private void setupEditor() 
    {
        QFont font = new QFont();
        font.setFamily("Lucida Console");
        font.setFixedPitch(true);
        font.setPointSize(10);
 
        textEdit = new QTextEdit();
        textEdit.setLineWrapMode(QTextEdit.LineWrapMode.NoWrap);
        textEdit.setFont(font);
 
        new Highlighter(textEdit.document());
        new CodeEditor(textEdit.document()); 
 
    }
    public class CodeEditor extends QPlainTextEdit
    {
    	public CodeEditor(QTextDocument textDocument)
    //	public CodeEditor()
        {
            lineNumberArea = new LineNumberArea(this);
 
            blockCountChanged.connect(this, "updateLineNumberAreaWidth(Integer)");
            updateRequest.connect(this, "updateLineNumberArea(QRect,Integer)");
            cursorPositionChanged.connect(this, "highlightCurrentLine()");
 
            updateLineNumberAreaWidth(0);
            highlightCurrentLine();
 
        }
    	 public int lineNumberAreaWidth()
    	    {
    	        int digits = 1;
    	        int max = Math.max(1, blockCount());
    	        while (max >= 10) {
    	            max /= 10;
    	            ++digits;
    	        }
 
    	        int space = 3 + fontMetrics().width('9') * digits;
 
    	        return space;
    	    }
    	    public void updateLineNumberAreaWidth(Integer newBlockCount)
    	    {
    	        setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
    	    }
    	    public void updateLineNumberArea(QRect rect, Integer dy)
    	    {
    	        if (dy > 0)
    	            lineNumberArea.scroll(0, dy);
    	        else
    	            lineNumberArea.update(0, rect.y(), lineNumberArea.width(),
    	                                  rect.height());
 
    	        if (rect.contains(viewport().rect()))
    	            updateLineNumberAreaWidth(0);
    	    }
    	    protected void resizeEvent(QResizeEvent e)
    	    {
    	        super.resizeEvent(e);
 
    	        QRect cr = contentsRect();
    	        lineNumberArea.setGeometry(new QRect(cr.left(), cr.top(),
    	                                   lineNumberAreaWidth(), cr.height()));
    	    }
    	    private void highlightCurrentLine()
    	    {
    	        List<QTextEdit_ExtraSelection> extraSelections =
    	            new Vector<QTextEdit_ExtraSelection>();
 
    	        if (!isReadOnly()) {
    	            QTextEdit_ExtraSelection selection =
    	                new QTextEdit_ExtraSelection();
 
    	            QColor lineColor = QColor.yellow.lighter(160);
 
    	            QTextCharFormat format = selection.format();
    	            format.setBackground(new QBrush(lineColor));
    	            format.setProperty(QTextFormat.Property.FullWidthSelection.value(), new Boolean(true));
    	            selection.setFormat(format);
    	            QTextCursor cursor = textCursor();
    	            cursor.clearSelection();
    	            selection.setCursor(cursor);
    	            extraSelections.add(selection);
    	        }
 
    	        setExtraSelections(extraSelections);
    	    }
    	    public void lineNumberAreaPaintEvent(QPaintEvent event)
    	    {
    	        QPainter painter = new QPainter(lineNumberArea);
    	        painter.setPen(new QPen(QColor.black));
    	        painter.fillRect(event.rect(), new QBrush(QColor.lightGray));
 
    	        QTextBlock block = firstVisibleBlock();
    	        int blockNumber = block.blockNumber();
    	        int top = (int) blockBoundingGeometry(block).translated(contentOffset()).top();
    	        int bottom = top + (int) blockBoundingRect(block).height();
 
    	        while (block.isValid() && top <= event.rect().bottom()) {
    	            if (block.isVisible() && bottom >= event.rect().top()) {
    	                String number = String.valueOf(blockNumber + 1);
    	                painter.drawText(0, top, lineNumberArea.width(), fontMetrics().height(),
    	                                Qt.AlignmentFlag.AlignRight.value(), number);
    	            }
 
    	            block = block.next();
    	            top = bottom;
    	            bottom = top + (int) blockBoundingRect(block).height();
    	            ++blockNumber;
    	        }
    	    } 
 
    	    private class LineNumberArea extends QWidget
    	    {
    	        public LineNumberArea(CodeEditor editor)
    	        {
    	            codeEditor = editor;
    	            setParent(codeEditor);
    	        }
    	        public QSize sizeHint()
    	        {
    	            return new QSize(codeEditor.lineNumberAreaWidth(), 0);
    	        }
    	        protected void paintEvent(QPaintEvent event)
    	        {
    	            codeEditor.lineNumberAreaPaintEvent(event);
    	        }
    	        private CodeEditor codeEditor;
    	    }
 
    	    private LineNumberArea lineNumberArea;
    }