The statusHandler is an object that will receive status updates from the engine during indexing.

A newer way to obtain status updates is to attach an object that implements the IIndexStatusHandler interface using setStatusHandler2. 

A statusHandler can be useful to give the user a status display (such as a progress bar) and an opportunity to cancel an indexing job in progress. 

The statusHandler object must implement a checkForAbort method that returns an AbortValue specifying whether the IndexJob should continue or halt. 

If checkForAbort returns AbortValue.Continue, the index update will continue. 

If checkForAbort returns AbortValue.Cancel, the index update will halt after saving information indexed so far. 

If checkForAbort returns AbortValue.CancelImmediately, the index update will halt without saving any changes to the index. 

On each callback, the value of getStatusPercentDone can be checked to update a progress bar.