Tweak UI elements at runtime to find the perfect values

Tweaks lets you make changes to your iOS app while it is running. This is especially useful if you are not sure about the right font size, colors or if you want to hide certain functionallities from some of your testers.

Add DDHTweaks.swift and DDHTweakUserInterface.swift to your project.

Tweak the font size of a label

DDHTweak.value(category: "Main View", collection: "Text", name: "Size", defaultValue: 20, min: 10, max: 40) { tweak in
  self.label.font = UIFont.systemFontOfSize(CGFloat(tweak.currentValue!))
}

Build and run the App. In the Simulator go to Hardware/Shake Gesture. Navigate to Main View and change the font size. Touch Done.

If you add an action to a tweak this is run when ever the value is changed.

1. Float
2. Double
3. Bool
4. String
5. UIColor

Tweaks without an action have to be run to update the value. This means these tweaks have to be defined in viewWillAppear() or viewDidAppear().

let textColor = Tweak.valueForCategory("Main View", collectionName: "Text", name: "Color", defaultValue: UIColor.blackColor())
label.textColor = textColor
        
let backgroundColor = Tweak.valueForCategory("Main View", collectionName: "Background", name: "Color", defaultValue: UIColor.whiteColor())
view.backgroundColor = backgroundColor
        
let text = Tweak.valueForCategory("Main View", collectionName: "Text", name: "Text", defaultValue: "Hello")
label.text = text

Dominik Hauser

App.net: @dasdom

Twitter: @dasdom

swiftandpainless.com

Thanks to facebook for the Objective-C version of Tweaks that I used as inspiration.

MIT Licence. See the LICENCE file for details.