Variables for colors in interface builder

Question

I have a project that I need to change overall color themes in the app. A lot of my UI elements are built through Interface Builder in Xcode 6.1. I need to set colors as variables in interface builder, so if I set a preprocessor telling the app to use a certain scheme then the colors will change in interface builder. Is this even possible?

Answer 1

I'm not aware of any way to do this with interface builder, however there is a way that you can set appearance properties in code for many IOS UI elements that will then apply globally. As an example see the following snippet of code:

UIToolbar.appearance().tintColor = UIColor.whiteColor()
UIToolbar.appearance().barTintColor = UIColor.blackColor()

UITableView.appearance().separatorColor = UIColor.grayColor()
UITableView.appearance().sectionIndexColor = UIColor.grayColor();

UINavigationBar.appearance().tintColor = UIColor.blueColor()
UINavigationBar.appearance().barTintColor = UIColor.blackColor()
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName : UIColor.whiteColor()]

The code sets a the default tint and bar color for all the UIToolbars, separator and section index colors for all UITableViews, and appearance properties for all the UINavigation views in my app..

You could use #if to set the appearance differently depending on the environment variables set in the compiler.

If you want to find out more about how this works Id suggest reading Apples documentation on UIAppearance properties here: UIAppearance Documentation