/** 
  * Bandscope Receiver Applet 1.0.0 [FREQUENCY-SPAN SELECTOR]
  * @author Robert J Morton <robmorton@clara.net> YE572246C
  * @version 13 March 2002, 22 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 freqspan {
  private static final int
    bandSpans[][] = {  // frequency extents (spans) for:
      {5,3,5,5,6,4,4,5,4,4,5,6,4,4,4,0,0},  // broadcast bands,
      {6,4,6,6,4,5,4,5,2,2,4,2,0,0},        // amateur bands,
      {6,4,6,6,4,4,4,6,4,5,6,5,5,5,0,0},    // aircraft bands
      {3,4,3,3,5,5,3,3,0}                   // marine bands.
    },
    KP[] = {100,50,20,10,5,2,1},  // twice kilohertz per pixel for each 
                                  // selectable band span
    SCH = 130;  // height of top of span choice box above bottom of graph

  private int 
    fs = 0,    // currently selected frequency span
    kp = 100;  // half-kilohertz per pixel (frequency scaling)
               // [the default MUST be non-zero].

  private String FR = "50";  // Frequency Resolution of graph in kHz/pixel.
  private JComboBox<String> SpanBox;  // frequency-span selector
  private JLabel SpanLab;  // frequency span label

  // References to the ...
  private scope sc;         // scope class instance
  private bands bd;         // bandtype and band selector instance
  private freqfigs ff;      // frequency scale figures class instance
  private ar86000 rx;       // receiver class instance
  private listeningon lo;   // "listening on" panel instance


  freqspan(Container cp, int GL, int GB, int h) {

    /* Create and fill the graph's frequency span choice box (located
    above the graph) then add it to the applet pane, set its position
    and size on the applet panel and create a listener to listen for
    selection events emanating from this object. */

    SpanBox = new JComboBox<String>();
    SpanBox.addItem("10 MHz");  SpanBox.addItem("5 MHz"); 
    SpanBox.addItem("2 MHz");   SpanBox.addItem("1 MHz");
    SpanBox.addItem("500 kHz"); SpanBox.addItem("200 kHz"); 
    SpanBox.addItem("100 kHz"); 

    cp.add(SpanBox); SpanBox.setBounds(GL + 50, GB - SCH, 100, h);
    SpanBox.addItemListener(new spchl(spchl.SPAN, this));

    /* Create the span label object, add it to the applet pane 
    then set its position and size within the applet panel. */

    SpanLab = new JLabel("50 kHz/pixel"); 
    cp.add(SpanLab); SpanLab.setBounds(GL + 155,GB - 135,100,15);
  }

  void setScope(scope sc) {this.sc = sc;}
  void setBands(bands bd) {this.bd = bd;}
  void setFreqFigs(freqfigs ff) {this.ff = ff;}
  void setAR86000(ar86000 rx) {this.rx = rx;}
  void setLo(listeningon lo) {this.lo = lo;}


  /* DONE WHEN A NEW BANDSCOPE FREQUENCY SPAN IS SELECTED: Get the index
  number of the frequency-span that has just been selected and show the
  corresponding number of kHz per pixel etc. */

  void selSpan() { fs = SpanBox.getSelectedIndex(); selSpan2(); }


  // ALLOWS THE BAND-SELECTOR TO SET THE FREQUENCY SPAN FOR THE SELECTED BAND
  void setSpan(int sbt, int sb) {
    fs = bandSpans[sbt][sb];       // get frequency span for this band
    SpanBox.setSelectedIndex(fs);  // set the appropriate span choice
    selSpan2();                    // set new frequency span
  }

  // SHOW THE kHz PER PIXEL LABEL + THE SET FREQUENCY SCALE FIGURES
  private void selSpan2() {

    kp = KP[fs];  // half-kHz per pixel for selected range

    /* If 100 kHz span is selected, set straight to half kHz/pixel;
    else, for all other spans, get the integral resolution in kHz/pixel
    and, if the 500 kHz span is selected, add the extra half sign for
    the 2.5 kHz/pixel. */

    if(fs == 6) FR = "½";
    else { FR = "" + (kp >> 1); if(fs == 4) FR += "½"; }

    lo.setReceiving(false);  // kill receiving

    // compute the signal level plots for the new frequency span
    rx.computePlots();
    SpanLab.setText(FR + " kHz/pixel");  // display the requency span label

    // display the appropriate figures on the frequency scale
    ff.atualizar(); sc.atualizar();
  }


  int getFreqSpan() {return fs;}  // called by "freqfigs" and "ar86000"
  int getKhzpixel() {return kp;}  // called by "mouse" and "scope"
}


// LISTENS FOR EVENTS FROM THE CHOICE MENU SELECTORS
class spchl implements ItemListener {

  //an event from the 'bandscope frequency span selector' choice menu
  static final int SPAN = 0;

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

  /* Constructor for a new Choice selection event: set the 'id' number
  pertaining to this instance of 'cl', set the reference to the instance
  of the 'bs' applet, from which it came. (there is only one instance). */

  public spchl(int id, freqspan ap) { this.id = id; this.ap = ap; }

  /* A Choice selection event has occurred from checkbox 'id' so execute the
     method in the above applet which deals with this choice. */

  public void itemStateChanged(ItemEvent e) {
     switch(id) { case SPAN: ap.selSpan(); break; }
  }
}