gc.fillRectangle(clientAreaWidth - rightMargin, 0, rightMargin, clientAreaHeight);
drawBackground(gc, clientAreaWidth - rightMargin, 0, rightMargin, clientAreaHeight);
void handlePaint(Event event) {	if (event.width == 0 || event.height == 0) return;	if (clientAreaWidth == 0 || clientAreaHeight == 0) return;	int startLine = getLineIndex(event.y);	int y = getLinePixel(startLine);	int endY = event.y + event.height;	GC gc = event.gc;	Color background = getBackground();	Color foreground = getForeground();	if (endY > 0) {		int lineCount = isSingleLine() ? 1 : content.getLineCount();		int x = leftMargin - horizontalScrollOffset;		for (int i = startLine; y < endY && i < lineCount; i++) {			y += renderer.drawLine(i, x, y, gc, background, foreground);		}		if (y < endY) {			gc.setBackground(background);			gc.fillRectangle(0, y, clientAreaWidth, endY - y);		}	}	// fill the margin background	gc.setBackground(background);	if (topMargin > 0) {		gc.fillRectangle(0, 0, clientAreaWidth, topMargin);	}	if (bottomMargin > 0) {		gc.fillRectangle(0, clientAreaHeight - bottomMargin, clientAreaWidth, bottomMargin);	}	if (leftMargin > 0) {		gc.fillRectangle(0, 0, leftMargin, clientAreaHeight);	}	if (rightMargin > 0) {		gc.fillRectangle(clientAreaWidth - rightMargin, 0, rightMargin, clientAreaHeight);	}}