Ideas for self study

Before moving on, it's a good idea to play around with the features and code we have covered in this chapter and explore what happens when changing some of the details to see what effect it has on the app and its interface.

One excellent candidate is the borderGroup object we used to fake the button border. If you option-click on the declaration at the top of the InterfaceController code, you will be presented with a pop-up window that provides you, with among much other useful information, a list of WKInterfaceGroup settable properties which are available to you. Start by typing self.borderGroup.set and let Xcode's code completion show you what's on offer:

A Command-click on one of the UIColor methods such as .redColor() will take you to a list of convenience methods which create a limited number of preset colors. Why stick to a choice of three? Why not 10? (But you'll have to scroll!)

You might also like to print() a warning to the console when the modal dialog returns nil after you select Cancel instead of a color from the modal view.