/** 
  * Plot Mode Selector for CtrlPanl.class re DifEqnAp.class
  * @author Robert J Morton UK-YE572246C
  * @version 27 November 1997 modified 07 August 2009, 18 April 2012 */

/*  This class contains a pair of radio buttons for choosing whether the
    program should plot the time graph as a series of lines joining con-
    secutive plots, or, simply mark successive spot values of x by short
    horizontal lines each of which is equal in lenght to the inter-iteration
    period as plotted on the Time Graph. */

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 selplot extends JPanel {

  private JLabel L;           // to hold reference to panel's 'heading'
  private ButtonGroup G;      // to hold reference to the JRadioButton group
  private JRadioButton a, b;  // and references to individual JRadioButtones
  private setbutt sb;         // instance reference of the setbutt panel
  private selscan ss;         // instance reference of the selscan panel
  private timegr tg;          // instance reference of the time-graph

  private boolean 
    Flags[] = {false, true},  // plot mode options

    PlotMode = false;  /* true: 'spot values' is selected
                            false: 'lines joining values' is selected */

  selplot(setbutt sb, selscan ss, timegr tg, Color pc) {
    this.sb = sb;  // setbutt's instance reference
    this.ss = ss;  // selscan's instance reference
    this.tg = tg;  // timegr's instance reference

    // set out objects as a vertical column of 3
    setLayout(new GridLayout(3, 0));

    setBackground(pc);  // set panel colour

    //create title label for this panel and add it to this panel
    L = new JLabel("Plot Mode:", Label.LEFT); add(L);

    /* Create a container group for radio-buttons then create
    two buttons and add each to both the group and this panel. */

    G = new ButtonGroup();
    a = new JRadioButton("Line Graph", true); G.add(a); add(a);
    b = new JRadioButton("Spot Value", false); G.add(b); add(b);

    // Create a listener for each button. 
    a.addItemListener(new plotbut(0, this));
    b.addItemListener(new plotbut(1, this));
  }


  void resetPlotMode() {  // called only by selscan
    PlotMode = false;     // set the plot-mode flag to 'line-graph'
    a.setSelected(true);  // tick the 'line-graph' button
    tg.setPM(PlotMode);   // transfer PlotMode state to the time graph panel
  }


  void selectPlotMode(int i) {  // called only from the listener class below
    sb.reset();           // hit the 'Reset' button
    PlotMode = Flags[i];  // set the new state of the plot-mode selector
    if(PlotMode)          // if in single plot mode
      ss.setSM(false);    // force Scan Mode to Single Scan
    tg.setPM(PlotMode);   // transfer PlotMode state to the time graph panel
  }
}


// LISTENS FOR EVENTS FROM PLOT MODE SELECTION BUTTONS
class plotbut implements ItemListener {
  int id;      // one of the above events
  selplot st;  // the application that called: always the above class

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

  public plotbut(int id, selplot st) { this.id = id; this.st = st; }

  // a JRadioButton event has occurred from JRadioButton 'id'
  public void itemStateChanged(ItemEvent e) {
    switch(id) {                            // Selected mode:
      case 0: st.selectPlotMode(0); break;  // line-graph
      case 1: st.selectPlotMode(1); break;  // single-shot
    }
  }
}