public class TestMetrics extends AbstractHandler {
	private static final String CHATSET="0987654321ABCDEFGHIJKLMNOPQRSTVUWXYZabcdefghijklmnopqrstuvwxyz!@#$%^&*()-_=+;:/<>~";

	@Override
	public Object execute(ExecutionEvent event) throws ExecutionException {
		Shell sh = HandlerUtil.getActiveShell(event);
		FontData fontDt = new FontData("Arial", 10, SWT.NORMAL);
		
		calcSizes (fontDt, sh);
		
		
		fontDt = new FontData("Arial", 10, SWT.BOLD);
		
		calcSizes (fontDt, sh);
		
		return null;
	}

	private void calcSizes(FontData fontData, Shell sh) {
		Font font = new Font(null, new FontData[] {fontData});
		
		GC gc = new GC(sh);
		gc.setFont(font);
		
		Point p = gc.textExtent(CHATSET);
		FontMetrics fm = gc.getFontMetrics();
		gc.dispose();
		
		System.out.format ("Font avg width: %.2f, calc width: %.2f %n", fm.getAverageCharacterWidth(), (double)p.x / (double)CHATSET.length());
		
	}
}