Release v1.6.2

Merge pull request #231 from SCENEE/prevent-found-nil-error
Prevent 'unexpectedly found nil' fatal error
2019-07-10 18:55:09 +09:00 · 2019-07-09 21:53:40 +09:00 · 2019-07-09 20:06:16 +09:00 · 2019-07-03 14:24:47 +09:00 · 2019-07-03 11:46:45 +09:00 · 2019-07-03 11:46:45 +09:00
31 changed files with 1504 additions and 412 deletions
@@ -22,6 +22,7 @@ xcuserdata/
 *.moved-aside
 *.xccheckout
 *.xcscmblueprint
+*.xcsettings

 ## Obj-C/Swift specific
 *.hmap
@@ -1,8 +1,7 @@
-language: swift
+language: objective-c
 branches:
  only:
    - master
-    - next
 cache:
  directories:
  - /usr/local/Homebrew
@@ -13,43 +12,51 @@ env:
  global:
  - LANG=en_US.UTF-8
  - LC_ALL=en_US.UTF-8
-skip_cleanup: true
 jobs:
  include:
-  - stage: Build framework(swift 4.1)
+  - stage: "Builds"
    osx_image: xcode9.4
-    script:
-    - xcodebuild -scheme FloatingPanel clean build
-
-  - stage: Build framework(swift 4.2)
+    script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=4.1 clean build
+    name: "Swift 4.1"
+  - script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=4.2 clean build
    osx_image: xcode10
-    script:
-    - xcodebuild -scheme FloatingPanel clean build
+    name: "Swift 4.2"
+  - script: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.0 clean build
+    osx_image: xcode10.2
+    name: "Swift 5.0"
+
+  - stage: "Tests"
+    osx_image: xcode10.2
+    script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=10.3.1,name=iPhone SE'
+    name: "iPhone SE (iOS 10.3)"
+  - script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=11.4,name=iPhone 7'
+    osx_image: xcode10.2
+    name: "iPhone 7 (iOS 11.4)"
+  - script: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=12.2,name=iPhone X'
+    osx_image: xcode10.2
+    name: "iPhone X (iOS 12.2)"

  - 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    - brew outdated carthage || brew upgrade carthage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
+  - stage: CocoaPods
+    osx_image: xcode10.2
    script:
    - pod spec lint
+    - pod lib lint

-  - stage: Build maps example
-    osx_image: xcode10
-    script:
-    - xcodebuild -scheme Maps -sdk iphonesimulator clean build
-
-  - stage: Build stocks example
-    osx_image: xcode10
-    script:
-    - xcodebuild -scheme Stocks -sdk iphonesimulator clean build
-
-  - stage: Build samples example
-    osx_image: xcode10
-    script:
-    - xcodebuild -scheme Samples -sdk iphonesimulator clean build
+  - stage: Build examples
+    osx_image: xcode10.2
+    script: xcodebuild -scheme Maps -sdk iphonesimulator clean build
+    name: "Maps"
+  - script: xcodebuild -scheme Stocks -sdk iphonesimulator clean build
+    osx_image: xcode10.2
+    name: "Stocks"
+  - script: xcodebuild -scheme Samples -sdk iphonesimulator clean build
+    osx_image: xcode10.2
+    name: "Samples"
@@ -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;
@@ -21,7 +21,11 @@ class ViewController: UIViewController, MKMapViewDelegate, UISearchBarDelegate,

        // Initialize FloatingPanelController and add the view
        fpc.surfaceView.backgroundColor = .clear
-        fpc.surfaceView.cornerRadius = 9.0
+        if #available(iOS 11, *) {
+            fpc.surfaceView.cornerRadius = 9.0
+        } else {
+            fpc.surfaceView.cornerRadius = 0.0
+        }
        fpc.surfaceView.shadowHidden = false

        searchVC = storyboard?.instantiateViewController(withIdentifier: "SearchPanel") as? SearchPanelViewController
@@ -135,7 +139,10 @@ class SearchPanelViewController: UIViewController, UITableViewDataSource, UITabl
    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var searchBar: UISearchBar!
    @IBOutlet weak var visualEffectView: UIVisualEffectView!
-    
+
+    // For iOS 10 only
+    private lazy var shadowLayer: CAShapeLayer = CAShapeLayer()
+
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.dataSource = self
@@ -150,9 +157,24 @@ class SearchPanelViewController: UIViewController, UITableViewDataSource, UITabl

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
-        if #available(iOS 10, *) {
+        if #available(iOS 11, *) {
+        } else {
+            // Exmaple: Add rounding corners on iOS 10
            visualEffectView.layer.cornerRadius = 9.0
            visualEffectView.clipsToBounds = true
+
+            // Exmaple: Add shadow manually on iOS 10
+            view.layer.insertSublayer(shadowLayer, at: 0)
+            let rect = visualEffectView.frame
+            let path = UIBezierPath(roundedRect: rect,
+                                    byRoundingCorners: [.topLeft, .topRight],
+                                    cornerRadii: CGSize(width: 9.0, height: 9.0))
+            shadowLayer.frame = visualEffectView.frame
+            shadowLayer.shadowPath = path.cgPath
+            shadowLayer.shadowColor = UIColor.black.cgColor
+            shadowLayer.shadowOffset = CGSize(width: 0.0, height: 1.0)
+            shadowLayer.shadowOpacity = 0.2
+            shadowLayer.shadowRadius = 3.0
        }
    }

@@ -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;
@@ -9,7 +9,7 @@
 import UIKit
 import FloatingPanel

-class SampleListViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, FloatingPanelControllerDelegate, FloatingPanelLayout {
+class SampleListViewController: UIViewController {
    @IBOutlet weak var tableView: UITableView!

    enum Menu: Int, CaseIterable {
@@ -19,9 +19,11 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        case showModal
        case showFloatingPanelModal
        case showTabBar
+        case showPageView
        case showNestedScrollView
        case showRemovablePanel
        case showIntrinsicView
+        case showContentInset

        var name: String {
            switch self {
@@ -31,9 +33,11 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
            case .showModal: return "Show Modal"
            case .showFloatingPanelModal: return "Show Floating Panel Modal"
            case .showTabBar: return "Show Tab Bar"
+            case .showPageView: return "Show Page View"
            case .showNestedScrollView: return "Show Nested ScrollView"
            case .showRemovablePanel: return "Show Removable Panel"
            case .showIntrinsicView: return "Show Intrinsic View"
+            case .showContentInset: return "Show with ContentInset"
            }
        }

@@ -45,9 +49,11 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
            case .showModal: return "ModalViewController"
            case .showFloatingPanelModal: return nil
            case .showTabBar: return "TabBarViewController"
+            case .showPageView: return nil
            case .showNestedScrollView: return "NestedScrollViewController"
            case .showRemovablePanel: return "DetailViewController"
            case .showIntrinsicView: return "IntrinsicViewController"
+            case .showContentInset: return nil
            }
        }
    }
@@ -61,6 +67,19 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
    var mainPanelObserves: [NSKeyValueObservation] = []
    var settingsObserves: [NSKeyValueObservation] = []

+    lazy var pages: [UIViewController] = {
+        let page1 = FloatingPanelController(delegate: self)
+        page1.view.backgroundColor = .blue
+        page1.show()
+        let page2 = FloatingPanelController(delegate: self)
+        page2.view.backgroundColor = .red
+        page2.show()
+        let page3 = FloatingPanelController(delegate: self)
+        page3.view.backgroundColor = .green
+        page3.show()
+        return [page1, page2, page3]
+    }()
+
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.dataSource = self
@@ -113,6 +132,11 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable

        // Enable tap-to-hide and removal interaction
        switch currentMenu {
+        case .trackingTableView:
+            let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSurface(tapGesture:)))
+            tapGesture.cancelsTouchesInView = false
+            tapGesture.numberOfTapsRequired = 2
+            mainPanelVC.surfaceView.addGestureRecognizer(tapGesture)
        case .showRemovablePanel, .showIntrinsicView:
            mainPanelVC.isRemovalInteractionEnabled = true

@@ -143,8 +167,14 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        mainPanelVC.addPanel(toParent: self, belowView: nil, animated: true)
    }

-    @objc func dismissDetailPanelVC()  {
-        detailPanelVC.removePanelFromParent(animated: true, completion: nil)
+    @objc
+    func handleSurface(tapGesture: UITapGestureRecognizer) {
+        switch mainPanelVC.position {
+        case .full:
+            mainPanelVC.move(to: .half, animated: true)
+        default:
+            mainPanelVC.move(to: .full, animated: true)
+        }
    }

    @objc func handleBackdrop(tapGesture: UITapGestureRecognizer) {
@@ -159,31 +189,6 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        }
    }

-    // MARK:- TableViewDatasource
-
-    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        if #available(iOS 11.0, *) {
-            if navigationController?.navigationBar.prefersLargeTitles == true {
-                return Menu.allCases.count + 30
-            } else {
-                return Menu.allCases.count
-            }
-        } else {
-            return Menu.allCases.count
-        }
-    }
-
-    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
-        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
-        if Menu.allCases.count > indexPath.row {
-            let menu = Menu.allCases[indexPath.row]
-            cell.textLabel?.text = menu.name
-        } else {
-            cell.textLabel?.text = "\(indexPath.row) row"
-        }
-        return cell
-    }
-
    // MARK:- Actions
    @IBAction func showDebugMenu(_ sender: UIBarButtonItem) {
        guard settingsPanelVC == nil else { return }
@@ -208,9 +213,34 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        //  Add FloatingPanel to self.view
        settingsPanelVC.addPanel(toParent: self, belowView: nil, animated: true)
    }
+}

-    // MARK:- TableViewDelegate
+extension SampleListViewController: UITableViewDataSource {
+    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        if #available(iOS 11.0, *) {
+            if navigationController?.navigationBar.prefersLargeTitles == true {
+                return Menu.allCases.count + 30
+            } else {
+                return Menu.allCases.count
+            }
+        } else {
+            return Menu.allCases.count
+        }
+    }

+    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
+        if Menu.allCases.count > indexPath.row {
+            let menu = Menu.allCases[indexPath.row]
+            cell.textLabel?.text = menu.name
+        } else {
+            cell.textLabel?.text = "\(indexPath.row) row"
+        }
+        return cell
+    }
+}
+
+extension SampleListViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        guard Menu.allCases.count > indexPath.row else { return }
        let menu = Menu.allCases[indexPath.row]
@@ -241,6 +271,22 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        case .showModal, .showTabBar:
            let modalVC = contentVC
            present(modalVC, animated: true, completion: nil)
+
+        case .showPageView:
+            let pageVC = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: [:])
+            let closeButton = UIButton(type: .custom)
+            pageVC.view.addSubview(closeButton)
+            closeButton.setTitle("Close", for: .normal)
+            closeButton.translatesAutoresizingMaskIntoConstraints = false
+            closeButton.addTarget(self, action: #selector(dismissPresentedVC), for: .touchUpInside)
+            NSLayoutConstraint.activate([
+                closeButton.topAnchor.constraint(equalTo: pageVC.layoutGuide.topAnchor, constant: 16.0),
+                closeButton.leftAnchor.constraint(equalTo: pageVC.view.leftAnchor, constant: 16.0),
+                ])
+            pageVC.dataSource = self
+            pageVC.setViewControllers([pages[0]], direction: .forward, animated: false, completion: nil)
+            present(pageVC, animated: true, completion: nil)
+
        case .showFloatingPanelModal:
            let fpc = FloatingPanelController()
            let contentVC = self.storyboard!.instantiateViewController(withIdentifier: "DetailViewController")
@@ -253,6 +299,18 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
            fpc.isRemovalInteractionEnabled = true

            self.present(fpc, animated: true, completion: nil)
+            
+        case .showContentInset:
+            let contentViewController = UIViewController()
+            contentViewController.view.backgroundColor = .green
+            
+            let fpc = FloatingPanelController()
+            fpc.set(contentViewController: contentViewController)
+            fpc.surfaceView.contentInsets = .init(top: 20, left: 20, bottom: 0, right: 20)
+            
+            fpc.delegate = self
+            fpc.isRemovalInteractionEnabled = true
+            self.present(fpc, animated: true, completion: nil)
        default:
            detailPanelVC?.removePanelFromParent(animated: true, completion: nil)
            mainPanelVC?.removePanelFromParent(animated: true) {
@@ -261,6 +319,12 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        }
    }

+    @objc func dismissPresentedVC() {
+        self.presentedViewController?.dismiss(animated: true, completion: nil)
+    }
+}
+
+extension SampleListViewController: FloatingPanelControllerDelegate {
    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
        if vc == settingsPanelVC {
            return IntrinsicPanelLayout()
@@ -285,6 +349,9 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
        switch currentMenu {
        case .showNestedScrollView:
            return (vc.contentViewController as? NestedScrollViewController)?.nestedScrollView.gestureRecognizers?.contains(gestureRecognizer) ?? false
+        case .showPageView:
+            // Tips: Need to allow recognizing the pan gesture of UIPageViewController simultaneously.
+            return true
        default:
            return false
        }
@@ -298,7 +365,14 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
            break
        }
    }
+}

+/**
+ - Attention: `FloatingPanelLayout` must not be applied by the parent view
+ controller of a floating panel. But here `SampleListViewController` adopts it
+ purposely to check if the library prints an appropriate warning.
+ */
+extension SampleListViewController: FloatingPanelLayout {
    var initialPosition: FloatingPanelPosition {
        return .half
    }
@@ -313,6 +387,23 @@ class SampleListViewController: UIViewController, UITableViewDataSource, UITable
    }
 }

+extension SampleListViewController: UIPageViewControllerDataSource {
+    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
+        guard
+            let index = pages.firstIndex(of: viewController),
+            index + 1 < pages.count
+            else { return nil }
+        return pages[index + 1]
+    }
+    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
+        guard
+            let index = pages.firstIndex(of: viewController),
+            index - 1 >= 0
+            else { return nil }
+        return pages[index - 1]
+    }
+}
+
 class IntrinsicPanelLayout: FloatingPanelIntrinsicLayout { }

 class RemovablePanelLayout: FloatingPanelIntrinsicLayout {
@@ -468,7 +559,7 @@ class InspectableViewController: UIViewController {
    }
 }

-class DebugTableViewController: InspectableViewController, UITableViewDataSource, UITableViewDelegate {
+class DebugTableViewController: InspectableViewController {
    weak var tableView: UITableView!
    var items: [String] = []
    var itemHeight: CGFloat = 66.0
@@ -586,7 +677,9 @@ class DebugTableViewController: InspectableViewController, UITableViewDataSource
        //  Remove FloatingPanel from a view
        (self.parent as! FloatingPanelController).removePanelFromParent(animated: true, completion: nil)
    }
+}

+extension DebugTableViewController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return items.count
    }
@@ -600,6 +693,12 @@ class DebugTableViewController: InspectableViewController, UITableViewDataSource
        cell.textLabel?.text = items[indexPath.row]
        return cell
    }
+}
+
+extension DebugTableViewController: UITableViewDelegate {
+    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        print("DebugTableViewController -- select row \(indexPath.row)")
+    }

    func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
        return [
@@ -812,7 +911,7 @@ class TabBarContentViewController: UIViewController {
        dismiss(animated: true, completion: nil)
    }

-    // MAKR: - Private
+    // MARK: - Private

    @objc
    private func changeTab3Mode(_ sender: UISwitch) {
@@ -828,6 +927,15 @@ class TabBarContentViewController: UIViewController {
 extension TabBarContentViewController: UITextViewDelegate {
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        guard self.tabBarItem.tag == 2 else { return }
+        // Reset an invalid content offset by a user after updating the layout
+        // of `consoleVC.textView`.
+        // NOTE: FloatingPanel doesn't implicitly reset the offset(i.e.
+        // Using KVO of `scrollView.contentOffset`). Because it can lead to an
+        // infinite loop if a user also resets a content offset as below and,
+        // in the situation, a user has to modify the library.
+        if fpc.position != .full, fpc.surfaceView.frame.minY < fpc.originYOfSurface(for: .full) {
+            scrollView.contentOffset = .zero
+        }
    }
 }

@@ -848,6 +956,15 @@ extension TabBarContentViewController: FloatingPanelControllerDelegate {
        }
    }

+    func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior? {
+        switch self.tabBarItem.tag {
+        case 1:
+            return TwoTabBarPanelBehavior()
+        default:
+            return nil
+        }
+    }
+
    func floatingPanelDidMove(_ vc: FloatingPanelController) {
        guard self.tabBarItem.tag == 2 else { return }

@@ -862,7 +979,7 @@ extension TabBarContentViewController: FloatingPanelControllerDelegate {
            }
        case .changeOffset:
            /*
-             Bad solution: Manipulate scoll content inset
+             Bad solution: Manipulate scroll content inset

             FloatingPanelController keeps a content offset in moving a panel
             so that changing content inset or offset causes a buggy behavior.
@@ -904,7 +1021,7 @@ extension TabBarContentViewController: FloatingPanelControllerDelegate {
            consoleVC.textViewTopConstraint?.constant = (vc.position == .full) ? vc.layoutInsets.top : 17.0

        case .changeOffset:
-            /* Bad Solution: Manipulate scoll content inset */
+            /* Bad Solution: Manipulate scroll content inset */
            guard let scrollView = consoleVC.textView else { return }
            var insets = vc.adjustedContentInsets
            insets.top = (vc.position == .full) ? vc.layoutInsets.top : 0.0
@@ -968,19 +1085,29 @@ class TwoTabBarPanelLayout: FloatingPanelLayout {
    var supportedPositions: Set<FloatingPanelPosition> {
        return [.full, .half]
    }
+    var topInteractionBuffer: CGFloat {
+        return 100.0
+    }
    var bottomInteractionBuffer: CGFloat {
        return 261.0 - 22.0
    }

    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
        switch position {
-        case .full: return 16.0
+        case .full: return 100.0
        case .half: return 261.0
        default: return nil
        }
    }
 }

+class TwoTabBarPanelBehavior: FloatingPanelBehavior {
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
+        return (edge == .bottom || edge == .top)
+    }
+}
+
+
 class ThreeTabBarPanelLayout: FloatingPanelFullScreenLayout {
    weak var parentVC: UIViewController!

@@ -1033,7 +1160,7 @@ class SettingsViewController: InspectableViewController {
    override func viewDidLoad() {
        versionLabel.text = "Version: \(Bundle.main.infoDictionary?["CFBundleVersion"] ?? "--")"
    }
-    
+
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        if #available(iOS 11.0, *) {
@@ -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;
@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|

  s.name                = "FloatingPanel"
-  s.version             = "1.4.0"
+  s.version             = "1.6.2"
  s.summary             = "FloatingPanel is a clean and easy-to-use UI component of a floating panel interface."
  s.description         = <<-DESC
 FloatingPanel is a clean and easy-to-use UI component for a new interface introduced in Apple Maps, Shortcuts and Stocks app.
@@ -14,7 +14,6 @@ The new interface displays the related contents and utilities in parallel as a u
  s.source              = { :git => "https://github.com/SCENEE/FloatingPanel.git", :tag => "v#{s.version}" }
  s.source_files        = "Framework/Sources/*.swift"
  s.swift_version       = "4.0"
-  s.pod_target_xcconfig = { 'SWIFT_WHOLE_MODULE_OPTIMIZATION' => 'YES', 'APPLICATION_EXTENSION_API_ONLY' => 'YES' }

  s.framework           = "UIKit"

@@ -7,20 +7,26 @@
 	objects = {

 /* Begin PBXBuildFile section */
+		542753C622C49A6E00D17955 /* FloatingPanelLayoutTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 542753C522C49A6E00D17955 /* FloatingPanelLayoutTests.swift */; };
+		542753C822C49A8F00D17955 /* Utils.swift in Sources */ = {isa = PBXBuildFile; fileRef = 542753C722C49A8F00D17955 /* Utils.swift */; };
 		54352E9621A51A2500CBCA08 /* FloatingPanelTransitioning.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54352E9521A51A2500CBCA08 /* FloatingPanelTransitioning.swift */; };
 		54352E9821A521CA00CBCA08 /* FloatingPanelView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54352E9721A521CA00CBCA08 /* FloatingPanelView.swift */; };
 		5450EEE421646DF500135936 /* FloatingPanelBehavior.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5450EEE321646DF500135936 /* FloatingPanelBehavior.swift */; };
 		545DB9CB2151169500CA77B8 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 545DB9C12151169500CA77B8 /* FloatingPanel.framework */; };
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@@ -31,26 +37,41 @@
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 /* End PBXContainerItemProxy section */

 /* Begin PBXFileReference section */
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 		54CFBFC4215CD09C006B5735 /* FloatingPanel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FloatingPanel.swift; sourceTree = "<group>"; };
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 /* Begin PBXFrameworksBuildPhase section */
@@ -69,6 +90,13 @@
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 /* End PBXFrameworksBuildPhase section */

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@@ -77,6 +105,7 @@
 			children = (
 				545DB9C32151169500CA77B8 /* Sources */,
 				545DB9CE2151169500CA77B8 /* Tests */,
+				54E740CB218AFD67005C1A34 /* TestingApp */,
 				545DB9C22151169500CA77B8 /* Products */,
 			);
 			sourceTree = "<group>";
@@ -86,6 +115,7 @@
 			children = (
 				545DB9C12151169500CA77B8 /* FloatingPanel.framework */,
 				545DB9CA2151169500CA77B8 /* FloatingPanelTests.xctest */,
+				54E740CA218AFD67005C1A34 /* FloatingPanelTesting.app */,
 			);
 			name = Products;
 			sourceTree = "<group>";
@@ -94,7 +124,7 @@
 			isa = PBXGroup;
 			children = (
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-				545DB9C42151169500CA77B8 /* FloatingPanelController.h */,
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 				54352E9521A51A2500CBCA08 /* FloatingPanelTransitioning.swift */,
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@@ -113,12 +143,26 @@
 		545DB9CE2151169500CA77B8 /* Tests */ = {
 			isa = PBXGroup;
 			children = (
-				545DB9CF2151169500CA77B8 /* ViewTests.swift */,
+				54A6B6B022968B530077F348 /* FloatingPanelTests.swift */,
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+				54A6B6B72296A8520077F348 /* FloatingPanelSurfaceViewTests.swift */,
+				545DB9CF2151169500CA77B8 /* FloatingPanelControllerTests.swift */,
+				542753C722C49A8F00D17955 /* Utils.swift */,
 				545DB9D12151169500CA77B8 /* Info.plist */,
 			);
 			path = Tests;
 			sourceTree = "<group>";
 		};
+		54E740CB218AFD67005C1A34 /* TestingApp */ = {
+			isa = PBXGroup;
+			children = (
+				54E740CC218AFD67005C1A34 /* AppDelegate.swift */,
+				54E740D8218AFD6A005C1A34 /* Info.plist */,
+				54A6B6B522968F710077F348 /* LaunchScreen.storyboard */,
+			);
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 /* End PBXGroup section */

 /* Begin PBXHeadersBuildPhase section */
@@ -126,7 +170,7 @@
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 			buildActionMask = 2147483647;
 			files = (
-				545DB9D22151169500CA77B8 /* FloatingPanelController.h in Headers */,
+				545DB9D22151169500CA77B8 /* FloatingPanel.h in Headers */,
 			);
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 		};
@@ -163,19 +207,37 @@
 			);
 			dependencies = (
 				545DB9CD2151169500CA77B8 /* PBXTargetDependency */,
+				54E740DD218AFE9F005C1A34 /* PBXTargetDependency */,
 			);
 			name = FloatingPanelTests;
 			productName = FloatingModalControllerTests;
 			productReference = 545DB9CA2151169500CA77B8 /* FloatingPanelTests.xctest */;
 			productType = "com.apple.product-type.bundle.unit-test";
 		};
+		54E740C9218AFD67005C1A34 /* TestingApp */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = 54E740D9218AFD6A005C1A34 /* Build configuration list for PBXNativeTarget "TestingApp" */;
+			buildPhases = (
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+				54E740C7218AFD67005C1A34 /* Frameworks */,
+				54E740C8218AFD67005C1A34 /* Resources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = TestingApp;
+			productName = TestingHost;
+			productReference = 54E740CA218AFD67005C1A34 /* FloatingPanelTesting.app */;
+			productType = "com.apple.product-type.application";
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 /* End PBXNativeTarget section */

 /* Begin PBXProject section */
 		545DB9B82151169500CA77B8 /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastSwiftUpdateCheck = 1000;
+				LastSwiftUpdateCheck = 1010;
 				LastUpgradeCheck = 1000;
 				ORGANIZATIONNAME = scenee;
 				TargetAttributes = {
@@ -185,6 +247,10 @@
 					};
 					545DB9C92151169500CA77B8 = {
 						CreatedOnToolsVersion = 10.0;
+						TestTargetID = 54E740C9218AFD67005C1A34;
+					};
+					54E740C9218AFD67005C1A34 = {
+						CreatedOnToolsVersion = 10.1;
 					};
 				};
 			};
@@ -194,6 +260,7 @@
 			hasScannedForEncodings = 0;
 			knownRegions = (
 				en,
+				Base,
 			);
 			mainGroup = 545DB9B72151169500CA77B8;
 			productRefGroup = 545DB9C22151169500CA77B8 /* Products */;
@@ -202,6 +269,7 @@
 			targets = (
 				545DB9C02151169500CA77B8 /* FloatingPanel */,
 				545DB9C92151169500CA77B8 /* FloatingPanelTests */,
+				54E740C9218AFD67005C1A34 /* TestingApp */,
 			);
 		};
 /* End PBXProject section */
@@ -221,6 +289,14 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		54E740C8218AFD67005C1A34 /* Resources */ = {
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+			buildActionMask = 2147483647;
+			files = (
+				54A6B6B622968F710077F348 /* LaunchScreen.storyboard in Resources */,
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+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXResourcesBuildPhase section */

 /* Begin PBXSourcesBuildPhase section */
@@ -239,6 +315,7 @@
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 				54352E9621A51A2500CBCA08 /* FloatingPanelTransitioning.swift in Sources */,
 				545DB9DE215118C800CA77B8 /* UIExtensions.swift in Sources */,
+				542753C822C49A8F00D17955 /* Utils.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -246,7 +323,18 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				545DB9D02151169500CA77B8 /* ViewTests.swift in Sources */,
+				54A6B6B122968B530077F348 /* FloatingPanelTests.swift in Sources */,
+				545DB9D02151169500CA77B8 /* FloatingPanelControllerTests.swift in Sources */,
+				542753C622C49A6E00D17955 /* FloatingPanelLayoutTests.swift in Sources */,
+				54A6B6B82296A8520077F348 /* FloatingPanelSurfaceViewTests.swift in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+		54E740C6218AFD67005C1A34 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				54E740CD218AFD67005C1A34 /* AppDelegate.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -258,6 +346,11 @@
 			target = 545DB9C02151169500CA77B8 /* FloatingPanel */;
 			targetProxy = 545DB9CC2151169500CA77B8 /* PBXContainerItemProxy */;
 		};
+		54E740DD218AFE9F005C1A34 /* PBXTargetDependency */ = {
+			isa = PBXTargetDependency;
+			target = 54E740C9218AFD67005C1A34 /* TestingApp */;
+			targetProxy = 54E740DC218AFE9F005C1A34 /* PBXContainerItemProxy */;
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 /* End PBXTargetDependency section */

 /* Begin XCBuildConfiguration section */
@@ -386,6 +479,7 @@
 		545DB9D62151169500CA77B8 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
@@ -405,6 +499,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
+				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
@@ -414,6 +509,7 @@
 		545DB9D72151169500CA77B8 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
@@ -432,6 +528,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanel;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
+				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
@@ -442,7 +539,9 @@
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Tests/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -450,8 +549,9 @@
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 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingModalControllerTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/FloatingPanelTesting.app/FloatingPanelTesting";
 			};
 			name = Debug;
 		};
@@ -460,7 +560,9 @@
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Tests/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				LD_RUNPATH_SEARCH_PATHS = (
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 					"@executable_path/Frameworks",
@@ -468,11 +570,177 @@
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 				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingModalControllerTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/FloatingPanelTesting.app/FloatingPanelTesting";
+			};
+			name = Release;
+		};
+		54E740DA218AFD6A005C1A34 /* Debug */ = {
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+			buildSettings = {
+				CODE_SIGN_STYLE = Automatic;
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+				INFOPLIST_FILE = TestingApp/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
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+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelTesting;
+				PRODUCT_NAME = FloatingPanelTesting;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Debug;
+		};
+		54E740DB218AFD6A005C1A34 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = TestingApp/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
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+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelTesting;
+				PRODUCT_NAME = FloatingPanelTesting;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
 		};
+		54E79ADF224F6C9800717BC6 /* Test */ = {
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+			buildSettings = {
+				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
+				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_MODULES = YES;
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+				CLANG_ENABLE_OBJC_WEAK = YES;
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+				CLANG_WARN_COMMA = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
+				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
+				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
+				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
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+				DEBUG_INFORMATION_FORMAT = dwarf;
+				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				ENABLE_TESTABILITY = YES;
+				GCC_C_LANGUAGE_STANDARD = gnu11;
+				GCC_DYNAMIC_NO_PIC = NO;
+				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_OPTIMIZATION_LEVEL = 0;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"DEBUG=1",
+					"$(inherited)",
+				);
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
+				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
+				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
+				GCC_WARN_UNUSED_FUNCTION = YES;
+				GCC_WARN_UNUSED_VARIABLE = YES;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
+				MTL_FAST_MATH = YES;
+				ONLY_ACTIVE_ARCH = YES;
+				SDKROOT = iphoneos;
+				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				VERSIONING_SYSTEM = "apple-generic";
+				VERSION_INFO_PREFIX = "";
+			};
+			name = Test;
+		};
+		54E79AE0224F6C9800717BC6 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
+				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_IDENTITY = "";
+				CODE_SIGN_STYLE = Automatic;
+				DEFINES_MODULE = YES;
+				DYLIB_COMPATIBILITY_VERSION = 1;
+				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_INSTALL_NAME_BASE = "@rpath";
+				INFOPLIST_FILE = Sources/Info.plist;
+				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanel;
+				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
+				SKIP_INSTALL = YES;
+				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "DEBUG __FP_LOG";
+				SWIFT_COMPILATION_MODE = wholemodule;
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 4.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Test;
+		};
+		54E79AE1224F6C9800717BC6 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = Tests/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingModalControllerTests;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/FloatingPanelTesting.app/FloatingPanelTesting";
+			};
+			name = Test;
+		};
+		54E8AC6A2286CFB6000C5A12 /* Test */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				DEVELOPMENT_TEAM = "";
+				INFOPLIST_FILE = TestingApp/Info.plist;
+				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				LD_RUNPATH_SEARCH_PATHS = "@executable_path/Frameworks";
+				PRODUCT_BUNDLE_IDENTIFIER = com.scenee.FloatingPanelTesting;
+				PRODUCT_NAME = FloatingPanelTesting;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Test;
+		};
 /* End XCBuildConfiguration section */

 /* Begin XCConfigurationList section */
@@ -480,6 +748,7 @@
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				545DB9D32151169500CA77B8 /* Debug */,
+				54E79ADF224F6C9800717BC6 /* Test */,
 				545DB9D42151169500CA77B8 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
@@ -489,6 +758,7 @@
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				545DB9D62151169500CA77B8 /* Debug */,
+				54E79AE0224F6C9800717BC6 /* Test */,
 				545DB9D72151169500CA77B8 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
@@ -498,11 +768,22 @@
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				545DB9D92151169500CA77B8 /* Debug */,
+				54E79AE1224F6C9800717BC6 /* Test */,
 				545DB9DA2151169500CA77B8 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
+		54E740D9218AFD6A005C1A34 /* Build configuration list for PBXNativeTarget "TestingApp" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				54E740DA218AFD6A005C1A34 /* Debug */,
+				54E740DB218AFD6A005C1A34 /* Release */,
+				54E8AC6A2286CFB6000C5A12 /* Test */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
 /* End XCConfigurationList section */
 	};
 	rootObject = 545DB9B82151169500CA77B8 /* Project object */;
@@ -23,12 +23,33 @@
      </BuildActionEntries>
   </BuildAction>
   <TestAction
-      buildConfiguration = "Debug"
+      buildConfiguration = "Test"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
+         <TestableReference
+            skipped = "NO"
+            parallelizable = "YES"
+            testExecutionOrdering = "random">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "545DB9C92151169500CA77B8"
+               BuildableName = "FloatingPanelTests.xctest"
+               BlueprintName = "FloatingPanelTests"
+               ReferencedContainer = "container:FloatingPanel.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
      </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "545DB9C02151169500CA77B8"
+            BuildableName = "FloatingPanel.framework"
+            BlueprintName = "FloatingPanel"
+            ReferencedContainer = "container:FloatingPanel.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
      <AdditionalOptions>
      </AdditionalOptions>
   </TestAction>
@@ -8,9 +8,9 @@ import UIKit.UIGestureRecognizerSubclass // For Xcode 9.4.1
 ///
 /// FloatingPanel presentation model
 ///
-class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate {
+class FloatingPanel: NSObject, UIGestureRecognizerDelegate {
    // MUST be a weak reference to prevent UI freeze on the presentation modally
-    weak var viewcontroller: FloatingPanelController!
+    weak var viewcontroller: FloatingPanelController?

    let surfaceView: FloatingPanelSurfaceView
    let backdropView: FloatingPanelBackdropView
@@ -21,14 +21,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        didSet {
            guard let scrollView = scrollView else { return }
            scrollView.panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
-            scrollBouncable = scrollView.bounces
-            scrollIndictorVisible = scrollView.showsVerticalScrollIndicator
        }
    }
-    weak var userScrollViewDelegate: UIScrollViewDelegate?

    private(set) var state: FloatingPanelPosition = .hidden {
-        didSet { viewcontroller.delegate?.floatingPanelDidChangePosition(viewcontroller) }
+        didSet {
+            if let vc = viewcontroller {
+                vc.delegate?.floatingPanelDidChangePosition(vc)
+            }
+        }
    }

    private var isBottomState: Bool {
@@ -40,6 +41,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
    var isRemovalInteractionEnabled: Bool = false

    fileprivate var animator: UIViewPropertyAnimator?
+
    private var initialFrame: CGRect = .zero
    private var initialTranslationY: CGFloat = 0
    private var initialLocation: CGPoint = .nan
@@ -91,7 +93,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
    }

    private func move(from: FloatingPanelPosition, to: FloatingPanelPosition, animated: Bool, completion: (() -> Void)? = nil) {
-        if to != .full {
+        guard let vc = viewcontroller else {
+            completion?()
+            return
+        }
+        if state != layoutAdapter.topMostState {
            lockScrollView()
        }
        tearDownActiveInteraction()
@@ -100,11 +106,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            let animator: UIViewPropertyAnimator
            switch (from, to) {
            case (.hidden, let to):
-                animator = behavior.addAnimator(self.viewcontroller, to: to)
+                animator = behavior.addAnimator(vc, to: to)
            case (let from, .hidden):
-                animator = behavior.removeAnimator(self.viewcontroller, from: from)
+                animator = behavior.removeAnimator(vc, from: from)
            case (let from, let to):
-                animator = behavior.moveAnimator(self.viewcontroller, from: from, to: to)
+                animator = behavior.moveAnimator(vc, from: from, to: to)
            }

            animator.addAnimations { [weak self] in
@@ -116,6 +122,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            animator.addCompletion { [weak self] _ in
                guard let `self` = self else { return }
                self.animator = nil
+                if self.state == self.layoutAdapter.topMostState {
+                    self.unlockScrollView()
+                } else {
+                    self.lockScrollView()
+                }
                completion?()
            }
            self.animator = animator
@@ -123,6 +134,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        } else {
            self.state = to
            self.updateLayout(to: to)
+            if self.state == self.layoutAdapter.topMostState {
+                self.unlockScrollView()
+            } else {
+                self.lockScrollView()
+            }
            completion?()
        }
    }
@@ -159,7 +175,8 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

        /* log.debug("shouldRecognizeSimultaneouslyWith", otherGestureRecognizer) */

-        if viewcontroller.delegate?.floatingPanel(viewcontroller, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) ?? false {
+        if let vc = viewcontroller,
+            vc.delegate?.floatingPanel(vc, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) ?? false {
            return true
        }

@@ -173,8 +190,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            // and handle them in self.handle(panGesture:)
            return scrollView?.gestureRecognizers?.contains(otherGestureRecognizer) ?? false
        default:
-            // Should always recognize tap/long press gestures in parallel
-            return true
+            // Should recognize tap/long press gestures in parallel when the surface view is at an anchor position.
+            let surfaceFrame = surfaceView.layer.presentation()?.frame ?? surfaceView.frame
+            return surfaceFrame.minY == layoutAdapter.positionY(for: state)
        }
    }

@@ -205,11 +223,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            }
        }

-        if viewcontroller.delegate?.floatingPanel(viewcontroller, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) ?? false {
+        if let vc = viewcontroller,
+            vc.delegate?.floatingPanel(vc, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) ?? false {
            return false
        }

-
        switch otherGestureRecognizer {
        case is UIPanGestureRecognizer,
             is UISwipeGestureRecognizer,
@@ -228,7 +246,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        let grabberAreaFrame = CGRect(x: surfaceView.bounds.origin.x,
                                     y: surfaceView.bounds.origin.y,
                                     width: surfaceView.bounds.width,
-                                     height: FloatingPanelSurfaceView.topGrabberBarHeight * 2)
+                                     height: surfaceView.topGrabberBarHeight * 2)
        return grabberAreaFrame
    }

@@ -252,34 +270,18 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

            if belowTop {
                // Scroll offset pinning
-                switch state {
-                case .full:
+                if state == layoutAdapter.topMostState {
                    if interactionInProgress {
                        log.debug("settle offset --", initialScrollOffset.y)
                        scrollView.setContentOffset(initialScrollOffset, animated: false)
                    } else {
                        if grabberAreaFrame.contains(location) {
                            // Preserve the current content offset in moving from full.
-                            scrollView.contentOffset.y = initialScrollOffset.y
-                        } else {
-                            if scrollView.contentOffset.y < 0 {
-                                fitToBounds(scrollView: scrollView)
-                                let translation = panGesture.translation(in: panGestureRecognizer.view!.superview)
-                                startInteraction(with: translation, at: location)
-                            }
+                            scrollView.setContentOffset(initialScrollOffset, animated: false)
                        }
                    }
-                case .half, .tip:
-                    guard scrollView.isDecelerating == false else {
-                        // Don't fix the scroll offset in animating the panel to half and tip.
-                        // It causes a buggy scrolling deceleration because `state` becomes
-                        // a target position in animating the panel on the interaction from full.
-                        return
-                    }
-                    // Fix the scroll offset in moving the panel from half and tip.
-                    scrollView.contentOffset.y = initialScrollOffset.y
-                case .hidden:
-                    break
+                } else {
+                    scrollView.setContentOffset(initialScrollOffset, animated: false)
                }

                // Always hide a scroll indicator at the non-top.
@@ -287,14 +289,17 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                    lockScrollView()
                }
            } else {
+                let offset = scrollView.contentOffset.y - scrollView.contentOffsetZero.y
                // Always show a scroll indicator at the top.
                if interactionInProgress {
-                    unlockScrollView()
+                    if offset > 0 {
+                        unlockScrollView()
+                    }
                } else {
-                    if state == .full, scrollView.contentOffset.y < 0, velocity.y > 0 {
-                        fitToBounds(scrollView: scrollView)
-                        let translation = panGesture.translation(in: panGestureRecognizer.view!.superview)
-                        startInteraction(with: translation, at: location)
+                    // Hide a scroll indicator just before starting an interaction by swiping a panel down.
+                    if state == layoutAdapter.topMostState,
+                        offset < 0, velocity.y > 0 {
+                        lockScrollView()
                    }
                }
            }
@@ -306,15 +311,22 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                "translation =  \(translation.y), location = \(location.y), velocity = \(velocity.y)")

            if let animator = self.animator {
+                log.debug("panel animation interrupted!!!")
                if animator.isInterruptible {
                    animator.stopAnimation(false)
                    animator.finishAnimation(at: .current)
                }
                self.animator = nil
+
+                // A user can stop a panel at the nearest Y of a target position
+                if abs(surfaceView.frame.minY - layoutAdapter.topY) < 1.0 {
+                    surfaceView.frame.origin.y = layoutAdapter.topY
+                }
            }

            if interactionInProgress == false,
-                viewcontroller.delegate?.floatingPanelShouldBeginDragging(viewcontroller) == false {
+                let vc = viewcontroller,
+                vc.delegate?.floatingPanelShouldBeginDragging(vc) == false {
                return
            }

@@ -360,8 +372,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        }

        guard
-            state == .full,                   // When not .full, don't scroll.
-            interactionInProgress == false    // When interaction already in progress, don't scroll.
+            state == layoutAdapter.topMostState,   // When not top most(i.e. .full), don't scroll.
+            interactionInProgress == false,        // When interaction already in progress, don't scroll.
+            surfaceView.frame.minY == layoutAdapter.topY
        else {
            return false
        }
@@ -379,18 +392,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        }

        let offset = scrollView.contentOffset.y - scrollView.contentOffsetZero.y
-        // 10 pt is introduced from my testing(there might be better one)
-        // It should be low as possible because a user scroll view frame will
-        // change as far as the specified value temporarily.
-        // The zero offset is an exception because the offset is usually zero
-        // when a panel moves from half or tip position to full.
-        if  offset > -10.0, offset != 0.0 {
+        // The zero offset must be excluded because the offset is usually zero
+        // after a panel moves from half/tip to full.
+        if  offset > 0.0 {
            return true
        }
        if scrollView.isDecelerating {
            return true
        }
-        if velocity.y < 0 {
+        if velocity.y <= 0 {
            return true
        }

@@ -403,12 +413,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        // So here just preserve the current state if needed.
        log.debug("panningBegan -- location = \(location.y)")
        initialLocation = location
-        switch state {
-        case .full:
+        if state == layoutAdapter.topMostState {
            if let scrollView = scrollView {
                initialScrollFrame = scrollView.frame
            }
-        default:
+        } else {
            if let scrollView = scrollView {
                initialScrollOffset = scrollView.contentOffset
            }
@@ -421,7 +430,8 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        let dy = translation.y - initialTranslationY

        layoutAdapter.updateInteractiveTopConstraint(diff: dy,
-                                                     allowsTopBuffer: allowsTopBuffer(for: dy))
+                                                     allowsTopBuffer: allowsTopBuffer(for: dy),
+                                                     with: behavior)

        backdropView.alpha = getBackdropAlpha(with: translation)
        preserveContentVCLayoutIfNeeded()
@@ -429,7 +439,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        let didMove = (pre != surfaceView.frame.minY)
        guard didMove else { return }

-        viewcontroller.delegate?.floatingPanelDidMove(viewcontroller)
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidMove(vc)
+        }
    }

    private func allowsTopBuffer(for translationY: CGFloat) -> Bool {
@@ -447,11 +459,12 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
    // Prevent stretching a view having a constraint to SafeArea.bottom in an overflow
    // from the full position because SafeArea is global in a screen.
    private func preserveContentVCLayoutIfNeeded() {
+        guard let vc = viewcontroller else { return }
        // Must include topY
        if (surfaceView.frame.minY <= layoutAdapter.topY) {
            if !disabledBottomAutoLayout {
-                viewcontroller.contentViewController?.view?.constraints.forEach({ (const) in
-                    switch viewcontroller.contentViewController?.layoutGuide.bottomAnchor {
+                vc.contentViewController?.view?.constraints.forEach({ (const) in
+                    switch vc.contentViewController?.layoutGuide.bottomAnchor {
                    case const.firstAnchor:
                        (const.secondItem as? UIView)?.disableAutoLayout()
                        const.isActive = false
@@ -466,8 +479,8 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            disabledBottomAutoLayout = true
        } else {
            if disabledBottomAutoLayout {
-                viewcontroller.contentViewController?.view?.constraints.forEach({ (const) in
-                    switch viewcontroller.contentViewController?.layoutGuide.bottomAnchor {
+                vc.contentViewController?.view?.constraints.forEach({ (const) in
+                    switch vc.contentViewController?.layoutGuide.bottomAnchor {
                    case const.firstAnchor:
                        (const.secondItem as? UIView)?.enableAutoLayout()
                        const.isActive = true
@@ -492,6 +505,12 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        }

        stopScrollDeceleration = (surfaceView.frame.minY > layoutAdapter.topY) // Projecting the dragging to the scroll dragging or not
+        if stopScrollDeceleration {
+            DispatchQueue.main.async { [weak self] in
+                guard let `self` = self else { return }
+                self.stopScrollingWithDeceleration(at: self.initialScrollOffset)
+            }
+        }

        let targetPosition = self.targetPosition(with: velocity)
        let distance = self.distance(to: targetPosition)
@@ -500,25 +519,34 @@ 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) {
-
-                viewcontroller.delegate?.floatingPanelDidEndDraggingToRemove(viewcontroller, withVelocity: velocity)
-                self.startRemovalAnimation(with: velocityVector) { [weak self] in
-                    guard let `self` = self else { return }
-                    self.viewcontroller.dismiss(animated: false, completion: { [weak self] in
-                        guard let `self` = self else { return }
-                        self.viewcontroller.delegate?.floatingPanelDidEndRemove(self.viewcontroller)
-                    })
+            if shouldStartRemovalAnimation(with: velocityVector), let vc = viewcontroller {
+                vc.delegate?.floatingPanelDidEndDraggingToRemove(vc, withVelocity: velocity)
+                startRemovalAnimation(vc, with: velocityVector) { [weak self] in
+                    self?.finishRemovalAnimation()
                }
                return
            }
        }

-        viewcontroller.delegate?.floatingPanelDidEndDragging(viewcontroller, withVelocity: velocity, targetPosition: targetPosition)
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidEndDragging(vc, withVelocity: velocity, targetPosition: targetPosition)
+        }
+
+        // Workaround: Disable a tracking scroll to prevent bouncing a scroll content in a panel animating
+        let isScrollEnabled = scrollView?.isScrollEnabled
+        if let scrollView = scrollView, targetPosition != .full {
+            scrollView.isScrollEnabled = false
+        }

        startAnimation(to: targetPosition, at: distance, with: velocity)
+
+        // Workaround: Reset `self.scrollView.isScrollEnabled`
+        if let scrollView = scrollView, targetPosition != .full,
+            let isScrollEnabled = isScrollEnabled {
+            scrollView.isScrollEnabled = isScrollEnabled
+        }
    }

    private func shouldStartRemovalAnimation(with velocityVector: CGVector) -> Bool {
@@ -537,8 +565,8 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        return true
    }

-    private func startRemovalAnimation(with velocityVector: CGVector, completion: (() -> Void)?) {
-        let animator = self.behavior.removalInteractionAnimator(self.viewcontroller, with: velocityVector)
+    private func startRemovalAnimation(_ vc: FloatingPanelController, with velocityVector: CGVector, completion: (() -> Void)?) {
+        let animator = behavior.removalInteractionAnimator(vc, with: velocityVector)

        animator.addAnimations { [weak self] in
            self?.updateLayout(to: .hidden)
@@ -551,16 +579,24 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        animator.startAnimation()
    }

+    private func finishRemovalAnimation() {
+        viewcontroller?.dismiss(animated: false) { [weak self] in
+            guard let vc = self?.viewcontroller else { return }
+            vc.delegate?.floatingPanelDidEndRemove(vc)
+        }
+    }
+
    private func startInteraction(with translation: CGPoint, at location: CGPoint) {
        /* Don't lock a scroll view to show a scroll indicator after hitting the top */
        log.debug("startInteraction  -- translation = \(translation.y), location = \(location.y)")
        guard interactionInProgress == false else { return }

        initialFrame = surfaceView.frame
-        if state == .full, let scrollView = scrollView {
+        if state == layoutAdapter.topMostState, let scrollView = scrollView {
            if grabberAreaFrame.contains(location) {
                initialScrollOffset = scrollView.contentOffset
            } else {
+                fitToBounds(scrollView: scrollView)
                settle(scrollView: scrollView)
                initialScrollOffset = scrollView.contentOffsetZero
            }
@@ -569,7 +605,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

        initialTranslationY = translation.y

-        viewcontroller.delegate?.floatingPanelWillBeginDragging(viewcontroller)
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelWillBeginDragging(vc)
+        }

        layoutAdapter.startInteraction(at: state)

@@ -586,7 +624,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        interactionInProgress = false

        // Prevent to keep a scroll view indicator visible at the half/tip position
-        if targetPosition != .full {
+        if state != layoutAdapter.topMostState {
            lockScrollView()
        }

@@ -601,12 +639,14 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

    private func startAnimation(to targetPosition: FloatingPanelPosition, at distance: CGFloat, with velocity: CGPoint) {
        log.debug("startAnimation to \(targetPosition) -- distance = \(distance), velocity = \(velocity.y)")
+        guard let vc = viewcontroller else { return }

        isDecelerating = true
-        viewcontroller.delegate?.floatingPanelWillBeginDecelerating(viewcontroller)

-        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: min(fabs(velocity.y)/distance, 30.0)) : .zero
-        let animator = behavior.interactionAnimator(self.viewcontroller, to: targetPosition, with: velocityVector)
+        vc.delegate?.floatingPanelWillBeginDecelerating(vc)
+
+        let velocityVector = (distance != 0) ? CGVector(dx: 0, dy: min(abs(velocity.y)/distance, 30.0)) : .zero
+        let animator = behavior.interactionAnimator(vc, to: targetPosition, with: velocityVector)
        animator.addAnimations { [weak self] in
            guard let `self` = self else { return }
            self.state = targetPosition
@@ -622,10 +662,13 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

    private func finishAnimation(at targetPosition: FloatingPanelPosition) {
        log.debug("finishAnimation to \(targetPosition)")
+
        self.isDecelerating = false
        self.animator = nil

-        self.viewcontroller.delegate?.floatingPanelDidEndDecelerating(self.viewcontroller)
+        if let vc = viewcontroller {
+            vc.delegate?.floatingPanelDidEndDecelerating(vc)
+        }

        if let scrollView = scrollView {
            log.debug("finishAnimation -- scroll offset = \(scrollView.contentOffset)")
@@ -633,27 +676,15 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

        stopScrollDeceleration = false
        // Don't unlock scroll view in animating view when presentation layer != model layer
-        if targetPosition == .full {
+        if state == layoutAdapter.topMostState {
            unlockScrollView()
        }
    }

    private func distance(to targetPosition: FloatingPanelPosition) -> CGFloat {
-        let topY = layoutAdapter.topY
-        let middleY = layoutAdapter.middleY
-        let bottomY = layoutAdapter.bottomY
        let currentY = surfaceView.frame.minY
-
-        switch targetPosition {
-        case .full:
-            return CGFloat(fabs(currentY - topY))
-        case .half:
-            return CGFloat(fabs(currentY - middleY))
-        case .tip:
-            return CGFloat(fabs(currentY - bottomY))
-        case .hidden:
-            fatalError("Now .hidden must not be used for a user interaction")
-        }
+        let targetY = layoutAdapter.positionY(for: targetPosition)
+        return CGFloat(abs(currentY - targetY))
    }

    private func directionalPosition(at currentY: CGFloat, with translation: CGPoint) -> FloatingPanelPosition {
@@ -689,11 +720,12 @@ 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)
    }

    private func targetPosition(with velocity: CGPoint) -> (FloatingPanelPosition) {
+        guard let vc = viewcontroller else { return state }
        let currentY = surfaceView.frame.minY
        let supportedPositions = layoutAdapter.supportedPositions

@@ -736,7 +768,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                fatalError("Now .hidden must not be used for a user interaction")
            }

-            let redirectionalProgress = max(min(behavior.redirectionalProgress(viewcontroller, from: state, to: nextState), 1.0), 0.0)
+            let redirectionalProgress = max(min(behavior.redirectionalProgress(vc, from: state, to: nextState), 1.0), 0.0)

            let th1: CGFloat
            let th2: CGFloat
@@ -749,7 +781,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                th2 = bottomY - (bottomY - middleY) * redirectionalProgress
            }

-            let decelerationRate = behavior.momentumProjectionRate(viewcontroller)
+            let decelerationRate = behavior.momentumProjectionRate(vc)

            let baseY = abs(bottomY - topY)
            let vecY = velocity.y / baseY
@@ -759,7 +791,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            case ..<th1:
                switch pY {
                case bottomY...:
-                    return behavior.shouldProjectMomentum(viewcontroller, for: .tip) ? .tip : .half
+                    return behavior.shouldProjectMomentum(vc, for: .tip) ? .tip : .half
                case middleY...:
                    return .half
                case topY...:
@@ -770,7 +802,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
            case ...middleY:
                switch pY {
                case bottomY...:
-                    return behavior.shouldProjectMomentum(viewcontroller, for: .tip) ? .tip : .half
+                    return behavior.shouldProjectMomentum(vc, for: .tip) ? .tip : .half
                case middleY...:
                    return .half
                case topY...:
@@ -787,7 +819,7 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                case topY...:
                    return .half
                default:
-                    return behavior.shouldProjectMomentum(viewcontroller, for: .full) ? .full : .half
+                    return behavior.shouldProjectMomentum(vc, for: .full) ? .full : .half
                }
            default:
                switch pY {
@@ -798,13 +830,14 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
                case topY...:
                    return .half
                default:
-                    return behavior.shouldProjectMomentum(viewcontroller, for: .full) ? .full : .half
+                    return behavior.shouldProjectMomentum(vc, for: .full) ? .full : .half
                }
            }
        }
    }

    private func targetPosition(from positions: [FloatingPanelPosition], at currentY: CGFloat, velocity: CGPoint) -> FloatingPanelPosition {
+        guard let vc = viewcontroller else { return state }
        assert(positions.count == 2)

        let top = positions[0]
@@ -814,11 +847,11 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
        let bottomY = layoutAdapter.positionY(for: bottom)

        let target = top == state ? bottom : top
-        let redirectionalProgress = max(min(behavior.redirectionalProgress(viewcontroller, from: state, to: target), 1.0), 0.0)
+        let redirectionalProgress = max(min(behavior.redirectionalProgress(vc, from: state, to: target), 1.0), 0.0)

        let th = topY + (bottomY - topY) * redirectionalProgress

-        let decelerationRate = behavior.momentumProjectionRate(viewcontroller)
+        let decelerationRate = behavior.momentumProjectionRate(vc)
        let pY = project(initialVelocity: velocity.y, decelerationRate: decelerationRate) + currentY

        switch currentY {
@@ -842,13 +875,21 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
    private func lockScrollView() {
        guard let scrollView = scrollView else { return }

+        if scrollView.isLocked {
+            log.debug("Already scroll locked.")
+            return
+        }
+
+        scrollBouncable = scrollView.bounces
+        scrollIndictorVisible = scrollView.showsVerticalScrollIndicator
+
        scrollView.isDirectionalLockEnabled = true
        scrollView.bounces = false
        scrollView.showsVerticalScrollIndicator = false
    }

    private func unlockScrollView() {
-        guard let scrollView = scrollView else { return }
+        guard let scrollView = scrollView, scrollView.isLocked else { return }

        scrollView.isDirectionalLockEnabled = false
        scrollView.bounces = scrollBouncable
@@ -869,8 +910,9 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate

    private func settle(scrollView: UIScrollView) {
        log.debug("settle scroll view")
-
+        let frame = surfaceView.layer.presentation()?.frame ?? surfaceView.frame
        surfaceView.transform = .identity
+        surfaceView.frame = frame
        scrollView.transform = .identity
        scrollView.frame = initialScrollFrame
        scrollView.contentOffset = scrollView.contentOffsetZero
@@ -878,36 +920,14 @@ class FloatingPanel: NSObject, UIGestureRecognizerDelegate, UIScrollViewDelegate
    }


-    // MARK: - UIScrollViewDelegate Intermediation
-    override func responds(to aSelector: Selector!) -> Bool {
-        return super.responds(to: aSelector) || userScrollViewDelegate?.responds(to: aSelector) == true
-    }
-
-    override func forwardingTarget(for aSelector: Selector!) -> Any? {
-        if userScrollViewDelegate?.responds(to: aSelector) == true {
-            return userScrollViewDelegate
-        } else {
-            return super.forwardingTarget(for: aSelector)
-        }
-    }
-
-    func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
-        if stopScrollDeceleration {
-            targetContentOffset.pointee = scrollView.contentOffset
-            stopScrollDeceleration = false
-        } else {
-            let targetOffset = targetContentOffset.pointee
-            userScrollViewDelegate?.scrollViewWillEndDragging?(scrollView, withVelocity: velocity, targetContentOffset: targetContentOffset)
-            // Stop scrolling on tip and half
-            if state != .full, targetOffset == targetContentOffset.pointee {
-                targetContentOffset.pointee.y = scrollView.contentOffset.y
-            }
-        }
+    private func stopScrollingWithDeceleration(at contentOffset: CGPoint) {
+        // Must use setContentOffset(_:animated) to force-stop deceleration
+        scrollView?.setContentOffset(contentOffset, animated: false)
    }
 }

 class FloatingPanelPanGestureRecognizer: UIPanGestureRecognizer {
-    fileprivate var floatingPanel: FloatingPanel?
+    fileprivate weak var floatingPanel: FloatingPanel?
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesBegan(touches, with: event)
        if floatingPanel?.animator != nil {
@@ -6,10 +6,10 @@
 import UIKit

 public protocol FloatingPanelBehavior {
-    /// Asks the behavior object if the floating panel should project a momentum of a user interaction to move the proposed position.
+    /// Asks the behavior if the floating panel should project a momentum of a user interaction to move the proposed position.
    ///
    /// The default implementation of this method returns true. This method is called for a layout to support all positions(tip, half and full).
-    /// Therfore, `proposedTargetPosition` can only be `FloatingPanelPosition.tip` or `FloatingPanelPosition.full`.
+    /// Therefore, `proposedTargetPosition` can only be `FloatingPanelPosition.tip` or `FloatingPanelPosition.full`.
    func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool

    /// Returns a deceleration rate to calculate a target position projected a dragging momentum.
@@ -19,7 +19,7 @@ public protocol FloatingPanelBehavior {

    /// Returns the progress to redirect to the previous position.
    ///
-    /// The progress is represented by a floating-point value between 0.0 and 1.0, inclusive, where 1.0 indicates the floating panel is impossible to move to the next posiiton. The default value is 0.5. Values less than 0.0 and greater than 1.0 are pinned to those limits.
+    /// The progress is represented by a floating-point value between 0.0 and 1.0, inclusive, where 1.0 indicates the floating panel is impossible to move to the next position. The default value is 0.5. Values less than 0.0 and greater than 1.0 are pinned to those limits.
    func redirectionalProgress(_ fpc: FloatingPanelController, from: FloatingPanelPosition, to: FloatingPanelPosition) -> CGFloat

    /// Returns a UIViewPropertyAnimator object to project a floating panel to a position on finger up if the user dragged.
@@ -57,6 +57,12 @@ public protocol FloatingPanelBehavior {
    ///
    /// Default is a spring animator with 1.0 damping ratio. This method is called when FloatingPanelController.isRemovalInteractionEnabled is true.
    func removalInteractionAnimator(_ fpc: FloatingPanelController, with velocity: CGVector) -> UIViewPropertyAnimator
+
+
+    /// Asks the behavior whether the rubber band effect is enabled in moving over a given edge of the surface view.
+    ///
+    /// This method allows the behavior to activate the rubber band effect to a given edge of the surface view. By default, the effect is disabled.
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool
 }

 public extension FloatingPanelBehavior {
@@ -72,14 +78,18 @@ 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)
    }

@@ -110,6 +120,10 @@ public extension FloatingPanelBehavior {
                                        initialVelocity: velocity)
        return UIViewPropertyAnimator(duration: 0, timingParameters: timing)
    }
+
+    func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
+        return false
+    }
 }

 private let defaultBehavior = FloatingPanelDefaultBehavior()
@@ -68,12 +68,16 @@ public enum FloatingPanelPosition: Int {
    case half
    case tip
    case hidden
+
+    static var allCases: [FloatingPanelPosition] {
+        return [.full, .half, .tip, .hidden]
+    }
 }

 ///
 /// A container view controller to display a floating panel to present contents in parallel as a user wants.
 ///
-public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGestureRecognizerDelegate {
+open class FloatingPanelController: UIViewController, UIScrollViewDelegate, UIGestureRecognizerDelegate {
    /// Constants indicating how safe area insets are added to the adjusted content inset.
    public enum ContentInsetAdjustmentBehavior: Int {
        case always
@@ -145,7 +149,8 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
    }
    private var _contentViewController: UIViewController?

-    private var floatingPanel: FloatingPanel!
+    private(set) var floatingPanel: FloatingPanel!
+    private var preSafeAreaInsets: UIEdgeInsets = .zero // Capture the latest one
    private var safeAreaInsetsObservation: NSKeyValueObservation?
    private let modalTransition = FloatingPanelModalTransition()

@@ -180,7 +185,7 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
    // MARK:- Overrides

    /// Creates the view that the controller manages.
-    override public func loadView() {
+    open override func loadView() {
        assert(self.storyboard == nil, "Storyboard isn't supported")

        let view = FloatingPanelPassThroughView()
@@ -195,16 +200,18 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
        self.view = view as UIView
    }

-    public override func viewDidLayoutSubviews() {
+    open override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        if #available(iOS 11.0, *) {}
        else {
            // Because {top,bottom}LayoutGuide is managed as a view
-            self.update(safeAreaInsets: layoutInsets)
+            if preSafeAreaInsets != layoutInsets {
+                self.update(safeAreaInsets: layoutInsets)
+            }
        }
    }

-    public override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
+    open override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)

        if view.translatesAutoresizingMaskIntoConstraints {
@@ -213,21 +220,25 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
        }
    }

-    public override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
+    open override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
        super.willTransition(to: newCollection, with: coordinator)
-
-        // Change layout for a new trait collection
-        reloadLayout(for: newCollection)
-        setUpLayout()
-
-        floatingPanel.behavior = fetchBehavior(for: newCollection)
+        self.prepare(for: newCollection)
    }

-    public override func viewWillDisappear(_ animated: Bool) {
+    open override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        safeAreaInsetsObservation = nil
    }

+    // MARK:- Internals
+    func prepare(for newCollection: UITraitCollection) {
+        guard newCollection.shouldUpdateLayout(from: traitCollection) else { return }
+        // Change a layout & behavior for a new trait collection
+        reloadLayout(for: newCollection)
+        activateLayout()
+        floatingPanel.behavior = fetchBehavior(for: newCollection)
+    }
+
    // MARK:- Privates

    private func fetchLayout(for traitCollection: UITraitCollection) -> FloatingPanelLayout {
@@ -245,15 +256,16 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI

    private func update(safeAreaInsets: UIEdgeInsets) {
        guard
-            floatingPanel.layoutAdapter.safeAreaInsets != safeAreaInsets,
+            preSafeAreaInsets != safeAreaInsets,
            self.floatingPanel.isDecelerating == false
            else { return }

        log.debug("Update safeAreaInsets", safeAreaInsets)

-        floatingPanel.layoutAdapter.safeAreaInsets = safeAreaInsets
+        // Prevent an infinite loop on iOS 10: setUpLayout() -> viewDidLayoutSubviews() -> setUpLayout()
+        preSafeAreaInsets = safeAreaInsets

-        setUpLayout()
+        activateLayout()

        switch contentInsetAdjustmentBehavior {
        case .always:
@@ -267,9 +279,18 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
    private func reloadLayout(for traitCollection: UITraitCollection) {
        floatingPanel.layoutAdapter.layout = fetchLayout(for: traitCollection)
        floatingPanel.layoutAdapter.prepareLayout(in: self)
+
+        if let parent = self.parent {
+            if let layout = layout as? UIViewController, layout == parent {
+                log.warning("A memory leak will occur by a retain cycle because \(self) owns the parent view controller(\(parent)) as the layout object. Don't let the parent adopt FloatingPanelLayout.")
+            }
+            if let behavior = behavior as? UIViewController, behavior == parent {
+                log.warning("A memory leak will occur by a retain cycle because \(self) owns the parent view controller(\(parent)) as the behavior object. Don't let the parent adopt FloatingPanelBehavior.")
+            }
+        }
    }

-    private func setUpLayout() {
+    private func activateLayout() {
        // preserve the current content offset
        let contentOffset = scrollView?.contentOffset

@@ -285,7 +306,7 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
    public func show(animated: Bool = false, completion: (() -> Void)? = nil) {
        // Must apply the current layout here
        reloadLayout(for: traitCollection)
-        setUpLayout()
+        activateLayout()

        if #available(iOS 11.0, *) {
            // Must track the safeAreaInsets of `self.view` to update the layout.
@@ -294,9 +315,9 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
            // inset's update expectedly.
            // 2. The safe area top inset can be variable on the large title navigation bar(iOS11+).
            // That's why it needs the observation to keep `adjustedContentInsets` correct.
-            safeAreaInsetsObservation = self.observe(\.view.safeAreaInsets) { [weak self] (vc, chaneg) in
-                guard let `self` = self else { return }
-                self.update(safeAreaInsets: vc.layoutInsets)
+            safeAreaInsetsObservation = self.observe(\.view.safeAreaInsets, options: [.initial, .new, .old]) { [weak self] (vc, change) in
+                guard change.oldValue != change.newValue else { return }
+                self?.update(safeAreaInsets: vc.layoutInsets)
            }
        } else {
            // KVOs for topLayoutGuide & bottomLayoutGuide are not effective.
@@ -338,7 +359,11 @@ 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
@@ -351,7 +376,11 @@ 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
        }
    }

@@ -367,9 +396,20 @@ 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?()
        }
    }
@@ -384,39 +424,53 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
        floatingPanel.move(to: to, animated: animated, completion: completion)
    }

-    /// Sets the view controller responsible for the content portion of the floating panel..
+    /// 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)
-            vc.view.removeFromSuperview()
-            vc.removeFromParentViewController()
+            #endif

-            if let scrollView = floatingPanel.scrollView,
-                let delegate = floatingPanel.userScrollViewDelegate,
-                vc.view.subviews.contains(scrollView) {
-                scrollView.delegate = delegate
-            }
+            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
    }

    @available(*, unavailable, renamed: "set(contentViewController:)")
-    public override func show(_ vc: UIViewController, sender: Any?) {
+    open  override func show(_ vc: UIViewController, sender: Any?) {
        if let target = self.parent?.targetViewController(forAction: #selector(UIViewController.show(_:sender:)), sender: sender) {
            target.show(vc, sender: sender)
        }
    }

    @available(*, unavailable, renamed: "set(contentViewController:)")
-    public override func showDetailViewController(_ vc: UIViewController, sender: Any?) {
+    open  override func showDetailViewController(_ vc: UIViewController, sender: Any?) {
        if let target = self.parent?.targetViewController(forAction: #selector(UIViewController.showDetailViewController(_:sender:)), sender: sender) {
            target.showDetailViewController(vc, sender: sender)
        }
@@ -428,33 +482,28 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
    ///
    /// - Parameters:
    ///     - scrollView: Specify a scroll view to continuously and seamlessly work in concert with interactions of the surface view or nil to cancel it.
-    /// - Attention:
-    ///     The specified scroll view must be already assigned to the delegate property because the controller intermediates between the various delegate methods.
    public func track(scrollView: UIScrollView?) {
-        if let trackingScrollView = floatingPanel.scrollView,
-            let delegate = floatingPanel.userScrollViewDelegate {
-            trackingScrollView.delegate = delegate // restore delegate
-            floatingPanel.userScrollViewDelegate = nil
-        }
-
        guard let scrollView = scrollView else {
            floatingPanel.scrollView = nil
            return
        }

        floatingPanel.scrollView = scrollView
-        if scrollView.delegate !== floatingPanel {
-            floatingPanel.userScrollViewDelegate = scrollView.delegate
-            scrollView.delegate = floatingPanel
-        }
+
        switch contentInsetAdjustmentBehavior {
        case .always:
            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
@@ -472,10 +521,10 @@ public class FloatingPanelController: UIViewController, UIScrollViewDelegate, UI
    /// animation block.
    public func updateLayout() {
        reloadLayout(for: traitCollection)
-        setUpLayout()
+        activateLayout()
    }

-    /// Returns the y-coordinate of the point at the origin of the surface view
+    /// Returns the y-coordinate of the point at the origin of the surface view.
    public func originYOfSurface(for pos: FloatingPanelPosition) -> CGFloat {
        switch pos {
        case .full:
@@ -508,10 +557,10 @@ 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 {
@@ -142,7 +142,9 @@ class FloatingPanelLayoutAdapter {
        }
    }

-    var safeAreaInsets: UIEdgeInsets = .zero
+    private var safeAreaInsets: UIEdgeInsets {
+        return vc?.layoutInsets ?? .zero
+    }

    private var initialConst: CGFloat = 0.0

@@ -178,6 +180,14 @@ class FloatingPanelLayoutAdapter {
        return supportedPositions
    }

+    var topMostState: FloatingPanelPosition {
+        return supportedPositions.sorted(by: { $0.rawValue < $1.rawValue }).first ?? .hidden
+    }
+
+    var bottomMostState: FloatingPanelPosition {
+        return supportedPositions.sorted(by: { $0.rawValue < $1.rawValue }).last ?? .hidden
+    }
+
    var topY: CGFloat {
        if supportedPositions.contains(.full) {
            switch layout {
@@ -258,7 +268,11 @@ 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, *) {
@@ -376,12 +390,10 @@ class FloatingPanelLayoutAdapter {
        case is FloatingPanelIntrinsicLayout:
            updateIntrinsicHeight()
            heightConstraint = surfaceView.heightAnchor.constraint(equalToConstant: intrinsicHeight + safeAreaInsets.bottom)
-        case is FloatingPanelFullScreenLayout:
-            heightConstraint =  surfaceView.heightAnchor.constraint(equalTo: vc.view.heightAnchor,
-                                                                    constant: -fullInset)
        default:
-            heightConstraint = surfaceView.heightAnchor.constraint(equalTo: vc.view.heightAnchor,
-                                                                   constant: -(safeAreaInsets.top + fullInset))
+            let const = -(positionY(for: topMostState))
+            heightConstraint =  surfaceView.heightAnchor.constraint(equalTo: vc.view.heightAnchor,
+                                                                    constant: const)
        }

        NSLayoutConstraint.activate([heightConstraint])
@@ -398,25 +410,22 @@ class FloatingPanelLayoutAdapter {
        }
    }

-    func updateInteractiveTopConstraint(diff: CGFloat, allowsTopBuffer: Bool) {
+    func updateInteractiveTopConstraint(diff: CGFloat, allowsTopBuffer: Bool, with behavior: FloatingPanelBehavior) {
        defer {
            surfaceView.superview!.layoutIfNeeded() // MUST call here to update `surfaceView.frame`
        }

-        let minY: CGFloat = {
+        let topMostConst: CGFloat = {
            var ret: CGFloat = 0.0
            switch layout {
-            case is FloatingPanelIntrinsicLayout:
+            case is FloatingPanelIntrinsicLayout, is FloatingPanelFullScreenLayout:
                ret = topY
            default:
-                ret = fullInset
-            }
-            if allowsTopBuffer {
-                ret -= layout.topInteractionBuffer
+                ret = topY - safeAreaInsets.top
            }
            return max(ret, 0.0) // The top boundary is equal to the related topAnchor.
        }()
-        let maxY: CGFloat = {
+        let bottomMostConst: CGFloat = {
            var ret: CGFloat = 0.0
            switch layout {
            case is FloatingPanelIntrinsicLayout, is FloatingPanelFullScreenLayout:
@@ -424,12 +433,34 @@ class FloatingPanelLayoutAdapter {
            default:
                ret = bottomY - safeAreaInsets.top
            }
-            ret += layout.bottomInteractionBuffer
            return min(ret, bottomMaxY)
        }()
-        let const = initialConst + diff
+        let minConst = allowsTopBuffer ? topMostConst - layout.topInteractionBuffer : topMostConst
+        let maxConst = bottomMostConst + layout.bottomInteractionBuffer

-        interactiveTopConstraint?.constant = max(minY, min(maxY, const))
+        var const = initialConst + diff
+
+        // Rubberbanding top buffer
+        if behavior.allowsRubberBanding(for: .top), const < topMostConst {
+            let buffer = topMostConst - const
+            const = topMostConst - rubberbandEffect(for: buffer, base: vc.view.bounds.height)
+        }
+
+        // Rubberbanding bottom buffer
+        if behavior.allowsRubberBanding(for: .bottom), const > bottomMostConst {
+            let buffer = const - bottomMostConst
+            const = bottomMostConst + rubberbandEffect(for: buffer, base: vc.view.bounds.height)
+        }
+
+        interactiveTopConstraint?.constant = max(minConst, min(maxConst, const))
+    }
+
+    // According to @chpwn's tweet: https://twitter.com/chpwn/status/285540192096497664
+    // x = distance from the edge
+    // c = constant value, UIScrollView uses 0.55
+    // d = dimension, either width or height
+    private func rubberbandEffect(for buffer: CGFloat, base: CGFloat) -> CGFloat {
+        return (1.0 - (1.0 / ((buffer * 0.55 / base) + 1.0))) * base
    }

    func activateLayout(of state: FloatingPanelPosition) {
@@ -476,8 +507,8 @@ class FloatingPanelLayoutAdapter {
    private func checkLayoutConsistance() {
        // Verify layout configurations
        assert(supportedPositions.count > 0)
-        assert(supportedPositions.contains(layout.initialPosition),
-               "Does not include an initial potision(\(layout.initialPosition)) in supportedPositions(\(supportedPositions))")
+        assert(supportedPositions.union([.hidden]).contains(layout.initialPosition),
+               "Does not include an initial position (\(layout.initialPosition)) in supportedPositions (\(supportedPositions))")

        if layout is FloatingPanelIntrinsicLayout {
            assert(layout.insetFor(position: .full) == nil, "Return `nil` for full position on FloatingPanelIntrinsicLayout")
@@ -5,8 +5,6 @@

 import UIKit

-class FloatingPanelSurfaceContentView: UIView {}
-
 /// A view that presents a surface interface in a floating panel.
 public class FloatingPanelSurfaceView: UIView {

@@ -14,15 +12,38 @@ public class FloatingPanelSurfaceView: UIView {
    ///
    /// To use a custom grabber handle, hide this and then add the custom one
    /// to the surface view at appropriate coordinates.
-    public var grabberHandle: GrabberHandleView!
+    public let grabberHandle: GrabberHandleView = GrabberHandleView()
+
+    /// Offset of the grabber handle from the top
+    public var grabberTopPadding: CGFloat = 6.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }

    /// The height of the grabber bar area
-    public static var topGrabberBarHeight: CGFloat {
-        return Default.grabberTopPadding * 2 + GrabberHandleView.Default.height // 17.0
+    public var topGrabberBarHeight: CGFloat {
+        return grabberTopPadding * 2 + grabberHandleHeight
    }

+    /// Grabber view width and height
+    public var grabberHandleWidth: CGFloat = 36.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }
+    public var grabberHandleHeight: CGFloat = 5.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }
+
    /// A root view of a content view controller
    public weak var contentView: UIView!
+    
+    /// The content insets specifying the insets around the content view.
+    ///
+    /// - important: Currently the `bottom` inset is ignored.
+    public var contentInsets: UIEdgeInsets = .zero {
+        didSet {
+            // Needs update constraints
+            self.setNeedsUpdateConstraints()
+        }
+    }

    private var color: UIColor? = .white { didSet { setNeedsLayout() } }
    var bottomOverflow: CGFloat = 0.0 // Must not call setNeedsLayout()
@@ -36,7 +57,10 @@ public class FloatingPanelSurfaceView: UIView {
    ///
    /// `self.contentView` is masked with the top rounded corners automatically on iOS 11 and later.
    /// On iOS 10, they are not automatically masked because of a UIVisualEffectView issue. See https://forums.developer.apple.com/thread/50854
-    public var cornerRadius: CGFloat = 0.0 { didSet { setNeedsLayout() } }
+    public var cornerRadius: CGFloat {
+        set { containerView.layer.cornerRadius = newValue; setNeedsLayout() }
+        get { return containerView.layer.cornerRadius }
+    }

    /// A Boolean indicating whether the surface shadow is displayed.
    public var shadowHidden: Bool = false  { didSet { setNeedsLayout() } }
@@ -59,108 +83,154 @@ public class FloatingPanelSurfaceView: UIView {
    /// The color of the surface border.
    public var borderWidth: CGFloat = 0.0  { didSet { setNeedsLayout() } }

-    private var backgroundView: UIView!
-    private var backgroundHeightConstraint: NSLayoutConstraint!
+    /// Offset of the container view from the top
+    public var containerTopInset: CGFloat = 0.0 { didSet {
+        setNeedsUpdateConstraints()
+    } }

-    private struct Default {
-        public static let grabberTopPadding: CGFloat = 6.0
-    }
+    /// The view presents an actual surface shape.
+    ///
+    /// It renders the background color, border line and top rounded corners,
+    /// specified by other properties. The reason why they're not be applied to
+    /// a content view directly is because it avoids any side-effects to the
+    /// content view.
+    public let containerView: UIView = UIView()
+
+    @available(*, unavailable, renamed: "containerView")
+    public var backgroundView: UIView!
+
+    private lazy var containerViewTopInsetConstraint: NSLayoutConstraint = containerView.topAnchor.constraint(equalTo: topAnchor, constant: containerTopInset)
+    private lazy var containerViewHeightConstraint: NSLayoutConstraint = containerView.heightAnchor.constraint(equalTo: heightAnchor, multiplier: 1.0)
+    
+    /// The content view top constraint
+    private var contentViewTopConstraint: NSLayoutConstraint?
+    /// The content view left constraint
+    private var contentViewLeftConstraint: NSLayoutConstraint?
+    /// The content right constraint
+    private var contentViewRightConstraint: NSLayoutConstraint?
+    /// The content height constraint
+    private var contentViewHeightConstraint: NSLayoutConstraint?
+
+    private lazy var grabberHandleWidthConstraint: NSLayoutConstraint = grabberHandle.widthAnchor.constraint(equalToConstant: grabberHandleWidth)
+    private lazy var grabberHandleHeightConstraint: NSLayoutConstraint = grabberHandle.heightAnchor.constraint(equalToConstant: grabberHandleHeight)
+    private lazy var grabberHandleTopConstraint: NSLayoutConstraint = grabberHandle.topAnchor.constraint(equalTo: topAnchor, constant: grabberTopPadding)

    override init(frame: CGRect) {
        super.init(frame: frame)
-        render()
+        addSubViews()
    }

    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
-        render()
+        addSubViews()
    }

-    private func render() {
+    private func addSubViews() {
        super.backgroundColor = .clear
        self.clipsToBounds = false

-        let backgroundView = UIView()
-        addSubview(backgroundView)
-        self.backgroundView = backgroundView
-
-        backgroundView.translatesAutoresizingMaskIntoConstraints = false
-        backgroundHeightConstraint = backgroundView.heightAnchor.constraint(equalTo: heightAnchor, multiplier: 1.0)
+        addSubview(containerView)
+        containerView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
-            backgroundView.topAnchor.constraint(equalTo: topAnchor, constant: 0.0),
-            backgroundView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0),
-            backgroundView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0),
-            backgroundHeightConstraint,
+            containerViewTopInsetConstraint,
+            containerView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0),
+            containerView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0),
+            containerViewHeightConstraint,
            ])

-
-        let grabberHandle = GrabberHandleView()
        addSubview(grabberHandle)
-        self.grabberHandle = grabberHandle
-
        grabberHandle.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
-            grabberHandle.topAnchor.constraint(equalTo: topAnchor, constant: Default.grabberTopPadding),
-            grabberHandle.widthAnchor.constraint(equalToConstant: grabberHandle.frame.width),
-            grabberHandle.heightAnchor.constraint(equalToConstant: grabberHandle.frame.height),
+            grabberHandleWidthConstraint,
+            grabberHandleHeightConstraint,
+            grabberHandleTopConstraint,
            grabberHandle.centerXAnchor.constraint(equalTo: centerXAnchor),
            ])
    }

    public override func updateConstraints() {
+        containerViewTopInsetConstraint.constant = containerTopInset
+        containerViewHeightConstraint.constant = bottomOverflow
+
+        contentViewTopConstraint?.constant = contentInsets.top
+        contentViewLeftConstraint?.constant = contentInsets.left
+        contentViewRightConstraint?.constant = contentInsets.right
+        contentViewHeightConstraint?.constant = -containerTopInset
+
+        grabberHandleTopConstraint.constant = grabberTopPadding
+        grabberHandleWidthConstraint.constant = grabberHandleWidth
+        grabberHandleHeightConstraint.constant = grabberHandleHeight
+
        super.updateConstraints()
-        backgroundHeightConstraint.constant = bottomOverflow
    }

    public override func layoutSubviews() {
        super.layoutSubviews()
        log.debug("surface view frame = \(frame)")

-        updateLayers()
-        updateContentViewMask()
+        containerView.backgroundColor = color

-        contentView?.layer.borderColor = borderColor?.cgColor
-        contentView?.layer.borderWidth = borderWidth
-        contentView?.frame = bounds
+        updateShadow()
+        updateCornerRadius()
+        updateBorder()
    }

-    private func updateLayers() {
-        backgroundView.backgroundColor = color
-        backgroundView.layer.masksToBounds = true
-        backgroundView.layer.cornerRadius = cornerRadius
-
+    private func updateShadow() {
        if shadowHidden == false {
-            layer.shadowColor = shadowColor.cgColor
-            layer.shadowOffset = shadowOffset
-            layer.shadowOpacity = shadowOpacity
-            layer.shadowRadius = shadowRadius
+            if #available(iOS 11, *) {
+                // For clear background. See also, https://github.com/SCENEE/FloatingPanel/pull/51.
+                layer.shadowColor = shadowColor.cgColor
+                layer.shadowOffset = shadowOffset
+                layer.shadowOpacity = shadowOpacity
+                layer.shadowRadius = shadowRadius
+            } else {
+                // Can't update `layer.shadow*` directly because of a UIVisualEffectView issue in iOS 10, https://forums.developer.apple.com/thread/50854
+                // Instead, a user should display shadow appropriately.
+            }
        }
    }

-    private func updateContentViewMask() {
+    private func updateCornerRadius() {
+        guard containerView.layer.cornerRadius != 0.0 else {
+            containerView.layer.masksToBounds = false
+            return
+        }
+        containerView.layer.masksToBounds = true
        if #available(iOS 11, *) {
            // Don't use `contentView.clipToBounds` because it prevents content view from expanding the height of a subview of it
            // for the bottom overflow like Auto Layout settings of UIVisualEffectView in Main.storyboard of Example/Maps.
            // Because the bottom of contentView must be fit to the bottom of a screen to work the `safeLayoutGuide` of a content VC.
-            contentView?.layer.masksToBounds = true
-            contentView?.layer.cornerRadius = cornerRadius
-            contentView?.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
+            containerView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
        } else {
-            // Don't use `contentView.layer.mask` because of a UIVisualEffectView issue in iOS 10, https://forums.developer.apple.com/thread/50854
-            // Instead, a user can mask the content view manually in an application.
+            // Can't use `containerView.layer.mask` because of a UIVisualEffectView issue in iOS 10, https://forums.developer.apple.com/thread/50854
+            // Instead, a user should display rounding corners appropriately.
        }
    }

+    private func updateBorder() {
+        containerView.layer.borderColor = borderColor?.cgColor
+        containerView.layer.borderWidth = borderWidth
+    }
+
    func add(contentView: UIView) {
-        insertSubview(contentView, belowSubview: grabberHandle)
+        containerView.addSubview(contentView)
        self.contentView = contentView
        /* contentView.frame = bounds */ // MUST NOT: Because the top safe area inset of a content VC will be incorrect.
        contentView.translatesAutoresizingMaskIntoConstraints = false
+
+        let topConstraint = contentView.topAnchor.constraint(equalTo: topAnchor, constant: contentInsets.top)
+        let leftConstraint = contentView.leftAnchor.constraint(equalTo: leftAnchor, constant: contentInsets.left)
+        let rightConstraint = rightAnchor.constraint(equalTo: contentView.rightAnchor, constant: contentInsets.right)
+        let heightConstraint = contentView.heightAnchor.constraint(equalTo: heightAnchor, constant: -containerTopInset)
        NSLayoutConstraint.activate([
-            contentView.topAnchor.constraint(equalTo: topAnchor, constant: 0.0),
-            contentView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0),
-            contentView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0),
-            contentView.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 0.0),
+            topConstraint,
+            leftConstraint,
+            rightConstraint,
+            heightConstraint,
            ])
+        self.contentViewTopConstraint = topConstraint
+        self.contentViewLeftConstraint = leftConstraint
+        self.contentViewRightConstraint = rightConstraint
+        self.contentViewHeightConstraint = heightConstraint
    }
 }
@@ -6,32 +6,30 @@
 import UIKit

 public class GrabberHandleView: UIView {
-    public struct Default {
-        public static let width: CGFloat = 36.0
-        public static let height: CGFloat = 5.0
-        public static let barColor = UIColor(displayP3Red: 0.76, green: 0.77, blue: 0.76, alpha: 1.0)
-    }
+
+    public var barColor = UIColor(displayP3Red: 0.76, green: 0.77, blue: 0.76, alpha: 1.0) { didSet { backgroundColor = barColor } }

    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
-        render()
    }

    init() {
-        let size = CGSize(width: Default.width,
-                          height: Default.height)
-        super.init(frame: CGRect(origin: .zero, size: size))
-        self.backgroundColor = Default.barColor
-        render()
+        super.init(frame: .zero)
+        backgroundColor = barColor
    }

-    private func render() {
-        self.layer.masksToBounds = true
-        self.layer.cornerRadius = frame.size.height * 0.5
+    public override func layoutSubviews() {
+        super.layoutSubviews()
+        render()
    }

    public override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        let view = super.hitTest(point, with: event)
        return view == self ? nil : view
    }
+
+    private func render() {
+        self.layer.masksToBounds = true
+        self.layer.cornerRadius = frame.size.height * 0.5
+    }
 }
@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.1.0</string>
+	<string>1.6.2</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 </dict>
@@ -10,39 +10,26 @@ var log = {
    return Logger()
 }()

-#if __FP_LOG
 struct Logger {
    private let osLog: OSLog
    private let s = DispatchSemaphore(value: 1)

-    private enum Level: Int, Comparable {
+    enum Level: Int, Comparable {
        case debug = 0
        case info = 1
        case warning = 2
        case error = 3
-        case fault = 4

-        var name: String {
-            switch self {
-            case .debug: return "DEBUG"
-            case .info: return "INFO"
-            case .warning: return "WARNING"
-            case .error: return "ERROR"
-            case .fault: return "FAULT"
-            }
-        }
-        var shortName: String {
+        var displayName: String {
            switch self {
            case .debug:
                return "D/"
            case .info:
                return "I/"
            case .warning:
-                return "W/"
+                return "Warning:"
            case .error:
-                return "E/"
-            case .fault:
-                return "F/"
+                return "Error:"
            }
        }
        @available(iOS 10.0, *)
@@ -50,9 +37,8 @@ struct Logger {
            switch self {
            case .debug: return .debug
            case .info: return .info
-            case .warning: return .info
+            case .warning: return .default
            case .error: return .error
-            case .fault: return .fault
            }
        }

@@ -61,6 +47,9 @@ struct Logger {
        }
    }

+    typealias Hook = ((String, Level) -> Void)
+    var hook: Hook?
+
    fileprivate init() {
        osLog = OSLog(subsystem: "com.scenee.FloatingPanel", category: "FloatingPanel")
    }
@@ -70,7 +59,16 @@ struct Logger {
        defer { s.signal() }

        let extraMessage: String = arguments.map({ String(describing: $0) }).joined(separator: " ")
-        let log = "\(level.shortName) \(message) \(extraMessage) (\(function):\(line))"
+        let log: String = {
+            switch level {
+            case .debug:
+                return "\(level.displayName) \(message) \(extraMessage) (\(function):\(line))"
+            default:
+                return "\(level.displayName) \(message) \(extraMessage)"
+            }
+        }()
+
+        hook?(log, level)

        os_log("%@", log: osLog, type: level.osLogType, log)
    }
@@ -84,7 +82,9 @@ struct Logger {
    }

    func debug(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
+        #if __FP_LOG
        self.log(.debug, log, arguments, function: getPrettyFunction(function, file), line: line)
+        #endif
    }

    func info(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
@@ -98,17 +98,4 @@ struct Logger {
    func error(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
        self.log(.error, log, arguments, function: getPrettyFunction(function, file), line: line)
    }
-
-    func fault(_ log: Any, _ arguments: Any..., function: String = #function, file: String  = #file, line: UInt = #line) {
-        self.log(.fault, log, arguments, function: getPrettyFunction(function, file), line: line)
-    }
 }
-#else
-struct Logger {
-    func debug(_ log: Any, _ arguments: Any...) { }
-    func info(_ log: Any, _ arguments: Any...) { }
-    func warning(_ log: Any, _ arguments: Any...) { }
-    func error(_ log: Any, _ arguments: Any...) { }
-    func fault(_ log: Any, _ arguments: Any...) { }
-}
-#endif
@@ -73,7 +73,21 @@ 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 {
@@ -86,11 +100,16 @@ extension UIGestureRecognizerState: CustomDebugStringConvertible {
        }
    }
 }
+#endif
+#endif

 extension UIScrollView {
    var contentOffsetZero: CGPoint {
        return CGPoint(x: 0.0, y: 0.0 - contentInset.top)
    }
+    var isLocked: Bool {
+        return !showsVerticalScrollIndicator && !bounces &&  isDirectionalLockEnabled
+    }
 }

 extension UISpringTimingParameters {
@@ -108,3 +127,12 @@ extension CGPoint {
                       y: CGFloat.nan)
    }
 }
+
+extension UITraitCollection {
+    func shouldUpdateLayout(from previous: UITraitCollection) -> Bool {
+        return previous.horizontalSizeClass != horizontalSizeClass
+            || previous.verticalSizeClass != verticalSizeClass
+            || previous.preferredContentSizeCategory != preferredContentSizeCategory
+            || previous.layoutDirection != layoutDirection
+    }
+}
@@ -0,0 +1,22 @@
+//
+//  Created by Shin Yamamoto on 2018/11/01.
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import UIKit
+@UIApplicationMain
+class AppDelegate: UIResponder, UIApplicationDelegate {
+    var window: UIWindow?
+
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
+        let rootVC = UIViewController(nibName: nil, bundle: nil)
+        rootVC.view.backgroundColor = .gray
+
+        let window = UIWindow()
+        window.rootViewController = rootVC
+        window.makeKeyAndVisible()
+        self.window = window
+
+        return true
+    }
+}
@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>
@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="13142" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12042"/>
+        <capability name="Constraints with non-1.0 multipliers" minToolsVersion="5.1"/>
+        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Copyright © 2019 scenee. All rights reserved." textAlignment="center" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" minimumFontSize="9" translatesAutoresizingMaskIntoConstraints="NO" id="obG-Y5-kRd">
+                                <rect key="frame" x="0.0" y="626.5" width="375" height="20.5"/>
+                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                            <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="TestingApp" textAlignment="center" lineBreakMode="middleTruncation" baselineAdjustment="alignBaselines" minimumFontSize="18" translatesAutoresizingMaskIntoConstraints="NO" id="GJd-Yh-RWb">
+                                <rect key="frame" x="0.0" y="202" width="375" height="43"/>
+                                <fontDescription key="fontDescription" type="boldSystem" pointSize="36"/>
+                                <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                        </subviews>
+                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                        <constraints>
+                            <constraint firstItem="Bcu-3y-fUS" firstAttribute="centerX" secondItem="obG-Y5-kRd" secondAttribute="centerX" id="5cz-MP-9tL"/>
+                            <constraint firstItem="Bcu-3y-fUS" firstAttribute="centerX" secondItem="GJd-Yh-RWb" secondAttribute="centerX" id="Q3B-4B-g5h"/>
+                            <constraint firstItem="obG-Y5-kRd" firstAttribute="leading" secondItem="Bcu-3y-fUS" secondAttribute="leading" constant="20" symbolic="YES" id="SfN-ll-jLj"/>
+                            <constraint firstAttribute="bottom" secondItem="obG-Y5-kRd" secondAttribute="bottom" constant="20" id="Y44-ml-fuU"/>
+                            <constraint firstItem="GJd-Yh-RWb" firstAttribute="centerY" secondItem="Ze5-6b-2t3" secondAttribute="bottom" multiplier="1/3" constant="1" id="moa-c2-u7t"/>
+                            <constraint firstItem="GJd-Yh-RWb" firstAttribute="leading" secondItem="Bcu-3y-fUS" secondAttribute="leading" constant="20" symbolic="YES" id="x7j-FC-K8j"/>
+                        </constraints>
+                        <viewLayoutGuide key="safeArea" id="Bcu-3y-fUS"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+</document>
@@ -0,0 +1,82 @@
+//
+//  Created by Shin Yamamoto on 2018/09/18.
+//  Copyright © 2018 Shin Yamamoto. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelControllerTests: XCTestCase {
+
+    override func setUp() {}
+
+    override func tearDown() {}
+
+    func test_warningRetainCycle() {
+        let myVC = MyZombieViewController(nibName: nil, bundle: nil)
+        let exp = expectation(description: "Warning retain cycle")
+        exp.expectedFulfillmentCount = 2 // For layout & behavior logs
+        log.hook = {(log, level) in
+            if log.contains("A memory leak will occur by a retain cycle because") {
+                XCTAssert(level == .warning)
+                exp.fulfill()
+            }
+        }
+        myVC.loadViewIfNeeded()
+        wait(for: [exp], timeout: 10)
+    }
+
+    func test_addPanel() {
+        guard let rootVC = UIApplication.shared.keyWindow?.rootViewController else { fatalError() }
+        let fpc = FloatingPanelController()
+        fpc.addPanel(toParent: rootVC)
+        XCTAssert(fpc.surfaceView.frame.minY ==  (fpc.view.bounds.height - fpc.layoutInsets.bottom) - fpc.layout.insetFor(position: .half)!)
+        fpc.move(to: .tip, animated: false)
+        XCTAssert(fpc.surfaceView.frame.minY == (fpc.view.bounds.height - fpc.layoutInsets.bottom) - fpc.layout.insetFor(position: .tip)!)
+    }
+
+    @available(iOS 12.0, *)
+    func test_updateLayout_willTransition() {
+        class MyDelegate: FloatingPanelControllerDelegate {
+            func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+                if newCollection.userInterfaceStyle == .dark {
+                    XCTFail()
+                }
+                return nil
+            }
+        }
+        let myDelegate = MyDelegate()
+        let fpc = FloatingPanelController(delegate: myDelegate)
+        let traitCollection = UITraitCollection(traitsFrom: [fpc.traitCollection,
+                                                             UITraitCollection(userInterfaceStyle: .dark)])
+        XCTAssertEqual(traitCollection.userInterfaceStyle, .dark)
+        fpc.prepare(for: traitCollection)
+    }
+}
+
+private class MyZombieViewController: UIViewController, FloatingPanelLayout, FloatingPanelBehavior, FloatingPanelControllerDelegate {
+    var fpc: FloatingPanelController?
+    override func viewDidLoad() {
+        fpc = FloatingPanelController(delegate: self)
+        fpc?.addPanel(toParent: self)
+    }
+    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+        return self
+    }
+
+    func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior? {
+        return self
+    }
+    var initialPosition: FloatingPanelPosition {
+        return .half
+    }
+
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        switch position {
+        case .full: return UIScreen.main.bounds.height == 667.0 ? 18.0 : 16.0
+        case .half: return 262.0
+        case .tip: return 69.0
+        case .hidden: return nil
+        }
+    }
+}
@@ -0,0 +1,41 @@
+//
+//  Created by Shin Yamamoto on 2019/06/27.
+//  Copyright © 2019 scenee. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelLayoutTests: XCTestCase {
+    override func setUp() {}
+    override func tearDown() {}
+
+    func test_layoutAdapter_topAndBottomMostState() {
+        let fpc = FloatingPanelController(delegate: nil)
+        fpc.loadViewIfNeeded()
+        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .full)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .tip)
+
+        class FloatingPanelLayoutWithHidden: FloatingPanelLayout {
+            func insetFor(position: FloatingPanelPosition) -> CGFloat? { return nil }
+            let initialPosition: FloatingPanelPosition = .hidden
+            let supportedPositions: Set<FloatingPanelPosition> = [.hidden, .half, .full]
+        }
+        class FloatingPanelLayout2Positions: FloatingPanelLayout {
+            func insetFor(position: FloatingPanelPosition) -> CGFloat? { return nil }
+            let initialPosition: FloatingPanelPosition = .tip
+            let supportedPositions: Set<FloatingPanelPosition> = [.tip, .half]
+        }
+        let delegate = FloatingPanelTestDelegate()
+        delegate.layout = FloatingPanelLayoutWithHidden()
+        fpc.delegate = delegate
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .full)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .half) // Will fixed on fix-hidden-position branch
+
+        delegate.layout = FloatingPanelLayout2Positions()
+        fpc.delegate = delegate
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.topMostState, .half)
+        XCTAssertEqual(fpc.floatingPanel.layoutAdapter.bottomMostState, .tip)
+    }
+}
@@ -0,0 +1,86 @@
+//
+//  Created by Shin Yamamoto on 2019/05/23.
+//  Copyright © 2019 Shin Yamamoto. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelSurfaceViewTests: XCTestCase {
+    override func setUp() {}
+
+    override func tearDown() {}
+
+    func test_surfaceView() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssert(surface.contentView == nil)
+        surface.layoutIfNeeded()
+        XCTAssert(surface.grabberHandle.frame.minY == 6.0)
+        XCTAssert(surface.grabberHandle.frame.width == surface.grabberHandleWidth)
+        XCTAssert(surface.grabberHandle.frame.height == surface.grabberHandleHeight)
+        surface.backgroundColor = .red
+        surface.layoutIfNeeded()
+        XCTAssert(surface.backgroundColor == surface.containerView.backgroundColor)
+    }
+
+    func test_surfaceView_constraintsUpdate() {
+        let window = UIWindow()
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        window.addSubview(surface)
+        window.makeKeyAndVisible()
+        XCTAssert(surface.contentView == nil)
+        surface.layoutIfNeeded()
+        XCTAssert(surface.grabberHandle.frame.minY == 6.0)
+        XCTAssert(surface.grabberHandle.frame.width == surface.grabberHandleWidth)
+        XCTAssert(surface.grabberHandle.frame.height == surface.grabberHandleHeight)
+
+        surface.grabberHandleWidth = 44.0
+        surface.grabberHandleHeight = 12.0
+        surface.layoutIfNeeded()
+        waitRunLoop(secs: 0.000_001)
+        XCTAssert(surface.grabberHandle.frame.width == surface.grabberHandleWidth, "\(surface.grabberHandle.frame.width) == \(surface.grabberHandleWidth)")
+        XCTAssert(surface.grabberHandle.frame.height == surface.grabberHandleHeight, "\(surface.grabberHandle.frame.height) == \(surface.grabberHandleHeight)")
+        window.resignKey()
+    }
+
+    func test_surfaceView_cornderRaduis() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssert(surface.cornerRadius == 0.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == false)
+
+        surface.cornerRadius = 10.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 10.0)
+        XCTAssert(surface.containerView.layer.cornerRadius == 10.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == true)
+
+        surface.containerView.layer.cornerRadius = 12.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 12.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == true)
+
+        surface.cornerRadius = 0.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 0.0)
+        XCTAssert(surface.containerView.layer.cornerRadius == 0.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == false)
+
+        surface.containerView.layer.cornerRadius = 12.0
+        surface.setNeedsLayout()
+        surface.layoutIfNeeded()
+        XCTAssert(surface.cornerRadius == 12.0)
+        XCTAssert(surface.containerView.layer.masksToBounds == true)
+    }
+
+    func test_surfaceView_border() {
+        let surface = FloatingPanelSurfaceView(frame: CGRect(x: 0.0, y: 0.0, width: 320.0, height: 480.0))
+        XCTAssert(surface.borderColor == nil)
+        XCTAssert(surface.borderWidth == 0.0)
+
+        surface.borderColor = .red
+        surface.borderWidth = 3.0
+        surface.layoutIfNeeded()
+        XCTAssert(surface.containerView.layer.borderColor == UIColor.red.cgColor)
+        XCTAssert(surface.containerView.layer.borderWidth == 3.0)
+    }
+}
@@ -0,0 +1,78 @@
+//
+//  Created by Shin Yamamoto on 2019/05/23.
+//  Copyright © 2019 Shin Yamamoto. All rights reserved.
+//
+
+import XCTest
+@testable import FloatingPanel
+
+class FloatingPanelTests: XCTestCase {
+
+    override func setUp() {}
+
+    override func tearDown() {}
+
+    func test_scrolllock() {
+        let fpc = FloatingPanelController()
+        fpc.loadViewIfNeeded()
+        fpc.view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
+        let contentVC1 = UITableViewController(nibName: nil, bundle: nil)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, true)
+        XCTAssertEqual(contentVC1.tableView.bounces, true)
+
+        fpc.set(contentViewController: contentVC1)
+        fpc.track(scrollView: contentVC1.tableView)
+        fpc.show(animated: false, completion: nil) // half
+        XCTAssertEqual(fpc.position, .half)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
+        XCTAssertEqual(contentVC1.tableView.bounces, false)
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, true)
+        XCTAssertEqual(contentVC1.tableView.bounces, true)
+
+        fpc.move(to: .tip, animated: false)
+        XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
+        XCTAssertEqual(contentVC1.tableView.bounces, false)
+
+        let exp1 = expectation(description: "move to full with animation")
+        fpc.move(to: .full, animated: true) {
+            XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, true)
+            XCTAssertEqual(contentVC1.tableView.bounces, true)
+            exp1.fulfill()
+        }
+        wait(for: [exp1], timeout: 1.0)
+
+        let exp2 = expectation(description: "move to tip with animation")
+        fpc.move(to: .tip, animated: false) {
+            XCTAssertEqual(contentVC1.tableView.showsVerticalScrollIndicator, false)
+            XCTAssertEqual(contentVC1.tableView.bounces, false)
+            exp2.fulfill()
+        }
+        wait(for: [exp2], timeout: 1.0)
+
+        // Reset the content vc
+        let contentVC2 = UITableViewController(nibName: nil, bundle: nil)
+        XCTAssertEqual(contentVC2.tableView.showsVerticalScrollIndicator, true)
+        XCTAssertEqual(contentVC2.tableView.bounces, true)
+        fpc.set(contentViewController: contentVC2)
+        fpc.track(scrollView: contentVC2.tableView)
+        fpc.show(animated: false, completion: nil)
+        XCTAssertEqual(fpc.position, .half)
+        XCTAssertEqual(contentVC2.tableView.showsVerticalScrollIndicator, false)
+        XCTAssertEqual(contentVC2.tableView.bounces, false)
+    }
+
+}
+
+private protocol FloatingPanelTestLayout: FloatingPanelLayout {}
+private extension FloatingPanelTestLayout {
+    func insetFor(position: FloatingPanelPosition) -> CGFloat? {
+        switch position {
+        case .full: return 18.0
+        case .half: return 262.0
+        case .tip: return 69.0
+        default: return nil
+        }
+    }
+}
@@ -0,0 +1,18 @@
+//
+//  Created by Shin Yamamoto on 2019/06/27.
+//  Copyright © 2019 scenee. All rights reserved.
+//
+
+import Foundation
+@testable import FloatingPanel
+
+func waitRunLoop(secs: TimeInterval = 0) {
+    RunLoop.main.run(until: Date(timeIntervalSinceNow: secs))
+}
+
+class FloatingPanelTestDelegate: FloatingPanelControllerDelegate {
+    var layout: FloatingPanelLayout?
+    func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
+        return layout
+    }
+}
@@ -1,14 +0,0 @@
-//
-//  Created by Shin Yamamoto on 2018/09/18.
-//  Copyright © 2018 Shin Yamamoto. All rights reserved.
-//
-
-import XCTest
-@testable import FloatingPanelController
-
-class ViewTests: XCTestCase {
-
-    override func setUp() {}
-
-    override func tearDown() {}
-}
@@ -0,0 +1,27 @@
+// swift-tools-version:5.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "FloatingPanel",
+    platforms: [
+        .iOS(.v10)
+    ],
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "FloatingPanel",
+            targets: ["FloatingPanel"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(name: "FloatingPanel", path: "Framework/Sources"),
+    ],
+    swiftLanguageVersions: [.version("5")]
+)
@@ -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

@@ -67,7 +68,9 @@ Examples are here.

 ## Requirements

-FloatingPanel is written in Swift. It can be built by Xcode 9.4.1 or later. Compatible with iOS 10.0+.
+FloatingPanel is written in Swift 4.0+. It can be built by Xcode 9.4.1 or later. Compatible with iOS 10.0+.
+
+✏️ The default Swift version is 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.

 ## Installation

@@ -80,6 +83,8 @@ it, simply add the following line to your Podfile:
 pod 'FloatingPanel'
 ```

+✏️ To suppress "Swift Conversion" warnings in Xcode, please set a Swift version to `SWIFT_VERSION` for the project in your Podfile. It will be resolved in CocoaPods v1.7.0.
+
 ### Carthage

 For [Carthage](https://github.com/Carthage/Carthage), add the following to your `Cartfile`:
@@ -141,7 +146,7 @@ self.present(fpc, animated: true, completion: nil)

 You can show a floating panel over UINavigationController from the container view controllers as a modality of `.overCurrentContext` style.

-NOTE: FloatingPanelController has the custom presentation controller. If you would like to customize the presentation/dismissal, please see [FloatingPanelTransitioning](https://github.com/SCENEE/FloatingPanel/blob/master/Framework/Sources/FloatingPanelTransitioning.swift).
+✏️ FloatingPanelController has the custom presentation controller. If you would like to customize the presentation/dismissal, please see [FloatingPanelTransitioning](https://github.com/SCENEE/FloatingPanel/blob/master/Framework/Sources/FloatingPanelTransitioning.swift).

 ## View hierarchy

@@ -151,8 +156,9 @@ NOTE: FloatingPanelController has the custom presentation controller. If you wou
 FloatingPanelController.view (FloatingPanelPassThroughView)
 ├─ .backdropView (FloatingPanelBackdropView)
 └─ .surfaceView (FloatingPanelSurfaceView)
-          ├─ .contentView  == FloatingPanelController.contentViewController.view
-          └─ .grabberHandle (GrabberHandleView)
+    ├─ .containerView (UIView)
+    │  └─ .contentView (FloatingPanelController.contentViewController.view)
+    └─ .grabberHandle (GrabberHandleView)
 ```

 ## Usage