private void displayLine(int lineNumber, boolean markCurrent) {
try {
if (markCurrent) {
/* remove previous highlight */
Highlighter hl = codeEditor.getHighlighter();
hl.changeHighlight(currentLineTag, 0, 0);
}
if (lineNumber >= 0) {
final int start = codeEditorLines.get(lineNumber);
int end = codeEditorLines.get(lineNumber+1);