beancontainer.java

这是JFrame的一些例子(chapter4)。可以参考一下。想要做GUI的人不妨看一看

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.beans.*;
import java.lang.reflect.*;

import javax.swing.*;

import dl.*;

public class BeanContainer extends JFrame implements FocusListener
{
  protected File m_currentDir = new File(".");
  protected Component m_activeBean;
  protected String m_className = "clock.Clock";
  protected JFileChooser m_chooser = new JFileChooser();

  public BeanContainer() {
    super("Simple Bean Container");
    getContentPane().setLayout(new FlowLayout());
   
    setSize(300, 300);

    JPopupMenu.setDefaultLightWeightPopupEnabled(false);

    JMenuBar menuBar = createMenuBar();
    setJMenuBar(menuBar);

    WindowListener wndCloser = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    addWindowListener(wndCloser);

    setVisible(true);
  }

  protected JMenuBar createMenuBar() {
    JMenuBar menuBar = new JMenuBar();
    
    JMenu mFile = new JMenu("File");

    JMenuItem mItem = new JMenuItem("New...");
    ActionListener lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {  
        Thread newthread = new Thread() {
          public void run() {
            String result = (String)JOptionPane.showInputDialog(
              BeanContainer.this, 
              "Please enter class name to create a new bean", 
              "Input", JOptionPane.INFORMATION_MESSAGE, null, 
              null, m_className);
            repaint();
            if (result==null)
              return;
            try {
              m_className = result;
              Class cls = Class.forName(result);
              Object obj = cls.newInstance();
              if (obj instanceof Component) {
                m_activeBean = (Component)obj;
                m_activeBean.addFocusListener(
                  BeanContainer.this);
                m_activeBean.requestFocus();
                getContentPane().add(m_activeBean);
              }
              validate();
            }
            catch (Exception ex) {
              ex.printStackTrace();
              JOptionPane.showMessageDialog(
                BeanContainer.this, "Error: "+ex.toString(),
                "Warning", JOptionPane.WARNING_MESSAGE);
            }
          }
        };
        newthread.start();
      }
    };
    mItem.addActionListener(lst);
    mFile.add(mItem);

    mItem = new JMenuItem("Load...");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {  
        Thread newthread = new Thread() {
          public void run() {
            m_chooser.setCurrentDirectory(m_currentDir);
            m_chooser.setDialogTitle(
              "Please select file with serialized bean");
            int result = m_chooser.showOpenDialog(
              BeanContainer.this);
            repaint();
            if (result != JFileChooser.APPROVE_OPTION)
              return;
            m_currentDir = m_chooser.getCurrentDirectory();
            File fChoosen = m_chooser.getSelectedFile();
            try {
              FileInputStream fStream = 
                new FileInputStream(fChoosen);
              ObjectInput  stream  =  
                new ObjectInputStream(fStream);
              Object obj = stream.readObject();
              if (obj instanceof Component) {
                m_activeBean = (Component)obj;
                m_activeBean.addFocusListener(
                  BeanContainer.this);
                m_activeBean.requestFocus();
                getContentPane().add(m_activeBean);
              }
              stream.close();
              fStream.close();
              validate();
            }
            catch (Exception ex) {
              ex.printStackTrace();
              JOptionPane.showMessageDialog(
                BeanContainer.this, "Error: "+ex.toString(),
                "Warning", JOptionPane.WARNING_MESSAGE);
            }
            repaint();
          }
        };
        newthread.start();
      }
    };
    mItem.addActionListener(lst);
    mFile.add(mItem);

    mItem = new JMenuItem("Save...");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
        Thread newthread = new Thread() {
          public void run() {
            if (m_activeBean == null)
              return;
            m_chooser.setDialogTitle(
              "Please choose file to serialize bean");
            m_chooser.setCurrentDirectory(m_currentDir);
            int result = m_chooser.showSaveDialog(
              BeanContainer.this);
            repaint();
            if (result != JFileChooser.APPROVE_OPTION)
              return;
            m_currentDir = m_chooser.getCurrentDirectory();
            File fChoosen = m_chooser.getSelectedFile();
            try {
              FileOutputStream fStream = 
                new FileOutputStream(fChoosen);
              ObjectOutput stream  =  
                new ObjectOutputStream(fStream);
              stream.writeObject(m_activeBean);
              stream.close();
              fStream.close();
            }
            catch (Exception ex) {
              ex.printStackTrace();
            JOptionPane.showMessageDialog(
              BeanContainer.this, "Error: "+ex.toString(),
              "Warning", JOptionPane.WARNING_MESSAGE);
            }
          }
        };
        newthread.start();
      }
    };
    mItem.addActionListener(lst);
    mFile.add(mItem);

    mFile.addSeparator();

    mItem = new JMenuItem("Exit");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
        System.exit(0);
      }
    };
    mItem.addActionListener(lst);
    mFile.add(mItem);
    menuBar.add(mFile);
    
    JMenu mEdit = new JMenu("Edit");

    mItem = new JMenuItem("Delete");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
        if (m_activeBean == null)
          return;
        getContentPane().remove(m_activeBean);
        m_activeBean = null;
        validate();
        repaint();
      }
    };
    mItem.addActionListener(lst);
    mEdit.add(mItem);
    menuBar.add(mEdit);

    JMenu mLayout = new JMenu("Layout");
    ButtonGroup group = new ButtonGroup();

    mItem = new JRadioButtonMenuItem("FlowLayout");
    mItem.setSelected(true);
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e){
        getContentPane().setLayout(new FlowLayout());
        validate();
        repaint();
      }
    };
    mItem.addActionListener(lst);
    group.add(mItem);
    mLayout.add(mItem);

    mItem = new JRadioButtonMenuItem("GridLayout");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e){
        int col = 3;
        int row = (int)Math.ceil(getContentPane().
          getComponentCount()/(double)col);
        getContentPane().setLayout(new GridLayout(row, col, 10, 10));
        validate();
        repaint();
      }
    };
    mItem.addActionListener(lst);
    group.add(mItem);
    mLayout.add(mItem);
    
    mItem = new JRadioButtonMenuItem("BoxLayout - X");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
        getContentPane().setLayout(new BoxLayout(
          getContentPane(), BoxLayout.X_AXIS));
        validate();
        repaint();
      }
    };
    mItem.addActionListener(lst);
    group.add(mItem);
    mLayout.add(mItem);
    
    mItem = new JRadioButtonMenuItem("BoxLayout - Y");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
        getContentPane().setLayout(new BoxLayout(
          getContentPane(), BoxLayout.Y_AXIS));
        validate();
        repaint();
      }
    };
    mItem.addActionListener(lst);
    group.add(mItem);
    mLayout.add(mItem);
    
    mItem = new JRadioButtonMenuItem("DialogLayout");
    lst = new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
        getContentPane().setLayout(new DialogLayout());
        validate();
        repaint();
      }
    };
    mItem.addActionListener(lst);
    group.add(mItem);
    mLayout.add(mItem);

    menuBar.add(mLayout);

    return menuBar;
  }

  public void focusGained(FocusEvent e) {
    m_activeBean = e.getComponent();
    repaint();
  }

  public void focusLost(FocusEvent e) {}

  // This is a heavyweight component so we override paint
  // instead of paintComponent. super.paint(g) will
  // paint all child components first, and then we 
  // simply draw over top of them.
  public void paint(Graphics g) {
    super.paint(g);

    if (m_activeBean == null)
      return;

    Point pt = getLocationOnScreen();
    Point pt1 = m_activeBean.getLocationOnScreen();
    int x = pt1.x - pt.x - 2;
    int y = pt1.y - pt.y - 2;
    int w = m_activeBean.getWidth() + 2;
    int h = m_activeBean.getHeight() + 2;

    g.setColor(Color.black);
    g.drawRect(x, y, w, h);
  }

  public static void main(String argv[]) {
    new BeanContainer();
  }
}