dialogseparator.jva

Java 图形界面入门实例

import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

public class DialogSeparator extends JLabel {
  public static final int OFFSET = 15;

  public DialogSeparator() {
  }

  public DialogSeparator(String text) {
    super(text);
  }

  public Dimension getPreferredSize() {
    return new Dimension(getParent().getWidth(), 20);
  }

  public Dimension getMinimumSize() {
    return getPreferredSize();
  }

  public Dimension getMaximumSize() {
    return getPreferredSize();
  }

  public void paint(Graphics g) {
    g.setColor(getBackground());
    g.fillRect(0, 0, getWidth(), getHeight());

    Dimension d = getSize();
    int y = (d.height - 3) / 2;
    g.setColor(Color.white);
    g.drawLine(1, y, d.width - 1, y);
    y++;
    g.drawLine(0, y, 1, y);
    g.setColor(Color.gray);
    g.drawLine(d.width - 1, y, d.width, y);
    y++;
    g.drawLine(1, y, d.width - 1, y);

    String text = getText();
    if (text.length() == 0)
      return;

    g.setFont(getFont());
    FontMetrics fm = g.getFontMetrics();
    y = (d.height + fm.getAscent()) / 2;
    int fontWidth = fm.stringWidth(text);

    g.setColor(getBackground());
    g.fillRect(OFFSET - 5, 0, OFFSET + fontWidth, d.height);

    g.setColor(getForeground());
    g.drawString(text, OFFSET, y);
  }
  public static void main(String argv[]) {
    new FlightReservation();
  }
}

class FlightReservation extends JFrame {
  public FlightReservation() {
    super("Dialog ");

    Container c = getContentPane();
        c.setLayout(new FlowLayout());
    c.add(new DialogSeparator("Options"));

    ButtonGroup group = new ButtonGroup();
    JRadioButton r1 = new JRadioButton("First class");
    group.add(r1);
    c.add(r1);

    JRadioButton r2 = new JRadioButton("Business");
    group.add(r2);
    c.add(r2);

    JRadioButton r3 = new JRadioButton("Coach");
    group.add(r3);
    c.add(r3);

    c.add(new DialogSeparator());

    JButton b3 = new JButton("Exit");
    c.add(b3);

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

    setSize(300,200);
    setVisible(true);
  }
}