Add support for scroll views inside of navigation controllers

SheetImagePicker.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		D6055E46234D1B31007BEF52 /* ContentTableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6055E45234D1B31007BEF52 /* ContentTableViewController.swift */; };
 		D610D2D6233945AF009EB06A /* SheetImagePicker.h in Headers */ = {isa = PBXBuildFile; fileRef = D610D2D4233945AF009EB06A /* SheetImagePicker.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		D610D2E3233945B9009EB06A /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = D610D2E2233945B9009EB06A /* AppDelegate.swift */; };
 		D610D2E5233945B9009EB06A /* SceneDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = D610D2E4233945B9009EB06A /* SceneDelegate.swift */; };
@@ -48,6 +49,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		D6055E45234D1B31007BEF52 /* ContentTableViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentTableViewController.swift; sourceTree = "<group>"; };
 		D610D2D1233945AF009EB06A /* SheetImagePicker.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = SheetImagePicker.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		D610D2D4233945AF009EB06A /* SheetImagePicker.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = SheetImagePicker.h; sourceTree = "<group>"; };
 		D610D2D5233945AF009EB06A /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
@@ -124,6 +126,7 @@
 				D610D2E2233945B9009EB06A /* AppDelegate.swift */,
 				D610D2E4233945B9009EB06A /* SceneDelegate.swift */,
 				D610D2E6233945B9009EB06A /* ViewController.swift */,
+				D6055E45234D1B31007BEF52 /* ContentTableViewController.swift */,
 				D610D2E8233945B9009EB06A /* Main.storyboard */,
 				D610D2EB233945BB009EB06A /* Assets.xcassets */,
 				D610D2ED233945BB009EB06A /* LaunchScreen.storyboard */,
@@ -267,6 +270,7 @@
 			files = (
 				D610D2E7233945B9009EB06A /* ViewController.swift in Sources */,
 				D610D2E3233945B9009EB06A /* AppDelegate.swift in Sources */,
+				D6055E46234D1B31007BEF52 /* ContentTableViewController.swift in Sources */,
 				D610D2E5233945B9009EB06A /* SceneDelegate.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -478,13 +482,13 @@
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_STYLE = Automatic;
-				DEVELOPMENT_TEAM = HGYVAQA9FW;
+				DEVELOPMENT_TEAM = 46G5674823;
 				INFOPLIST_FILE = SheetImagePickerTest/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = net.shadowfacts.SheetImagePickerTest;
+				PRODUCT_BUNDLE_IDENTIFIER = net.shadowfacts.dev.SheetImagePickerTest;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
@@ -497,13 +501,13 @@
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_STYLE = Automatic;
-				DEVELOPMENT_TEAM = HGYVAQA9FW;
+				DEVELOPMENT_TEAM = 46G5674823;
 				INFOPLIST_FILE = SheetImagePickerTest/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = net.shadowfacts.SheetImagePickerTest;
+				PRODUCT_BUNDLE_IDENTIFIER = net.shadowfacts.dev.SheetImagePickerTest;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";

SheetImagePicker/SheetContainerViewController.swift

@@ -11,6 +11,8 @@ import UIKit
 public protocol SheetContainerViewControllerDelegate {
     func sheetContainer(_ sheetContainer: SheetContainerViewController, willSnapToDetent detent: Detent) -> Bool
     func sheetContainer(_ sheetContainer: SheetContainerViewController, didSnapToDetent detent: Detent)
+    func sheetContainerContentScrollView(_ sheetContainer: SheetContainerViewController) -> UIScrollView?
+    func sheetContainer(_ sheetContainer: SheetContainerViewController, topContentOffsetForScrollView scrollView: UIScrollView) -> CGFloat
 }
 
 // default no-op implementation
@@ -19,13 +21,19 @@ public extension SheetContainerViewControllerDelegate {
         return true
     }
     func sheetContainer(_ sheetContainer: SheetContainerViewController, didSnapToDetent detent: Detent) {}
+    func sheetContainerContentScrollView(_ sheetContainer: SheetContainerViewController) -> UIScrollView? {
+        return nil
+    }
+    func sheetContainer(_ sheetContainer: SheetContainerViewController, topContentOffsetForScrollView scrollView: UIScrollView) -> CGFloat {
+        return 0
+    }
 }
 
 public class SheetContainerViewController: UIViewController {
 
     public var delegate: SheetContainerViewControllerDelegate?
     
-    let content: UIViewController
+    public let content: UIViewController
     
     public var detents: [Detent] = [.bottom, .middle, .top]
     var topDetent: (detent: Detent, offset: CGFloat) {
@@ -45,6 +53,10 @@ public class SheetContainerViewController: UIViewController {
     public var minimumDimmingAlpha: CGFloat = 0
     public var maximumDimmingAlpha: CGFloat = 0.75
     
+    var contentScrollView: UIScrollView? {
+        delegate?.sheetContainerContentScrollView(self) ?? content.view as? UIScrollView
+    }
+
     public init(content: UIViewController) {
         self.content = content
         
@@ -85,7 +97,12 @@ public class SheetContainerViewController: UIViewController {
         ])
         
         let panGesture = UIPanGestureRecognizer(target: self, action: #selector(panGestureRecognized(_:)))
+        panGesture.delegate = self
         content.view.addGestureRecognizer(panGesture)
+        
+        if let scrollView = contentScrollView {
+            scrollView.panGestureRecognizer.addTarget(self, action: #selector(scrollViewPanGestureRecognized))
+        }
     }
 
     @objc func panGestureRecognized(_ recognizer: UIPanGestureRecognizer) {
@@ -95,44 +112,88 @@ public class SheetContainerViewController: UIViewController {
             
         case .changed:
             let translation = recognizer.translation(in: content.view)
-            var realOffset = initialConstant + translation.y
+            let realOffset = initialConstant + translation.y
-            let topOffset = topDetent.offset
+            setTopOffset(realOffset)
-            if realOffset < topOffset {
-                let smoothed = smoothstep(value: realOffset, from: topOffset, to: 0)
-                realOffset = topOffset - smoothed * maximumStretchDistance
-                
-            }
-            topConstraint.constant = realOffset
-            dimmingView.alpha = lerp(realOffset, min: topOffset, max: bottomDetent.offset, from: maximumDimmingAlpha, to: minimumDimmingAlpha)
 
         case .ended:
             let velocity = recognizer.velocity(in: view)
+            springToNearestDetent(verticalVelocity: velocity.y)
 
-            let springToDetent: (Detent, CGFloat)
-            if abs(velocity.y) > minimumDetentJumpVelocity,
-                let detentInVelocityDirection = nearestDetentOffset(currentOffset: topConstraint.constant, direction: velocity.y) {
-                springToDetent = detentInVelocityDirection
-            } else if let nearestDetent = nearestDetentOffset(currentOffset: topConstraint.constant) {
-                springToDetent = nearestDetent
-            } else {
-                return
-            }
-            
-            if delegate?.sheetContainer(self, willSnapToDetent: springToDetent.0) ?? true {
-                let springDistance = abs(topConstraint.constant - springToDetent.1)
-                self.topConstraint.constant = springToDetent.1
-                let springVelocity = velocity.y / springDistance
-                
-                UIView.animate(withDuration: 0.35, delay: 0, usingSpringWithDamping: 0.75, initialSpringVelocity: springVelocity, animations: {
-                    self.view.layoutIfNeeded()
-                    self.dimmingView.alpha = lerp(springToDetent.1, min: self.topDetent.offset, max: self.bottomDetent.offset, from: self.maximumDimmingAlpha, to: self.minimumDimmingAlpha)
-                }, completion: { (finished) in
-                    self.delegate?.sheetContainer(self, didSnapToDetent: springToDetent.0)
-                })
-            }
         default:
+            break
+        }
+    }
+    
+    @objc func scrollViewPanGestureRecognized(_ recognizer: UIPanGestureRecognizer) {
+        guard let scrollView = recognizer.view as? UIScrollView else { return }
+
+        let velocity = recognizer.velocity(in: scrollView)
+
+        let topContentOffset: CGFloat = delegate?.sheetContainer(self, topContentOffsetForScrollView: scrollView) ?? 0
+        let shouldMoveSheetDown = scrollView.contentOffset.y <= topContentOffset && velocity.y > 0 // scrolled to top and dragging down
+        let shouldMoveSheetUp = topConstraint.constant > topDetent.offset && velocity.y < 0 // not fully expanded and dragging up
+
+        let shouldMoveSheet = shouldMoveSheetDown || shouldMoveSheetUp
+        if shouldMoveSheet {
+            scrollView.bounces = false
+            scrollView.setContentOffset(CGPoint(x: 0, y: topContentOffset), animated: false)
+        }
+
+        switch recognizer.state {
+        case .changed:
+            if shouldMoveSheet {
+                let translation = recognizer.translation(in: scrollView)
+                setTopOffset(topConstraint.constant + translation.y)
+                recognizer.setTranslation(.zero, in: scrollView)
+            }
+
+        case .ended:
+            scrollView.bounces = true
+            if shouldMoveSheet {
+                springToNearestDetent(verticalVelocity: velocity.y)
+            }
+
+        default:
+            break
+        }
+    }
+    
+    func setTopOffset(_ offset: CGFloat) {
+        var offset = offset
+        
+        let topOffset = topDetent.offset
+        if offset < topOffset {
+            let smoothed = smoothstep(value: offset, from: topOffset, to: 0)
+            offset = topOffset - smoothed * maximumStretchDistance
+            
+        }
+        topConstraint.constant = offset
+        dimmingView.alpha = lerp(offset, min: topOffset, max: bottomDetent.offset, from: maximumDimmingAlpha, to: minimumDimmingAlpha)
+    }
+    
+    func springToNearestDetent(verticalVelocity velocity: CGFloat) {
+        let springToDetent: (Detent, CGFloat)
+        if abs(velocity) > minimumDetentJumpVelocity,
+            let detentInVelocityDirection = nearestDetentOffset(currentOffset: topConstraint.constant, direction: velocity) {
+            springToDetent = detentInVelocityDirection
+        } else if let nearestDetent = nearestDetentOffset(currentOffset: topConstraint.constant) {
+            springToDetent = nearestDetent
+        } else {
             return
         }
+        
+        if delegate?.sheetContainer(self, willSnapToDetent: springToDetent.0) ?? true {
+            let springDistance = abs(topConstraint.constant - springToDetent.1)
+            self.topConstraint.constant = springToDetent.1
+            let springVelocity = velocity / springDistance
+            
+            UIView.animate(withDuration: 0.35, delay: 0, usingSpringWithDamping: 0.75, initialSpringVelocity: springVelocity, animations: {
+                self.view.layoutIfNeeded()
+                self.dimmingView.alpha = lerp(springToDetent.1, min: self.topDetent.offset, max: self.bottomDetent.offset, from: self.maximumDimmingAlpha, to: self.minimumDimmingAlpha)
+            }, completion: { (finished) in
+                self.delegate?.sheetContainer(self, didSnapToDetent: springToDetent.0)
+            })
+        }
     }
     
     func nearestDetentOffset(currentOffset: CGFloat) -> (Detent, CGFloat)? {
@@ -154,6 +215,15 @@ public class SheetContainerViewController: UIViewController {
     
 }
 
+extension SheetContainerViewController: UIGestureRecognizerDelegate {
+    public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
+        if topConstraint.constant <= topDetent.offset {
+            return (gestureRecognizer as! UIPanGestureRecognizer).translation(in: gestureRecognizer.view!).y > 0
+        }
+        return true
+    }
+}
+
 extension SheetContainerViewController: UIViewControllerTransitioningDelegate {
     public func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
         return SheetContainerPresentationAnimationController()

SheetImagePickerTest/Base.lproj/Main.storyboard

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="15400" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="BYZ-38-t0r">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="15702" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="BYZ-38-t0r">
     <device id="retina6_1" orientation="portrait" appearance="light"/>
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="15404"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="15704"/>
         <capability name="Safe area layout guides" minToolsVersion="9.0"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
@@ -15,18 +15,44 @@
                         <rect key="frame" x="0.0" y="0.0" width="414" height="896"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="tfd-T0-fMO">
+                            <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" translatesAutoresizingMaskIntoConstraints="NO" id="hIF-hV-InX">
-                                <rect key="frame" x="184" y="433" width="46" height="30"/>
+                                <rect key="frame" x="173" y="388" width="68" height="120"/>
-                                <state key="normal" title="Button"/>
+                                <subviews>
-                                <connections>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="tfd-T0-fMO">
-                                    <action selector="buttonPressed:" destination="BYZ-38-t0r" eventType="touchUpInside" id="tmi-VL-j61"/>
+                                        <rect key="frame" x="0.0" y="0.0" width="68" height="30"/>
-                                </connections>
+                                        <state key="normal" title="Plain"/>
-                            </button>
+                                        <connections>
+                                            <action selector="plainPressed:" destination="BYZ-38-t0r" eventType="touchUpInside" id="tmi-VL-j61"/>
+                                        </connections>
+                                    </button>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="fT8-yG-J2R">
+                                        <rect key="frame" x="0.0" y="30" width="68" height="30"/>
+                                        <state key="normal" title="Table"/>
+                                        <connections>
+                                            <action selector="tablePressed:" destination="BYZ-38-t0r" eventType="touchUpInside" id="PZl-oC-0t4"/>
+                                        </connections>
+                                    </button>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="39x-b2-4Hx">
+                                        <rect key="frame" x="0.0" y="60" width="68" height="30"/>
+                                        <state key="normal" title="Nav"/>
+                                        <connections>
+                                            <action selector="navPressed:" destination="BYZ-38-t0r" eventType="touchUpInside" id="Jc9-R9-VZW"/>
+                                        </connections>
+                                    </button>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="eUF-7N-Qgr">
+                                        <rect key="frame" x="0.0" y="90" width="68" height="30"/>
+                                        <state key="normal" title="Nav Table"/>
+                                        <connections>
+                                            <action selector="navTablePressed:" destination="BYZ-38-t0r" eventType="touchUpInside" id="fSY-4h-jE3"/>
+                                        </connections>
+                                    </button>
+                                </subviews>
+                            </stackView>
                         </subviews>
                         <color key="backgroundColor" systemColor="systemBackgroundColor" cocoaTouchSystemColor="whiteColor"/>
                         <constraints>
-                            <constraint firstItem="tfd-T0-fMO" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="Cpn-cM-hYr"/>
+                            <constraint firstItem="hIF-hV-InX" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="MT3-wG-T9R"/>
-                            <constraint firstItem="tfd-T0-fMO" firstAttribute="centerY" secondItem="8bC-Xf-vdC" secondAttribute="centerY" id="YJH-oX-yBz"/>
+                            <constraint firstItem="hIF-hV-InX" firstAttribute="centerY" secondItem="8bC-Xf-vdC" secondAttribute="centerY" id="Unx-Jo-GQK"/>
                         </constraints>
                         <viewLayoutGuide key="safeArea" id="6Tk-OE-BBY"/>
                     </view>

SheetImagePickerTest/ContentTableViewController.swift

@@ -0,0 +1,60 @@
+//
+//  ContentTableViewController.swift
+//  SheetImagePickerTest
+//
+//  Created by Shadowfacts on 10/8/19.
+//  Copyright © 2019 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+
+class ContentTableViewController: UITableViewController {
+    init() {
+        super.init(style: .plain)
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError()
+    }
+    
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        
+        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "testCell")
+    }
+
+    // MARK: - Table view data source
+
+    override func numberOfSections(in tableView: UITableView) -> Int {
+        return 1
+    }
+
+    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        return 40
+    }
+    
+    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: "testCell", for: indexPath)
+        
+        cell.textLabel!.text = "\(indexPath.row)"
+        
+        return cell
+    }
+    
+    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        guard let navController = navigationController else { return }
+        
+        let vc = UIViewController()
+        vc.view.backgroundColor = .systemBackground
+        let label = UILabel()
+        label.translatesAutoresizingMaskIntoConstraints = false
+        label.text = "\(indexPath.row)"
+        vc.view.addSubview(label)
+        NSLayoutConstraint.activate([
+            label.centerXAnchor.constraint(equalTo: vc.view.centerXAnchor),
+            label.centerYAnchor.constraint(equalTo: vc.view.centerYAnchor)
+        ])
+
+        navController.pushViewController(vc, animated: true)
+    }
+}

SheetImagePickerTest/ViewController.swift

@@ -17,12 +17,9 @@ class ViewController: UIViewController {
         view.backgroundColor = .green
     }
 
-    @IBAction func buttonPressed(_ sender: Any) {
+    @IBAction func plainPressed(_ sender: Any) {
         let content = UIViewController()
         content.view.translatesAutoresizingMaskIntoConstraints = false
-        content.view.layer.masksToBounds = true
-        content.view.layer.cornerRadius = view.bounds.width * 0.02
-        
         let blurEffect = UIBlurEffect(style: .systemChromeMaterial)
         let blurView = UIVisualEffectView(effect: blurEffect)
         blurView.translatesAutoresizingMaskIntoConstraints = false
@@ -47,6 +44,57 @@ class ViewController: UIViewController {
         present(sheet, animated: true)
     }
     
+    @IBAction func tablePressed(_ sender: Any) {
+        let content = ContentTableViewController()
+        content.view.translatesAutoresizingMaskIntoConstraints = false
+        content.view.layer.masksToBounds = true
+        content.view.layer.cornerRadius = view.bounds.width * 0.02
+        
+        let sheet = SheetContainerViewController(content: content)
+        sheet.delegate = self
+        sheet.detents = [.bottom, .middle, .top]
+        
+        present(sheet, animated: true)
+    }
+    
+    @IBAction func navPressed(_ sender: Any) {
+        let root = UIViewController()
+        root.view.backgroundColor = .systemBackground
+        let label = UILabel()
+        label.text = "Root VC"
+        label.translatesAutoresizingMaskIntoConstraints = false
+        root.view.addSubview(label)
+        NSLayoutConstraint.activate([
+            label.centerXAnchor.constraint(equalTo: root.view.centerXAnchor),
+            label.centerYAnchor.constraint(equalTo: root.view.centerYAnchor)
+        ])
+        
+        let nav = UINavigationController(rootViewController: root)
+        nav.view.translatesAutoresizingMaskIntoConstraints = false
+        nav.view.layer.masksToBounds = true
+        nav.view.layer.cornerRadius = view.bounds.width * 0.02
+
+        let sheet = SheetContainerViewController(content: nav)
+        sheet.delegate = self
+        sheet.detents = [.bottom, .middle, .top]
+        
+        present(sheet, animated: true)
+    }
+    
+    @IBAction func navTablePressed(_ sender: Any) {
+        let table = ContentTableViewController()
+        
+        let nav = UINavigationController(rootViewController: table)
+        nav.view.translatesAutoresizingMaskIntoConstraints = false
+        nav.view.layer.masksToBounds = true
+        nav.view.layer.cornerRadius = view.bounds.width * 0.02
+        
+        let sheet = SheetContainerViewController(content: nav)
+        sheet.delegate = self
+        sheet.detents = [.bottom, .middle, .top]
+        
+        present(sheet, animated: true)
+    }
 }
 
 extension ViewController: SheetContainerViewControllerDelegate {
@@ -57,4 +105,18 @@ extension ViewController: SheetContainerViewControllerDelegate {
         }
         return true
     }
+    func sheetContainerContentScrollView(_ sheetContainer: SheetContainerViewController) -> UIScrollView? {
+        if let navController = sheetContainer.content as? UINavigationController, let scrollView = navController.visibleViewController?.view as? UIScrollView {
+            return scrollView
+        } else {
+            return nil
+        }
+    }
+    func sheetContainer(_ sheetContainer: SheetContainerViewController, topContentOffsetForScrollView scrollView: UIScrollView) -> CGFloat {
+        if let navController = sheetContainer.content as? UINavigationController, navController.visibleViewController?.view is UIScrollView {
+            return -navController.navigationBar.bounds.height
+        } else {
+            return 0
+        }
+    }
 }