[CM-1243] Support for reduce motion accessibility. (#15)

* [CM-1243] Support for reduce motion accessibility.

* [CM-1243] Comments updated.

* Expand unit test coverage

* Update dependencies

---------

Co-authored-by: Mark Pospesel <[email protected]>

Author: devkaranCT

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.6
+// swift-tools-version: 5.5
 
 import PackageDescription
 
@@ -17,11 +17,11 @@ let package = Package(
     dependencies: [
         .package(
             url: "https://github.com/yml-org/YCoreUI.git",
-            from: "1.4.0"
+            from: "1.5.0"
         ),
         .package(
             url: "https://github.com/yml-org/YMatterType.git",
-            from: "1.4.0"
+            from: "1.6.0"
         )
     ],
     targets: [

Sources/YBottomSheet/Animation/BottomSheetAnimator.swift

@@ -12,6 +12,17 @@ import UIKit
 class BottomSheetAnimator: NSObject {
     /// Bottom sheet controller.
     let sheetViewController: BottomSheetController
+
+    /// Override for isReduceMotionEnabled. Default is `nil`.
+    ///
+    /// For unit testing. When non-`nil` it will be returned instead of
+    /// `UIAccessibility.isReduceMotionEnabled`,
+    var reduceMotionOverride: Bool?
+
+    /// Accessibility reduce motion is enabled or not.
+    var isReduceMotionEnabled: Bool {
+        reduceMotionOverride ?? UIAccessibility.isReduceMotionEnabled
+    }
 
     /// Initializes a bottom sheet animator.
     /// - Parameter sheetViewController: the sheet being animated.

Sources/YBottomSheet/Animation/BottomSheetDismissAnimator.swift

@@ -37,7 +37,11 @@ class BottomSheetDismissAnimator: BottomSheetAnimator {
             delay: .zero,
             options: [.beginFromCurrentState, sheet.appearance.dismissAnimationCurve]
         ) {
-            sheet.sheetView.frame = sheetFrame
+            if self.isReduceMotionEnabled {
+                sheet.sheetView.alpha = 0
+            } else {
+                sheet.sheetView.frame = sheetFrame
+            }
         } completion: { _ in
             if !transitionContext.transitionWasCancelled {
                 fromViewController.view.removeFromSuperview()

Sources/YBottomSheet/Animation/BottomSheetPresentAnimator.swift

@@ -21,11 +21,15 @@ class BottomSheetPresentAnimator: BottomSheetAnimator {
         sheet.view.layoutSubviews()
         sheet.dimmerView.alpha = 0
 
-        let toFinalFrame = transitionContext.finalFrame(for: toViewController)
-        var sheetFrame = sheet.sheetView.frame
-        sheetFrame.origin.y = toFinalFrame.maxY + (sheet.appearance.elevation?.extent.top ?? 0)
-        sheet.sheetView.frame = sheetFrame
-        sheet.view.setNeedsLayout()
+        if isReduceMotionEnabled {
+            sheet.sheetView.alpha = 0
+        } else {
+            let toFinalFrame = transitionContext.finalFrame(for: toViewController)
+            var sheetFrame = sheet.sheetView.frame
+            sheetFrame.origin.y = toFinalFrame.maxY + (sheet.appearance.elevation?.extent.top ?? 0)
+            sheet.sheetView.frame = sheetFrame
+            sheet.view.setNeedsLayout()
+        }
 
         let duration = transitionDuration(using: transitionContext)
 
@@ -42,7 +46,11 @@ class BottomSheetPresentAnimator: BottomSheetAnimator {
             delay: .zero,
             options: [.beginFromCurrentState, sheet.appearance.presentAnimationCurve]
         ) {
-            sheet.view.layoutIfNeeded()
+            if self.isReduceMotionEnabled {
+                sheet.sheetView.alpha = 1
+            } else {
+                sheet.view.layoutIfNeeded()
+            }
         } completion: { _ in
             transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
         }

Tests/YBottomSheetTests/Animation/BottomSheetDismissAnimatorTests.swift

@@ -11,11 +11,7 @@ import XCTest
 
 final class BottomSheetDismissAnimatorTests: XCTestCase {
     func test_animate() throws {
-        let sheetController = BottomSheetController(
-            title: "Bottom Sheet",
-            childView: UIView(),
-            appearance: BottomSheetController.Appearance(animationDuration: 0.0)
-        )
+        let sheetController = makeSheet()
         let (sut, context) = try makeSUT(sheetViewController: sheetController, to: sheetController)
 
         XCTAssertTrue(sut is BottomSheetDismissAnimator)
@@ -26,15 +22,44 @@ final class BottomSheetDismissAnimatorTests: XCTestCase {
         RunLoop.current.run(until: Date(timeIntervalSinceNow: 0.01))
         XCTAssertTrue(context.wasCompleteCalled)
         XCTAssertTrue(context.didComplete)
+    }
+
+    func test_animateWithoutReduceMotion_TranslatesDown() throws {
+        let sheetController = makeSheet()
+        let (sut, context) = try makeSUT(
+            sheetViewController: sheetController,
+            to: sheetController,
+            isReduceMotionEnabled: false
+        )
+
+        sut.animateTransition(using: context)
+
+        // Wait for the run loop to tick (animate keyboard)
+        RunLoop.current.run(until: Date(timeIntervalSinceNow: 0.01))
         XCTAssertEqual(sheetController.dimmerView.alpha, 0)
+        XCTAssertEqual(sheetController.sheetView.alpha, 1)
         XCTAssertEqual(sheetController.sheetView.frame.minY, context.containerView.bounds.maxY)
     }
 
-    func test_animateWithoutTo_Fails() throws {
-        let sheetController = BottomSheetController(
-            title: "Bottom Sheet",
-            childView: UIView()
+    func test_animateWithReduceMotion_FadesOut() throws {
+        let sheetController = makeSheet()
+        let (sut, context) = try makeSUT(
+            sheetViewController: sheetController,
+            to: sheetController,
+            isReduceMotionEnabled: true
         )
+
+        sut.animateTransition(using: context)
+
+        // Wait for the run loop to tick (animate keyboard)
+        RunLoop.current.run(until: Date(timeIntervalSinceNow: 0.01))
+        XCTAssertEqual(sheetController.dimmerView.alpha, 0)
+        XCTAssertEqual(sheetController.sheetView.alpha, 0)
+        XCTAssertLessThan(sheetController.sheetView.frame.minY, context.containerView.bounds.maxY)
+    }
+
+    func test_animateWithoutTo_Fails() throws {
+        let sheetController = makeSheet()
         let (sut, context) = try makeSUT(sheetViewController: sheetController, to: nil)
 
         XCTAssertFalse(context.wasCompleteCalled)
@@ -49,14 +74,31 @@ private extension BottomSheetDismissAnimatorTests {
     func makeSUT(
         sheetViewController: BottomSheetController,
         to: UIViewController?,
+        isReduceMotionEnabled: Bool? = nil,
         file: StaticString = #filePath,
         line: UInt = #line
     ) throws -> (UIViewControllerAnimatedTransitioning, MockAnimationContext) {
         let main = UIViewController()
-        let animator = try XCTUnwrap(sheetViewController.animationController(forDismissed: sheetViewController))
+        let animator = try XCTUnwrap(
+            sheetViewController.animationController(forDismissed: sheetViewController) as? BottomSheetAnimator
+        )
+        animator.reduceMotionOverride = isReduceMotionEnabled
         let context = MockAnimationContext(from: main, to: to)
         trackForMemoryLeaks(animator, file: file, line: line)
         trackForMemoryLeaks(context, file: file, line: line)
         return (animator, context)
     }
+
+    func makeSheet(
+        file: StaticString = #filePath,
+        line: UInt = #line
+    ) -> BottomSheetController {
+        let sheet = BottomSheetController(
+            title: "Bottom Sheet",
+            childView: UIView(),
+            appearance: BottomSheetController.Appearance(animationDuration: 0.0)
+        )
+        trackForMemoryLeaks(sheet)
+        return sheet
+    }
 }

Tests/YBottomSheetTests/Animation/BottomSheetPresentAnimatorTests.swift

@@ -11,11 +11,7 @@ import XCTest
 
 final class BottomSheetPresentAnimatorTests: XCTestCase {
     func test_animate() throws {
-        let sheetController = BottomSheetController(
-            title: "Bottom Sheet",
-            childView: UIView(),
-            appearance: BottomSheetController.Appearance(animationDuration: 0.0)
-        )
+        let sheetController = makeSheet()
         let (sut, context) = try makeSUT(sheetViewController: sheetController, to: sheetController)
 
         XCTAssertTrue(sut is BottomSheetPresentAnimator)
@@ -26,15 +22,42 @@ final class BottomSheetPresentAnimatorTests: XCTestCase {
         RunLoop.current.run(until: Date(timeIntervalSinceNow: 0.01))
         XCTAssertTrue(context.wasCompleteCalled)
         XCTAssertTrue(context.didComplete)
+    }
+
+    func test_animateWithoutReduceMotion_TranslatesUp() throws {
+        let sheetController = makeSheet()
+        let (sut, context) = try makeSUT(
+            sheetViewController: sheetController,
+            to: sheetController,
+            isReduceMotionEnabled: false
+        )
+
+        sut.animateTransition(using: context)
+
+        // Wait for the run loop to tick (animate keyboard)
+        RunLoop.current.run(until: Date(timeIntervalSinceNow: 0.01))
         XCTAssertEqual(sheetController.dimmerView.alpha, 1)
         XCTAssertLessThan(sheetController.sheetView.frame.minY, context.containerView.bounds.maxY)
     }
 
-    func test_animateWithoutTo_Fails() throws {
-        let sheetController = BottomSheetController(
-            title: "Bottom Sheet",
-            childView: UIView()
+    func test_animateWithReduceMotion_FadesIn() throws {
+        let sheetController = makeSheet()
+        let (sut, context) = try makeSUT(
+            sheetViewController: sheetController,
+            to: sheetController,
+            isReduceMotionEnabled: true
         )
+
+        sut.animateTransition(using: context)
+
+        // Wait for the run loop to tick (animate keyboard)
+        RunLoop.current.run(until: Date(timeIntervalSinceNow: 0.01))
+        XCTAssertEqual(sheetController.dimmerView.alpha, 1)
+        XCTAssertEqual(sheetController.sheetView.alpha, 1)
+    }
+
+    func test_animateWithoutTo_Fails() throws {
+        let sheetController = makeSheet()
         let (sut, context) = try makeSUT(sheetViewController: sheetController, to: nil)
 
         XCTAssertFalse(context.wasCompleteCalled)
@@ -49,16 +72,35 @@ private extension BottomSheetPresentAnimatorTests {
     func makeSUT(
         sheetViewController: BottomSheetController,
         to: UIViewController?,
+        isReduceMotionEnabled: Bool? = nil,
         file: StaticString = #filePath,
         line: UInt = #line
     ) throws -> (UIViewControllerAnimatedTransitioning, MockAnimationContext) {
         let main = UIViewController()
         let animator = try XCTUnwrap(
-            sheetViewController.animationController(forPresented: sheetViewController, presenting: main, source: main)
+            sheetViewController.animationController(
+                forPresented: sheetViewController,
+                presenting: main,
+                source: main
+            ) as? BottomSheetAnimator
         )
+        animator.reduceMotionOverride = isReduceMotionEnabled
         let context = MockAnimationContext(from: main, to: to)
         trackForMemoryLeaks(animator, file: file, line: line)
         trackForMemoryLeaks(context, file: file, line: line)
         return (animator, context)
     }
+
+    func makeSheet(
+        file: StaticString = #filePath,
+        line: UInt = #line
+    ) -> BottomSheetController {
+        let sheet = BottomSheetController(
+            title: "Bottom Sheet",
+            childView: UIView(),
+            appearance: BottomSheetController.Appearance(animationDuration: 0.0)
+        )
+        trackForMemoryLeaks(sheet)
+        return sheet
+    }
 }