I've got a button that will do some math when tapped.
Depending on the equation that the user enters, the button will be tapped, but then stay down, as the app takes a while to do the math in the button's function. It would be great if I could have a progress bar show the user during that time. I added one, but the problem is that it doesn't show up when the button has been tapped, as the button is lagging.. it seems that no changes can occur on the screen while the button is tapped down and lagging.

Sorry... I'm a bit of a noob... but I'm stuck...