Showing a "Please wait..." box while slot function is running

Question

I have a slot function in my GUI that takes time to complete (10-15 seconds). I would like to gray the layout and show a box of "Please wait..." that will disappear when the slot function is done.

I need it to be async as I want to use a QProgressBar widget in the "Please wait..." Window.

How can this be done?

Answer 1

Your long running slot should be running in a QThread, while your "Please wait..." widget should be modal in the main GUI thread.

You could use QProgressDialog and maybe choose a windowflag that suits your display needs, or a custom widget. But the long running operation should signal the modal blocking dialog when it has completed, causing the dialog to then hide.