/** 
  * Stop/Start/Reset Buttons for CtrlPanl.class re DifEqnAp.class
  * @author Robert J Morton
  * @version 27 November 1997 modified 07 August 2009, 18 April 2012 */

/*  This Panel class contains 4 buttons: Stop, Start, Reset, Spot
    to control the operation of the applet */

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 setbutt extends JPanel {

  private difeqnap ap;   // instance reference of the main applet class
  private timegr tg;     // instance reference of the timegr class
  private bouncegr bg;   // instance reference of the bouncegr class
  private formula f;     // instance reference of the formula class
  private JButton a, b;  // references for the 2 buttons
  private boolean 
    RunFlag = false;  // applet starts of with the equation not iterating
  private int ls =0;  // language switch: default = English
  private String s;   // for multi-language


  setbutt(difeqnap ap, timegr tg, bouncegr bg, formula f, int ls) {

    this.ap = ap;  // instance ref. of main applet class to local variable
    this.tg = tg;  // instance ref. of timegr class to local variable
    this.bg = bg;  // instance ref. of bouncegr class to local variable
    this.f = f;    // instance ref. of formula class to local variable
    this.ls = ls;  // language switch

    setLayout(null);  // to allow the button panel to be laid out manually
    s = "Start";      // English/Portuguese
    if(ls != 0)
      s = "Iniciar";
    a = new JButton();  // create the 'start' button
    a.setText(s);       // annotate it with the word "Start"
    add(a);             // add it to this panel
    a.setBounds(5,1,110,33);  // set its position and size
    a.addActionListener(   // add a listener 
      new stopbut(0,this)  // to listen for when it is pressed
    );
    s = "Clear";        // English/Portuguese
    if(ls != 0)
      s = "Limpar";
    b = new JButton();  // create the 'clear' button
    b.setText(s);       // annotate it with the word "Clear"
    add(b);             // add it to this panel
    b.setBounds(120,1,110,33);  // set its position and size 
    b.addActionListener(   // add a listener 
      new stopbut(1,this)  // to listen for when it is pressed
    );
  }


  void Stop() {                //stop the iteration process
    Relabel(RunFlag = false);  //clear the 'run' flag to stop iteration
    ap.setRF(false);           //update the Run Flag state in main applet
  }


  void reset() {      // USED BY RESET BUTTON, EQN CHANGE, C CHANGE
    RunFlag = false;  // stop the program from iterating
    Relabel(false);   // relabel the button to 'Start'
    ap.setRF(false);  // stop the iteration loop in the main applet
    tg.reset();       // reinitialise the time graph
    bg.reset();       // reinitialise the bounce graph
    System.out.println("stbutt.java: graph cleared:");
    System.out.println("iteration process stopped and reset.");
  }


  private void Relabel(boolean Flag) {
    if(Flag) {     // if the run flag is set
      s = "Stop";  // English/Portuguese
      if(ls != 0)
        s = "Parar";
      a.setText(s);  // re-label the button 'Stop'
      System.out.println("setbutt.java:");
      System.out.println("App is iterating the equation...");
    } else {         // otherwise...
      s = "Start";   // English/Portuguese
      if(ls != 0)
        s = "Iniciar";
      a.setText(s);  // re-label the button 'Start'
      System.out.println("setbutt.java: Stopped because");
      System.out.println("the iteration process halted.");
    }
  }


  // only called by the listener class below
  void whichButton(int i) {  // IF A CONTROL BUTTON HAS BEEN PRESSED
    if(i == 0) {             // if 'Start/Stop' button has been pressed
      Relabel(RunFlag = !RunFlag);  // start selected equation iterating
      if(RunFlag) f.reset(); // if starting, initialise formula class
      ap.setRF(RunFlag);     // update the Run Flag state in main applet
    } else                   // if CLEAR button has been pressed
      reset();               // clear graphs and reset x to start value
  }
}



// LISTENS FOR EVENTS FROM START/STOP AND CLEAR BUTTONS
class stopbut implements ActionListener {
  int id;      // one of the above events
  setbutt sb;  // the application that called: always the above class

  public stopbut(int id, setbutt sb) { //constructor for a new checkbox event
    this.id = id;  //s et id number pertaining to this instance
    this.sb = sb;  // set the reference to the instance of the class
  }                // from which it came. (there will only be one instance)

  //an event has occurred from checkbox 'id'
  public void actionPerformed(ActionEvent e) {
    switch(id) {
      case 0: sb.whichButton(0); break; // the stop/start button was pressed
      case 1: sb.whichButton(1);        // the clear button was pressed
    }
  }
}