//package components;

/* A 1.4 class used by TextComponentDemo.java. */

import javax.swing.*;
import javax.swing.text.*;
import java.awt.Toolkit;

public class DocumentSizeFilter extends DocumentFilter {
  int maxCharacters;
  boolean DEBUG = false;

  public DocumentSizeFilter(int maxChars) {
    maxCharacters = maxChars;
  }

  public void insertString(FilterBypass fb, int offs,
			   String str, AttributeSet a)
      throws BadLocationException {
    if (DEBUG) {
      System.out.println("in DocumentSizeFilter's insertString method");
    }

    //This rejects the entire insertion if it would make
    //the contents too long. Another option would be
    //to truncate the inserted string so the contents
    //would be exactly maxCharacters in length.
    if ((fb.getDocument().getLength() + str.length()) <= maxCharacters)
      super.insertString(fb, offs, str, a);
    else
      Toolkit.getDefaultToolkit().beep();
  }
    
  public void replace(FilterBypass fb, int offs,
		      int length, 
		      String str, AttributeSet a)
      throws BadLocationException {
    if (DEBUG) {
      System.out.println("in DocumentSizeFilter's replace method");
    }
    //This rejects the entire replacement if it would make
    //the contents too long. Another option would be
    //to truncate the replacement string so the contents
    //would be exactly maxCharacters in length.
    if ((fb.getDocument().getLength() + str.length()
	 - length) <= maxCharacters)
      super.replace(fb, offs, length, str, a);
    else
      Toolkit.getDefaultToolkit().beep();
  }

}