1/*
2 * Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25package sun.jvm.hotspot.ui;
26
27import javax.swing.text.*;
28
29/** This class implements a special type of document in which edits
30    can only be performed at the end, from "mark" to the end of the
31    document. Thanks to Scott Violet for suggesting to subclass a
32    Document implementation for this purpose. (Can't do it with
33    DocumentEvents or UndoableEditEvents; however, in 1.4, there will
34    be a DocumentFilter which will allow this kind of functionality.)  */
35
36public class EditableAtEndDocument extends PlainDocument {
37  private int mark;
38
39  public void insertString(int offset, String text, AttributeSet a)
40    throws BadLocationException {
41    int len = getLength();
42    super.insertString(len, text, a);
43  }
44
45  public void remove(int offs, int len) throws BadLocationException {
46    int start = offs;
47    int end = offs + len;
48
49    int markStart = mark;
50    int markEnd = getLength();
51
52    if ((end < markStart) || (start > markEnd)) {
53      // no overlap
54      return;
55    }
56
57    // Determine interval intersection
58    int cutStart = Math.max(start, markStart);
59    int cutEnd = Math.min(end, markEnd);
60    super.remove(cutStart, cutEnd - cutStart);
61  }
62
63  public void setMark() {
64    mark = getLength();
65  }
66
67  public String getMarkedText() throws BadLocationException {
68    return getText(mark, getLength() - mark);
69  }
70
71  /** Used to reset the contents of this document */
72  public void clear() {
73    try {
74      super.remove(0, getLength());
75      setMark();
76    }
77    catch (BadLocationException e) {
78    }
79  }
80}
81