#1948 Qt ScintillaEditBase loses mouse tracking when hidden

[Baldur Karlsson]

The Qt ScintillaEdit does setMouseTracking(true) in the constructor so that it can get mouse-move events over its widget.

Commit 45bacc97f7396fcea110428b55965d541935377d then tweaked this a little so that when the widget is hidden mouse tracking is turned off. That's reasonable, but it doesn't have any code to turn it back on again when the widget is shown again.

This means that if you e.g. have the scintilla in a tab widget and it becomes hidden temporarily while switching tabs, when it comes back then things like dwelling don't work properly as the mousemove events aren't received regularly.

I think the fix for this is relatively simple - I've attached a potential patch which just adds an additional case to pick up on the show event and re-enable tracking.

[Neil Hodgson]

Committed as [d0038c].

[Baldur Karlsson]

Thanks for the quick turnaround!