/** 
  * Map Scale Selection Panel for Rob's Moving Map package
  * @author Robert J Morton
  * @version 27 November 1997
*/
/*  This class contains a group of 3 radio buttons for choosing
    which of the three map scales is to be used. */

import javax.swing.*;     // Java Swing GUI utilities
import java.awt.*;        // Java Abstract Windowing Toolkit
import java.awt.event.*;  // for the new-fangled 1.1 event handling

public class selmap extends JPanel implements navconst {

  private static final long 
    serialVersionUID = 12L;  // what the hell this is for, I don't know!

  private static selmap sm;  // reference to current object
  private airmap am;         // reference to the air map object
  private ButtonGroup G;     // reference for this JRadioButton group

  private int I = 3;     // number of buttons
  private double Scale;  // scaling factor of currently-selected map size
  private double S[];    // array for the 3 possible scaling factors
  private double da;     // angular increment for drawing guide circle dots
  private double A[];    // array of the above for each of the 3 map sizes
  private movmap mm;     // object reference to the main applet
  private Color bg;      // background colour for buttons

  private JRadioButton
    a,
    b,  // references to individual JRadioButtones within it
    c;


  selmap(movmap mm) {  // construct the radio button panel

    this.bg = bg;  // background colour for selector buttons
    this.mm = mm;  // local variable for object reference to main applet
    sm = this;     // reference to sel map object
    setOpaque(false);
    setLayout(new GridLayout(I,1));  // to make the buttons lie
                                     // in a single column

    G = new ButtonGroup();  // incorporate them into a 
                            // mutually-exclusive group

    /* Add radio buttons to this panel, create Item Listeners
    for then, add them to event handler list. */

    a = new JRadioButton("",false);
    G.add(a);
    add(a);
    a.addItemListener(new mapbut(0,this));
    a.setOpaque(false);

    b = new JRadioButton("",true);
    G.add(b); add(b);
    b.addItemListener(new mapbut(1,this));
    b.setOpaque(false);

    c = new JRadioButton("",false);
    G.add(c);
    add(c);
    c.addItemListener(new mapbut(2,this));
    c.setOpaque(false);

    S = new double[3];   // create the array for the scaling factors
    S[0] = KPR;          // scaling factor for 300 by 300 map
    S[1] = KPR * 3 / 2;  // scaling factor for 200 by 200 map
    S[2] = KPR * 3;      // scaling factor for 100 by 100 map
    Scale = S[1];        // preselect 200 by 200 as default scale

    A = new double[3];   // create array for map sizes
    A[2] = pi / 120;     // does 120 dots round the guide circle
    A[1] = pi / 80;      // does 80 dots round the guide circle
    A[0] = pi / 40;      // does 40 dots round the guide circle
    da = A[1];           // circle incrementer for drawing guide circles
  }


  void setAirmap(airmap am) {this.am = am;}


  void selectMap(int i) {  // MAP SCALE i HAS JUST BEEN SELECTED

    Scale = S[i];    // set the appropriate scaling factor
    da = A[i];       // set angular increment for drawing guide circle dots
    am.atualizar();  // update the air map
  }


  double getScale() {return Scale;}  // access currently selected map scale
  double getMapSize() {return da;}  // return map size selection range 1 to 3
}



// LISTENS FOR EVENTS FROM THE MAP SCALE SELECTION BUTTONS
class mapbut implements ItemListener {

  int id;     // one of the above events
  selmap ap;  // the application that called: always the above applet!

  // constructor for a new JRadioButton event
  public mapbut(int id, selmap ap) {
    this.id = id;  // set id number pertaining to this instance of 'mapbut'
    this.ap = ap;  // set the reference to the instance of the applet
  }                // from which it came. (there will only be one instance)

  // a JRadioButton event has occurred from JRadioButton 'id'
  public void itemStateChanged(ItemEvent e) {
    switch(id) {
      case 0: ap.selectMap(0); break;
      case 1: ap.selectMap(1); break;
      case 2: ap.selectMap(2);
    }
  }
}