--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/ui/EditableAtEndDocument.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2000 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package sun.jvm.hotspot.ui;
+
+import javax.swing.text.*;
+
+/** This class implements a special type of document in which edits
+    can only be performed at the end, from "mark" to the end of the
+    document. Thanks to Scott Violet for suggesting to subclass a
+    Document implementation for this purpose. (Can't do it with
+    DocumentEvents or UndoableEditEvents; however, in 1.4, there will
+    be a DocumentFilter which will allow this kind of functionality.)  */
+
+public class EditableAtEndDocument extends PlainDocument {
+  private int mark;
+
+  public void insertString(int offset, String text, AttributeSet a)
+    throws BadLocationException {
+    int len = getLength();
+    super.insertString(len, text, a);
+  }
+
+  public void remove(int offs, int len) throws BadLocationException {
+    int start = offs;
+    int end = offs + len;
+
+    int markStart = mark;
+    int markEnd = getLength();
+
+    if ((end < markStart) || (start > markEnd)) {
+      // no overlap
+      return;
+    }
+
+    // Determine interval intersection
+    int cutStart = Math.max(start, markStart);
+    int cutEnd = Math.min(end, markEnd);
+    super.remove(cutStart, cutEnd - cutStart);
+  }
+
+  public void setMark() {
+    mark = getLength();
+  }
+
+  public String getMarkedText() throws BadLocationException {
+    return getText(mark, getLength() - mark);
+  }
+
+  /** Used to reset the contents of this document */
+  public void clear() {
+    try {
+      super.remove(0, getLength());
+      setMark();
+    }
+    catch (BadLocationException e) {
+    }
+  }
+}