/* Sample Solution from Ken Been
 */
import java.net.*;
import java.io.*;
import java.applet.*;
import java.awt.*;

public class Hw5example
  extends Applet 
{
  private String[] lines;
  private final static int MAX_NUM_LINES = 50;
  private int numLines;
  private URL url;
  private BufferedReader in;

  public void init()
  {
    // create array of strings
    lines = new String[MAX_NUM_LINES];

    // make it white writing on black background
    setBackground(Color.black);
    setForeground(Color.white);

    // create url object
    url = null;
    try {
      url = new URL("http://cs.nyu.edu/been/v22.0310-004/eg/hw5example/input.txt");
    }
    catch (MalformedURLException e) {
      reportError("bad url");
      return;
    }
  }

  public void start()
  {
    // create and open input stream
    in = null;
    try {
      in = new BufferedReader(new InputStreamReader(url.openStream()));
    }
    catch (IOException e) {
      reportError("io problem opening input stream: " + e);
      return;
    }

    // Set this point in the input (the beginning) to be the point
    // that will be returned to whenever in.reset() is called.
    try {
      in.mark(300);
    }
    catch (IOException e) {
      reportError("problem marking stream: " + e);
      return;
    }
  }

  public void stop()
  {
    // close input stream
    try {
      in.close();
    }
    catch (IOException e) {
      reportError("problem closing file:" + e);
      return;
    }
  }

  public void paint(Graphics g)
  {
    // reset input stream to the beginning
    try {
      in.reset();
    }
    catch (IOException e) {
      reportError("couldn't reset stream: " + e);
      return;
    }

    // temporary string for reading in the input
    String s = null;

    // set font to be larger and more readable
    g.setFont(new Font("Dialog", Font.PLAIN, 20));

    // placement of first string, y direction
    int y = g.getFont().getSize()+10;

    // space to skip between strings, y direction
    int yIncrement = g.getFont().getSize();

    // number of lines read in so far
    numLines = 0;

    // read input file; create one string per line, store in array
    try {
      s = in.readLine();
    }
    catch (IOException e) {
      reportError("io exception: " + e);
      return;
    }

    while (s != null && numLines < MAX_NUM_LINES) {
      lines[numLines] = s;
      numLines++;

      snapshot(y, g);
      y += yIncrement;

      try {
        s = in.readLine();
      }
      catch (IOException e) {
        reportError("io exception: " + e);
        return;
      }
    }
  }

  private void snapshot(int y, Graphics g)
  {
    // placement of first string, x direction
    int x = 10;

    // space to skip between strings, in x direction
    int xIncrement = g.getFont().getSize()*3;

    // draw each string in the array
    for (int i = 0; i < numLines; i++) {
      g.drawString(lines[i], x, y);
      x += xIncrement;
    }
  }

  // just put error message into string array, and make it the only one;
  // will be viewed when paint() is called
  private void reportError(String err)
  {
    // make array of size one
    lines = new String[1];

    // put error message there
    lines[0] = err;
  }
}