Your developers are going to love this update! As part of our Flinto for Mac 1.3 release we’ve made two huge improvements to support the handoff from designer to developer.

1. Added a UIKit spring option to the easing inspector.

When you use the UIKit spring, the values are the exact same ones that are in Apple’s frameworks so a developer can easily plug them in.

This spring’s options match the parameters to Apple’s UIKit Spring for easy handoff to developer trying to match springs designed in Flinto for Mac.

This chart shows the names used in Flinto for Mac and their corresponding UIKit parameter values.

Flinto for Mac	UIKit
Damping	usingSpringWithDamping
Velocity	initialSpringVelocity
Duration	duration

As an example, if you set damping 0.8, velocity 0, duration 300ms, this is what the actual UIKit API call looks like:

UIView.animateWithDuration(0.3,
                       delay: 0,
      usingSpringWithDamping: 0.8,
       initialSpringVelocity: 0,
                     options: nil,
                  animations: { // move layers, change opacity, etc },
                  completion: nil)

2. Open-sourced our default spring in Swift.

It’s called the RK4 spring, and you can find our implementation on GitHub. When you use our RK4 spring, your developer can drop in our small RK4 spring library and use the same values you set in Flinto for Mac for a precise match of spring behavior.

These details are also written out in our documenation.

If you missed the update, you can read all about the other features and fixes in version 1.3 here.