--- /dev/null
+package tim.prune.load;
+
+import javax.swing.text.AttributeSet;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.PlainDocument;
+
+/**
+ * Document class to restrict text input to single character
+ * for selection of custom delimiter
+ */
+public class OneCharDocument extends PlainDocument
+{
+ public void insertString(int offs, String str, AttributeSet a)
+ throws BadLocationException
+ {
+ //This rejects the insertion if it would make
+ //the contents too long.
+ if ((getLength() + str.length()) <= 1)
+ super.insertString(offs, str, a);
+ }
+}