filecanvas.java

和YACC一样

/*

File:	 FileCanvas.java
Author:  zerksis d. umrigar ([e-mail])
Copyright (C) 1997 Zerksis D. Umrigar
Last Update Time-stamp: "97/07/27 23:25:40 zdu"

This code is distributed under the terms of the GNU General Public License.
See the file COPYING with this distribution, or

		http://www.fsf.org/copyleft/gpl.html

THERE IS ABSOLUTELY NO WARRANTY FOR THIS PROGRAM.

*/

package zdu.zydebug;

import zdu.zydebug.TextCanvas;

import java.awt.*;
import java.io.*;

/** Displays the contents of a text-file in a scrollable text-canvas.  The
 * contents are initialized from the file during construction.
 */
class FileCanvas extends TextCanvas {

  /** Create a file-canvas of dimension width x height pixels, with
   * contents initialized by the input-stream d.
   * Terminated by EOF or a line containing just a '.'.
   * @param d		input stream for initializing contents.
   * @param width	width of the canvas in pixels.
   * @param height	height of the canvas in pixels.
   */
  FileCanvas(DataInputStream d, int width, int height, String mouseHint) {
    super(width, height, mouseHint);
    try {
      String line;
      while ((line= d.readLine()) != null) {
	int len= line.length();
	if (len >= 1 && line.charAt(0) == '.') {
	  if (len == 1) {
	    break;
	  }
	  else {
	    line= line.substring(1);
	  }
	}
	addLine(line);
      }
    }
    catch (IOException e) {
      System.err.println("IO Exception");
      System.exit(1);
    }
  }

  FileCanvas(DataInputStream d, int width, int height) {
    this(d, width, height, null);
  }

  /** Test program which displays the contents of this file. */
  static public void main(String[] args) {
    InputStream i= System.in;
    String fName=  "zdu/zydebug/FileCanvas.java";
    try {
      i= new FileInputStream(fName);
    }
    catch (FileNotFoundException e) {
      System.err.println("FileCanvas.main() " + e + " " + fName);
      System.exit(1);
    }
    catch (SecurityException e) {
      throw new InternalError("FileCanvas.main() " + e);
    }
    DataInputStream d= new DataInputStream(i);
    FileCanvas f= new FileCanvas(d, 200, 200);
    Frame frame= new Frame("FileCanvas Test");
    frame.setLayout(new FlowLayout());
    frame.add(f.getComponent());
    f.setFont(new Font("Helvetica", 0, 18));
    frame.resize(400, 400);
    frame.show();
    f.select(0, 7);
    
  }
}