/** 
  * Iteration Rate Selection Panel for DifEqnAp.class
  * @author Robert J Morton UK-YE572246C
  * @version 27 November 1997 modified 07 August 2009, 18 April 2012 */

/*  This class contains a group of 5 radio buttons for choosing
    how often the selected difference equation is iterated and
    its updated value plotted on the graphs. */

import java.awt.*;        // for graphics operations (GUI)
import java.awt.event.*;  // for the new-fangled 1.1 event handling
import javax.swing.*;     // library for constructing Swing GUI

public class selper extends JPanel {

  // update interval choices in milliseconds
  private static final long T[] = {2000, 1000, 500, 250, 100};

  private long Period = 100;  // currently selected iteration period

  private difeqnap ap;    // instance reference of the main applet
  private JLabel L;       // period selection panel heading label
  private ButtonGroup G;  // to hold the reference for this checkbox group
  private JRadioButton    // to hold the references to 
    a, b, c, d, e;        // the individual radio buttons within it

  selper(difeqnap x, Color pc) {  // construct the radio button panel

    ap = x;             // applet instance
    setBackground(pc);  // set panel colour

    // lay out items in a single vertical column of 6
    setLayout(new GridLayout(6, 0));

    // Create the Scan Selector's title label, and add it to this panel.
    L = new JLabel("Plot every:", Label.LEFT); add(L);

    /* Create a radio button group, then create and add the
    5 buttons for selecting the desired iteration period. */

    G = new ButtonGroup();
    a = new JRadioButton("2 secs", false); G.add(a);
    b = new JRadioButton("1 sec ", false); G.add(b);
    c = new JRadioButton("500ms", false);  G.add(c);
    d = new JRadioButton("250ms", false);  G.add(d);
    e = new JRadioButton("100ms", true);   G.add(e);

    /* Add the radio buttons also to this panel, create an Item
    Listener for each button and add it to the event handler list. */

    add(a); a.addItemListener(new perbut(0, this));
    add(b); b.addItemListener(new perbut(1, this));
    add(c); c.addItemListener(new perbut(2, this));
    add(d); d.addItemListener(new perbut(3, this));
    add(e); e.addItemListener(new perbut(4, this));
  }

  /* Set the newly-selected iteration period, then up-
  date the iteration period value in the main applet. */
 
  void selectPeriod(int i) { Period = T[i]; ap.setPeriod(Period); }
}


// LISTENS FOR EVENTS FROM PERIOD SELECTION BUTTONS
class perbut implements ItemListener {

  int id;      //one of the above events
  selper sp;   //the application that called: always the above class

  /* constructor for a new checkbox event: sets 'id' number pertaining
  to this instance and the reference to the instance of the class from
  which it came. (there will only be one instance). */

  public perbut(int id, selper sp) { this.id = id; this.sp = sp; }

  // a checkbox event has occurred from checkbox 'id'
  public void itemStateChanged(ItemEvent e) {
    switch(id) {
      case 0: sp.selectPeriod(0); break;
      case 1: sp.selectPeriod(1); break;
      case 2: sp.selectPeriod(2); break;
      case 3: sp.selectPeriod(3); break;
      case 4: sp.selectPeriod(4); break;
    }
  }
}