yellow,Color.pink,Color.orange,Color.cyan,Color.magenta,Color.gray,Color.black};
  static String [] s = {"Red","Green","Blue","Yellow","Pink","Orange","Cyan","Magenta","Gray","Black"};
  static int mode;

  public static void main(String arg[]){
    final JFrame f=new JFrame("Paint");
    Container p=f.getContentPane();
    JPanel jpanel = new JPanel();
    p.setLayout(new FlowLayout());

    JMenuBar jmbar = new JMenuBar();
    JMenu jm = new JMenu("File");
    JMenuItem [] jmitem = {new JMenuItem("New"),new JMenuItem("Load"),new JMenuItem("Save"),new JMenuItem("Exit")};

    final BufferedImage ibuff;

    f.setJMenuBar(jmbar);
    jmbar.add(jm);
    for(int i=0;i<4;i++)
        jm.add(jmitem[i]);
    jmitem[0].addActionListener(new ActionListener()
       {
           public void actionPerformed(ActionEvent e)
           {
               Graphics g = f.getGraphics();
               
               Color col = g.getColor();
               g.setColor(Color.white);
               g.fillRect(0,0,f.getWidth(),f.getHeight());
               g.setColor(col);
           }
       }
    );
    jmitem[1].addActionListener(new ActionListener()
       {
           public void actionPerformed(ActionEvent e)
           {
               Graphics g = f.getGraphics();
               JFileChooser jfc = new JFileChooser();
               //jfc.setFileFilter(new JPGFilter());
              int option = jfc.showOpenDialog(f);
              if (option == JFileChooser.CANCEL_OPTION)
                  return;
              File file = jfc.getSelectedFile();
              Image img = Toolkit.getDefaultToolkit().getImage(file.getAbsolutePath());
              g.drawImage(img,0,0,f.getWidth(),f.getHeight(),f); 
           }
       }
     );
    jmitem[2].addActionListener(new ActionListener()
       {
           public void actionPerformed(ActionEvent e)
           {
               JFileChooser jfc = new JFileChooser();
               //jfc.setFileFilter(new JPGFilter());
               int option = jfc.showSaveDialog(f);
               if (option == JFileChooser.CANCEL_OPTION)
                  return;
               File file = jfc.getSelectedFile();
               //ImageIO.write(ibuff,"JPG",file);
            }
       }
     );
    jmitem[3].addActionListener(new ActionListener()
        {
           public void actionPerformed(ActionEvent e)
           {System.exit(0);}
        }
    );  
     
    jpanel.setBackground(Color.white);
    p.add(jpanel);

    JButton [] jb = new JButton[10]; 
    final JComboBox jc = new JComboBox();
    jc.addItem("Lines");
    jc.addItem("Rectangles");
    jc.addItem("Ovals");
    jc.addItem("Points");
    jc.addItemListener(new ItemListener()
       {
           public void itemStateChanged(ItemEvent e)
           {
               if (e.getStateChange() == ItemEvent.SELECTED)
                   mode = jc.getSelectedIndex();
           }
       }
    );
    jpanel.add(jc);
    
   //Graphics g.setColor(new Color(255,0,0));
   //ButtonEvent arg=new ButtonEvent(arg);


   for (int i=0;i<10;i++)
    {   
        jb[i] = new JButton(s[i]);
        jb[i].addActionListener(new HuaTu());
        p.add(jb[i]);
    }
    
    
    p.addMouseMotionListener(new  HuaTu());
    p.addMouseListener(new MouseAdapter()
       {
           int x1,y1,x2,y2;
           int temp;
           public void mousePressed(MouseEvent e)
           {
               if (mode!=3)
               {
                   x1 = e.getX();
                   y1 = e.getY();
               }
           }
           public void mouseReleased(MouseEvent e)
           {
               Container c = (Container)e.getSource();
               Graphics g = c.getGraphics();
               if (mode!=3)
               {
                   x2 = e.getX();
                   y2 = e.getY();
                   if (mode!=0){
                   if (x1>x2)
                   {
                      temp = x1;
                      x1 = x2;
                      x2 = temp;
                   }
                   if (y1>y2)
                   {
                      temp = y1;
                      y1 = y2;
                      y2 = temp;
                   }
                   }
                   g.setColor(color[flag]);
                   switch(mode)
                   {
                      case 0:
                         g.drawLine(x1,y1,x2,y2);break;
                      case 1:
                         g.drawRect(x1,y1,x2-x1,y2-y1);break;
                      case 2:
                         g.drawOval(x1,y1,x2-x1,y2-y1);break;
                   }
               }
           }
       }
    );                     
   
    f.setSize(800,800);
    f.setVisible(true);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  } 
  public void actionPerformed(ActionEvent e){
    for (int i=0;i<10;i++)
       if (e.getActionCommand().equals(s[i]))
       {
           flag = i;
           System.out.println(flag);
           break;
       }
  }
  public void mouseDragged(MouseEvent e){
    if (mode == 3)
    {
    Container c=(Container)e.getSource();
    Graphics g=c.getGraphics();
     if (ox>=0) {
      g.setColor(color[flag]);
      g.drawLine(ox,oy,e.getX(),e.getY());}
    
    ox=e.getX();oy=e.getY();
    }
  }
  public void mouseMoved(MouseEvent e){
    if (mode == 3)
       ox=-1;oy=-1;
  }
  
}