/**
 Holds application wide common theme, all controls use this for base values before their own or subclass customisation
 */
public class CommonTheme {
	struct appearance {
		var defaultBorderColor: UIColor
	}

	//Defaults, set/changed at app / module startup
	static var appearance: Appearance = Appearance( var defaultBorderColor: UIColor.black)
}

/**
 A custom control using cascading theme settings - Common theme, can be overridden by module specific theme, can be overridden by subclass specific theme, can be overriden by IB settings
 */
public class CustomControl {
    struct Appearance {
        var defaultBorderColor: UIColor
		var backgroundImage: UIImage?
	}

	//Defaults if application specific subclass doesn't override
	var appearance: Appearance {
		return Appearance(
			defaultBorderColor: CommonTheme.appearance.defaultBorderColor
			backgroundImage: nil)
	}

	//If left as default in IB, will use class settings
	@IBInspectable var defaultBorderColor: UIColor!
	@IBInspectable var backgroundImage: UIImage?

	/**
	 Use IB override if available, else use class default
	 */
	fileprivate func setupDefaults() {
		if defaultBorderColor == nil {
			defaultBorderColor = appearance.defaultBorderColor
		}

		if backgroundImage == nil {
			backgroundImage = appearance.backgroundImage
		}
	}

	//Functionality for control goes here
}

/**
 Customise module specific settings for control
 */
class MoneyAppCustomControl: CustomControl {
	override var appear: Appearance {
		return Appearance(
			defaultBorderColor: super.defaultBorderColor,	//No class specific override
			backgroundImage: UIImage(named: "CustomControlBackgroundImage"))
		)
	}

	//Nothing else goes here, this one is just customising the appearance struct
}