Questions on the OutlookRibbonXCS example

Hi,

I studied the OutlookRibbonXCS example but don't understand everything completely.

Looking at

public bool ColorWidgetsGroup_GetVisible(Office.IRibbonControl control)
{
Debug.WriteLine("ColorWidgetsGroup_GetVisible");
OutlookInspector window = FindOutlookInspector(control.Context);
if (window != null)
{
Outlook.ContactItem contact = window.CurrentItem;
//Make the group visible only if an address exists
if (String.IsNullOrEmpty(contact.BusinessAddress) &...

Questions on the OutlookRibbonXCS example