001: /* ========================================================================
002: * JCommon : a free general purpose class library for the Java(tm) platform
003: * ========================================================================
004: *
005: * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006: *
007: * Project Info: http://www.jfree.org/jcommon/index.html
008: *
009: * This library is free software; you can redistribute it and/or modify it
010: * under the terms of the GNU Lesser General Public License as published by
011: * the Free Software Foundation; either version 2.1 of the License, or
012: * (at your option) any later version.
013: *
014: * This library is distributed in the hope that it will be useful, but
015: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017: * License for more details.
018: *
019: * You should have received a copy of the GNU Lesser General Public
020: * License along with this library; if not, write to the Free Software
021: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022: * USA.
023: *
024: * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025: * in the United States and other countries.]
026: *
027: * ---------------------------
028: * LengthLimitingDocument.java
029: * ---------------------------
030: * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
031: *
032: * Original Author: Thomas Morgner;
033: * Contributor(s): David Gilbert (for Object Refinery Limited);
034: *
035: * $Id: LengthLimitingDocument.java,v 1.3 2005/10/18 13:18:34 mungady Exp $
036: *
037: * Changes
038: * -------
039: * 22-Jan-2003 : Initial version
040: * 05-Feb-2003 : Documentation
041: *
042: */
043:
044: package org.jfree.ui;
045:
046: import javax.swing.text.AttributeSet;
047: import javax.swing.text.BadLocationException;
048: import javax.swing.text.PlainDocument;
049:
050: /**
051: * This Document restricts the size of the contained plain text to the given number of
052: * characters.
053: *
054: * @author Thomas Morgner
055: */
056: public class LengthLimitingDocument extends PlainDocument {
057:
058: /** The maximum length. */
059: private int maxlen;
060:
061: /**
062: * Creates a new LengthLimitingDocument, with no limitation.
063: */
064: public LengthLimitingDocument() {
065: this (-1);
066: }
067:
068: /**
069: * Creates a new LengthLimitingDocument with the given limitation. No more than
070: * maxlen characters can be added to the document. If maxlen is negative, then
071: * no length check is performed.
072: *
073: * @param maxlen the maximum number of elements in this document
074: */
075: public LengthLimitingDocument(final int maxlen) {
076: super ();
077: this .maxlen = maxlen;
078: }
079:
080: /**
081: * Sets the maximum number of characters for this document. Existing characters
082: * are not removed.
083: *
084: * @param maxlen the maximum number of characters in this document.
085: */
086: public void setMaxLength(final int maxlen) {
087: this .maxlen = maxlen;
088: }
089:
090: /**
091: * Returns the defined maximum number characters for this document.
092: * @return the maximum number of characters
093: */
094: public int getMaxLength() {
095: return this .maxlen;
096: }
097:
098: /**
099: * Inserts the string into the document. If the length of the document would
100: * violate the maximum characters restriction, then the string is cut down so
101: * that
102: * @param offs the offset, where the string should be inserted into the document
103: * @param str the string that should be inserted
104: * @param a the attribute set assigned for the document
105: * @throws javax.swing.text.BadLocationException if the offset is not correct
106: */
107: public void insertString(final int offs, final String str,
108: final AttributeSet a) throws BadLocationException {
109: if (str == null) {
110: return;
111: }
112:
113: if (this .maxlen < 0) {
114: super .insertString(offs, str, a);
115: }
116:
117: final char[] numeric = str.toCharArray();
118: final StringBuffer b = new StringBuffer();
119: b.append(numeric, 0, Math.min(this.maxlen, numeric.length));
120: super.insertString(offs, b.toString(), a);
121: }
122:
123: }
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