42 - Use Animated Images in SwiftUI

Animations add life to any static image and can make the user interface more engaging and interactive. SwiftUI makes it easy to animate images with the help of the Image view and its built-in animation features.

To create animations in SwiftUI, you can use the withAnimation function along with the desired animation type, duration and other parameters. This function allows you to animate state transitions, which subsequently animates the affected views. You can trigger these animations based on certain conditions or events, such as when a view appears on the screen.

For example, you might animate an image scaling up and down by applying the scaleEffect modifier in response to a state variable change, which is then animated within a withAnimation block, like so:

struct ContentView: View {
  @State private var isAnimating = false

  var body: some View {
    Image("HelloHedgy")
      .resizable()
      .scaledToFit()
      .scaleEffect(isAnimating ? 1.5 : 1.0)
      .onAppear() {
        withAnimation(.easeInOut(duration: 1.0).repeatForever(autoreverses: true)) {
          isAnimating = true
        }
      }
  }
}

The preview should look as follows:

You can easily animate images in SwiftUI.

Here’s how this code works:

• @State private var isAnimating = false a state variable is declared called isAnimating and initialized with false. @State is a property wrapper provided by SwiftUI which allows us to create mutable state for our views.

• Image("HelloHedgy") an Image view is declared with the image name HelloHedgy. This loads an image from the app’s asset catalog.

• .resizable() modifies the image to be resizable, meaning it can be scaled to different sizes.

• .scaledToFit() modifies the image to scale it to fit within its parent view, maintaining its aspect ratio.

• .scaleEffect(isAnimating ? 1.5 : 1.0) modifies the image to scale it up by 1.5 times when isAnimating is true, and to its original size (1.0 times) when isAnimating is false.

• .onAppear(): Declares an action to perform when the image appears on screen.

• withAnimation(Animation.easeInOut(duration: 1.0).repeatForever(autoreverses: true))specifies that any changes inside the closure should be animated with an ease-in-out animation over 1.0 seconds, repeating forever and reversing each time.

• isAnimating = true sets isAnimating to true. Because this is within the withAnimation closure, changing isAnimating from false to true will be animated, which in turn animates the scale effect on the image.

Using this approach, we can create various types of animations for images, including rotations, fades and translations. We can also combine multiple animations together and create complex animations that can dynamically change with user interactions.

In conclusion, animated images are a powerful tool to create dynamic and interactive user interfaces in SwiftUI. With its easy-to-use animation features, SwiftUI makes it possible to create stunning animations that engage users and enhance the user experience.