draggingAnimation modifier

Deprecating pagingAnimation. New modifier will be used onChanged and onEnded

Documentation/Usage.md

@@ -227,21 +227,15 @@ Transform your `Pager` into an endless sroll by using `loopPages`:
 
 ## Page Transitions
 
-Use `pagingAnimation` to customize the _transition_ to the next page once the drag has ended. This is achieve by a block with a `DragResult`which contains:
-* Current page
-* Next page
-* Total shift
-* Velocity
-
-By default, `pagingAnimation`is set to `standard`(a.k.a, `.easeOut`) for `singlePagination`and `steep`([custom bezier curve](https://cubic-bezier.com/#.2,1,.9,1)) for `multiplePagination`. If you wish to change the animation, you could do it as follows:
+Use `draggingAnimation(_:)`  to customize the _transition_ to the next page.
 
 ```swift
 Pager(...)
-    .pagingAnimation({ currentPage, nextPage, totalShift, velocity in
-        return PagingAnimation.custom(animation: .easeInOut)
-    })
+    .draggingAnimation(.interactive)
 ```
 
+By default, `draggingAnimation` is set to `.easeOut`.
+
 ## Events
 
 Use `onPageWillChange` or `onPageChanged` to react to changes on the page index:

Sources/SwiftUIPager/PageConfiguration/PagingAnimation.swift

@@ -8,6 +8,9 @@
 
 import SwiftUI
 
+@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
+public typealias DraggingAnimation = PagingAnimation
+
 /// Animation to be used when the user stops dragging
 @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
 public enum PagingAnimation: Equatable {
@@ -24,6 +27,9 @@ public enum PagingAnimation: Equatable {
     /// - Parameter duration: duration of the animation
     case standard(duration: TimeInterval)
 
+    /// Interactive spring with a response of 0.3, dampingFraction: 0.8, and blendDuration: 0.5
+    case interactive
+
     /// Pass your custom animation
     ///
     /// - Parameter animation: animation to be applied
@@ -43,6 +49,8 @@ public enum PagingAnimation: Equatable {
             return Animation.timingCurve(0.2, 1, 0.9, 1, duration: duration)
         case .standard(let duration):
             return Animation.easeOut(duration: duration)
+        case .interactive:
+            return .interactiveSpring(response: 0.3, dampingFraction: 0.8, blendDuration: 0.5)
         case .custom(let animation):
             return animation
         }

Sources/SwiftUIPager/Pager+Buildable.swift

@@ -17,6 +17,7 @@ extension Pager: Buildable {
     /// Sets the animation to be applied when the user stops dragging
     ///
     /// - Parameter value: callback to get an animation based on the result of dragging
+    @available(*, deprecated, message: "This method will no longer be mantained in future versions. Please use `draggingAnimation(_:)` instead")
     public func pagingAnimation(_ value: ((DragResult) -> PagingAnimation)?) -> Self {
         mutating(keyPath: \.pagingAnimation, value: value)
     }
@@ -69,6 +70,13 @@ extension Pager: Buildable {
 
     #if !os(tvOS)
 
+    /// Sets the explicit animation used for dragging
+    ///
+    /// - Parameter value: explicit animation
+    public func draggingAnimation(_ value: DraggingAnimation?) -> Self {
+        mutating(keyPath: \.draggingAnimation, value: value)
+    }
+
     /// Sensitivity used to determine whether or not to swipe the page
     ///
     /// - Parameter value: sensitivity to be applied when paginating

Sources/SwiftUIPager/Pager.swift

@@ -72,6 +72,9 @@ public struct Pager<Element, ID, PageView>: View  where PageView: View, Element:
     /// Animation to be applied when the user stops dragging
     var pagingAnimation: ((DragResult) -> PagingAnimation)?
 
+    /// Animation used for dragging
+    var draggingAnimation: DraggingAnimation?
+
     /// Sensitivity used to determine whether or not to swipe the page
     var sensitivity: PaginationSensitivity = .default
 
@@ -211,6 +214,7 @@ public struct Pager<Element, ID, PageView>: View  where PageView: View, Element:
             .onDraggingChanged(onDraggingChanged)
             .onDraggingEnded(onDraggingEnded)
             .bounces(bounces)
+            .draggingAnimation(draggingAnimation)
           #endif
 
         pagerContent = allowsMultiplePagination ? pagerContent.multiplePagination() : pagerContent

Sources/SwiftUIPager/PagerContent+Buildable.swift

@@ -70,6 +70,13 @@ extension Pager.PagerContent: Buildable {
 
     #if !os(tvOS)
 
+    /// Sets the explicit animation used for dragging
+    ///
+    /// - Parameter value: explicit animation
+    func draggingAnimation(_ value: DraggingAnimation?) -> Self {
+        mutating(keyPath: \.draggingAnimation, value: value)
+    }
+
     /// Sensitivity used to determine whether or not to swipe the page
     ///
     /// - Parameter value: sensitivity to be applied when paginating

Sources/SwiftUIPager/PagerContent.swift

@@ -56,6 +56,9 @@ extension Pager {
         /// Animation to be applied when the user stops dragging
         var pagingAnimation: ((DragResult) -> PagingAnimation)?
 
+        /// Animation used for dragging
+        var draggingAnimation: DraggingAnimation?
+
         /// Sensitivity used to determine whether or not to swipe the page
         var sensitivity: PaginationSensitivity = .default
 
@@ -222,7 +225,8 @@ extension Pager.PagerContent {
     }
 
     func onDragChanged(with value: DragGesture.Value) {
-        withAnimation(.linear(duration: 0.1)) {
+        let animation = draggingAnimation?.animation ?? .default
+        withAnimation(animation) {
             if self.lastDraggingValue == nil {
                 onDraggingBegan?()
             }
@@ -276,7 +280,7 @@ extension Pager.PagerContent {
             speed = 1 / min(4, Double(pageIncrement))
         }
 
-        let pagingAnimation = self.pagingAnimation?((page, newPage, draggingOffset, draggingVelocity)) ?? defaultPagingAnimation
+        let pagingAnimation = self.draggingAnimation ?? self.pagingAnimation?((page, newPage, draggingOffset, draggingVelocity)) ?? defaultPagingAnimation
 
         let animation = pagingAnimation.animation.speed(speed)
         if page != newPage {

Tests/SwiftUIPagerTests/Pager+Buildable_Tests.swift

@@ -35,6 +35,7 @@ final class Pager_Buildable_Tests: XCTestCase {
         XCTAssertEqual(pager.contentLoadingPolicy, .default)
         XCTAssertEqual(pager.allowsMultiplePagination, false)
         XCTAssertNil(pager.pagingAnimation)
+        XCTAssertNil(pager.draggingAnimation)
         XCTAssertEqual(pager.sensitivity, .default)
         XCTAssertEqual(pager.pageRatio, 1)
         XCTAssertTrue(pager.bounces)
@@ -113,6 +114,14 @@ final class Pager_Buildable_Tests: XCTestCase {
         XCTAssertEqual(pagingAnimation, PagingAnimation.steep)
     }
 
+    func test_GivenPager_WhenDraggingAnimation_ThenDraggingAnimationNotNil() throws {
+        var pager = givenPager
+        pager = pager.draggingAnimation(.steep)
+        let pagerContent = pager.content(for: CGSize(width: 100, height: 100))
+        let animation = try XCTUnwrap(pagerContent.draggingAnimation)
+        XCTAssertEqual(animation, PagingAnimation.steep)
+    }
+
     func test_GivenPager_WhenMultiplePagination_ThenAllowsMultiplePagination() {
         var pager = givenPager
         pager = pager.multiplePagination()
@@ -608,6 +617,7 @@ final class Pager_Buildable_Tests: XCTestCase {
         ("test_GivenPagerWith3DRotation_WhenInteractive_ThenInteractiveScaleNotChanged", test_GivenPagerWith3DRotation_WhenInteractive_ThenInteractiveScaleNotChanged),
         ("test_GivenPager_When3DRotation_ThenShouldRotate", test_GivenPager_When3DRotation_ThenShouldRotate),
         ("test_GivenPagerWith3DRotation_When3DRotationFalse_ThenShouldRotateFalse", test_GivenPagerWith3DRotation_When3DRotationFalse_ThenShouldRotateFalse),
+        ("test_GivenPager_WhenDraggingAnimation_ThenDraggingAnimationNotNil", test_GivenPager_WhenDraggingAnimation_ThenDraggingAnimationNotNil),
         ("test_GivenPager_WhenHorizontalRightToLeft_ThenScrollAngle", test_GivenPager_WhenHorizontalRightToLeft_ThenScrollAngle),
         ("test_GivenPager_WhenAlignment_ThenAlignmentSet", test_GivenPager_WhenAlignment_ThenAlignmentSet),
         ("test_GivenPager_WhenVerticalBottomToTop_ThenScrollAngle", test_GivenPager_WhenVerticalBottomToTop_ThenScrollAngle),

Tests/SwiftUIPagerTests/PagingAnimation_Tests.swift

@@ -30,6 +30,13 @@ final class PagingAnimation_Tests: XCTestCase {
         XCTAssertEqual(animation, input)
     }
 
+    func test_GivenPagingAnimationInteractive_WhenAnimation_ThenExpectedAnimationValues() {
+        let input = Animation.interactiveSpring(response: 0.3, dampingFraction: 0.8, blendDuration: 0.5)
+        let pagingAnimation: PagingAnimation = .interactive
+        let animation = pagingAnimation.animation
+        XCTAssertEqual(animation, input)
+    }
+
     static var allTests = [
         ("test_GivenPagingAnimationSteep_WhenAnimation_ThenExpectedAnimationValues", test_GivenPagingAnimationSteep_WhenAnimation_ThenExpectedAnimationValues),
         ("test_GivenPagingAnimationStandard_WhenAnimation_ThenExpectedAnimationValues", test_GivenPagingAnimationStandard_WhenAnimation_ThenExpectedAnimationValues),