While developing apps for OSX or iOS you will be wondering how to disable IBAction button programatically.
Here is how to do it.
Assumption: I assume you are using Storyboards for developing your apps within Xcode.
Step 01: Drag UIButton (iOS) or NSButton (OSX) on Storyboard. I Also assume that you have dragged three buttons on storyboard & you have named it as Start, Pause & Reset.