// Template provided by Paul Amer for use in Project 3
// of CISC451/561: Data Compression for Multimedia
// This applet opens a text window and echos the contents
// of an ASCII file in that window.  Students must complete
// this template with their code for decoding amerRLE encoded
// files.


import java.net.*;
import java.io.*;
import java.applet.Applet;
import java.awt.*;  // Abstract Windowing Toolkit package is imported.

public class EchoApplet extends Applet {

   private String filename;
   private TextArea outputArea;
 
   public void init ()   // init invoked automatically by browser.
      {
      outputArea = new TextArea(15, 65);  // rows, columns
      outputArea.setEditable(false);      // make applet read-only
      outputArea.setFont(new Font("Courier", Font.PLAIN, 12)); // fixed-width font
      add(outputArea);          // show empty text area in applet 

      try {
          // file to be decoded should be a param in the html file 
          // if param doesn't exist the html file, give error message
          filename = getParameter("FileToBeEchoed");  
          if (filename == null)
              {
              outputArea.append("Error: parameter FileToBeEchoed missing in html file");
              return;
              }

          // create http connection to later get compressed file
          URL ourURLConnection = new URL(filename);

          // open the stream to be used for downloading the compressed file
          DataInputStream inFile = 
              new DataInputStream(ourURLConnection.openStream()); 

          // STUDENTS:  You will need to replace the following loop with 
          // a call to a method that decodes and outputs the compressed input file

          // read and echo each character until EOF
          int inputChar;
          while ((inputChar = inFile.read()) != -1)
             {
             outputArea.append(String.valueOf((char)inputChar));
             }

          inFile.close();
          }
      catch (Exception e) { e.printStackTrace(); } 
      }
}