NEW: Learn SwiftUI with my free YouTube video series! >>

< How to create basic animations   How to animate changes in binding values >

How to create a spring animation

SwiftUI has built-in support for spring animations, which are animations that move to their target point, overshoot a little, then bounce back.

If you just use .spring() by itself, with no parameters, you get a sensible default. So, this creates a spring animation that rotates a button by 45 degrees every time it’s tapped:

struct ContentView: View {
    @State private var angle: Double = 0

    var body: some View {
        Button(action: {
            self.angle += 45
        }) {
            Text("Tap here")
                .padding()
                .rotationEffect(.degrees(angle))
                .animation(.spring())
        }
    }
}

If you want fine-grained control over the spring animation, send in any of the parameters that interest you: the mass of the object, how stiff the spring should be, how quickly the springiness slows down, and how fast it starts moving at launch.

For example, this creates a button with a moderate amount spring damping, which means it will bounce back and forth a few times time before reaching its target angle:

Button(action: {
    self.angle += 45
}) {
    Text("Tap here")
        .padding()
        .rotationEffect(.degrees(angle))
        .animation(.interpolatingSpring(mass: 1, stiffness: 1, damping: 0.5, initialVelocity: 5))
}

Note: This is an interpolating spring, which means if you trigger the animation several times the spring effect will get stronger and stronger as the springs combine.

LEARN SWIFTUI FOR FREE I wrote a massive, free SwiftUI tutorial collection, and also have a growing list of free SwiftUI tutorials on YouTube – get started today!

< How to create basic animations   How to animate changes in binding values >
MASTER SWIFT NOW
Buy Testing Swift Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Average rating: 4.7/5

Click here to visit the Hacking with Swift store >>