/** 
  * Search Engine Applet 1.0.1
  * @author Robert John Morton
  * @version 22 October 1999 modified 10 July 2009, 10 April 2012
  * @copyright Robert John Morton (all rights reserved) */

import java.applet.*;  // all the gubbins to make the applet work
import javax.swing.*;  // Swing GUI
import java.awt.*;     // for graphics operations (GUI)
import java.net.*;     // for downloading data from the remote server

public class img2panel extends JPanel {  // MESSAGE DISPLAY PANEL

  /* Declare two fonts for the lettering used on this panel. The first
  is for the mesages summary number and the second is for the URL. */

  private static final Font 
    font1 = new Font("Sans",Font.PLAIN,18),
    font2 = new Font("Sans",Font.PLAIN,12);

  private Color bg;         // background colour for the message panel
  private String msg = "";  // string to hold the displayed message text
  private search hf;        // instance reference of the search applet

  private boolean          // WHEN SET 'TRUE', THESE FLAGS INDICATE THAT
    redMsg = false,        // the message must be displayed in red lettering
    imagesLoaded = false,  // the background images have been loaded
    smallFont = true;      // messgae must be printed in the small font size

  private int 
    W, H,  // width and height of message panel
    h,     // height of the text base-line common
    h1,    // height of the text base-line for big font
    h2;    // height of the text base-line for small font


  img2panel(int W, int H, Color bg, search hf) {  // INSTANCE CONSTRUCTOR

    this.W = W;    // set width of message panel to local variable
    this.H = H;    // set height of message panel to local variable
    this.bg = bg;  // set panel's background colour to local variable
    this.hf = hf;  // copy applet's instance reference to local variable

    /* compute the baseline height 'h' for each font
    for lettering within a panel of height 'H' */

    FontMetrics fm1 = getFontMetrics(font1); 
    h1 = fm1.getAscent() + (H - fm1.getHeight()) / 2;
    FontMetrics fm2 = getFontMetrics(font2); 
    h2 = fm2.getAscent() + (H - fm2.getHeight()) / 2;
  }

  void setImagesLoaded() {imagesLoaded = true;}


  // NORMAL MESSAGES (INCLUDING ERROR MESSAGES)

  void showMsg(String msg, boolean redMsg) {

    this.msg = msg;        // copy message and its display colour switch
    this.redMsg = redMsg;  // to local variables
    if(redMsg)             // A red error message tends to be long,
      smallFont = true;    // so display it in the small font,
    else                   // otherwise it is a normal message
      smallFont = false;   // so display it in the large font.

    repaint();  // schedule a repaint via the event despatching thread
  }


  // SHOW THE URL OF THE HTML PAGE FROM WHICH THIS SUMMARY WAS RETRIEVED

  void showURL(URL url) {
    msg = "" + url;    // convert the URL to a string
    redMsg = false;    // URLs do not appear in red
    smallFont = true;  // they tend to be long, so use a small font
    repaint();         // schedule a repaint via the event despatching thread
  }


  // DISPLAY THE MESSAGE IN THE MESSAGE PANEL

  public void paint(Graphics g) {
    if(imagesLoaded)        // Provided the window background images
      g.drawImage(hf.IMG2,0,0,this); // have all been loaded, draw them
    else {                  // onto the applet canvas, otherwise set
      g.setColor(bg);       // background colour for message dislpay
      g.fillRect(0,0,W,H);  // area and wipe it of any previous text.
    }
    if(smallFont){       // If using the small font,
      g.setFont(font2);  // set it as the active font
      h = h2;            // set its baseline height as active baseline height
    } else {             // Otherwise,
      g.setFont(font1);  // set the large font as the active font
      h = h1;            // set its baseline height as active baseline height
    }
    /*  , . */

    if(redMsg)                  // If message must be displayed in red
      g.setColor(Color.red);    // set text's foreground colour to 'red'
    else                        // otherwise
      g.setColor(Color.black);  // set it to 'black'
    g.drawString(msg, 5, h);    // draw the message string
  }
}