package baf.sci;

import com.sun.java.swing.JTextArea;
import java.awt.Font;

public class GenericViewer extends JTextArea {
  final byte b[];
  final int offset, len;
  static final Font font = Font.getFont("Courier");

  /** Creates a viewer for an entire buffer.
   */
  public GenericViewer(byte b[]) {
    this.b = b;
    this.offset = 0;
    this.len = b.length;
    setFont(font);
    process();
  }

  /** Creates a viewer for a part of a buffer.
   */
  public GenericViewer(byte b[], int offset, int len) {
    this.b = b;
    this.offset = offset;
    this.len = len;
    setFont(font);
    process();
  }

  private final void process() {
    int end = offset+len;
    int col = 0;
    for (int i=offset; i<end; i++) {
      // Beginning of line gets an address and an extra space
      if (col == 0) {
	append(wordString(i)+" ");
      }
      // Separator is a hyphen at the halfway point, a space everywhere else.
      append((col == 8)? "-" : " ");
      // append the byte
      append(byteString(b[i]));
      col++;
      // new line every 16 bytes
      if (col == 16) {
	append("\n");
	col = 0;
      }
    }

    setEditable(false);
  }

  /** Returns a String suitable for displaying the parameter as a
      16-bit word.
  */
  private final String wordString(int n) {
    String s = Integer.toHexString(n&0xff).toUpperCase();
    switch (s.length()) {
    case 1: return "000"+s;
    case 2: return "00"+s;
    case 3: return "0"+s;
    default: return s;
    }
  }

  /** Returns a String suitable for displaying the parameter as a byte
   */
  private final String byteString(int n) {
    String s = Integer.toHexString(n&0xff).toUpperCase();
    if (s.length() == 1) return "0"+s;
    else return s;
  }
}