/** 
  * Bandscope Receiver Applet 1.0.0 [MOUSE FREQUENCY PANEL]
  * @author Robert J Morton <robmorton@clara.net> YE572246C
  * @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)

class mousefreq extends JPanel {
  private int 
    W,      // width of mouse frequency display panel
    H,      // height of mouse frequency panel
    I = 5,  // text inset from beginning of text area
    tb;     // text base line for panel of height H

  private String mFs = "--------------MHz";  // mouse pointer frequency

  private Color bg;       // background colour
  private Font font;      // font for the lettering on this panel
  private scope sc;       // reference to the "scope" object
  private freqspan sp;    // reference to the "frequency span" object
  private centrefreq cf;  // reference to the "centre frequency" panel object
  private smeter sm;      // S-Meter display class instance reference


  mousefreq(bs hf, Color bg, Font font, freqspan sp,  // CONSTRUCTOR
            centrefreq cf, smeter sm, int W, int H) {
    this.bg = bg;  // panel colour
    this.sp = sp;  // frequency span selector instance reference
    this.cf = cf;  // scentre-requency entry field instance reference
    this.sm = sm;  // S-Meter display class instance reference
    this.W = W;    // width of mouse frequency panel
    this.H = H;    // height of mouse frequency panel

    // get the font to be used on mouse frequency panel and its dimensions
    this.font = font; FontMetrics fm = getFontMetrics(font);

    // compute y-coordinate for lettering within a field of depth H
    tb = fm.getAscent() + (H - fm.getHeight()) / 2;
    mouseExited();  // see below
  }


  // set scope panel class instance reference to local variable
  void setScope(scope sc) {this.sc = sc;}


  void scamper(int x) {  // EXECUTED EVERY TIME THE MOUSE MOVES
    // Convert mouse frequency to string with 4 decimal places of MHz.
    mFs = convert.toMHz(pixTokHz(x), 4) + " MHz";
    sm.atualizar(sc.getPlot(x));  // display current S-Meter signal strength
    repaint();  // shedule a repaint via the event-despatching thread
  }


  void mouseExited() {
    mFs = "-------------- MHz";  // display the blank frequency string
    sm.atualizar(0);  // display the current S-Meter signal strength as zero
    repaint();        // shedule a repaint via the event-despatching thread
  }


  public void paint(Graphics g) {  // DISPLAY FREQUENCY AT MOUSE POINTER
    g.setColor(bg);           // set to panel colour
    g.fillRect(0, 0, W, H);   // clear mouse frequency area
    g.setColor(Color.black);  // colour of text
    g.setFont(font);
    convert.rightString(g,mFs,W - I,tb);  // display the mouse frequency
  }


  int pixTokHz(int x) {  // convert pixels to half-kHz
    return cf.getCF() + (x - 100) * sp.getKhzpixel();    
  }
}