//
// COSC 387 imageView
// Marcus A. Maloof
// Department of Computer Science
// Georgetown University
// Fall 2000
//
// This Java application provides a basic tool for displaying a raw,
// grayscale image format.  The format of the image file should be:
//
// <width> <height>
// <pixel-value_{1}> <pixel-value_{2}> ...
// ... pixel-value_{n}>
//
// where n = <width> * <height> and each pixel value, pixel-value_{i},
// is an integer [0, 255], black being 0, white being 255.
//
// Compile the code using the command:
//
//   javac imageView.java
//
// Then run it using the command:
//
//   java imageView image.raw
//
// where image.raw is a file containing the image in the format described
// above.
//

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.StringTokenizer;

/*=======================================================================*/

public class imageView extends Frame {

  ImageFile iF;
  ImageArea image;
  TextField textfield;

  public imageView(String filename) {

    super("COSC 387 imageView");                    // Create the window

    iF = new ImageFile(filename);                   // Load in the image

    this.setLayout(new BorderLayout());

    this.setSize(iF.width, iF.height);              // Specify frame's size
    this.setResizable(false);                       // Prevent resizing
    
    // Create a ScrollPane
    ScrollPane pane = new ScrollPane(ScrollPane.SCROLLBARS_NEVER);
    pane.setSize(iF.width, iF.height);              // Specify the pane's size
    this.add(pane, "Center");                       // Add it to the frame

    PixelMap pixMap = new PixelMap();               // Create a grayscale
    pixMap.MakeGrayScale();                         // pixel map

    image = new ImageArea(this, iF, pixMap);        // Create an image area

    image.addMouseMotionListener(new MouseMotionAdapter() { 
      public void mouseMoved(MouseEvent e) {
        textfield.setText(iF.getText(e.getX(),e.getY()));
      } // mouseMoved
    });
    image.addMouseMotionListener(new MouseMotionAdapter() { 
      public void mouseDragged(MouseEvent e) {
        textfield.setText(iF.getText(e.getX(),e.getY()));
      } // mouseDragged
    });
    image.addMouseListener(new MouseAdapter() { 
      public void mouseEntered(MouseEvent e) {
        image.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
      } // mouseDragged
    });
    image.addMouseListener(new MouseAdapter() { 
      public void mouseExited(MouseEvent e) {
        image.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
      } // mouseDragged
    });

    pane.add(image);                                // Add it to the ScrollPane

    MenuBar menubar = new MenuBar();                // Create a menubar
    this.setMenuBar(menubar);                       // Add it to the frame
    Menu file = new Menu("File");                   // Create a File menu
    menubar.add(file);                              // Add to menubar

    textfield = new TextField();
    textfield.setEditable(false);
    textfield.setFont(new Font("TimesRoman", Font.PLAIN, 9));
    this.add(textfield, "South");
    
    // Create a quit menu item with a shortcut, and add it to the menu
    MenuItem q;
    file.add(q = new MenuItem("Quit", new MenuShortcut(KeyEvent.VK_Q)));

    // Create and register an action listener object for the menu item.
    q.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) { System.exit(0); }
    });

    // Create and register action listener for the window closing event.
    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) { System.exit(0); }
    });

    // Set the window size and pop it up.
    this.pack();
    this.show();
  } // imageView

  public static void main(String[] args) {
    if (args.length == 1) {
      new imageView(args[0]);
    } // if
    else {
      System.err.println("Usage: java imageView <filename>");
    } // else
  } // main

} // imageView class

/*=======================================================================*/

class PixelMap {

  int map[];

  int colors;

  public PixelMap() {
    colors = 256;
    map = new int[colors];
  } // PixelMap

  public PixelMap(int colors) {
    this.colors = colors;
    map = new int[this.colors];
  } // PixelMap

  public void MakeGrayScale() {
    int i, red, blue, green;

    map[0] = 0xff000000;
    for (i = 1; i < this.colors; i++) {
      map[i] = (255 << 24) | (i << 16) | (i << 8) | i;
    } // for
    map[this.colors-1] = 0xffffffff;
  } // MakeGrayScale

  public void MakeColored() {
    int i, red, blue, green;

    map[0] = 0xffffffff;
    for (i = 1; i < this.colors; i++) {
      red = i;
      green = (i<128) ? i << 1 : 255-(i<<1);
      blue = this.colors - i;
      map[i] = (255 << 24) | (red << 16) | (green << 8) | blue;
    } // for
    map[this.colors-1] = 0xff000000;
  } // MakeColored

} // PixelMap class

/*=======================================================================*/

class ImageFile {

  int width, height;

  String filename;

  int pixels[];

  public ImageFile(String filename) {
    this.filename = filename;
    LoadImageFile(this.filename);
  } // ImageFile

  private void LoadImageFile(String filename) {
    int i = 0;
    try {
      BufferedReader bfr = new BufferedReader(new FileReader(filename));
      String line;
      StringTokenizer tokens;
      if ((line = bfr.readLine()) != null) {
        tokens = new StringTokenizer(line, " ");
        this.width = Integer.parseInt(tokens.nextToken());
        this.height = Integer.parseInt(tokens.nextToken());
        this.pixels = new int[this.width * this.height];
        while ((line = bfr.readLine()) != null) {
          tokens = new StringTokenizer(line, " ");
          while (tokens.hasMoreElements()) {
            this.pixels[i] = Integer.parseInt(tokens.nextToken());
            i++;
          } // while
        } // while
      } // if
      bfr.close();
    } // try
    catch (IOException e) {
      System.err.println(e);
      System.exit(-1);
    } // catch
  } // LoadImageFile

  public String getText(int x, int y)
  {
		if (x > 0 && x < this.width && y > 0 && y < this.height) {
      return new String("("+x+","+y+")="+this.pixels[width*y+x]);
		} // if
		else {
			return new String();
		} // else
  } // getText

} // ImageFile class

/*=======================================================================*/

class ImageArea extends Component {

  Image theImage = null;

  protected Frame frame;

  public ImageArea(Frame frame, ImageFile iF, PixelMap pixMap) {

    int i, pixels[] = new int[iF.width * iF.height];
    for (i = 0; i < iF.width*iF.height; i++) {
      pixels[i] = pixMap.map[iF.pixels[i]];
    } // for
    this.frame = frame;
    theImage = createImage(
      new MemoryImageSource(iF.width, iF.height, pixels, 0, iF.width));
  } // ImageArea

  public void paint (Graphics g) {
    update(g);
  } // update

  public void update(Graphics g) {
    g.drawImage(theImage, 0, 0, this);
  } // paint

} // ImageArea class