ButtonGroups.java

//: c14:ButtonGroups.java
// Uses reflection to create groups
// of different types of AbstractButton.
// <applet code=ButtonGroups width=500 height=300></applet>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.border.*;
import java.lang.reflect.*;
import com.bruceeckel.swing.*;

public class ButtonGroups extends JApplet {
  private static String[] ids = {
    "June", "Ward", "Beaver",
    "Wally", "Eddie", "Lumpy",
  };
  static JPanel makeBPanel(Class klass, String[] ids) {
    ButtonGroup bg = new ButtonGroup();
    JPanel jp = new JPanel();
    String title = klass.getName();
    title = title.substring(title.lastIndexOf('.') + 1);
    jp.setBorder(new TitledBorder(title));
    for(int i = 0; i < ids.length; i++) {
      AbstractButton ab = new JButton("failed");
      try {
        // Get the dynamic constructor method
        // that takes a String argument:
        Constructor ctor =
          klass.getConstructor(new Class[]{String.class});
        // Create a new object:
        ab = (AbstractButton)
          ctor.newInstance(new Object[] { ids[i] });
      } catch(Exception ex) {
        System.err.println("can't create " + klass);
      }
      bg.add(ab);
      jp.add(ab);
    }
    return jp;
  }
  public void init() {
    Container cp = getContentPane();
    cp.setLayout(new FlowLayout());
    cp.add(makeBPanel(JButton.class, ids));
    cp.add(makeBPanel(JToggleButton.class, ids));
    cp.add(makeBPanel(JCheckBox.class, ids));
    cp.add(makeBPanel(JRadioButton.class, ids));
  }
  public static void main(String[] args) {
    Console.run(new ButtonGroups(), 500, 300);
  }
} ///:~