Slow GUI operations should show WaitCursor

Slow GUI operations should show the wait cursor until the operation completes. Buttons to cover:

• Display Data
• Display Statistics
• Display Plot
• Load
• Display Global Attrs.

This may be a bit complex, as many (all?) of the buttons are hooked up to a register/listener pattern. While calling into the listener is probably blocking, it doesn't seem like something that would be guaranteed.

At the moment the listener calls are blocking, so this shouldn't be super hard to do.

assigned to @evas

marked the checklist item Display Global Attrs. as completed

marked the checklist item Display Plot as completed

marked the checklist item Display Raw Data as completed

marked the checklist item Display Statistics as completed

changed the description

marked the checklist item Display Data as completed

There appears to be about a 5 second lag on Qt changing the cursor to a wait cursor, so if the program takes less than that to do the various actions you won't see any cursor change, even though there will be a very long pause when nothing happens.

marked the checklist item Load as completed

closed