Add Cell highlight animation customizable (#2)

Author: muukii

Sources/DynamicList/DynamicListView.swift

@@ -51,7 +51,7 @@ public final class DynamicListView<Section: Hashable, Data: Hashable>: UIView,
       withConfiguration contentConfiguration: @escaping @MainActor (
         VersatileCell, UICellConfigurationState
       ) -> Configuration
-    ) -> some UICollectionViewCell {
+    ) -> VersatileCell {
 
       let _reuseIdentifier = reuseIdentifier ?? "\(file):\(line):\(column)"
 
@@ -83,7 +83,7 @@ public final class DynamicListView<Section: Hashable, Data: Hashable>: UIView,
       column: UInt = #column,
       reuseIdentifier: String? = nil,
       @ViewBuilder content: @escaping @MainActor (UICellConfigurationState) -> some View
-    ) -> UICollectionViewCell {
+    ) -> VersatileCell {
 
       if #available(iOS 16, *) {
         return self.cell(

Sources/DynamicList/VersatileCell.swift

@@ -1,29 +1,72 @@
 import UIKit
 
-open class VersatileCell: UICollectionViewCell {
+public struct CellHighlightAnimationContext {
+  public let cell: UICollectionViewCell
+}
+
+public protocol CellHighlightAnimation {
+
+  @MainActor
+  func onChange(isHighlighted: Bool, context: CellHighlightAnimationContext)
+}
+
+public struct DisabledCellHighlightAnimation: CellHighlightAnimation {
+
+  public func onChange(isHighlighted: Bool, context: CellHighlightAnimationContext) {
+    // no operation
+  }
+}
 
-  let animator = UIViewPropertyAnimator(duration: 0.4, dampingRatio: 1)
+public struct ShrinkCellHighlightAnimation: CellHighlightAnimation {
+
+  public func onChange(isHighlighted: Bool, context: CellHighlightAnimationContext) {
+
+    let animator = UIViewPropertyAnimator(duration: 0.4, dampingRatio: 1)
+
+    if isHighlighted {
+      animator.addAnimations {
+        context.cell.transform = .init(scaleX: 0.95, y: 0.95)
+      }
+    } else {
+      animator.addAnimations {
+        context.cell.transform = .identity
+      }
+    }
+    animator.startAnimation()
+  }
+}
+
+extension CellHighlightAnimation {
+
+  public static func shrink(
+    duration: TimeInterval = 0.4,
+    dampingRatio: CGFloat = 1
+  ) -> Self where Self == ShrinkCellHighlightAnimation {
+    ShrinkCellHighlightAnimation()
+  }
+
+}
+
+extension CellHighlightAnimation where Self == DisabledCellHighlightAnimation {
+  public static var disabled: Self {
+    DisabledCellHighlightAnimation()
+  }
+}
+
+open class VersatileCell: UICollectionViewCell {
 
   open override var isHighlighted: Bool {
     didSet {
       guard oldValue != isHighlighted else { return }
-
-      if isHighlighted {
-        animator.addAnimations { [self] in
-          transform = .init(scaleX: 0.95, y: 0.95)
-        }
-      } else {
-        animator.addAnimations { [self] in
-          transform = .identity
-        }
-      }
-      animator.startAnimation()
+      _highlightAnimation.onChange(isHighlighted: isHighlighted, context: .init(cell: self))
     }
   }
 
   public var _updateConfigurationHandler:
   @MainActor (_ cell: VersatileCell, _ state: UICellConfigurationState) -> Void = { _, _ in }
 
+  private var _highlightAnimation: any CellHighlightAnimation = .disabled
+
   public override init(
     frame: CGRect
   ) {
@@ -92,4 +135,9 @@ open class VersatileCell: UICollectionViewCell {
     }
   }
 
+  public func highlightAnimation(_ animation: any CellHighlightAnimation) -> Self {
+    self._highlightAnimation = animation
+    return self
+  }
+
 }