package net.mmss.swing.group;

import java.awt.event.*;
import java.util.Vector;
import java.util.Enumeration;
import java.io.Serializable;
import javax.swing.*;

public class JRadioButtonGroup
    extends ButtonGroup implements Serializable {

  protected Vector buttons = new Vector();

  ButtonModel selection = null;

  public JRadioButtonGroup() {}

  public void add(AbstractButton b) {
    if (b == null) {
      return;
    }
    buttons.addElement(b);

    if (b.isSelected()) {
      if (selection == null) {
        selection = b.getModel();
      }
      else {
        b.setSelected(false);
      }
    }

    b.getModel().setGroup(this);
  }

  public void remove(AbstractButton b) {
    if (b == null) {
      return;
    }
    buttons.removeElement(b);
    if (b.getModel() == selection) {
      selection = null;
    }
    b.getModel().setGroup(null);
  }

  public Enumeration getElements() {
    return buttons.elements();
  }

  public ButtonModel getSelection() {
    return selection;
  }

  public void setSelected(ButtonModel m, boolean b) {
    if (b && m != null && m != selection) {
      ButtonModel oldSelection = selection;
      selection = m;
      if (oldSelection != null) {
        oldSelection.setSelected(false);
      }
      m.setSelected(true);
    }
  }

  public void deselectAll() {
    ButtonModel oldSelection = selection;
    selection = null;
    if (oldSelection != null) {
      oldSelection.setSelected(false);
    }
  }

  public boolean isSelected(ButtonModel m) {
    return (m == selection);
  }

  public int getButtonCount() {
    if (buttons == null) {
      return 0;
    }
    else {
      return buttons.size();
    }
  }

}