'Cancel' for PromiseKit -- provides the ability to cancel promises and promise chains

Author: dougzilla32

.travis.yml

@@ -11,6 +11,9 @@ matrix:
     - {osx_image: xcode9.4, env: 'PLAT=iOS   SWFT=3.3  DST="OS=11.4,name=iPhone 5s"'}
     - {osx_image: xcode9.4, env: 'PLAT=tvOS  SWFT=3.3  DST="OS=11.4,name=Apple TV"'}
 
+    - {osx_image: xcode10,  env: 'PLAT=iOS   SWFT=3.4  DST="OS=12.0,name=iPhone SE"'}
+    - {osx_image: xcode10,  env: 'PLAT=tvOS  SWFT=3.4  DST="OS=12.0,name=Apple TV"'}
+
     - {osx_image: xcode9.2, env: 'PLAT=iOS   SWFT=4.0  DST="OS=11.2,name=iPhone SE"'}
     - {osx_image: xcode9.2, env: 'PLAT=tvOS  SWFT=4.0  DST="OS=11.2,name=Apple TV"'}
 
@@ -21,6 +24,9 @@ matrix:
     - {osx_image: xcode9.3, env: 'PLAT=tvOS  SWFT=4.1  DST="OS=9.2,name=Apple TV 1080p"'}
     - {osx_image: xcode9.3, env: 'PLAT=tvOS  SWFT=4.1  DST="OS=10.2,name=Apple TV 1080p"'}
     - {osx_image: xcode9.4, env: 'PLAT=tvOS  SWFT=4.1  DST="OS=11.4,name=Apple TV"'}
+
+    - {osx_image: xcode10,  env: 'PLAT=iOS   SWFT=4.2  DST="OS=12.0,name=iPhone SE"'}
+    - {osx_image: xcode10,  env: 'PLAT=tvOS  SWFT=4.2  DST="OS=12.0,name=Apple TV"'}
 cache:                                                
   directories:
   - Carthage

Cartfile

@@ -1 +1,2 @@
-github "mxcl/PromiseKit" ~> 6.0
+#github "mxcl/PromiseKit" ~> 6.0
+github "dougzilla32/PromiseKit" "CoreCancel"

Cartfile.resolved

@@ -1 +1 @@
-github "mxcl/PromiseKit" "6.3.3"
+github "dougzilla32/PromiseKit" "ff694600d4d03458121515bdc027ba76df14f7ef"

PMKUIKit.xcodeproj/project.pbxproj

@@ -25,6 +25,7 @@
 		63C9C4581D5D339B00101ECE /* Default-568h@2x.png in Resources */ = {isa = PBXBuildFile; fileRef = 630B2DF51D5D0AD400DC10E9 /* Default-568h@2x.png */; };
 		63C9C45E1D5D341600101ECE /* PMKUIKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 63C7FFA71D5BEE09003BAE60 /* PMKUIKit.framework */; };
 		63C9C45F1D5D341600101ECE /* PMKUIKit.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 63C7FFA71D5BEE09003BAE60 /* PMKUIKit.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		911E6FC620F571F7006F49B9 /* TestUIViewPropertyAnimator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 911E6FC520F571F7006F49B9 /* TestUIViewPropertyAnimator.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -95,6 +96,7 @@
 		63C9C4451D5D334700101ECE /* PMKTestsHost.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = PMKTestsHost.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		63CCF8121D5C0C4E00503216 /* Cartfile */ = {isa = PBXFileReference; lastKnownFileType = text; path = Cartfile; sourceTree = "<group>"; };
 		63CCF8171D5C11B500503216 /* Carthage.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Carthage.xcconfig; sourceTree = "<group>"; };
+		911E6FC520F571F7006F49B9 /* TestUIViewPropertyAnimator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestUIViewPropertyAnimator.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -186,6 +188,7 @@
 				637E2C8E1D5C2E720043E370 /* TestUIImagePickerController.swift */,
 				637E2C8F1D5C2E720043E370 /* TestUIViewController.m */,
 				6332142A1D83CD17009F67CE /* TestUIView.swift */,
+				911E6FC520F571F7006F49B9 /* TestUIViewPropertyAnimator.swift */,
 				637E2C9A1D5C2F600043E370 /* infrastructure.swift */,
 			);
 			path = Tests;
@@ -402,6 +405,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				911E6FC620F571F7006F49B9 /* TestUIViewPropertyAnimator.swift in Sources */,
 				637E2C951D5C2E720043E370 /* TestUIImagePickerController.swift in Sources */,
 				637E2C961D5C2E720043E370 /* TestUIViewController.m in Sources */,
 				637E2C9B1D5C2F600043E370 /* infrastructure.swift in Sources */,

Sources/UIImagePickerController+Promise.swift

@@ -6,6 +6,18 @@ import UIKit
 #if !os(tvOS)
 
 extension UIViewController {
+#if swift(>=4.2)
+    /// Presents the UIImagePickerController, resolving with the user action.
+    public func promise(_ vc: UIImagePickerController, animate: PMKAnimationOptions = [.appear, .disappear], completion: (() -> Void)? = nil) -> Promise<[UIImagePickerController.InfoKey: Any]> {
+        let animated = animate.contains(.appear)
+        let proxy = UIImagePickerControllerProxy()
+        vc.delegate = proxy
+        present(vc, animated: animated, completion: completion)
+        return proxy.promise.ensure {
+            vc.presentingViewController?.dismiss(animated: animated, completion: nil)
+        }
+    }
+#else
     /// Presents the UIImagePickerController, resolving with the user action.
     public func promise(_ vc: UIImagePickerController, animate: PMKAnimationOptions = [.appear, .disappear], completion: (() -> Void)? = nil) -> Promise<[String: Any]> {
         let animated = animate.contains(.appear)
@@ -16,21 +28,33 @@ extension UIViewController {
             vc.presentingViewController?.dismiss(animated: animated, completion: nil)
         }
     }
+#endif
 }
 
 @objc private class UIImagePickerControllerProxy: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
+#if swift(>=4.2)
+    let (promise, seal) = Promise<[UIImagePickerController.InfoKey: Any]>.pending()
+#else
     let (promise, seal) = Promise<[String: Any]>.pending()
+#endif
     var retainCycle: AnyObject?
 
     required override init() {
         super.init()
         retainCycle = self
     }
 
+#if swift(>=4.2)
+    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
+        seal.fulfill(info)
+        retainCycle = nil
+    }
+#else
     func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String: Any]) {
         seal.fulfill(info)
         retainCycle = nil
     }
+#endif
 
     func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
         seal.reject(UIImagePickerController.PMKError.cancelled)

Sources/UIView+Promise.swift

@@ -19,6 +19,53 @@ import PromiseKit
     import PromiseKit
 */
 public extension UIView {
+#if swift(>=4.2)
+/**
+     Animate changes to one or more views using the specified duration, delay,
+     options, and completion handler.
+
+     - Parameter duration: The total duration of the animations, measured in
+     seconds. If you specify a negative value or 0, the changes are made
+     without animating them.
+
+     - Parameter delay: The amount of time (measured in seconds) to wait before
+     beginning the animations. Specify a value of 0 to begin the animations
+     immediately.
+
+     - Parameter options: A mask of options indicating how you want to perform the
+     animations. For a list of valid constants, see UIViewAnimationOptions.
+
+     - Parameter animations: A block object containing the changes to commit to the
+     views.
+
+     - Returns: A promise that fulfills with a boolean NSNumber indicating
+     whether or not the animations actually finished.
+    */
+    @discardableResult
+    static func animate(_: PMKNamespacer, duration: TimeInterval, delay: TimeInterval = 0, options: UIView.AnimationOptions = [], animations: @escaping () -> Void) -> Guarantee<Bool> {
+        return Guarantee { animate(withDuration: duration, delay: delay, options: options, animations: animations, completion: $0) }
+    }
+
+    @discardableResult
+    static func animate(_: PMKNamespacer, duration: TimeInterval, delay: TimeInterval, usingSpringWithDamping damping: CGFloat, initialSpringVelocity: CGFloat, options: UIView.AnimationOptions = [], animations: @escaping () -> Void) -> Guarantee<Bool> {
+        return Guarantee { animate(withDuration: duration, delay: delay, usingSpringWithDamping: damping, initialSpringVelocity: initialSpringVelocity, options: options, animations: animations, completion: $0) }
+    }
+
+    @discardableResult
+    static func transition(_: PMKNamespacer, with view: UIView, duration: TimeInterval, options: UIView.AnimationOptions = [], animations: (() -> Void)?) -> Guarantee<Bool> {
+        return Guarantee { transition(with: view, duration: duration, options: options, animations: animations, completion: $0) }
+    }
+
+    @discardableResult
+    static func transition(_: PMKNamespacer, from: UIView, to: UIView, duration: TimeInterval, options: UIView.AnimationOptions = []) -> Guarantee<Bool> {
+        return Guarantee { transition(from: from, to: to, duration: duration, options: options, completion: $0) }
+    }
+
+    @discardableResult
+    static func perform(_: PMKNamespacer, animation: UIView.SystemAnimation, on views: [UIView], options: UIView.AnimationOptions = [], animations: (() -> Void)?) -> Guarantee<Bool> {
+        return Guarantee { perform(animation, on: views, options: options, animations: animations, completion: $0) }
+    }
+#else
     /**
      Animate changes to one or more views using the specified duration, delay,
      options, and completion handler.
@@ -64,4 +111,5 @@ public extension UIView {
     static func perform(_: PMKNamespacer, animation: UISystemAnimation, on views: [UIView], options: UIViewAnimationOptions = [], animations: (() -> Void)?) -> Guarantee<Bool> {
         return Guarantee { perform(animation, on: views, options: options, animations: animations, completion: $0) }
     }
+#endif
 }

Sources/UIViewPropertyAnimator+Promise.swift

@@ -4,11 +4,28 @@ import PromiseKit
 import UIKit
 
 @available(iOS 10, tvOS 10, *)
-public extension UIViewPropertyAnimator {
+public extension UIViewPropertyAnimator: CancellableTask {
     func startAnimation(_: PMKNamespacer) -> Guarantee<UIViewAnimatingPosition> {
-        return Guarantee {
+        return Guarantee<UIViewAnimatingPosition>(cancellableTask: self) {
             addCompletion($0)
             startAnimation()
         }
     }
+    
+    public func cancel() {
+        stopAnimation(true)
+    }
+    
+    public var isCancelled: Bool {
+        return (state == .inactive) && (fractionComplete < 1.0)
+    }
+}
+
+//////////////////////////////////////////////////////////// Cancellable wrapper
+
+@available(iOS 10, tvOS 10, *)
+extension UIViewPropertyAnimator {
+    public func cancellableStartAnimation(_: PMKNamespacer) -> CancellablePromise<UIViewAnimatingPosition> {
+        return cancellable(startAnimation(.promise))
+    }
 }

Tests/TestUIViewPropertyAnimator.swift

@@ -0,0 +1,46 @@
+import PromiseKit
+import PMKUIKit
+import XCTest
+import UIKit
+
+@available(iOS 10, tvOS 10, *)
+class UIViewPropertyAnimatorTests: XCTestCase {
+    func test() {
+        let ex1 = expectation(description: "")
+        let ex2 = expectation(description: "")
+
+        let animator = UIViewPropertyAnimator(duration: 0.1, curve: .easeIn, animations: { [weak self] in
+            ex1.fulfill()
+        })
+        animator.startAnimation(.promise).done { _ in
+            ex2.fulfill()
+        }
+
+        waitForExpectations(timeout: 1)
+    }
+}
+
+//////////////////////////////////////////////////////////// Cancellation
+
+@available(iOS 10, tvOS 10, *)
+extension UIViewPropertyAnimatorTests {
+    func testCancel() {
+        let ex1 = expectation(description: "")
+        let ex2 = expectation(description: "")
+        
+        let animator = UIViewPropertyAnimator(duration: 0.1, curve: .easeIn, animations: { [weak self] in
+            ex1.fulfill()
+        })
+        let p = animator.cancellableStartAnimation(.promise).done { _ in
+            XCTFail()
+        }.catch(policy: .allErrors) { error in
+            error.isCancelled ? ex2.fulfill() : XCTFail("Error: \(error)")
+        }
+        p.cancel()
+        
+        XCTAssert(animator.isCancelled)
+        XCTAssert(p.isCancelled)
+
+        waitForExpectations(timeout: 1)
+    }
+}