/** 
  * Bandscope Receiver Applet 1.0.0 [CENTRE-FREQUENCY ENTRY FIELD]
  * @author Robert J Morton <robmorton@clara.net>
  * @version 13 March 2002, 20 March 2012
  * @copyright Robert J Morton (all rights reserved) */


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

class centrefreq {
  private static final int
    bandCentres[][] = {  // band centre frequencies for:
      {250,1000,2400,3300,3950,4900,6100,7200,9700,        // broadcast bands
       11800,13700,15550,17700,21650,25850,93000,103000},
      {1850,3650,7050,10150,14200,18100,21200,24900,       // amateur bands
       29000,51000,70250,145000,435000,1245000},
      {550,3000,3450,4700,5600,6600,8900,10050,11300,      // aircraft bands
       13300,15050,17950,21950,23250,123000,133000},
      {2500,6350,8500,12800,18850,19750,22600,25300,       // marine bands
       160000}
    },
    Y = 220,  // y-coordinate of Centre-Frequency components
    H = 30;   // height of text field

  private JTextField FrqFld;        // centre frequency entry field
  private JButton EntBut;           // button to enter the centre frequency
  private JLabel CFlab;             // annotation in front of text field
  private boolean CFvalid = false;  // centre frequency valid flag
  private int CF = 186000;          // entered centre frequency in half-kHz

  private ar86000 rx;      // reference to the ar86000-specific class
  private freqfigs ff;     // reference to the frequency scale panel class
  private listeningon lo;  // ref to "listening on" frequency display panel
  private scope sc;        // reference to the "scope" display panel
  private msgpanel mp;     // reference to the message panel instance
  private bands bd;        // reference to the bands class instance
  private freqspan sp;     // reference to the freqspan class instance


  centrefreq(bs cp, int X, Color bg, Font font, msgpanel mp, freqspan sp) {
    this.sp = sp;
    this.mp = mp;
    CFlab = new JLabel(            // create annotation label 
      "Centre Frequency MHz:"      // for centre-frequency text field
    );
    cp.add(CFlab);                 // add it to the applet's content pane 
    CFlab.setBounds(10,Y,200,30);  // set its position and size

    FrqFld = new JTextField("93.000");  // set up centre frequency entry field
    cp.add(FrqFld);                 // add it to the applet's content pane
    FrqFld.setBackground(bg);       // set its background colour
    FrqFld.setBounds(X+55,Y,90,H);  // set its position and size on app panel

    FrqFld.setFont(font);
    FrqFld.addActionListener(     // set up action listener to listen for 
      new cfbl(cfbl.FRQFLD,this)  // carriage-return events from text field
    );
    EntBut = new JButton("Enter");   // set up the Enter button 
    cp.add(EntBut);                  // add it to the applet's content pane
    EntBut.setBounds(X+155,Y,80,H);  // set its position and size

    EntBut.addActionListener(      // set up action listener to listen for 
      new cfbl(cfbl.ENTBUT, this)  // the "Enter" button being pressed
    );
  }


  // set reference to the ar86000-specific class
  void setAR86000(ar86000 rx) {this.rx = rx;}

  // set reference to the frequency scale panel class
  void setFreqFigs(freqfigs ff) {this.ff = ff;}

  // set reference to the "listening on" frequency display panel
  void setLo(listeningon lo) {this.lo = lo;}

  // set reference to the "listening on" frequency display panel
  void setScope(scope sc) {this.sc = sc;}

  // set reference to the "listening on" frequency display panel
  void setBands(bands bd) {this.bd = bd;}


  void pressFrqFld() {  // DO WHEN C/R RECEIVED FROM CENTRE FREQUENCY FIELD
    bd.setSelectedType(0);  // set selected band type to "None"
    bd.setSelectedBand(0);  // set selected band to null

    pressFrqFld2();  // do when C/R received from centre frequency field

    if(CFvalid) {      // if the current centre-frequency is a valid value
      sc.killPlots();  // erase all scan information
      ff.atualizar();  // so frequency scale will be re-drawn
      sc.atualizar();  // update the bandscope graph
      mp.showMsg("Please update bandscope data.", false);
    }
  }


  // DO WHEN C/R RECEIVED FROM CENTRE FREQUENCY FIELD
  private void pressFrqFld2() { 
    lo.setReceiving(false);     //stop receiving on last selected frequency

    // get the text present in the centre-frequency text field
    String s = FrqFld.getText();
    int x = s.indexOf(".");//try to locate a decimal point within it
    if(x == -1) {          //if text does not contain a decimal point
      s += ".0";          //append a decimal point with a trailing zero
      x = s.indexOf("."); //find index of inserted point
      FrqFld.setText(s);  //redisplay amended text in centre-frequency field
    }
    String k = s.substring(x,s.length()); //isolate decimal point + digits
    s = s.substring(0, x);                //isolate the integral MHz

    int l = k.length();    //length of decimal (point+digits) part
    if(l > 1) {            //if more than just the decimal point on its own
      if(l > 3) l = 3;    //limit to 2 decimal places of MHz

      k = k.substring(1,l);    //isolate the decimal digits
      while(k.length() < 2)    //pad out with zeros to 3 digits
        k += "0";

    } else k = "00";       //no decimal places, so add 3 zeros
    s += k;                //s now contains integral 10 kHz
    CFvalid = false;       //initially, show centre-frequency is not valid

    try {                                 //try to
      x = Integer.parseInt(s + "0");     //parse string as an integer

      /* if the frequency is within range of receiver scanner, set new valid 
      centre frequency (in integral half-kHz) and trigger a repaint(). */

      if(x < 2040000 && x > 100) {
        CF = x << 1;
        CFvalid = true;
      }

      /* else it is out of range of the scanner
      so, show error message in scope area. */

      else mp.showMsg("Frequency out of range!",true);
    }

    /* if what was entered cannot be parsed into an int-
    eger, show appropriate error message in scope area. */

    catch(NumberFormatException e) {
        mp.showMsg("Invalid centre frequency!", true);
    }
  }


  // ALLOWS BANDS CLASS TO SET CENTRE FREQUENCY FOR NEW BAND
  void setCF(int sbt, int sb) {
    CF = (bandCentres[sbt][sb]) << 1;  // get centre frequency for this band
 
    FrqFld.setText(        // set the centre frequency CF
      convert.toMHz(CF,4)  // converted from integer to String
    );                     // set it in the CF text entry field
    pressFrqFld2();        // enter the centre frequency 
  }
  int getCF() {return CF;}  // return centre frequency of current scan band



  // TO ENABLE freqfigs TO SET THE CORRECTED CENTRE-FREQUENCY
  void setCF2(int CF, int d) {
    this.CF = CF;
    FrqFld.setText(convert.toMHz(CF,d));
  }
}



class cfbl implements ActionListener {
  static final int ENTBUT = 0;  // Enter button pressed event
  static final int FRQFLD = 1;  // C/R from centre frequency entry field event

  int id;         // one of the above
  centrefreq ap;  // the application that called: always the above app

  public cfbl(int id, centrefreq ap) {  // constructor for a new command
    this.id = id;
    this.ap = ap;
  }

  // one of the buttons has been clicked
  public void actionPerformed(ActionEvent e) {
    switch(id) {  // id of this instance of ActionEvent, which was either:
      case ENTBUT: ap.pressFrqFld(); break;  // 'Enter' button
      case FRQFLD: ap.pressFrqFld();         // 'C/R' 
    }
  }
}