It’s a cube animation like Instagram.
If you would like to customize the cube animation, change cubeDegree.
If cubeDegree is 90, it moves like a regular hexahedron.

collectionView.gemini
    .cubeAnimation()
    .cubeDegree(90)

An animation moves in a circle. You can change circleRadius and CircleRotationDirection.

collectionView.gemini
    .circleRotationAnimation()
    .radius(450) // The radius of the circle
    .rotateDirection(.clockwise) // Direction of rotation. 
    .itemRotationEnabled(true) // Whether the item rotates or not.

Available for Roll, Pitch and Yaw animation. These rotation animation are designed based on 3-Dimensional vector. Figure-1 shows direction of rotation based on device.

Figure-1 Pitch, roll, and yaw axes

Each types of rotation animation has RotationEffect(e.g. RollRotationEffect) and degree of rotation.

Customize RotationEffect (up, down, sineWave, reverseSineWave) and degree of rotation.

In the case of rollRotation, like this:

collectionView.gemini
    .rollRotationAnimation()
    .degree(45)
    .rollEffect(.rollUp)

The scaleUp gradually increases frame size, scaleDown decreases.

collectionView.gemini
    .scaleAnimation()
    .scale(0.75)
    .scaleEffect(.scaleUp) // or .scaleDown

You can flexibly and easily customize scroll animation. Customize properties of GeminiAnimation.custom such as scale, scaleEffect, rotationAngle, translation, easing, shadowEffect, alpha, cornerRadius, backgroundColor, anchorPoint, etc.

The animation of gif is customized in the following way:

collectionView.gemini
    .customAnimation()
    .translation(y: 50)
    .rotationAngle(y: 13)
    .ease(.easeOutExpo)
    .shadowEffect(.fadeIn)
    .maxShadowAlpha(0.3)

Or right side of gifs is customized as follows:

collectionView.gemini
    .customAnimation()
    .backgroundColor(startColor: lightGreenColor, endColor: lightBlueColor)
    .ease(.easeOutSine)
    .cornerRadius(75)

Gemini supports various easing functions based on distance of scroll.

• linear
• easeInQuad
• easeOutQuad
• easeInOutQuad
• easeInCubic
• easeOutCubic
• easeInOutCubic
• easeInQuart
• easeOutQuart
• easeInOutQuart
• easeInQuint
• easeOutQuint
• easeInOutQuint
• easeInSine
• easeOutSine
• easeInOutSine
• easeInExpo
• easeOutExpo
• easeInOutExpo
• easeInCirc
• easeOutCirc
• easeInOutCirc

Default value is ShadowEffect.none. Return shadowView in your custom class, which is a subclass of GeminiCell.

• fadeIn
• nextFadeIn
• previousFadeIn
• fadeOut
• none

class CustomCollectionViewCell: GeminiCell {
    @IBOutlet weak var customShadowView: UIView!
    override var shadowView: UIView? {
        return customShadowView
    }
}

1. Use Gemini classes

Gemini is designed to be easy to use. Use GeminiCollectionView and GeminiCell. These classes is subclass of UICollectionView, UICollectionViewCell.

2. Configure animation

Configure animation with fluent interface based on method chaining. You can develop expressive code that enhances readability.

3. Call function for animation

Finally, call animateVisibleCells() in scrollViewDidScroll(_:)

NOTE: If you want to adapt animation immediately after view is displayed, call animateCell(_:) in collectionView(_:cellForItemAt:) and collectionView(_:willDisplay:forItemAt:).

// Import Gemini
import Gemini

// Inherite GeminiCell
class CustomCell: GeminiCell {
    ...
}

// Conform to UICollectionViewDelegate and UICollectionViewDataSource
class CustomViewController: UIViewController: UICollectionViewDelegate, UICollectionViewDataSource {

    // Inherite GeminiCollectionView
    @IBOutlet weak var collectionView: GeminiCollectionView!

    ...

    // Configure animation and properties
    func configureAnimation() {
        collectionView.gemini
            .circleRotationAnimation()
            .radius(400)
            .rotateDirection(.clockwise)
    }

    // Call animation function
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        collectionView.animateVisibleCells()
    }

    func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
        if let cell = cell as? GeminiCell {
            self.collectionView.animateCell(cell)
        }
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell
        self.collectionView.animateCell(cell)
        return cell
    }

• Xcode 10.2.1
• Swift 5.0

CocoaPods

Shohei Yokoyama