Thread-loke object keeping track of the last edited measurement.
Object responsible for tracking the currently edited measurement.
The tracking relies on the last focus that got focus.
Start the working thread.
Stop the working thread.
Enqueue a newly selected widget.
Method called by the working thread.
Get the currently selected measurement.
The measurement is returned only when thread in done processing the enqueued widgets.
Set the currently selected measurement.
This is used when the selected measurement does not result from focusing.