fix bug show() is called at the end of prg

[kerautret]

PR Description

Fix a bug which appears with this case of use:

viewer << Z3i::Point(0,0,0);
viewer << MyViewer::updateDisplay;
viewer.show();
return application.exec();

instead :

viewer.show();
viewer << Z3i::Point(0,0,0);
viewer << MyViewer::updateDisplay;
return application.exec();

Checklist

• [n.a. ] Unit-test of your feature with Catch.
• Doxygen documentation of the code completed (classes, methods, types, members...)
• [n.a. ] Documentation module page added or updated.
• New entry in the ChangeLog.md added.
• No warning raised in Debug cmake mode (otherwise, Travis C.I. will fail).
• All continuous integration tests pass (Travis & appveyor)

[dcoeurjo]

just wondering: can't we force the show() (when doing updateDisplay for instance) so that the user won't have to call this function ?

[kerautret]

calling show() in qt is more to display the window on screen perhaps strange if we hide it (cc @akrah ?).
We could add a flag to check it but however sometimes to do offline screenshot it should be not good.

[dcoeurjo]

at the END of the main ?

[kerautret]

yes thanks

[dcoeurjo]

thanks merging.