Support both of Swift 5 and 4.2

The default Swift version leaves 4.0. Because it avoids build errors
with Carthage on each Xcode version from the source compatibility
between Swift 4.0, 4.2 and 5.0.

With regard to CocoaPods, the pod spec is going to support
`swift_versions` introduced in CocoaPods v1.7.0. For now, a user needs
to override `SWIFT_VERSION` appropriately in Podfile.

.travis.yml

@@ -2,7 +2,6 @@ language: swift
 branches:
   only:
     - master
-    - next
 cache:
   directories:
   - /usr/local/Homebrew
@@ -19,37 +18,42 @@ jobs:
   - stage: Build framework(swift 4.1)
     osx_image: xcode9.4
     script:
-    - xcodebuild -scheme FloatingPanel clean build
+    - xcodebuild -scheme FloatingPanel SWIFT_VERSION=4.1 clean build
 
   - stage: Build framework(swift 4.2)
     osx_image: xcode10
     script:
-    - xcodebuild -scheme FloatingPanel clean build
+    - xcodebuild -scheme FloatingPanel SWIFT_VERSION=4.2 clean build
+
+  - stage: Build framework(swift 5.0)
+    osx_image: xcode10.2
+    script:
+    - xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.0 clean build
 
   - stage: Carthage
-    osx_image: xcode10
+    osx_image: xcode10.2
     before_install:
     - brew update
     - brew outdated carthage || brew upgrade carthage
     script:
     - carthage build --no-skip-current
 
   - stage: Podspec
-    osx_image: xcode10
+    osx_image: xcode10.2
     script:
     - pod spec lint
 
   - stage: Build maps example
-    osx_image: xcode10
+    osx_image: xcode10.2
     script:
     - xcodebuild -scheme Maps -sdk iphonesimulator clean build
 
   - stage: Build stocks example
-    osx_image: xcode10
+    osx_image: xcode10.2
     script:
     - xcodebuild -scheme Stocks -sdk iphonesimulator clean build
 
   - stage: Build samples example
-    osx_image: xcode10
+    osx_image: xcode10.2
     script:
     - xcodebuild -scheme Samples -sdk iphonesimulator clean build

Examples/Maps/Maps.xcodeproj/project.pbxproj

@@ -312,7 +312,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Maps;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -331,7 +331,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Maps;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;

Examples/Samples/Samples.xcodeproj/project.pbxproj

@@ -499,7 +499,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelSample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -518,7 +518,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelSample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;

Examples/Stocks/Stocks.xcodeproj/project.pbxproj

@@ -312,7 +312,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Stocks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -331,7 +331,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.Stocks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;

Framework/Sources/FloatingPanel.swift

@@ -307,7 +307,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                 self.animator = nil
 
                 // A user can stop a panel at the nearest Y of a target position
-                if fabs(surfaceView.frame.minY - layoutAdapter.topY) < 1 {
+                if abs(surfaceView.frame.minY - layoutAdapter.topY) < 1 {
                     surfaceView.frame.origin.y = layoutAdapter.topY
                 }
             }
@@ -502,7 +502,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
 
         if isRemovalInteractionEnabled, isBottomState {
             let velocityVector = (distance != 0) ? CGVector(dx: 0,
-                                                            dy: min(fabs(velocity.y)/distance, behavior.removalVelocity)) : .zero
+                                                            dy: min(abs(velocity.y)/distance, behavior.removalVelocity)) : .zero
 
             if shouldStartRemovalAnimation(with: velocityVector) {
 
@@ -619,7 +619,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
         isDecelerating = true
         viewcontroller.delegate?.floatingPanelWillBeginDecelerating(viewcontroller)
 
-        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: min(fabs(velocity.y)/distance, 30.0)) : .zero
+        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: min(abs(velocity.y)/distance, 30.0)) : .zero
         let animator = behavior.interactionAnimator(self.viewcontroller, to: targetPosition, with: velocityVector)
         animator.addAnimations { [weak self] in
             guard let `self` = self else { return }
@@ -660,11 +660,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
 
         switch targetPosition {
         case .full:
-            return CGFloat(fabs(currentY - topY))
+            return CGFloat(abs(currentY - topY))
         case .half:
-            return CGFloat(fabs(currentY - middleY))
+            return CGFloat(abs(currentY - middleY))
         case .tip:
-            return CGFloat(fabs(currentY - bottomY))
+            return CGFloat(abs(currentY - bottomY))
         case .hidden:
             fatalError("Now .hidden must not be used for a user interaction")
         }
@@ -703,7 +703,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
 
     // Distance travelled after decelerating to zero velocity at a constant rate.
     // Refer to the slides p176 of [Designing Fluid Interfaces](https://developer.apple.com/videos/play/wwdc2018/803/)
-    private func project(initialVelocity: CGFloat, decelerationRate: CGFloat = UIScrollViewDecelerationRateNormal) -> CGFloat {
+    private func project(initialVelocity: CGFloat, decelerationRate: CGFloat) -> CGFloat {
         return (initialVelocity / 1000.0) * decelerationRate / (1.0 - decelerationRate)
     }
 

Framework/Sources/FloatingPanelBehavior.swift

@@ -72,14 +72,18 @@ public extension FloatingPanelBehavior {
     }
 
     func momentumProjectionRate(_ fpc: FloatingPanelController) -> CGFloat {
+        #if swift(>=4.2)
+        return UIScrollView.DecelerationRate.normal.rawValue
+        #else
         return UIScrollViewDecelerationRateNormal
+        #endif
     }
 
     func redirectionalProgress(_ fpc: FloatingPanelController, from: FloatingPanelPosition, to: FloatingPanelPosition) -> CGFloat {
         return 0.5
     }
 
-    public func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
+    func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
         return defaultBehavior.interactionAnimator(fpc, to: targetPosition, with: velocity)
     }
 

Framework/Sources/FloatingPanelController.swift

@@ -351,7 +351,11 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
             parent.view.addSubview(self.view)
         }
 
+        #if swift(>=4.2)
+        parent.addChild(self)
+        #else
         parent.addChildViewController(self)
+        #endif
 
         view.frame = parent.view.bounds // Needed for a correct safe area configuration
         view.translatesAutoresizingMaskIntoConstraints = false
@@ -364,7 +368,11 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
 
         show(animated: animated) { [weak self] in
             guard let `self` = self else { return }
+            #if swift(>=4.2)
+            self.didMove(toParent: self)
+            #else
             self.didMove(toParentViewController: self)
+            #endif
         }
     }
 
@@ -380,9 +388,20 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
 
         hide(animated: animated) { [weak self] in
             guard let `self` = self else { return }
+            #if swift(>=4.2)
+            self.willMove(toParent: nil)
+            #else
             self.willMove(toParentViewController: nil)
+            #endif
+
             self.view.removeFromSuperview()
+
+            #if swift(>=4.2)
+            self.removeFromParent()
+            #else
             self.removeFromParentViewController()
+            #endif
+
             completion?()
         }
     }
@@ -400,16 +419,36 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
     /// Sets the view controller responsible for the content portion of the floating panel.
     public func set(contentViewController: UIViewController?) {
         if let vc = _contentViewController {
+            #if swift(>=4.2)
+            vc.willMove(toParent: nil)
+            #else
             vc.willMove(toParentViewController: nil)
+            #endif
+
             vc.view.removeFromSuperview()
+
+            #if swift(>=4.2)
+            vc.removeFromParent()
+            #else
             vc.removeFromParentViewController()
+            #endif
         }
 
         if let vc = contentViewController {
+            #if swift(>=4.2)
+            addChild(vc)
+            #else
             addChildViewController(vc)
+            #endif
+
             let surfaceView = floatingPanel.surfaceView
             surfaceView.add(contentView: vc.view)
+
+            #if swift(>=4.2)
+            vc.didMove(toParent: self)
+            #else
             vc.didMove(toParentViewController: self)
+            #endif
         }
 
         _contentViewController = contentViewController
@@ -448,9 +487,15 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
             if #available(iOS 11.0, *) {
                 scrollView.contentInsetAdjustmentBehavior = .never
             } else {
+                #if swift(>=4.2)
+                children.forEach { (vc) in
+                    vc.automaticallyAdjustsScrollViewInsets = false
+                }
+                #else
                 childViewControllers.forEach { (vc) in
                     vc.automaticallyAdjustsScrollViewInsets = false
                 }
+                #endif
             }
         default:
             break
@@ -504,10 +549,10 @@ extension FloatingPanelController {
 }
 
 public extension UIViewController {
-    @objc public func fp_original_dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
+    @objc func fp_original_dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
         // Implementation will be replaced by IMP of self.dismiss(animated:completion:)
     }
-    @objc public func fp_dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
+    @objc func fp_dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
         // Call dismiss(animated:completion:) to a content view controller
         if let fpc = parent as? FloatingPanelController {
             if fpc.presentingViewController != nil {

Framework/Sources/FloatingPanelLayout.swift

@@ -270,7 +270,11 @@ class FloatingPanelLayoutAdapter {
     }
 
     func updateIntrinsicHeight() {
+        #if swift(>=4.2)
+        let fittingSize = UIView.layoutFittingCompressedSize
+        #else
         let fittingSize = UILayoutFittingCompressedSize
+        #endif
         var intrinsicHeight = surfaceView.contentView?.systemLayoutSizeFitting(fittingSize).height ?? 0.0
         var safeAreaBottom: CGFloat = 0.0
         if #available(iOS 11.0, *) {

Framework/Sources/UIExtensions.swift

@@ -74,6 +74,20 @@ extension UIView {
 }
 
 #if __FP_LOG
+#if swift(>=4.2)
+extension UIGestureRecognizer.State: CustomDebugStringConvertible {
+    public var debugDescription: String {
+        switch self {
+        case .began: return "began"
+        case .changed: return "changed"
+        case .failed: return "failed"
+        case .cancelled: return "cancelled"
+        case .ended: return "endeded"
+        case .possible: return "possible"
+        }
+    }
+}
+#else
 extension UIGestureRecognizerState: CustomDebugStringConvertible {
     public var debugDescription: String {
         switch self {
@@ -87,6 +101,7 @@ extension UIGestureRecognizerState: CustomDebugStringConvertible {
     }
 }
 #endif
+#endif
 
 extension UIScrollView {
     var contentOffsetZero: CGPoint {

README.md

@@ -4,6 +4,7 @@
 [![Platform](https://img.shields.io/cocoapods/p/FloatingPanel.svg)](https://cocoapods.org/pods/FloatingPanel)
 [![Swift 4.1](https://img.shields.io/badge/Swift-4.1-orange.svg?style=flat)](https://swift.org/)
 [![Swift 4.2](https://img.shields.io/badge/Swift-4.2-orange.svg?style=flat)](https://swift.org/)
+[![Swift 5.0](https://img.shields.io/badge/Swift-5.0-orange.svg?style=flat)](https://swift.org/)
 
 #  FloatingPanel