public void initGraphicData() {
		final int W = 200;
		final int H = 100;
		boolean changed = false;
		int x = 10;
		int y = 10;
		if (x < 0) x = 0;
		if (y < 0) y = 0;
		for (int i = 0; i < nodeList.size(); i++) {
			y = y + H + 10;
			Rectangle rect = new Rectangle(x, y, W, H);
			circles.addElement(rect);
			drawingPane.scrollRectToVisible(rect);
			if (area.width < x) {
				area.width = x;
			}
			
			if (area.height < y) {
				area.height = y;
			}
			// Update client's preferred size because the area taken
			// up by the graphics has gotten larger or smaller(id cleared)
			drawingPane.setPreferredSize(area);
			
			// Let the scroll pane know to update itself and its scrollbars
			drawingPane.revalidate();
		}
		
		
		drawingPane.repaint();
	}