Version 2.6.0

This commit sets the initial scroll offset to the pinning offset.
The previous implementation, which set it to the current content offset,
leads various scroll tracking bugs. This reproduction is one of issues.

Using 'Scroll tracking(UITableView)' in Samples app.
1. Bounce the scroll content at the top most anchor.
2. Pull down the panel in bouncing at a minus content offset. (the
   scroll content stops at the minus offset.)
3. Pull up it

The previous implementation was implemented for #526/#527. But now the
issue hasn't been reproduced in v2.5.6.

.github/workflows/ci.yml

@@ -10,94 +10,122 @@ on:
 
 jobs:
   build:
-    runs-on: macOS-11
+    runs-on: ${{ matrix.runsOn }}
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - swift: "5.7"
+            xcode: "14.1"
+            runsOn: macos-12
+          - swift: "5.6"
+            xcode: "13.3.1"
+            runsOn: macos-12
+          - swift: "5.5"
+            xcode: "13.2.1"
+            runsOn: macos-11
+          - swift: "5.4"
+            xcode: "12.5.1"
+            runsOn: macos-11
+          - swift: "5.3"
+            xcode: "12.4"
+            runsOn: macos-10.15
+          - swift: "5.2"
+            xcode: "11.7"
+            runsOn: macos-10.15
+          - swift: "5.1"
+            xcode: "11.3.1"
+            runsOn: macos-10.15
     steps:
-    - uses: actions/checkout@v1
-    - name: "Swift 5.4"
-      run: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.4 clean build
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_12.5.1.app/Contents/Developer
-    - name: "Swift 5.5"
-      run: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.5 clean build
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_13.0.app/Contents/Developer
+      - uses: actions/checkout@v2
+      - name: Building in Swift ${{ matrix.swift }}
+        run: xcodebuild -scheme FloatingPanel SWIFT_VERSION=${{ matrix.swift }} clean build
 
-  build_compat:
-    runs-on: macOS-10.15
+  test:
+    runs-on: ${{ matrix.runsOn }}
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: "16.1"
+            xcode: "14.1"
+            sim: "iPhone 14 Pro"
+            runsOn: macos-12
+          - os: "15.4"
+            xcode: "13.3.1"
+            sim: "iPhone 13 Pro"
+            runsOn: macos-12
+          - os: "15.2"
+            xcode: "13.2.1"
+            sim: "iPhone 13 Pro"
+            runsOn: macos-11
+          - os: "14.5"
+            xcode: "12.5.1"
+            sim: "iPhone 12 Pro"
+            runsOn: macos-11
+          - os: "14.4"
+            xcode: "12.4"
+            sim: "iPhone 12 Pro"
+            runsOn: macos-10.15
+          - os: "13.7"
+            xcode: "11.7"
+            sim: "iPhone 11 Pro"
+            runsOn: macos-10.15
     steps:
-    - uses: actions/checkout@v1
-    - name: "Swift 5.1"
-      run: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.1 clean build
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_11.3.1.app/Contents/Developer
-    - name: "Swift 5.2"
-      run: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.2 clean build
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_11.7.app/Contents/Developer
-    - name: "Swift 5.3"
-      run: xcodebuild -scheme FloatingPanel SWIFT_VERSION=5.3 clean build
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_12.4.app/Contents/Developer
-
-  testing:
-    runs-on: macOS-11
-    steps:
-    - uses: actions/checkout@v1
-    - name: "Testing in iOS 14.5"
-      run: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=14.5,name=iPhone 12 Pro'
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_12.5.1.app/Contents/Developer
-    - name: "Testing in iOS 15.0"
-      run: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=15.0,name=iPhone 13 Pro'
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_13.0.app/Contents/Developer
-
-  testing_compat:
-    runs-on: macOS-10.15
-    steps:
-    - uses: actions/checkout@v1
-    - name: "Testing in iOS 13.7"
-      run: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=13.7,name=iPhone 11 Pro'
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_11.7.app/Contents/Developer
-    - name: "Testing in iOS 14.4"
-      run: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=14.4,name=iPhone 12 Pro'
-      env:
-        DEVELOPER_DIR: /Applications/Xcode_12.4.app/Contents/Developer
+    - uses: actions/checkout@v2
+    - name: Testing in iOS ${{ matrix.os }}
+      run: xcodebuild clean test -scheme FloatingPanel -workspace FloatingPanel.xcworkspace -destination 'platform=iOS Simulator,OS=${{ matrix.os }},name=${{ matrix.sim }}'
 
   example:
-    runs-on: macOS-11
+    runs-on: macos-12
     env:
-      DEVELOPER_DIR: /Applications/Xcode_13.0.app/Contents/Developer
+      DEVELOPER_DIR: /Applications/Xcode_14.1.app/Contents/Developer
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - example: "Maps"
+          - example: "Stocks"
+          - example: "Samples"
     steps:
-    - uses: actions/checkout@v1
-    - name: "Build Maps"
-      run: xcodebuild -workspace FloatingPanel.xcworkspace -scheme Maps -sdk iphonesimulator clean build
-    - name: "Build Stocks"
-      run: xcodebuild -workspace FloatingPanel.xcworkspace -scheme Stocks -sdk iphonesimulator clean build
-    - name: "Build Samples"
-      run: xcodebuild -workspace FloatingPanel.xcworkspace -scheme Samples -sdk iphonesimulator clean build
+    - uses: actions/checkout@v2
+    - name: Building ${{ matrix.example }}
+      run: xcodebuild -workspace FloatingPanel.xcworkspace -scheme ${{ matrix.example }} -sdk iphonesimulator clean build
 
   swiftpm:
-    runs-on: macOS-11
+    runs-on: macos-12
     env:
-      DEVELOPER_DIR: /Applications/Xcode_13.0.app/Contents/Developer
+      DEVELOPER_DIR: /Applications/Xcode_14.1.app/Contents/Developer
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # 15.7
+          - target: "x86_64-apple-ios15.7-simulator"
+          - target: "arm64-apple-ios15.7-simulator"
+          # 16.1
+          - target: "x86_64-apple-ios16.1-simulator"
+          - target: "arm64-apple-ios16.1-simulator"
     steps:
-    - uses: actions/checkout@v1
-    - name: "Swift Package build"
-      run: swift build -Xswiftc "-sdk" -Xswiftc "`xcrun --sdk iphonesimulator --show-sdk-path`" -Xswiftc "-target" -Xswiftc "x86_64-apple-ios14.3-simulator"
+    - uses: actions/checkout@v2
+    - name: "Swift Package Manager build"
+      run: swift build -Xswiftc "-sdk" -Xswiftc "`xcrun --sdk iphonesimulator --show-sdk-path`" -Xswiftc "-target" -Xswiftc "${{ matrix.target }}"
 
   carthage:
-    runs-on: macOS-11
+    runs-on: macos-11
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: "Carthage build"
       run: carthage build --use-xcframeworks --no-skip-current
 
   cocoapods:
-    runs-on: macOS-11
+    runs-on: macos-12
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: "CocoaPods: pod lib lint"
       run: pod lib lint --allow-warnings
     - name: "CocoaPods: pod spec lint"

.swiftformat

@@ -1,3 +0,0 @@
---header "// Copyright 2018-Present Shin Yamamoto. All rights reserved. MIT license."
---disable andOperator,anyObjectProtocol,blankLinesAroundMark,blankLinesAtEndOfScope,blankLinesAtStartOfScope,blankLinesBetweenScopes,braces,consecutiveBlankLines,consecutiveSpaces,duplicateImports,elseOnSameLine,emptyBraces,hoistPatternLet,indent,isEmpty,leadingDelimiters,linebreakAtEndOfFile,linebreaks,numberFormatting,redundantBackticks,redundantBreak,redundantExtensionACL,redundantFileprivate,redundantGet,redundantInit,redundantLet,redundantLetError,redundantNilInit,redundantObjc,redundantParens,redundantPattern,redundantRawValues,redundantReturn,redundantSelf,redundantVoidReturnType,semicolons,sortedImports,spaceAroundBraces,spaceAroundBrackets,spaceAroundComments,spaceAroundGenerics,spaceAroundOperators,spaceAroundParens,spaceInsideBraces,spaceInsideBrackets,spaceInsideComments,spaceInsideGenerics,spaceInsideParens,specifiers,strongOutlets,strongifiedSelf,todos,trailingClosures,trailingCommas,trailingSpace,typeSugar,unusedArguments,void,wrapArguments,yodaConditions
-

Examples/Maps-SwiftUI/Maps/FloatingPanel/FloatingPanelView.swift

@@ -96,8 +96,20 @@ struct FloatingPanelView<Content: View, FloatingPanelContent: View>: UIViewContr
                 ignoresKeyboard: true
             )
             hostingViewController.view.backgroundColor = nil
-            fpc.set(contentViewController: hostingViewController)
-            fpc.addPanel(toParent: parentViewController, at: 1, animated: false)
+            let contentViewController = UIViewController()
+            contentViewController.view.addSubview(hostingViewController.view)
+            fpc.set(contentViewController: contentViewController)
+            fpc.addPanel(toParent: parentViewController, animated: false)
+
+            hostingViewController.view.translatesAutoresizingMaskIntoConstraints = false
+            let bottomConstraint = hostingViewController.view.bottomAnchor.constraint(equalTo: contentViewController.view.bottomAnchor)
+            bottomConstraint.priority = .defaultHigh
+            NSLayoutConstraint.activate([
+                hostingViewController.view.topAnchor.constraint(equalTo: contentViewController.view.topAnchor),
+                hostingViewController.view.leadingAnchor.constraint(equalTo: contentViewController.view.leadingAnchor),
+                hostingViewController.view.trailingAnchor.constraint(equalTo: contentViewController.view.trailingAnchor),
+                bottomConstraint
+            ])
         }
 
         func updateIfNeeded() {

Examples/Maps-SwiftUI/Maps/SearchPanelPhoneDelegate.swift

@@ -1,6 +1,7 @@
 // Copyright 2021 the FloatingPanel authors. All rights reserved. MIT license.
 
 import FloatingPanel
+import UIKit
 
 final class SearchPanelPhoneDelegate: FloatingPanelControllerDelegate {
     func floatingPanelWillBeginDragging(_ vc: FloatingPanelController) {

Examples/Maps/Maps.xcodeproj/project.pbxproj

@@ -18,6 +18,7 @@
 		54B51134216C3D860033A6F3 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 54B51132216C3D860033A6F3 /* LaunchScreen.storyboard */; };
 		54E26CB624A989090066C720 /* Utils.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54E26CB524A989090066C720 /* Utils.swift */; };
 		54E26CB824A98E310066C720 /* DetailViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54E26CB724A98E310066C720 /* DetailViewController.swift */; };
+		5D82A6A728D18422006A44BA /* libswiftCoreGraphics.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 5D82A6A628D1841E006A44BA /* libswiftCoreGraphics.tbd */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -47,6 +48,7 @@
 		54B51135216C3D860033A6F3 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		54E26CB524A989090066C720 /* Utils.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Utils.swift; sourceTree = "<group>"; };
 		54E26CB724A98E310066C720 /* DetailViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DetailViewController.swift; sourceTree = "<group>"; };
+		5D82A6A628D1841E006A44BA /* libswiftCoreGraphics.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libswiftCoreGraphics.tbd; path = usr/lib/swift/libswiftCoreGraphics.tbd; sourceTree = SDKROOT; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -55,6 +57,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				543844BD23D2BE2000D5EDE4 /* MapKit.framework in Frameworks */,
+				5D82A6A728D18422006A44BA /* libswiftCoreGraphics.tbd in Frameworks */,
 				549D23D2233C77D5008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -65,6 +68,7 @@
 		543844BB23D2BE1F00D5EDE4 /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
+				5D82A6A628D1841E006A44BA /* libswiftCoreGraphics.tbd */,
 				543844BC23D2BE2000D5EDE4 /* MapKit.framework */,
 			);
 			name = Frameworks;
@@ -336,6 +340,10 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.Maps;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
@@ -355,6 +363,10 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.Maps;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;

Examples/Maps/Maps/MainViewController.swift

@@ -210,12 +210,10 @@ class SearchPanelPhoneDelegate: NSObject, FloatingPanelControllerDelegate, UIGes
 class SearchPanelLandscapeLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition  = .bottom
     let initialState: FloatingPanelState = .tip
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 69.0, edge: .bottom, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 69.0, edge: .bottom, referenceGuide: .safeArea),
+    ]
     func prepareLayout(surfaceView: UIView, in view: UIView) -> [NSLayoutConstraint] {
         if #available(iOS 11.0, *) {
             return [
@@ -244,11 +242,9 @@ class DetailPanelPhoneDelegate: NSObject, FloatingPanelControllerDelegate, UIGes
 
 class DetailPanelPhoneLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition  = .bottom
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
+    ]
     let initialState: FloatingPanelState = .full
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.0
@@ -297,13 +293,11 @@ class SearchPanelPadDelegate: NSObject, FloatingPanelControllerDelegate, UIGestu
 class SearchPanelPadLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition  = .top
     let initialState: FloatingPanelState = .tip
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 80.0, edge: .top, referenceGuide: .superview),
-            .half: FloatingPanelLayoutAnchor(absoluteInset: 200.0, edge: .top, referenceGuide: .superview),
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 60.0, edge: .bottom, referenceGuide: .superview),
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 80.0, edge: .top, referenceGuide: .superview),
+        .half: FloatingPanelLayoutAnchor(absoluteInset: 200.0, edge: .top, referenceGuide: .superview),
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 60.0, edge: .bottom, referenceGuide: .superview),
+    ]
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.0
     }
@@ -357,11 +351,9 @@ class DetailPanelPadDelegate: NSObject, FloatingPanelControllerDelegate, UIGestu
 
 class DetailPanelPadLeftLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition  = .left
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 375, edge: .left, referenceGuide: .superview)
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 375, edge: .left, referenceGuide: .superview)
+    ]
     let initialState: FloatingPanelState = .full
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.0
@@ -370,11 +362,9 @@ class DetailPanelPadLeftLayout: FloatingPanelLayout {
 
 class DetailPanelPadRightLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition  = .right
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 375, edge: .right, referenceGuide: .superview)
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 375, edge: .right, referenceGuide: .superview)
+    ]
     let initialState: FloatingPanelState = .full
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.0

Examples/Samples/Samples.xcodeproj/project.pbxproj

@@ -18,6 +18,7 @@
 		5442E24A25FC53C100A26F43 /* DebugTextViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5442E24925FC53C100A26F43 /* DebugTextViewController.swift */; };
 		5442E25225FC541700A26F43 /* NestedScrollViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5442E25125FC541700A26F43 /* NestedScrollViewController.swift */; };
 		54496C59263A7E5A0031E0C8 /* UseCaseController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54496C58263A7E5A0031E0C8 /* UseCaseController.swift */; };
+		544BC56826CC918200D0A436 /* AdaptiveLayoutTestViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 544BC56726CC918200D0A436 /* AdaptiveLayoutTestViewController.swift */; };
 		545DB9EE21511E6300CA77B8 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DB9ED21511E6300CA77B8 /* AppDelegate.swift */; };
 		545DB9F021511E6300CA77B8 /* MainViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 545DB9EF21511E6300CA77B8 /* MainViewController.swift */; };
 		545DB9F321511E6300CA77B8 /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 545DB9F121511E6300CA77B8 /* Main.storyboard */; };
@@ -33,6 +34,7 @@
 		54CDC5D8215BBE23007D205C /* SupplementaryViews.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CDC5D7215BBE23007D205C /* SupplementaryViews.swift */; };
 		54EAD35B263A75EB006A36EA /* PanelLayouts.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54EAD35A263A75EB006A36EA /* PanelLayouts.swift */; };
 		54EAD365263A765F006A36EA /* PagePanelController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54EAD364263A765F006A36EA /* PagePanelController.swift */; };
+		5D82A6AD28D1843C006A44BA /* libswiftCoreGraphics.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 5D82A6AC28D18438006A44BA /* libswiftCoreGraphics.tbd */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -78,6 +80,7 @@
 		5442E24925FC53C100A26F43 /* DebugTextViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DebugTextViewController.swift; sourceTree = "<group>"; };
 		5442E25125FC541700A26F43 /* NestedScrollViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NestedScrollViewController.swift; sourceTree = "<group>"; };
 		54496C58263A7E5A0031E0C8 /* UseCaseController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UseCaseController.swift; sourceTree = "<group>"; };
+		544BC56726CC918200D0A436 /* AdaptiveLayoutTestViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AdaptiveLayoutTestViewController.swift; sourceTree = "<group>"; };
 		545DB9EA21511E6300CA77B8 /* Samples.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Samples.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		545DB9ED21511E6300CA77B8 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		545DB9EF21511E6300CA77B8 /* MainViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainViewController.swift; sourceTree = "<group>"; };
@@ -98,6 +101,7 @@
 		54CDC5D7215BBE23007D205C /* SupplementaryViews.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SupplementaryViews.swift; sourceTree = "<group>"; };
 		54EAD35A263A75EB006A36EA /* PanelLayouts.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PanelLayouts.swift; sourceTree = "<group>"; };
 		54EAD364263A765F006A36EA /* PagePanelController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PagePanelController.swift; sourceTree = "<group>"; };
+		5D82A6AC28D18438006A44BA /* libswiftCoreGraphics.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libswiftCoreGraphics.tbd; path = usr/lib/swift/libswiftCoreGraphics.tbd; sourceTree = SDKROOT; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -105,6 +109,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				5D82A6AD28D1843C006A44BA /* libswiftCoreGraphics.tbd in Frameworks */,
 				549D23CB233C7779008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -139,6 +144,7 @@
 				5442E22725FC51E200A26F43 /* MultiPanelController.swift */,
 				5442E22B25FC521F00A26F43 /* SettingsViewController.swift */,
 				5442E22F25FC525200A26F43 /* TabBarViewController.swift */,
+				544BC56726CC918200D0A436 /* AdaptiveLayoutTestViewController.swift */,
 			);
 			path = ContentViewControllers;
 			sourceTree = "<group>";
@@ -151,6 +157,7 @@
 				545DBA0121511E6400CA77B8 /* Tests */,
 				545DBA0C21511E6400CA77B8 /* UITests */,
 				545DB9EB21511E6300CA77B8 /* Products */,
+				5D82A6AB28D18438006A44BA /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -211,6 +218,14 @@
 			path = UseCases;
 			sourceTree = "<group>";
 		};
+		5D82A6AB28D18438006A44BA /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				5D82A6AC28D18438006A44BA /* libswiftCoreGraphics.tbd */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -347,6 +362,7 @@
 				54496C59263A7E5A0031E0C8 /* UseCaseController.swift in Sources */,
 				54CDC5D8215BBE23007D205C /* SupplementaryViews.swift in Sources */,
 				54B51116216AFE5F0033A6F3 /* Extensions.swift in Sources */,
+				544BC56826CC918200D0A436 /* AdaptiveLayoutTestViewController.swift in Sources */,
 				5442E24A25FC53C100A26F43 /* DebugTextViewController.swift in Sources */,
 				546341AC25C6426500CA0596 /* CustomState.swift in Sources */,
 				5442E23A25FC52CD00A26F43 /* ModalViewController.swift in Sources */,
@@ -541,11 +557,15 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Sources/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.Samples;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
@@ -560,11 +580,15 @@
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Sources/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.Samples;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;

Examples/Samples/Sources/Base.lproj/Main.storyboard

@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="19455" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="RoN-h0-uBD">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="21507" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="RoN-h0-uBD">
     <device id="retina6_1" orientation="portrait" appearance="light"/>
     <dependencies>
         <deployment identifier="iOS"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="19454"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="21505"/>
         <capability name="Safe area layout guides" minToolsVersion="9.0"/>
         <capability name="Stack View standard spacing" minToolsVersion="9.0"/>
         <capability name="System colors in document resources" minToolsVersion="11.0"/>
@@ -15,7 +15,7 @@
             <objects>
                 <navigationController storyboardIdentifier="RootNavigationController" id="RoN-h0-uBD" sceneMemberID="viewController">
                     <navigationBar key="navigationBar" contentMode="scaleToFill" insetsLayoutMarginsFromSafeArea="NO" largeTitles="YES" id="hNW-5m-Omi">
-                        <rect key="frame" x="0.0" y="44" width="375" height="96"/>
+                        <rect key="frame" x="0.0" y="48" width="414" height="96"/>
                         <autoresizingMask key="autoresizingMask"/>
                     </navigationBar>
                     <connections>
@@ -31,22 +31,22 @@
             <objects>
                 <viewController id="jF4-A0-Eq6" customClass="MainViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="Smh-Bd-AAc">
-                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <rect key="frame" x="0.0" y="0.0" width="414" height="896"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <tableView clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="prototypes" style="plain" separatorStyle="default" rowHeight="-1" estimatedRowHeight="-1" sectionHeaderHeight="28" sectionFooterHeight="28" translatesAutoresizingMaskIntoConstraints="NO" id="7IS-PU-x0P">
-                                <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                                <rect key="frame" x="0.0" y="0.0" width="414" height="896"/>
                                 <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                                 <prototypes>
                                     <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="default" indentationWidth="10" reuseIdentifier="Cell" textLabel="M0G-C8-hAO" style="IBUITableViewCellStyleDefault" id="ySY-oA-g81">
-                                        <rect key="frame" x="0.0" y="28" width="600" height="43.5"/>
+                                        <rect key="frame" x="0.0" y="50" width="414" height="43.5"/>
                                         <autoresizingMask key="autoresizingMask"/>
                                         <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" preservesSuperviewLayoutMargins="YES" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="ySY-oA-g81" id="sXB-nH-2g2">
-                                            <rect key="frame" x="0.0" y="0.0" width="600" height="43.5"/>
+                                            <rect key="frame" x="0.0" y="0.0" width="414" height="43.5"/>
                                             <autoresizingMask key="autoresizingMask"/>
                                             <subviews>
                                                 <label opaque="NO" multipleTouchEnabled="YES" contentMode="left" insetsLayoutMarginsFromSafeArea="NO" text="Title" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" id="M0G-C8-hAO">
-                                                    <rect key="frame" x="16" y="0.0" width="568" height="43.5"/>
+                                                    <rect key="frame" x="20" y="0.0" width="374" height="43.5"/>
                                                     <autoresizingMask key="autoresizingMask"/>
                                                     <fontDescription key="fontDescription" type="system" pointSize="17"/>
                                                     <nil key="textColor"/>
@@ -87,7 +87,7 @@
             <objects>
                 <viewController storyboardIdentifier="SettingsViewController" id="C1X-9Z-TyQ" customClass="SettingsViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" insetsLayoutMarginsFromSafeArea="NO" id="af9-Zr-Ppc">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="197.33000000000001"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="197"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" distribution="fillProportionally" spacing="16" translatesAutoresizingMaskIntoConstraints="NO" id="n93-ZL-fmC">
@@ -125,7 +125,7 @@
                                                     <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" translatesAutoresizingMaskIntoConstraints="NO" id="js8-Qv-lUC">
                                                         <rect key="frame" x="262" y="0.5" width="51" height="31"/>
                                                         <connections>
-                                                            <action selector="toggleLargeTitle:" destination="C1X-9Z-TyQ" eventType="valueChanged" id="FJS-Ty-mCY"/>
+                                                            <action selector="toggleLargeTitle:" destination="C1X-9Z-TyQ" eventType="valueChanged" id="CxM-wn-r09"/>
                                                         </connections>
                                                     </switch>
                                                 </subviews>
@@ -142,7 +142,7 @@
                                                     <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" translatesAutoresizingMaskIntoConstraints="NO" id="s6b-j9-8Kw">
                                                         <rect key="frame" x="262" y="0.5" width="51" height="31"/>
                                                         <connections>
-                                                            <action selector="toggleTranslucent:" destination="C1X-9Z-TyQ" eventType="valueChanged" id="nL4-3L-9hh"/>
+                                                            <action selector="toggleTranslucent:" destination="C1X-9Z-TyQ" eventType="valueChanged" id="w7r-AV-RqX"/>
                                                         </connections>
                                                     </switch>
                                                 </subviews>
@@ -163,8 +163,8 @@
                     </view>
                     <size key="freeformSize" width="375" height="197.33000000000001"/>
                     <connections>
-                        <outlet property="largeTitlesSwicth" destination="js8-Qv-lUC" id="FOm-6k-ffi"/>
-                        <outlet property="translucentSwicth" destination="s6b-j9-8Kw" id="jmf-WH-bzZ"/>
+                        <outlet property="largeTitlesSwitch" destination="js8-Qv-lUC" id="szl-pU-uRE"/>
+                        <outlet property="translucentSwitch" destination="s6b-j9-8Kw" id="8yK-Du-jkM"/>
                         <outlet property="versionLabel" destination="WmC-Tq-NDN" id="Woh-kK-U0m"/>
                     </connections>
                 </viewController>
@@ -177,11 +177,11 @@
             <objects>
                 <viewController id="RpE-lI-27a" customClass="TabBarContentViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="JER-jz-KSq">
-                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <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="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="IvG-yp-yzI">
-                                <rect key="frame" x="20" y="0.0" width="39" height="30"/>
+                                <rect key="frame" x="20" y="48" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="RpE-lI-27a" eventType="touchUpInside" id="hj3-Xv-6Gq"/>
@@ -208,11 +208,11 @@
             <objects>
                 <viewController id="pOk-Zm-vD9" customClass="TabBarContentViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="85d-ub-G8k">
-                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <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="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="NbG-e8-HdI">
-                                <rect key="frame" x="20" y="0.0" width="39" height="30"/>
+                                <rect key="frame" x="20" y="48" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="pOk-Zm-vD9" eventType="touchUpInside" id="111-PD-Pop"/>
@@ -239,11 +239,11 @@
             <objects>
                 <viewController id="lto-Zc-Vtp" customClass="TabBarContentViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="ji9-Ez-N7i">
-                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <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="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="eFN-tN-4Ct">
-                                <rect key="frame" x="20" y="0.0" width="39" height="30"/>
+                                <rect key="frame" x="20" y="48" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="YL4-GP-ZEZ"/>
@@ -383,22 +383,22 @@
             <objects>
                 <viewController storyboardIdentifier="ModalViewController" id="bYI-y3-Rzb" customClass="ModalViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="qwo-GK-p1U">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="720"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="vut-mK-Y4t" customClass="SafeAreaView" customModule="Samples" customModuleProvider="target">
-                                <rect key="frame" x="0.0" y="758" width="375" height="0.0"/>
+                                <rect key="frame" x="0.0" y="720" width="375" height="0.0"/>
                                 <color key="backgroundColor" white="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                             </view>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="sbF-Az-7sy">
-                                <rect key="frame" x="20" y="0.0" width="39" height="30"/>
+                                <rect key="frame" x="20" y="48" width="39" height="30"/>
                                 <state key="normal" title="Close"/>
                                 <connections>
                                     <action selector="closeWithSender:" destination="bYI-y3-Rzb" eventType="touchUpInside" id="MSC-ch-YJK"/>
                                 </connections>
                             </button>
                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" alignment="top" spacing="44" translatesAutoresizingMaskIntoConstraints="NO" id="9p4-06-y2T">
-                                <rect key="frame" x="134.5" y="88" width="106" height="326"/>
+                                <rect key="frame" x="134.5" y="136" width="106" height="326"/>
                                 <subviews>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="i9x-x5-n1q">
                                         <rect key="frame" x="0.0" y="0.0" width="80" height="30"/>
@@ -598,11 +598,11 @@
                                 </constraints>
                             </view>
                             <view alpha="0.5" contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Kva-Z7-0qY" customClass="OnSafeAreaView" customModule="Samples" customModuleProvider="target">
-                                <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
+                                <rect key="frame" x="0.0" y="48" width="375" height="730"/>
                                 <color key="backgroundColor" red="0.0078431372550000003" green="0.72156862749999995" blue="0.45882352939999999" alpha="1" colorSpace="calibratedRGB"/>
                             </view>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="noi-1a-5bZ" customClass="CloseButton" customModule="Samples" customModuleProvider="target">
-                                <rect key="frame" x="319" y="0.0" width="44" height="44"/>
+                                <rect key="frame" x="319" y="48" width="44" height="44"/>
                                 <constraints>
                                     <constraint firstAttribute="height" constant="44" id="0jg-5D-A1F"/>
                                     <constraint firstAttribute="width" constant="44" id="1Cq-PA-wgW"/>
@@ -612,7 +612,7 @@
                                 </connections>
                             </button>
                             <stackView opaque="NO" contentMode="scaleToFill" distribution="fillProportionally" alignment="center" spacing="8" translatesAutoresizingMaskIntoConstraints="NO" id="qux-uG-4o2">
-                                <rect key="frame" x="8" y="8" width="148" height="31"/>
+                                <rect key="frame" x="8" y="56" width="148" height="31"/>
                                 <subviews>
                                     <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="fitToBounds" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="7lq-d3-PKi">
                                         <rect key="frame" x="0.0" y="5.5" width="91" height="20.5"/>
@@ -660,19 +660,19 @@
                         <color key="backgroundColor" red="1" green="0.83234566450000003" blue="0.47320586440000001" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                         <gestureRecognizers/>
                         <constraints>
-                            <constraint firstItem="noi-1a-5bZ" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" id="EQy-cr-F2Y"/>
+                            <constraint firstItem="noi-1a-5bZ" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" priority="750" id="EQy-cr-F2Y"/>
                             <constraint firstItem="tP3-oJ-4EB" firstAttribute="centerX" secondItem="aOK-7l-cA6" secondAttribute="centerX" id="EsD-Vf-dNZ"/>
                             <constraint firstItem="Kva-Z7-0qY" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" id="Fff-HL-4mo"/>
-                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="bottom" secondItem="g7l-kO-y7q" secondAttribute="bottom" id="JOL-wC-w74"/>
+                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="bottom" secondItem="g7l-kO-y7q" secondAttribute="bottom" priority="750" id="JOL-wC-w74"/>
                             <constraint firstItem="8yw-OC-Ubk" firstAttribute="leading" secondItem="aOK-7l-cA6" secondAttribute="leading" id="RiJ-Hb-OOZ"/>
                             <constraint firstItem="8yw-OC-Ubk" firstAttribute="trailing" secondItem="aOK-7l-cA6" secondAttribute="trailing" id="Sof-yL-mwK"/>
-                            <constraint firstItem="tP3-oJ-4EB" firstAttribute="top" secondItem="g7l-kO-y7q" secondAttribute="top" constant="88" id="Zhb-Ss-epe"/>
+                            <constraint firstItem="tP3-oJ-4EB" firstAttribute="top" secondItem="g7l-kO-y7q" secondAttribute="top" priority="750" constant="88" id="Zhb-Ss-epe"/>
                             <constraint firstItem="Kva-Z7-0qY" firstAttribute="trailing" secondItem="aOK-7l-cA6" secondAttribute="trailing" id="kkp-Yo-FQW"/>
                             <constraint firstItem="aOK-7l-cA6" firstAttribute="trailing" secondItem="noi-1a-5bZ" secondAttribute="trailing" constant="12" id="lv9-Nf-HNB"/>
                             <constraint firstItem="qux-uG-4o2" firstAttribute="top" secondItem="aOK-7l-cA6" secondAttribute="top" constant="8" id="naa-cf-ZIc"/>
                             <constraint firstItem="Kva-Z7-0qY" firstAttribute="leading" secondItem="aOK-7l-cA6" secondAttribute="leading" id="oVC-i1-TwS"/>
-                            <constraint firstItem="aOK-7l-cA6" firstAttribute="bottom" secondItem="Kva-Z7-0qY" secondAttribute="bottom" id="rW2-mF-5DR"/>
-                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="top" relation="greaterThanOrEqual" secondItem="tP3-oJ-4EB" secondAttribute="bottom" constant="88" id="vKQ-h9-uKt"/>
+                            <constraint firstItem="aOK-7l-cA6" firstAttribute="bottom" secondItem="Kva-Z7-0qY" secondAttribute="bottom" priority="750" id="rW2-mF-5DR"/>
+                            <constraint firstItem="8yw-OC-Ubk" firstAttribute="top" relation="greaterThanOrEqual" secondItem="tP3-oJ-4EB" secondAttribute="bottom" priority="750" constant="88" id="vKQ-h9-uKt"/>
                             <constraint firstItem="qux-uG-4o2" firstAttribute="leading" secondItem="g7l-kO-y7q" secondAttribute="leading" constant="8" id="zXb-R9-bMO"/>
                         </constraints>
                         <connections>
@@ -782,7 +782,57 @@ Section 1.10.33 of "de Finibus Bonorum et Malorum", written by Cicero in 45 BC
             </objects>
             <point key="canvasLocation" x="-1" y="734"/>
         </scene>
+        <!--Adaptive Layout Test View Controller-->
+        <scene sceneID="rDI-lU-wEx">
+            <objects>
+                <viewController storyboardIdentifier="AdaptiveLayoutTestViewController" id="5nC-6E-bXf" customClass="AdaptiveLayoutTestViewController" customModule="Samples" customModuleProvider="target" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="jXL-Ss-NCJ">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <tableView clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" showsHorizontalScrollIndicator="NO" showsVerticalScrollIndicator="NO" dataMode="prototypes" style="plain" separatorStyle="default" rowHeight="-1" estimatedRowHeight="-1" sectionHeaderHeight="28" sectionFooterHeight="28" translatesAutoresizingMaskIntoConstraints="NO" id="W7W-ET-Wco" customClass="IntrinsicTableView" customModule="Samples" customModuleProvider="target">
+                                <rect key="frame" x="0.0" y="0.0" width="375" height="778"/>
+                                <color key="backgroundColor" systemColor="systemBackgroundColor"/>
+                                <prototypes>
+                                    <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" restorationIdentifier="Cell" insetsLayoutMarginsFromSafeArea="NO" selectionStyle="blue" hidesAccessoryWhenEditing="NO" indentationLevel="1" indentationWidth="0.0" id="Mqi-zK-WA7">
+                                        <rect key="frame" x="0.0" y="50" width="375" height="43.5"/>
+                                        <autoresizingMask key="autoresizingMask"/>
+                                        <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="Mqi-zK-WA7" id="X46-Fp-6Hr">
+                                            <rect key="frame" x="0.0" y="0.0" width="375" height="43.5"/>
+                                            <autoresizingMask key="autoresizingMask"/>
+                                        </tableViewCellContentView>
+                                    </tableViewCell>
+                                </prototypes>
+                                <connections>
+                                    <outlet property="dataSource" destination="5nC-6E-bXf" id="RHg-aY-HNW"/>
+                                    <outlet property="delegate" destination="5nC-6E-bXf" id="0YX-fh-bB8"/>
+                                </connections>
+                            </tableView>
+                        </subviews>
+                        <viewLayoutGuide key="safeArea" id="ZfG-sd-dcQ"/>
+                        <color key="backgroundColor" systemColor="systemBackgroundColor"/>
+                        <constraints>
+                            <constraint firstItem="W7W-ET-Wco" firstAttribute="trailing" secondItem="ZfG-sd-dcQ" secondAttribute="trailing" id="3kP-rg-7c6"/>
+                            <constraint firstAttribute="bottom" secondItem="W7W-ET-Wco" secondAttribute="bottom" id="FdS-X9-D1D"/>
+                            <constraint firstItem="W7W-ET-Wco" firstAttribute="leading" secondItem="ZfG-sd-dcQ" secondAttribute="leading" id="HXa-oO-jag"/>
+                            <constraint firstItem="W7W-ET-Wco" firstAttribute="top" secondItem="jXL-Ss-NCJ" secondAttribute="top" id="gMX-Wq-7G8"/>
+                        </constraints>
+                    </view>
+                    <size key="freeformSize" width="375" height="778"/>
+                    <connections>
+                        <outlet property="tableView" destination="W7W-ET-Wco" id="N54-Fv-2Jq"/>
+                    </connections>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="7hJ-XW-9az" userLabel="First Responder" customClass="UIResponder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="4005" y="734"/>
+        </scene>
     </scenes>
+    <designables>
+        <designable name="noi-1a-5bZ">
+            <size key="intrinsicContentSize" width="30" height="30"/>
+        </designable>
+    </designables>
     <inferredMetricsTieBreakers>
         <segue reference="r1P-2i-NDe"/>
     </inferredMetricsTieBreakers>

Examples/Samples/Sources/ContentViewControllers/AdaptiveLayoutTestViewController.swift

@@ -0,0 +1,89 @@
+// Copyright 2018-Present Shin Yamamoto. All rights reserved. MIT license.
+
+import UIKit
+import FloatingPanel
+
+final class AdaptiveLayoutTestViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
+    class PanelLayout: FloatingPanelLayout {
+        let position: FloatingPanelPosition = .bottom
+        let initialState: FloatingPanelState = .full
+
+        private unowned var targetGuide: UILayoutGuide
+
+        init(targetGuide: UILayoutGuide) {
+            self.targetGuide = targetGuide
+        }
+
+        var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
+            return [
+                .full: FloatingPanelAdaptiveLayoutAnchor(
+                    absoluteOffset: 0.0,
+                    contentLayout: targetGuide,
+                    referenceGuide: .superview,
+                    contentBoundingGuide: .safeArea
+                ),
+                .half: FloatingPanelAdaptiveLayoutAnchor(
+                    fractionalOffset: 0.5,
+                    contentLayout: targetGuide,
+                    referenceGuide: .superview,
+                    contentBoundingGuide: .safeArea
+                ),
+            ]
+        }
+    }
+
+    @IBOutlet weak var tableView: IntrinsicTableView!
+    private let cellID = "Cell"
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        tableView.rowHeight = UITableView.automaticDimension
+        tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellID)
+    }
+
+    // MARK: - UITableViewDataSource
+
+    func numberOfSections(in tableView: UITableView) -> Int {
+        1
+    }
+
+    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        50
+    }
+
+    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: cellID, for: indexPath)
+        cell.textLabel?.text = "\(indexPath.row)"
+        return cell
+    }
+
+    // MARK: - UITableViewDelegate
+
+    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
+        let headerView = UIView()
+        headerView.backgroundColor = .orange
+        return headerView
+    }
+
+    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
+        44.0
+    }
+
+    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
+        40
+    }
+}
+
+class IntrinsicTableView: UITableView {
+
+    override var contentSize:CGSize {
+        didSet {
+            invalidateIntrinsicContentSize()
+        }
+    }
+
+    override var intrinsicContentSize: CGSize {
+        layoutIfNeeded()
+        return CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
+    }
+}

Examples/Samples/Sources/ContentViewControllers/ImageViewController.swift

@@ -5,29 +5,25 @@ import FloatingPanel
 
 final class ImageViewController: UIViewController {
     class PanelLayout: FloatingPanelLayout {
-        weak var targetGuide: UILayoutGuide?
-        init(targetGuide: UILayoutGuide?) {
+        private unowned var targetGuide: UILayoutGuide
+        init(targetGuide: UILayoutGuide) {
             self.targetGuide = targetGuide
         }
         let position: FloatingPanelPosition = .bottom
         let initialState: FloatingPanelState = .full
         var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-            if #available(iOS 11.0, *), let targetGuide = targetGuide {
-                return [
-                    .full: FloatingPanelAdaptiveLayoutAnchor(absoluteOffset: 0,
-                                                             contentLayout: targetGuide,
-                                                             referenceGuide: .superview),
-                    .half: FloatingPanelAdaptiveLayoutAnchor(fractionalOffset: 0.5,
-                                                             contentLayout: targetGuide,
-                                                             referenceGuide: .superview)
-                ]
-            } else {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 500,
-                                                     edge: .bottom,
-                                                     referenceGuide: .superview)
-                ]
-            }
+            return [
+                .full: FloatingPanelAdaptiveLayoutAnchor(
+                    absoluteOffset: 0,
+                    contentLayout: targetGuide,
+                    referenceGuide: .superview
+                ),
+                .half: FloatingPanelAdaptiveLayoutAnchor(
+                    fractionalOffset: 0.5,
+                    contentLayout: targetGuide,
+                    referenceGuide: .superview
+                )
+            ]
         }
     }
 

Examples/Samples/Sources/ContentViewControllers/ModalViewController.swift

@@ -65,14 +65,12 @@ final class ModalViewController: UIViewController, FloatingPanelControllerDelega
     }
 
     class ModalSecondLayout: FloatingPanelLayout {
-        var position: FloatingPanelPosition = .bottom
-        var initialState: FloatingPanelState { .half }
-        var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-            return [
-                .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
-                .half: FloatingPanelLayoutAnchor(absoluteInset: 262, edge: .top, referenceGuide: .safeArea),
-                .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .bottom, referenceGuide: .safeArea)
-            ]
-        }
+        let position: FloatingPanelPosition = .bottom
+        let initialState: FloatingPanelState = .half
+        let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+            .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
+            .half: FloatingPanelLayoutAnchor(absoluteInset: 262, edge: .top, referenceGuide: .safeArea),
+            .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .bottom, referenceGuide: .safeArea)
+        ]
     }
 }

Examples/Samples/Sources/ContentViewControllers/MultiPanelController.swift

@@ -57,11 +57,9 @@ final class MultiPanelController: FloatingPanelController, FloatingPanelControll
     private final class FirstViewLayout: FloatingPanelLayout {
         let position: FloatingPanelPosition = .bottom
         let initialState: FloatingPanelState = .full
-        var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-            return [
-                .full: FloatingPanelLayoutAnchor(absoluteInset: 40.0, edge: .top, referenceGuide: .superview)
-            ]
-        }
+        let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+            .full: FloatingPanelLayoutAnchor(absoluteInset: 40.0, edge: .top, referenceGuide: .superview)
+        ]
     }
 }
 

Examples/Samples/Sources/ContentViewControllers/SettingsViewController.swift

@@ -4,8 +4,8 @@ import UIKit
 import FloatingPanel
 
 final class SettingsViewController: InspectableViewController {
-    @IBOutlet weak var largeTitlesSwicth: UISwitch!
-    @IBOutlet weak var translucentSwicth: UISwitch!
+    @IBOutlet weak var largeTitlesSwitch: UISwitch!
+    @IBOutlet weak var translucentSwitch: UISwitch!
     @IBOutlet weak var versionLabel: UILabel!
 
     override func viewDidLoad() {
@@ -16,12 +16,12 @@ final class SettingsViewController: InspectableViewController {
         super.viewDidLayoutSubviews()
         if #available(iOS 11.0, *) {
             let prefersLargeTitles = navigationController!.navigationBar.prefersLargeTitles
-            largeTitlesSwicth.setOn(prefersLargeTitles, animated: false)
+            largeTitlesSwitch.setOn(prefersLargeTitles, animated: false)
         } else {
-            largeTitlesSwicth.isEnabled = false
+            largeTitlesSwitch.isEnabled = false
         }
         let isTranslucent = navigationController!.navigationBar.isTranslucent
-        translucentSwicth.setOn(isTranslucent, animated: false)
+        translucentSwitch.setOn(isTranslucent, animated: false)
     }
 
     @IBAction func toggleLargeTitle(_ sender: UISwitch) {
@@ -30,7 +30,19 @@ final class SettingsViewController: InspectableViewController {
         }
     }
     @IBAction func toggleTranslucent(_ sender: UISwitch) {
-        navigationController?.navigationBar.isTranslucent = sender.isOn
+        // White non-translucent navigation bar, supports dark appearance
+        if #available(iOS 15, *) {
+            let appearance = UINavigationBarAppearance()
+            if sender.isOn {
+                appearance.configureWithTransparentBackground()
+            } else {
+                appearance.configureWithOpaqueBackground()
+            }
+            navigationController?.navigationBar.standardAppearance = appearance
+            navigationController?.navigationBar.scrollEdgeAppearance = appearance
+        } else {
+            navigationController?.navigationBar.isTranslucent = sender.isOn
+        }
     }
 }
 

Examples/Samples/Sources/ContentViewControllers/TabBarViewController.swift

@@ -195,14 +195,12 @@ class OneTabBarPanelLayout: FloatingPanelLayout {
 }
 
 class TwoTabBarPanelLayout: FloatingPanelLayout {
-    var initialState: FloatingPanelState { .half }
-    var position: FloatingPanelPosition { .bottom }
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 100.0, edge: .top, referenceGuide: .safeArea),
-            .half: FloatingPanelLayoutAnchor(absoluteInset: 261.0, edge: .bottom, referenceGuide: .safeArea)
-        ]
-    }
+    let initialState: FloatingPanelState = .half
+    let position: FloatingPanelPosition = .bottom
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 100.0, edge: .top, referenceGuide: .safeArea),
+        .half: FloatingPanelLayoutAnchor(absoluteInset: 261.0, edge: .bottom, referenceGuide: .safeArea)
+    ]
 }
 
 class TwoTabBarPanelBehavior: FloatingPanelBehavior {

Examples/Samples/Sources/Extensions.swift

@@ -2,6 +2,20 @@
 
 import UIKit
 
+extension UIView {
+    func makeBoundsLayoutGuide() -> UILayoutGuide {
+        let guide = UILayoutGuide()
+        addLayoutGuide(guide)
+        NSLayoutConstraint.activate([
+            guide.topAnchor.constraint(equalTo: topAnchor),
+            guide.leftAnchor.constraint(equalTo: leftAnchor),
+            guide.bottomAnchor.constraint(equalTo: bottomAnchor),
+            guide.rightAnchor.constraint(equalTo: rightAnchor),
+        ])
+        return guide
+    }
+}
+
 protocol LayoutGuideProvider {
     var topAnchor: NSLayoutYAxisAnchor { get }
     var bottomAnchor: NSLayoutYAxisAnchor { get }

Examples/Samples/Sources/PanelLayouts.swift

@@ -23,14 +23,11 @@ extension MainViewController: FloatingPanelLayout {
 class TopPositionedPanelLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .top
     let initialState: FloatingPanelState = .full
-
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 88.0, edge: .bottom, referenceGuide: .safeArea),
-            .half: FloatingPanelLayoutAnchor(absoluteInset: 216.0, edge: .top, referenceGuide: .safeArea),
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .top, referenceGuide: .safeArea)
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 88.0, edge: .bottom, referenceGuide: .safeArea),
+        .half: FloatingPanelLayoutAnchor(absoluteInset: 216.0, edge: .top, referenceGuide: .safeArea),
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .top, referenceGuide: .safeArea)
+    ]
 }
 
 class IntrinsicPanelLayout: FloatingPanelBottomLayout {
@@ -45,13 +42,10 @@ class IntrinsicPanelLayout: FloatingPanelBottomLayout {
 class RemovablePanelLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .half
-
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
             .full: FloatingPanelIntrinsicLayoutAnchor(fractionalOffset: 0.0, referenceGuide: .safeArea),
             .half: FloatingPanelLayoutAnchor(absoluteInset: 130.0, edge: .bottom, referenceGuide: .safeArea)
-        ]
-    }
+    ]
 
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.3
@@ -61,13 +55,10 @@ class RemovablePanelLayout: FloatingPanelLayout {
 class RemovablePanelLandscapeLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .full
-
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelIntrinsicLayoutAnchor(fractionalOffset: 0.0, referenceGuide: .safeArea),
-            .half: FloatingPanelLayoutAnchor(absoluteInset: 216.0, edge: .bottom, referenceGuide: .safeArea)
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelIntrinsicLayoutAnchor(fractionalOffset: 0.0, referenceGuide: .safeArea),
+        .half: FloatingPanelLayoutAnchor(absoluteInset: 216.0, edge: .bottom, referenceGuide: .safeArea)
+    ]
 
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.3
@@ -77,12 +68,9 @@ class RemovablePanelLandscapeLayout: FloatingPanelLayout {
 class ModalPanelLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .full
-
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelIntrinsicLayoutAnchor(absoluteOffset: 0.0, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelIntrinsicLayoutAnchor(absoluteOffset: 0.0, referenceGuide: .safeArea),
+    ]
 
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.3

Examples/Samples/Sources/UseCases/UseCase.swift

@@ -50,7 +50,9 @@ extension UseCase {
         case .showCustomStatePanel: return "Show Panel with Custom state"
         }
     }
+}
 
+extension UseCase {
     private enum Content {
         case storyboard(String)
         case viewController(UIViewController)
@@ -76,7 +78,7 @@ extension UseCase {
         case .showNavigationController: return .storyboard("RootNavigationController") // Storyboard only
         case .showTopPositionedPanel: return .viewController(DebugTableViewController())
         case .showAdaptivePanel: return .storyboard(String(describing: ImageViewController.self))
-        case .showAdaptivePanelWithCustomGuide: return .storyboard(String(describing: ImageViewController.self))
+        case .showAdaptivePanelWithCustomGuide: return .storyboard(String(describing: AdaptiveLayoutTestViewController.self))
         case .showCustomStatePanel: return .viewController(DebugTableViewController())
         }
     }
@@ -86,6 +88,7 @@ extension UseCase {
         case .storyboard(let id):
             return storyboard.instantiateViewController(withIdentifier: id)
         case .viewController(let vc):
+            vc.loadViewIfNeeded()
             return vc
         }
     }

Examples/Samples/Sources/UseCases/UseCaseController.swift

@@ -212,28 +212,40 @@ extension UseCaseController {
             addMain(panel: fpc)
 
         case .showTopPositionedPanel: // For debug
-            let fpc = FloatingPanelController()
+            let fpc = FloatingPanelController(delegate: self)
             let contentVC = UIViewController()
             contentVC.view.backgroundColor = .red
             fpc.set(contentViewController: contentVC)
             addMain(panel: fpc)
 
-        case .showAdaptivePanel, .showAdaptivePanelWithCustomGuide:
+        case .showAdaptivePanel:
             let fpc = FloatingPanelController()
             fpc.isRemovalInteractionEnabled = true
             fpc.set(contentViewController: contentVC)
             fpc.ext_trackScrollView(in: contentVC)
             if case let contentVC as ImageViewController = contentVC {
-                if #available(iOS 11.0, *) {
-                    let mode: ImageViewController.Mode = (useCase == .showAdaptivePanelWithCustomGuide) ? .withHeaderFooter : .onlyImage
-                    let layoutGuide = contentVC.layoutGuideFor(mode: mode)
-                    fpc.layout = ImageViewController.PanelLayout(targetGuide: layoutGuide)
-                } else {
-                    fpc.layout = ImageViewController.PanelLayout(targetGuide: nil)
-                }
+                let mode: ImageViewController.Mode = (useCase == .showAdaptivePanelWithCustomGuide) ? .withHeaderFooter : .onlyImage
+                let layoutGuide = contentVC.layoutGuideFor(mode: mode)
+                fpc.layout = ImageViewController.PanelLayout(targetGuide: layoutGuide)
             }
             addMain(panel: fpc)
 
+        case .showAdaptivePanelWithCustomGuide:
+            let fpc = FloatingPanelController()
+            fpc.isRemovalInteractionEnabled = true
+            fpc.contentInsetAdjustmentBehavior = .always
+            fpc.surfaceView.appearance = {
+                let appearance = SurfaceAppearance()
+                appearance.cornerRadius = 6.0
+                return appearance
+            }()
+
+
+            fpc.set(contentViewController: contentVC)
+            fpc.ext_trackScrollView(in: contentVC)
+            fpc.layout = AdaptiveLayoutTestViewController.PanelLayout(targetGuide: contentVC.view.makeBoundsLayoutGuide())
+            addMain(panel: fpc)
+
         case .showCustomStatePanel:
             let fpc = FloatingPanelController()
             fpc.delegate = self
@@ -283,7 +295,7 @@ extension UseCaseController {
         }
     }
 
-   @objc
+    @objc
     private func handleSurface(tapGesture: UITapGestureRecognizer) {
         switch mainPanelVC.state {
         case .full:
@@ -377,6 +389,9 @@ private extension FloatingPanelController {
         case let contentVC as ImageViewController:
             track(scrollView: contentVC.scrollView)
 
+        case let contentVC as AdaptiveLayoutTestViewController:
+            track(scrollView: contentVC.tableView)
+
         default:
             break
         }

Examples/SamplesObjC/SamplesObjC.xcodeproj/project.pbxproj

@@ -15,6 +15,7 @@
 		545BA71421BA3217007F7846 /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = 545BA71321BA3217007F7846 /* main.m */; };
 		545BA72621BA3BAF007F7846 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 545BA72521BA3BAF007F7846 /* FloatingPanel.framework */; };
 		545BA72721BA3BAF007F7846 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 545BA72521BA3BAF007F7846 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		5D82A6B028D18447006A44BA /* libswiftCoreGraphics.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 5D82A6AF28D18443006A44BA /* libswiftCoreGraphics.tbd */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -44,6 +45,7 @@
 		545BA71321BA3217007F7846 /* main.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = main.m; sourceTree = "<group>"; };
 		545BA72221BA3867007F7846 /* SamplesObjC-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "SamplesObjC-Bridging-Header.h"; sourceTree = "<group>"; };
 		545BA72521BA3BAF007F7846 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		5D82A6AF28D18443006A44BA /* libswiftCoreGraphics.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libswiftCoreGraphics.tbd; path = usr/lib/swift/libswiftCoreGraphics.tbd; sourceTree = SDKROOT; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -51,6 +53,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				5D82A6B028D18447006A44BA /* libswiftCoreGraphics.tbd in Frameworks */,
 				545BA72621BA3BAF007F7846 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -64,6 +67,7 @@
 				545BA72521BA3BAF007F7846 /* FloatingPanel.framework */,
 				545BA70321BA3214007F7846 /* SamplesObjC */,
 				545BA70221BA3214007F7846 /* Products */,
+				5D82A6AE28D18443006A44BA /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -92,6 +96,14 @@
 			path = SamplesObjC;
 			sourceTree = "<group>";
 		};
+		5D82A6AE28D18443006A44BA /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				5D82A6AF28D18443006A44BA /* libswiftCoreGraphics.tbd */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -320,6 +332,10 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.SamplesObjC;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "SamplesObjC/SamplesObjC-Bridging-Header.h";
@@ -342,6 +358,10 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.SamplesObjC;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "SamplesObjC/SamplesObjC-Bridging-Header.h";

Examples/SamplesObjC/SamplesObjC/MainViewController.m

@@ -29,7 +29,6 @@ static FloatingPanelState *_lastQuart;
 
     FloatingPanelController *fpc = [[FloatingPanelController alloc] init];
     [fpc setContentViewController:nil];
-    [fpc trackScrollView:nil];
     [fpc setDelegate:self];
 
     [fpc setLayout: [MyFloatingPanelLayout new]];

Examples/Stocks/Stocks.xcodeproj/project.pbxproj

@@ -14,6 +14,7 @@
 		548DF95E21705BE10041922A /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 548DF95C21705BE10041922A /* LaunchScreen.storyboard */; };
 		549D23CF233C77CF008EF4D7 /* FloatingPanel.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */; };
 		549D23D0233C77CF008EF4D7 /* FloatingPanel.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		5D82A6AA28D18432006A44BA /* libswiftCoreGraphics.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 5D82A6A928D1842B006A44BA /* libswiftCoreGraphics.tbd */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -39,6 +40,7 @@
 		548DF95D21705BE10041922A /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		548DF95F21705BE10041922A /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = FloatingPanel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		5D82A6A928D1842B006A44BA /* libswiftCoreGraphics.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libswiftCoreGraphics.tbd; path = usr/lib/swift/libswiftCoreGraphics.tbd; sourceTree = SDKROOT; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -46,6 +48,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				5D82A6AA28D18432006A44BA /* libswiftCoreGraphics.tbd in Frameworks */,
 				549D23CF233C77CF008EF4D7 /* FloatingPanel.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -59,6 +62,7 @@
 				549D23CE233C77CF008EF4D7 /* FloatingPanel.framework */,
 				548DF95221705BE00041922A /* Stocks */,
 				548DF95121705BE00041922A /* Products */,
+				5D82A6A828D1842A006A44BA /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -83,6 +87,14 @@
 			path = Stocks;
 			sourceTree = "<group>";
 		};
+		5D82A6A828D1842A006A44BA /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				5D82A6A928D1842B006A44BA /* libswiftCoreGraphics.tbd */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -312,6 +324,10 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.Stocks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
@@ -331,6 +347,10 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
+				LIBRARY_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(SDKROOT)/usr/lib/swift",
+				);
 				PRODUCT_BUNDLE_IDENTIFIER = example.Stocks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;

Examples/Stocks/Stocks/MainViewController.swift

@@ -101,14 +101,12 @@ class FloatingPanelStocksLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .tip
 
-    var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 56.0, edge: .top, referenceGuide: .safeArea),
-            .half: FloatingPanelLayoutAnchor(absoluteInset: 262.0, edge: .bottom, referenceGuide: .safeArea),
-             /* Visible + ToolView */
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 85.0 + 44.0, edge: .bottom, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 56.0, edge: .top, referenceGuide: .safeArea),
+        .half: FloatingPanelLayoutAnchor(absoluteInset: 262.0, edge: .bottom, referenceGuide: .safeArea),
+         /* Visible + ToolView */
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 85.0 + 44.0, edge: .bottom, referenceGuide: .safeArea),
+    ]
 
     func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
         return 0.0

FloatingPanel.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name                = "FloatingPanel"
-  s.version             = "2.5.2"
+  s.version             = "2.6.0"
   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 +14,7 @@ The new interface displays the related contents and utilities in parallel as a u
   s.platform            = :ios, "10.0"
   s.source              = { :git => "https://github.com/SCENEE/FloatingPanel.git", :tag => s.version.to_s }
   s.source_files        = "Sources/*.swift"
-  s.swift_versions      = ['5.1', '5.2', '5.3']
+  s.swift_version       = '5.0'
 
   s.framework           = "UIKit"
 

FloatingPanel.xcodeproj/project.pbxproj

@@ -22,7 +22,7 @@
 		5469F4AE24B30D7E00537F8A /* State.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5469F4AD24B30D7E00537F8A /* State.swift */; };
 		5469F4B024B30E1500537F8A /* LayoutAnchoring.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5469F4AF24B30E1500537F8A /* LayoutAnchoring.swift */; };
 		5469F4B224B30F1100537F8A /* Position.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5469F4B124B30F1100537F8A /* Position.swift */; };
-		5469F4B424B30F3500537F8A /* LayoutReferences.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5469F4B324B30F3500537F8A /* LayoutReferences.swift */; };
+		5469F4B424B30F3500537F8A /* LayoutProperties.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5469F4B324B30F3500537F8A /* LayoutProperties.swift */; };
 		549C371F2361E15E007D8058 /* ExtensionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 549C371E2361E15D007D8058 /* ExtensionTests.swift */; };
 		549E944522CF295D0050AECF /* StateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 549E944422CF295D0050AECF /* StateTests.swift */; };
 		54A6B6B122968B530077F348 /* CoreTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54A6B6B022968B530077F348 /* CoreTests.swift */; };
@@ -34,6 +34,7 @@
 		54CFBFC5215CD09C006B5735 /* Core.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54CFBFC4215CD09C006B5735 /* Core.swift */; };
 		54DBA3DC262E938500D75969 /* Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 54DBA3DB262E938500D75969 /* Extensions.swift */; };
 		54E3992727141F5100A8F9ED /* FloatingPanel.docc in Sources */ = {isa = PBXBuildFile; fileRef = 54E3992627141F5100A8F9ED /* FloatingPanel.docc */; };
+		5D82A6B528D18464006A44BA /* libswiftCoreGraphics.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 5D82A6B428D18461006A44BA /* libswiftCoreGraphics.tbd */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -73,7 +74,7 @@
 		5469F4AD24B30D7E00537F8A /* State.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = State.swift; sourceTree = "<group>"; };
 		5469F4AF24B30E1500537F8A /* LayoutAnchoring.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LayoutAnchoring.swift; sourceTree = "<group>"; };
 		5469F4B124B30F1100537F8A /* Position.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Position.swift; sourceTree = "<group>"; };
-		5469F4B324B30F3500537F8A /* LayoutReferences.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LayoutReferences.swift; sourceTree = "<group>"; };
+		5469F4B324B30F3500537F8A /* LayoutProperties.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LayoutProperties.swift; sourceTree = "<group>"; };
 		549C371E2361E15D007D8058 /* ExtensionTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExtensionTests.swift; sourceTree = "<group>"; };
 		549E944422CF295D0050AECF /* StateTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StateTests.swift; sourceTree = "<group>"; };
 		54A6B6B022968B530077F348 /* CoreTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoreTests.swift; sourceTree = "<group>"; };
@@ -86,6 +87,7 @@
 		54DBA3DB262E938500D75969 /* Extensions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Extensions.swift; sourceTree = "<group>"; };
 		54E3992627141F5100A8F9ED /* FloatingPanel.docc */ = {isa = PBXFileReference; lastKnownFileType = folder.documentationcatalog; path = FloatingPanel.docc; sourceTree = "<group>"; };
 		54E740CA218AFD67005C1A34 /* FloatingPanelTesting.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = FloatingPanelTesting.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		5D82A6B428D18461006A44BA /* libswiftCoreGraphics.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libswiftCoreGraphics.tbd; path = Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/lib/swift/libswiftCoreGraphics.tbd; sourceTree = DEVELOPER_DIR; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -93,6 +95,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				5D82A6B528D18464006A44BA /* libswiftCoreGraphics.tbd in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -120,6 +123,7 @@
 				545DB9C32151169500CA77B8 /* Sources */,
 				545DB9CE2151169500CA77B8 /* Tests */,
 				545DB9C22151169500CA77B8 /* Products */,
+				5D82A6B328D18460006A44BA /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -141,7 +145,7 @@
 				5469F4B124B30F1100537F8A /* Position.swift */,
 				54CFBFC4215CD09C006B5735 /* Core.swift */,
 				54CFBFC2215CD045006B5735 /* Layout.swift */,
-				5469F4B324B30F3500537F8A /* LayoutReferences.swift */,
+				5469F4B324B30F3500537F8A /* LayoutProperties.swift */,
 				5469F4AF24B30E1500537F8A /* LayoutAnchoring.swift */,
 				5450EEE321646DF500135936 /* Behavior.swift */,
 				54352E9721A521CA00CBCA08 /* PassthroughView.swift */,
@@ -184,6 +188,14 @@
 			path = TestingApp;
 			sourceTree = "<group>";
 		};
+		5D82A6B328D18460006A44BA /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				5D82A6B428D18461006A44BA /* libswiftCoreGraphics.tbd */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXHeadersBuildPhase section */
@@ -329,7 +341,7 @@
 				5469F4B024B30E1500537F8A /* LayoutAnchoring.swift in Sources */,
 				54CDC5D3215B6D5A007D205C /* SurfaceView.swift in Sources */,
 				54CFBFC3215CD045006B5735 /* Layout.swift in Sources */,
-				5469F4B424B30F3500537F8A /* LayoutReferences.swift in Sources */,
+				5469F4B424B30F3500537F8A /* LayoutProperties.swift in Sources */,
 				54CDC5D5215B6D8D007D205C /* BackdropView.swift in Sources */,
 				54352E9821A521CA00CBCA08 /* PassthroughView.swift in Sources */,
 				54CFBFC5215CD09C006B5735 /* Core.swift in Sources */,

README.md

@@ -269,13 +269,11 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
 class MyFloatingPanelLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .tip
-    var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
-            .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .bottom, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
+        .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .bottom, referenceGuide: .safeArea),
+    ]
 }
 ```
 
@@ -321,12 +319,11 @@ class ViewController: UIViewController, FloatingPanelControllerDelegate {
 class LandscapePanelLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .tip
-    var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 69.0, edge: .bottom, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .safeArea),
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 69.0, edge: .bottom, referenceGuide: .safeArea),
+    ]
+    
     func prepareLayout(surfaceView: UIView, in view: UIView) -> [NSLayoutConstraint] {
         return [
             surfaceView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor, constant: 8.0),
@@ -345,12 +342,10 @@ class LandscapePanelLayout: FloatingPanelLayout {
 class IntrinsicPanelLayout: FloatingPanelLayout {
     let position: FloatingPanelPosition = .bottom
     let initialState: FloatingPanelState = .full
-    var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelIntrinsicLayoutAnchor(absoluteOffset: 0, referenceGuide: .safeArea),
-            .half: FloatingPanelIntrinsicLayoutAnchor(fractionalOffset: 0.5, referenceGuide: .safeArea),
-        ]
-    }
+    let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelIntrinsicLayoutAnchor(absoluteOffset: 0, referenceGuide: .safeArea),
+        .half: FloatingPanelIntrinsicLayoutAnchor(fractionalOffset: 0.5, referenceGuide: .safeArea),
+    ]
     ...
 }
 ```
@@ -364,14 +359,11 @@ Use `.superview` reference guide in your anchors.
 ```swift
 class MyFullScreenLayout: FloatingPanelLayout {
     ...
-    var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] {
-        return [
-            .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .superview),
-            .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .superview),
-            .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .bottom, referenceGuide: .superview),
-        ]
-
-    }
+    let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+        .full: FloatingPanelLayoutAnchor(absoluteInset: 16.0, edge: .top, referenceGuide: .superview),
+        .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .superview),
+        .tip: FloatingPanelLayoutAnchor(absoluteInset: 44.0, edge: .bottom, referenceGuide: .superview),
+    ]
 }
 ```
 

Sources/BackdropView.swift

@@ -7,5 +7,19 @@ import UIKit
 public class BackdropView: UIView {
 
     /// The gesture recognizer for tap gestures to dismiss a panel.
-    @objc public var dismissalTapGestureRecognizer: UITapGestureRecognizer!
+    ///
+    /// By default, this gesture recognizer is disabled as following the default behavior of iOS modalities.
+    /// To dismiss a panel by tap gestures on the backdrop, `dismissalTapGestureRecognizer.isEnabled` is set to true.
+    @objc public var dismissalTapGestureRecognizer: UITapGestureRecognizer
+
+    init() {
+        dismissalTapGestureRecognizer = UITapGestureRecognizer()
+        dismissalTapGestureRecognizer.isEnabled = false
+        super.init(frame: .zero)
+        addGestureRecognizer(dismissalTapGestureRecognizer)
+    }
+
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
 }

Sources/Controller.swift

@@ -37,9 +37,9 @@ import UIKit
     @objc optional
     func floatingPanelShouldBeginDragging(_ fpc: FloatingPanelController) -> Bool
 
-    /// Called when the user drags the surface or the surface is attracted to a state anchor.
+    /// Called while the user drags the surface or the surface moves to a state anchor.
     @objc optional
-    func floatingPanelDidMove(_ fpc: FloatingPanelController) // any surface frame changes in dragging
+    func floatingPanelDidMove(_ fpc: FloatingPanelController)
 
     /// Called on start of dragging (may require some time and or distance to move)
     @objc optional
@@ -316,7 +316,7 @@ open class FloatingPanelController: UIViewController {
         // Change a layout for the new view size
         if let newLayout = self.delegate?.floatingPanel?(self, layoutFor: size) {
             layout = newLayout
-            activateLayout(forceLayout: false)
+            activateLayout(forceLayout: true)
         }
 
         if view.translatesAutoresizingMaskIntoConstraints {
@@ -335,7 +335,7 @@ open class FloatingPanelController: UIViewController {
         // Change a layout for the new trait collection
         if let newLayout = self.delegate?.floatingPanel?(self, layoutFor: newCollection) {
             self.layout = newLayout
-            activateLayout(forceLayout: false)
+            activateLayout(forceLayout: true)
         }
     }
 
@@ -401,8 +401,10 @@ open class FloatingPanelController: UIViewController {
     }
 
     private func activateLayout(forceLayout: Bool = false) {
-        floatingPanel.activateLayout(forceLayout: forceLayout,
-                                     contentInsetAdjustmentBehavior: contentInsetAdjustmentBehavior)
+        floatingPanel.activateLayout(
+            forceLayout: forceLayout,
+            contentInsetAdjustmentBehavior: contentInsetAdjustmentBehavior
+        )
     }
 
     func remove() {

Sources/Core.swift

@@ -66,9 +66,6 @@ class Core: NSObject, UIGestureRecognizerDelegate {
     private var stopScrollDeceleration: Bool = false
     private var scrollBounce = false
     private var scrollIndictorVisible = false
-    private var grabberAreaFrame: CGRect {
-        return surfaceView.grabberAreaFrame
-    }
 
     // MARK: - Interface
 
@@ -76,6 +73,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         ownerVC = vc
 
         surfaceView = SurfaceView()
+        surfaceView.position = layout.position
         surfaceView.backgroundColor = .white
 
         backdropView = BackdropView()
@@ -98,11 +96,9 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
         panGestureRecognizer.delegate = self
 
-        // Set tap-to-dismiss in the backdrop view
-        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
-        tapGesture.isEnabled = false
-        backdropView.dismissalTapGestureRecognizer = tapGesture
-        backdropView.addGestureRecognizer(tapGesture)
+        // Set the tap-to-dismiss action of the backdrop view.
+        // It's disabled by default. See also BackdropView.dismissalTapGestureRecognizer.
+        backdropView.dismissalTapGestureRecognizer.addTarget(self, action: #selector(handleBackdrop(tapGesture:)))
     }
 
     deinit {
@@ -199,8 +195,10 @@ class Core: NSObject, UIGestureRecognizerDelegate {
 
     // MARK: - Layout update
 
-    func activateLayout(forceLayout: Bool = false,
-                        contentInsetAdjustmentBehavior: FloatingPanelController.ContentInsetAdjustmentBehavior) {
+    func activateLayout(
+        forceLayout: Bool = false,
+        contentInsetAdjustmentBehavior: FloatingPanelController.ContentInsetAdjustmentBehavior
+    ) {
         layoutAdapter.prepareLayout()
 
         // preserve the current content offset if contentInsetAdjustmentBehavior is `.always`
@@ -210,7 +208,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         }
 
         layoutAdapter.updateStaticConstraint()
-        layoutAdapter.activateLayout(for: state, forceLayout: true)
+        layoutAdapter.activateLayout(for: state, forceLayout: forceLayout)
 
         // Update the backdrop alpha only when called in `Controller.show(animated:completion:)`
         // Because that prevents a backdrop flicking just before presenting a panel(#466).
@@ -277,7 +275,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
              is UIRotationGestureRecognizer,
              is UIScreenEdgePanGestureRecognizer,
              is UIPinchGestureRecognizer:
-            if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
+            if surfaceView.grabberAreaContains(gestureRecognizer.location(in: surfaceView)) {
                 return true
             }
             // all gestures of the tracking scroll view should be recognized in parallel
@@ -308,7 +306,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
             return true
         }
 
-        if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
+        if surfaceView.grabberAreaContains(gestureRecognizer.location(in: surfaceView)) {
             return true
         }
 
@@ -336,7 +334,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
                 scrollGestureRecognizers.contains(otherGestureRecognizer) {
                 switch otherGestureRecognizer {
                 case scrollView.panGestureRecognizer:
-                    if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
+                    if surfaceView.grabberAreaContains(gestureRecognizer.location(in: surfaceView)) {
                         return false
                     }
                     return allowScrollPanGesture(for: scrollView)
@@ -364,7 +362,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
                 // Should begin the pan gesture without waiting the dismiss gesture of a sheet modal.
                 return false
             }
-            if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
+            if surfaceView.grabberAreaContains(gestureRecognizer.location(in: surfaceView)) {
                 return false
             }
             // Do not begin the pan gesture until these gestures fail
@@ -409,7 +407,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
                         log.debug("settle offset --", value(of: initialScrollOffset))
                         stopScrolling(at: initialScrollOffset)
                     } else {
-                        if grabberAreaFrame.contains(location) {
+                        if surfaceView.grabberAreaContains(location) {
                             // Preserve the current content offset in moving from full.
                             stopScrolling(at: initialScrollOffset)
                         }
@@ -452,7 +450,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
                     }
                     if state == layoutAdapter.mostExpandedState {
                         // Adjust a small gap of the scroll offset just after swiping down starts in the grabber area.
-                        if grabberAreaFrame.contains(location), grabberAreaFrame.contains(initialLocation) {
+                        if surfaceView.grabberAreaContains(location), surfaceView.grabberAreaContains(initialLocation) {
                             stopScrolling(at: initialScrollOffset)
                         }
                     }
@@ -477,7 +475,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
                             }
                         }
                         // Adjust a small gap of the scroll offset just before swiping down starts in the grabber area,
-                        if grabberAreaFrame.contains(location), grabberAreaFrame.contains(initialLocation) {
+                        if surfaceView.grabberAreaContains(location), surfaceView.grabberAreaContains(initialLocation) {
                             stopScrolling(at: initialScrollOffset)
                         }
                     }
@@ -524,7 +522,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
                     // doesn't pass through .changed state after an interruptible animator is interrupted.
                     let diff = translation - .leastNonzeroMagnitude
                     layoutAdapter.updateInteractiveEdgeConstraint(diff: value(of: diff),
-                                                                  overflow: true,
+                                                                  scrollingContent: true,
                                                                   allowsRubberBanding: behaviorAdapter.allowsRubberBanding(for:))
                 }
                 panningEnd(with: translation, velocity: velocity)
@@ -585,19 +583,19 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         }
 
         // When the current point is within grabber area but the initial point is not, do scroll.
-        if grabberAreaFrame.contains(point), !grabberAreaFrame.contains(initialLocation) {
+        if surfaceView.grabberAreaContains(point), !surfaceView.grabberAreaContains(initialLocation) {
             return true
         }
 
         // When the initial point is within grabber area and the current point is out of surface, don't scroll.
-        if grabberAreaFrame.contains(initialLocation), !surfaceView.frame.contains(point) {
+        if surfaceView.grabberAreaContains(initialLocation), !surfaceView.frame.contains(point) {
             return false
         }
 
         let scrollViewFrame = scrollView.convert(scrollView.bounds, to: surfaceView)
         guard
             scrollViewFrame.contains(initialLocation), // When the initial point not in scrollView, don't scroll.
-            !grabberAreaFrame.contains(point)          // When point within grabber area, don't scroll.
+            !surfaceView.grabberAreaContains(point)        // When point within grabber area, don't scroll.
         else {
             return false
         }
@@ -640,7 +638,7 @@ class Core: NSObject, UIGestureRecognizerDelegate {
 
         guard let scrollView = scrollView else { return }
         if state == layoutAdapter.mostExpandedState {
-            if grabberAreaFrame.contains(location) {
+            if surfaceView.grabberAreaContains(location) {
                 initialScrollOffset = scrollView.contentOffset
             }
         } else {
@@ -653,10 +651,9 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         let pre = value(of: layoutAdapter.surfaceLocation)
         let diff = value(of: translation - initialTranslation)
         let next = pre + diff
-        let overflow = shouldOverflow(from: pre, to: next)
 
         layoutAdapter.updateInteractiveEdgeConstraint(diff: diff,
-                                                      overflow: overflow,
+                                                      scrollingContent: shouldScrollingContentInMoving(from: pre, to: next),
                                                       allowsRubberBanding: behaviorAdapter.allowsRubberBanding(for:))
 
         let cur = value(of: layoutAdapter.surfaceLocation)
@@ -670,32 +667,36 @@ class Core: NSObject, UIGestureRecognizerDelegate {
         }
     }
 
-    private func shouldOverflow(from pre: CGFloat, to next: CGFloat) -> Bool {
+    private func shouldScrollingContentInMoving(from pre: CGFloat, to next: CGFloat) -> Bool {
+        // Don't allow scrolling if the initial panning location is in the grabber area.
+        if surfaceView.grabberAreaContains(initialLocation) {
+            return false
+        }
         if let scrollView = scrollView, scrollView.panGestureRecognizer.state == .changed {
             switch layoutAdapter.position {
             case .top:
                 if pre > .zero, pre < next,
                     scrollView.contentSize.height > scrollView.bounds.height || scrollView.alwaysBounceVertical {
-                    return false
+                    return true
                 }
             case .left:
                 if pre > .zero, pre < next,
                     scrollView.contentSize.width > scrollView.bounds.width || scrollView.alwaysBounceHorizontal {
-                    return false
+                    return true
                 }
             case .bottom:
                 if pre > .zero, pre > next,
                     scrollView.contentSize.height > scrollView.bounds.height || scrollView.alwaysBounceVertical {
-                    return false
+                    return true
                 }
             case .right:
                 if pre > .zero, pre > next,
                     scrollView.contentSize.width > scrollView.bounds.width || scrollView.alwaysBounceHorizontal {
-                    return false
+                    return true
                 }
             }
         }
-        return true
+        return false
     }
 
     private func panningEnd(with translation: CGPoint, velocity: CGPoint) {
@@ -798,19 +799,24 @@ class Core: NSObject, UIGestureRecognizerDelegate {
 
         initialSurfaceLocation = layoutAdapter.surfaceLocation
         if state == layoutAdapter.mostExpandedState, let scrollView = scrollView {
-            if grabberAreaFrame.contains(location) {
+            if surfaceView.grabberAreaContains(location) {
                 initialScrollOffset = scrollView.contentOffset
             } else {
-                initialScrollOffset = scrollView.contentOffset
-                let offsetDiff = scrollView.contentOffset - contentOffsetForPinning(of: scrollView)
+                let pinningOffset = contentOffsetForPinning(of: scrollView)
+
+                // `scrollView.contentOffset` can be a value in [-30, 0) at this time by `allowScrollPanGesture(for:)`.
+                // Therefore the initial scroll offset must be reset to the pinning offset. Otherwise, the following
+                // `Fit the surface bounds` logic don't working and also the scroll content offset can be invalid.
+                initialScrollOffset = pinningOffset
+
+                // Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
+                let offsetDiff = scrollView.contentOffset - pinningOffset
                 switch layoutAdapter.position {
                 case .top, .left:
-                    // Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
                     if value(of: offsetDiff) > 0 {
                         offset = -offsetDiff
                     }
                 case .bottom, .right:
-                    // Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
                     if value(of: offsetDiff) < 0 {
                         offset = -offsetDiff
                     }

Sources/FloatingPanel.docc/FloatingPanel.md

@@ -44,6 +44,7 @@ The new interface displays the related contents and utilities in parallel as a u
 - ``FloatingPanelPosition``
 - ``FloatingPanelReferenceEdge``
 - ``FloatingPanelLayoutReferenceGuide``
+- ``FloatingPanelLayoutContentBoundingGuide``
 
 ### Behaviors
 

Sources/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>2.5.2</string>
+	<string>2.6.0</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 </dict>

Sources/Layout.swift

@@ -92,6 +92,9 @@ class LayoutAdapter {
 
     private var staticConstraint: NSLayoutConstraint?
 
+    /// A layout constraint to limit the content size in ``FloatingPanelAdaptiveLayoutAnchor``.
+    private var contentBoundingConstraint: NSLayoutConstraint?
+
     private var anchorStates: Set<FloatingPanelState> {
         return Set(layout.anchors.keys)
     }
@@ -330,12 +333,27 @@ class LayoutAdapter {
                 if anchor.referenceGuide == .safeArea {
                     referenceBoundsLength += position.inset(safeAreaInsets)
                 }
-                return dimension - diff
+                let maxPosition: CGFloat = {
+                    if let maxBounds = anchor.contentBoundingGuide.maxBounds(vc) {
+                        return layout.position.mainLocation(maxBounds.origin)
+                            + layout.position.mainDimension(maxBounds.size)
+                    } else {
+                        return .infinity
+                    }
+                }()
+                return min(dimension - diff, maxPosition)
             case .bottom, .right:
                 if anchor.referenceGuide == .safeArea {
                     referenceBoundsLength -= position.inset(safeAreaInsets)
                 }
-                return referenceBoundsLength - dimension + diff
+                let minPosition: CGFloat = {
+                    if let maxBounds = anchor.contentBoundingGuide.maxBounds(vc) {
+                        return layout.position.mainLocation(maxBounds.origin)
+                    } else {
+                        return -(.infinity)
+                    }
+                }()
+                return max(referenceBoundsLength - dimension + diff, minPosition)
             }
         case let anchor as FloatingPanelLayoutAnchor:
             let referenceBounds = anchor.referenceGuide == .safeArea ? bounds.inset(by: safeAreaInsets) : bounds
@@ -629,8 +647,9 @@ class LayoutAdapter {
     // The method is separated from prepareLayout(to:) for the rotation support
     // It must be called in FloatingPanelController.traitCollectionDidChange(_:)
     func updateStaticConstraint() {
-        NSLayoutConstraint.deactivate(constraint: staticConstraint)
+        NSLayoutConstraint.deactivate([staticConstraint, contentBoundingConstraint].compactMap{ $0 })
         staticConstraint = nil
+        contentBoundingConstraint = nil
 
         if vc.contentMode == .fitToBounds {
             surfaceView.containerOverflow = 0
@@ -654,7 +673,18 @@ class LayoutAdapter {
                 constant = 0.0
             }
             let baseAnchor = position.mainDimensionAnchor(anchor.contentLayoutGuide)
-            staticConstraint = surfaceAnchor.constraint(equalTo: baseAnchor, constant: constant)
+            if let boundingLayoutGuide = anchor.contentBoundingGuide.layoutGuide(vc) {
+                if anchor.isAbsolute {
+                    contentBoundingConstraint = baseAnchor.constraint(lessThanOrEqualTo: position.mainDimensionAnchor(boundingLayoutGuide),
+                                                               constant: anchor.offset)
+                } else {
+                    contentBoundingConstraint = baseAnchor.constraint(lessThanOrEqualTo: position.mainDimensionAnchor(boundingLayoutGuide),
+                                                               multiplier: anchor.offset)
+                }
+                staticConstraint = surfaceAnchor.constraint(lessThanOrEqualTo: baseAnchor, constant: constant)
+            } else {
+                staticConstraint = surfaceAnchor.constraint(equalTo: baseAnchor, constant: constant)
+            }
         default:
             switch position {
             case .top, .left:
@@ -673,12 +703,12 @@ class LayoutAdapter {
             staticConstraint?.identifier = "FloatingPanel-static-width"
         }
 
-        NSLayoutConstraint.activate(constraint: staticConstraint)
+        NSLayoutConstraint.activate([staticConstraint, contentBoundingConstraint].compactMap{ $0 })
 
         surfaceView.containerOverflow = position.mainDimension(vc.view.bounds.size)
     }
 
-    func updateInteractiveEdgeConstraint(diff: CGFloat, overflow: Bool, allowsRubberBanding: (UIRectEdge) -> Bool) {
+    func updateInteractiveEdgeConstraint(diff: CGFloat, scrollingContent: Bool, allowsRubberBanding: (UIRectEdge) -> Bool) {
         defer {
             log.debug("update surface location = \(surfaceLocation)")
         }
@@ -701,7 +731,7 @@ class LayoutAdapter {
             const = maxConst + rubberBandEffect(for: buffer, base: base)
         }
 
-        if overflow == false {
+        if scrollingContent {
             const = min(max(const, minConst), maxConst)
         }
 

Sources/LayoutAnchoring.swift

@@ -15,6 +15,11 @@ import UIKit
     ///
     /// The inset is an amount to inset a panel from an edge of the reference guide.  The edge refers to a panel
     /// positioning.
+    ///
+    /// - Parameters:
+    ///     - absoluteOffset: An absolute offset to attach the panel from the edge.
+    ///     - edge: Specify the edge of ``FloatingPanelController``'s view. This is the staring point of the offset.
+    ///     - referenceGuide: The rectangular area to lay out the content. If it's set to `.safeArea`, the panel content lays out inside the safe area of its ``FloatingPanelController``'s view.
     @objc public init(absoluteInset: CGFloat, edge: FloatingPanelReferenceEdge, referenceGuide: FloatingPanelLayoutReferenceGuide) {
         self.inset = absoluteInset
         self.referenceGuide = referenceGuide
@@ -27,6 +32,11 @@ import UIKit
     /// The inset is an amount to inset a panel from the edge of the specified reference guide. The value is
     /// a floating-point number in the range 0.0 to 1.0, where 0.0 represents zero distance from the edge and
     /// 1.0 represents a distance to the opposite edge.
+    ///
+    /// - Parameters:
+    ///     - fractionalOffset: A fractional value of the size of ``FloatingPanelController``'s view to attach the panel from the edge.
+    ///     - edge: Specify the edge of ``FloatingPanelController``'s view. This is the staring point of the offset.
+    ///     - referenceGuide: The rectangular area to lay out the content. If it's set to `.safeArea`, the panel content lays out inside the safe area of its ``FloatingPanelController``'s view.
     @objc public init(fractionalInset: CGFloat, edge: FloatingPanelReferenceEdge, referenceGuide: FloatingPanelLayoutReferenceGuide) {
         self.inset = fractionalInset
         self.referenceGuide = referenceGuide
@@ -49,7 +59,7 @@ public extension FloatingPanelLayoutAnchor {
         case .left:
             return layoutConstraints(layoutGuide, for: vc.surfaceView.rightAnchor)
         case .bottom:
-            return layoutConstraints(layoutGuide, for:  vc.surfaceView.topAnchor)
+            return layoutConstraints(layoutGuide, for: vc.surfaceView.topAnchor)
         case .right:
             return layoutConstraints(layoutGuide, for: vc.surfaceView.leftAnchor)
         }
@@ -101,6 +111,10 @@ public extension FloatingPanelLayoutAnchor {
     ///
     /// The offset is an amount to offset a position of panel that displays the entire content from an edge of
     /// the reference guide.  The edge refers to a panel positioning.
+    ///
+    /// - Parameters:
+    ///     - absoluteOffset: An absolute offset from the content size in the main dimension(i.e. y axis for a bottom panel) to attach the panel.
+    ///     - referenceGuide: The rectangular area to lay out the content. If it's set to `.safeArea`, the panel content lays out inside the safe area of its ``FloatingPanelController``'s view.
     @objc public init(absoluteOffset offset: CGFloat, referenceGuide: FloatingPanelLayoutReferenceGuide = .safeArea) {
         self.offset = offset
         self.referenceGuide = referenceGuide
@@ -111,6 +125,10 @@ public extension FloatingPanelLayoutAnchor {
     ///
     /// The offset value is a floating-point number in the range 0.0 to 1.0, where 0.0 represents the full content
     /// is displayed and 0.5 represents the half of content is displayed.
+    ///
+    /// - Parameters:
+    ///     - fractionalOffset: A fractional offset of the content size in the main dimension(i.e. y axis for a bottom panel) to attach the panel.
+    ///     - referenceGuide: The rectangular area to lay out the content. If it's set to `.safeArea`, the panel content lays out inside the safe area of its ``FloatingPanelController``'s view.
     @objc public init(fractionalOffset offset: CGFloat, referenceGuide: FloatingPanelLayoutReferenceGuide = .safeArea) {
         self.offset = offset
         self.referenceGuide = referenceGuide
@@ -144,37 +162,72 @@ public extension FloatingPanelIntrinsicLayoutAnchor {
 /// An object that defines how to settles a panel with a layout guide of a content view.
 @objc final public class FloatingPanelAdaptiveLayoutAnchor: NSObject, FloatingPanelLayoutAnchoring /*, NSCopying */ {
 
-    /// Returns a layout anchor with the specified offset by an absolute value, layout guide to display content and reference guide for a panel.
+    /// Returns a layout anchor with the specified offset by an absolute value to display a panel with its intrinsic content size.
     ///
     /// The offset is an amount to offset a position of panel that displays the entire content of the specified guide from an edge of
     /// the reference guide.  The edge refers to a panel positioning.
-    @objc public init(absoluteOffset offset: CGFloat, contentLayout: UILayoutGuide, referenceGuide: FloatingPanelLayoutReferenceGuide = .safeArea) {
+    ///
+    ///  ``contentBoundingGuide`` restricts the content size which a panel displays. For example, given ``referenceGuide`` is `.superview` and ``contentBoundingGuide`` is `.safeArea` for a bottom positioned panel, the panel content is laid out inside the superview of the view of FloatingPanelController(not its safe area), but its content size is limited to its safe area size. Normally both of ``referenceGuide`` and ``contentBoundingGuide`` are specified with the same rectangle area.
+    ///
+    /// - Parameters:
+    ///     - absoluteOffset: An absolute offset from the content size in the main dimension(i.e. y axis for a bottom panel) to attach the panel.
+    ///     - contentLayout: The content layout guide to calculate the content size in the panel.
+    ///     - referenceGuide: The rectangular area to lay out the content of a panel. If it's set to `.safeArea`, the panel content displays inside the safe area of its ``FloatingPanelController``'s view. This argument doesn't limit its content size.
+    ///     - contentBoundingGuide: The rectangular area to restrict the content size of a panel in the main dimension(i.e. y axis is the main dimension for a bottom panel).
+    ///
+    /// - Warning: If ``contentBoundingGuide`` is set to none, the panel may expand out of the screen size, depending on the intrinsic size of its content.
+    @objc public init(
+        absoluteOffset offset: CGFloat,
+        contentLayout: UILayoutGuide,
+        referenceGuide: FloatingPanelLayoutReferenceGuide,
+        contentBoundingGuide: FloatingPanelLayoutContentBoundingGuide = .none
+    ) {
         self.offset = offset
         self.contentLayoutGuide = contentLayout
         self.referenceGuide = referenceGuide
+        self.contentBoundingGuide = contentBoundingGuide
         self.isAbsolute = true
-
     }
 
-    /// Returns a layout anchor with the specified offset by a fractional value, layout guide to display content and reference guide for a panel.
+    /// Returns a layout anchor with the specified offset by a fractional value to display a panel with its intrinsic content size.
     ///
     /// The offset value is a floating-point number in the range 0.0 to 1.0, where 0.0 represents the full content
     /// is displayed and 0.5 represents the half of content is displayed.
-    @objc public init(fractionalOffset offset: CGFloat, contentLayout: UILayoutGuide, referenceGuide: FloatingPanelLayoutReferenceGuide = .safeArea) {
+    ///
+    ///  ``contentBoundingGuide`` restricts the content size which a panel displays. For example, given ``referenceGuide`` is `.superview` and ``contentBoundingGuide`` is `.safeArea` for a bottom positioned panel, the panel content is laid out inside the superview of the view of FloatingPanelController(not its safe area), but its content size is limited to its safe area size. Normally both of ``referenceGuide`` and ``contentBoundingGuide`` are specified with the same rectangle area.
+    ///
+    /// - Parameters:
+    ///     - fractionalOffset: A fractional offset of the content size in the main dimension(i.e. y axis for a bottom panel) to attach the panel.
+    ///     - contentLayout: The content layout guide to calculate the content size in the panel.
+    ///     - referenceGuide: The rectangular area to lay out the content of a panel. If it's set to `.safeArea`, the panel content displays inside the safe area of its ``FloatingPanelController``'s view. This argument doesn't limit its content size.
+    ///     - contentBoundingGuide: The rectangular area to restrict the content size of a panel in the main dimension(i.e. y axis is the main dimension for a bottom panel).
+    ///
+    /// - Warning: If ``contentBoundingGuide`` is set to none, the panel may expand out of the screen size, depending on the intrinsic size of its content.
+    @objc public init(
+        fractionalOffset offset: CGFloat,
+        contentLayout: UILayoutGuide,
+        referenceGuide: FloatingPanelLayoutReferenceGuide,
+        contentBoundingGuide: FloatingPanelLayoutContentBoundingGuide = .none
+    ) {
         self.offset = offset
         self.contentLayoutGuide = contentLayout
         self.referenceGuide = referenceGuide
+        self.contentBoundingGuide = contentBoundingGuide
         self.isAbsolute = false
     }
-    fileprivate let offset: CGFloat
-    fileprivate let isAbsolute: Bool
+    let offset: CGFloat
+    let isAbsolute: Bool
     let contentLayoutGuide: UILayoutGuide
     @objc public let referenceGuide: FloatingPanelLayoutReferenceGuide
+    @objc public let contentBoundingGuide: FloatingPanelLayoutContentBoundingGuide
 }
 
 public extension FloatingPanelAdaptiveLayoutAnchor {
     func layoutConstraints(_ vc: FloatingPanelController, for position: FloatingPanelPosition) -> [NSLayoutConstraint] {
+        var constraints = [NSLayoutConstraint]()
+
         let layoutGuide = referenceGuide.layoutGuide(vc: vc)
+        let offsetConstraint: NSLayoutConstraint
         let offsetAnchor: NSLayoutDimension
         switch position {
         case .top:
@@ -187,10 +240,13 @@ public extension FloatingPanelAdaptiveLayoutAnchor {
             offsetAnchor = vc.surfaceView.leftAnchor.anchorWithOffset(to: layoutGuide.rightAnchor)
         }
         if isAbsolute {
-            return [offsetAnchor.constraint(equalTo: position.mainDimensionAnchor(contentLayoutGuide), constant: -offset)]
+            offsetConstraint = offsetAnchor.constraint(equalTo: position.mainDimensionAnchor(contentLayoutGuide), constant: -offset)
         } else {
-            return [offsetAnchor.constraint(equalTo: position.mainDimensionAnchor(contentLayoutGuide), multiplier: (1 - offset))]
+            offsetConstraint = offsetAnchor.constraint(equalTo: position.mainDimensionAnchor(contentLayoutGuide), multiplier: (1 - offset))
         }
+        constraints.append(offsetConstraint)
+
+        return constraints
     }
 }
 

Sources/LayoutProperties.swift

@@ -27,7 +27,7 @@ extension FloatingPanelReferenceEdge {
     }
 }
 
-/// Constants that specify a layout guide to lay out a panel.
+/// A representation to specify a rectangular area to lay out a panel.
 @objc public enum FloatingPanelLayoutReferenceGuide: Int {
     case superview = 0
     case safeArea = 1
@@ -43,3 +43,34 @@ extension FloatingPanelLayoutReferenceGuide {
         }
     }
 }
+
+/// A representation to specify a bounding box which limit the content size of a panel.
+@objc public enum FloatingPanelLayoutContentBoundingGuide: Int {
+    case none = 0
+    case superview = 1
+    case safeArea = 2
+}
+
+extension FloatingPanelLayoutContentBoundingGuide {
+    func layoutGuide(_ fpc: FloatingPanelController) -> LayoutGuideProvider? {
+        switch self {
+        case .superview:
+            return fpc.view
+        case .safeArea:
+            return fpc.fp_safeAreaLayoutGuide
+        case .none:
+            return nil
+        }
+    }
+    func maxBounds(_ fpc: FloatingPanelController) -> CGRect? {
+        switch self {
+        case .superview:
+            return fpc.view.bounds
+        case .safeArea:
+            return fpc.view.bounds.inset(by: fpc.fp_safeAreaInsets)
+        case .none:
+            return nil
+        }
+    }
+
+}

Sources/SurfaceView.swift

@@ -54,7 +54,12 @@ public class SurfaceAppearance: NSObject {
     ///
     /// Defaults to `.circular`.
     @available(iOS 13.0, *)
-    public lazy var cornerCurve: CALayerCornerCurve = .circular
+    public var cornerCurve: CALayerCornerCurve {
+        get { _cornerCurve ?? .circular }
+        set { _cornerCurve = newValue }
+    }
+
+    private var _cornerCurve: CALayerCornerCurve?
 
     /// An array of shadows used to create drop shadows underneath a surface view.
     public var shadows: [Shadow] = [Shadow()]
@@ -442,4 +447,22 @@ public class SurfaceView: UIView {
     func hasStackView() -> Bool {
         return contentView?.subviews.reduce(false) { $0 || ($1 is UIStackView) } ?? false
     }
+
+    func grabberAreaContains(_ location: CGPoint) -> Bool {
+        // Sometimes a dragging finger's location is out of surface frame.
+        let cappedLocation: CGPoint
+        // Because the maximum width / height is out of bounds in CGRect.contains(_:)
+        let adjustment = 1 / fp_displayScale
+        switch position {
+        case .top:
+            cappedLocation = CGPoint(x: location.x, y: min(location.y, bounds.height - adjustment))
+        case .left:
+            cappedLocation = CGPoint(x: min(location.x, bounds.width - adjustment), y: location.y)
+        case .bottom:
+            cappedLocation = CGPoint(x: location.x, y: max(location.y, 0))
+        case .right:
+            cappedLocation = CGPoint(x: max(location.x, 0), y: location.y)
+        }
+        return grabberAreaFrame.contains(cappedLocation)
+    }
 }

Sources/Transitioning.swift

@@ -104,7 +104,10 @@ class ModalPresentTransition: NSObject, UIViewControllerAnimatedTransitioning {
             fpc?.suspendTransitionAnimator(false)
             transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
         }
-        return fpc.transitionAnimator!
+        guard let transitionAnimator = fpc.transitionAnimator else {
+            fatalError("The panel state must be `hidden` but it is `\(fpc.state)`")
+        }
+        return transitionAnimator
     }
 
     func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {

Tests/ControllerTests.swift

@@ -336,8 +336,7 @@ private class MyZombieViewController: UIViewController, FloatingPanelLayout, Flo
         return .half
     }
 
-    var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-        return [
+    let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
             .full: FloatingPanelLayoutAnchor(absoluteInset: UIScreen.main.bounds.height == 667.0 ? 18.0 : 16.0,
                                              edge: .top,
                                              referenceGuide: .superview),
@@ -347,6 +346,5 @@ private class MyZombieViewController: UIViewController, FloatingPanelLayout, Flo
             .tip: FloatingPanelLayoutAnchor(absoluteInset: 60.0,
                                             edge: .bottom,
                                             referenceGuide: .superview),
-        ]
-    }
+    ]
 }

Tests/CoreTests.swift

@@ -61,9 +61,8 @@ class CoreTests: XCTestCase {
         class FloatingPanelLayout1Positions: FloatingPanelLayout {
             let initialState: FloatingPanelState = .full
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [.full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview)]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] =
+                [.full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview)]
         }
 
         let delegate = FloatingPanelTestDelegate()
@@ -106,12 +105,10 @@ class CoreTests: XCTestCase {
         class FloatingPanelLayout2Positions: FloatingPanelLayout {
             let initialState: FloatingPanelState = .half
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
-                    .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
+                .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
+            ]
         }
 
         let delegate = FloatingPanelTestDelegate()
@@ -198,26 +195,41 @@ class CoreTests: XCTestCase {
                 }
             }
         }
-        let fpc = FloatingPanelController()
+        class BackdropTestLayout2: FloatingPanelTestLayout {
+            func backdropAlpha(for state: FloatingPanelState) -> CGFloat {
+                return 0.0
+            }
+        }
+        class TestDelegate: FloatingPanelControllerDelegate {
+            var layout: FloatingPanelLayout = BackdropTestLayout2()
+            func floatingPanel(_ fpc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout { layout }
+            func floatingPanel(_ fpc: FloatingPanelController, layoutFor size: CGSize) -> FloatingPanelLayout { layout }
+        }
+        func _floor(_ alpha: CGFloat) -> CGFloat {
+            return floor(fpc.backdropView.alpha * 1e+06) / 1e+06
+        }
+
+        let delegate = TestDelegate()
+        let fpc = FloatingPanelController(delegate: delegate)
         fpc.layout = BackdropTestLayout()
 
         fpc.showForTest()
 
         fpc.move(to: .full, animated: false)
-        XCTAssertEqual(floor(fpc.backdropView.alpha * 1000_000) / 1000_000, 0.3)
+        XCTAssertEqual(_floor(fpc.backdropView.alpha), 0.3)
 
         fpc.move(to: .half, animated: false)
         XCTAssertEqual(fpc.backdropView.alpha, 0.0)
 
         fpc.move(to: .tip, animated: false)
-        XCTAssertEqual(floor(fpc.backdropView.alpha * 1000_000) / 1000_000, 0.3)
+        XCTAssertEqual(_floor(fpc.backdropView.alpha), 0.3)
 
         let exp1 = expectation(description: "move to full with animation")
         fpc.move(to: .full, animated: true) {
             exp1.fulfill()
         }
         wait(for: [exp1], timeout: 1.0)
-        XCTAssertEqual(floor(fpc.backdropView.alpha * 1000_000) / 1000_000, 0.3)
+        XCTAssertEqual(_floor(fpc.backdropView.alpha), 0.3)
 
         let exp2 = expectation(description: "move to half with animation")
         fpc.move(to: .half, animated: true) {
@@ -226,23 +238,66 @@ class CoreTests: XCTestCase {
         wait(for: [exp2], timeout: 1.0)
         XCTAssertEqual(fpc.backdropView.alpha, 0.0)
 
+        // Test a content mode change of FloatingPanelController
+
         let exp3 = expectation(description: "move to tip with animation")
         fpc.move(to: .tip, animated: true) {
             exp3.fulfill()
         }
         fpc.contentMode = .fitToBounds
-        XCTAssertEqual(fpc.backdropView.alpha, 0.0) // Must not affect the backdrop alpha by changing the content mode
+        XCTAssertEqual(fpc.backdropView.alpha, 0.0)  // Must not affect the backdrop alpha by changing the content mode
         wait(for: [exp3], timeout: 1.0)
-        XCTAssertEqual(floor(fpc.backdropView.alpha * 1000_000) / 1000_000, 0.3)
+        XCTAssertEqual(_floor(fpc.backdropView.alpha), 0.3)
+
+        // Test a size class change of FloatingPanelController.view
+
+        fpc.move(to: .full, animated: false)
+        XCTAssertEqual(_floor(fpc.backdropView.alpha), 0.3)
+        fpc.willTransition(to: UITraitCollection(horizontalSizeClass: .regular), with: MockTransitionCoordinator())
+        XCTAssertEqual(fpc.backdropView.alpha, 0.0) // Must update the alpha by BackdropTestLayout2 in TestDelegate.
+
+        // Test a view size change of FloatingPanelController.view
+
+        fpc.move(to: .full, animated: false)
+        delegate.layout = BackdropTestLayout()
+        fpc.invalidateLayout()
+        XCTAssertEqual(_floor(fpc.backdropView.alpha), 0.3)
+
+        delegate.layout = BackdropTestLayout2()
+        fpc.viewWillTransition(to: CGSize.zero, with: MockTransitionCoordinator())
+        XCTAssertEqual(fpc.backdropView.alpha, 0.0) // Must update the alpha by BackdropTestLayout2 in TestDelegate.
+    }
+
+    func test_initial_surface_position() {
+        class FloatingPanelTestDelegate: FloatingPanelControllerDelegate {
+            class Layout: FloatingPanelLayout {
+                let initialState: FloatingPanelState = .full
+                let position: FloatingPanelPosition = .top
+                let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring]
+                    = [.full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .bottom, referenceGuide: .superview)]
+            }
+            func floatingPanel(_ fpc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout {
+                Layout()
+            }
+        }
+        do {
+            let delegate = FloatingPanelTestDelegate()
+            let fpc = FloatingPanelController(delegate: delegate)
+            XCTAssertEqual(fpc.surfaceView.position, .top)
+        }
+        do {
+            let fpc = FloatingPanelController()
+            fpc.layout = FloatingPanelTestDelegate.Layout()
+            XCTAssertEqual(fpc.surfaceView.position, .top)
+        }
     }
 
     func test_targetPosition_1positions() {
         class FloatingPanelLayout1Positions: FloatingPanelLayout {
             let initialState: FloatingPanelState = .full
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [.full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview)]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring]
+                = [.full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview)]
         }
 
         let delegate = FloatingPanelTestDelegate()
@@ -269,12 +324,10 @@ class CoreTests: XCTestCase {
         class FloatingPanelLayout2Positions: FloatingPanelLayout {
             let initialState: FloatingPanelState = .half
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
-                    .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
+                .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
+            ]
         }
 
         let delegate = FloatingPanelTestDelegate()
@@ -326,12 +379,10 @@ class CoreTests: XCTestCase {
         class FloatingPanelLayout2Positions: FloatingPanelLayout {
             let initialState: FloatingPanelState = .hidden
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
-                    .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
+                .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
+            ]
         }
 
         let delegate = FloatingPanelTestDelegate()
@@ -689,13 +740,11 @@ class CoreTests: XCTestCase {
         class FloatingPanelLayout3PositionsWithHidden: FloatingPanelLayout {
             let initialState: FloatingPanelState = .hidden
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
-                    .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
-                    .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 20.0, edge: .top, referenceGuide: .superview),
+                .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
+                .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
+            ]
         }
         let delegate = FloatingPanelTestDelegate()
         let fpc = FloatingPanelController(delegate: delegate)
@@ -721,13 +770,11 @@ class CoreTests: XCTestCase {
         class FloatingPanelLayout3Positions: FloatingPanelLayout {
             let initialState: FloatingPanelState = .hidden
             let position: FloatingPanelPosition = .bottom
-            var anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] {
-                return [
-                    .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
-                    .tip: FloatingPanelLayoutAnchor(absoluteInset: 60.0, edge: .bottom, referenceGuide: .superview),
-                    .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState : FloatingPanelLayoutAnchoring] = [
+                .half: FloatingPanelLayoutAnchor(absoluteInset: 250.0, edge: .bottom, referenceGuide: .superview),
+                .tip: FloatingPanelLayoutAnchor(absoluteInset: 60.0, edge: .bottom, referenceGuide: .superview),
+                .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
+            ]
         }
 
         let delegate = FloatingPanelTestDelegate()

Tests/LayoutTests.swift

@@ -17,23 +17,19 @@ class LayoutTests: XCTestCase {
         XCTAssertEqual(fpc.floatingPanel.layoutAdapter.leastExpandedState, .tip)
 
         class FloatingPanelLayoutWithHidden: FloatingPanelLayout {
-            var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring]  {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 18.0, edge: .top, referenceGuide: .safeArea),
-                    .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
-                    .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview)
-                ]
-            }
+            let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 18.0, edge: .top, referenceGuide: .safeArea),
+                .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
+                .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview)
+            ]
             let initialState: FloatingPanelState = .hidden
             let position: FloatingPanelPosition = .bottom
         }
         class FloatingPanelLayout2Positions: FloatingPanelLayout {
-            var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring]  {
-                return [
-                    .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
-                    .tip: FloatingPanelLayoutAnchor(absoluteInset: 69.0, edge: .bottom, referenceGuide: .safeArea),
-                ]
-            }
+            let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+                .half: FloatingPanelLayoutAnchor(fractionalInset: 0.5, edge: .bottom, referenceGuide: .safeArea),
+                .tip: FloatingPanelLayoutAnchor(absoluteInset: 69.0, edge: .bottom, referenceGuide: .safeArea),
+            ]
             let initialState: FloatingPanelState = .tip
             let position: FloatingPanelPosition = .bottom
         }
@@ -138,31 +134,31 @@ class LayoutTests: XCTestCase {
         var next: CGFloat
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: -100.0,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos + 100.0)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: tipPos - fullPos,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, tipPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: tipPos - fullPos + 100.0,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, tipPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: tipPos - fullPos + 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, tipPos + 100.0)
@@ -190,31 +186,31 @@ class LayoutTests: XCTestCase {
         var next: CGFloat
         pre = fpc.surfaceLocation.y
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: -100.0,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, pre)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, tipPos + 100.0)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: fullPos - tipPos,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: fullPos - tipPos + 100,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: fullPos - tipPos + 100,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos + 100.0)
@@ -224,12 +220,10 @@ class LayoutTests: XCTestCase {
 
     func test_updateInteractiveEdgeConstraintWithHidden() {
         class FloatingPanelLayout2Positions: FloatingPanelLayout {
-            var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring]  {
-                return [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 18.0, edge: .bottom, referenceGuide: .safeArea),
-                    .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 18.0, edge: .bottom, referenceGuide: .safeArea),
+                .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .bottom, referenceGuide: .superview),
+            ]
             let initialState: FloatingPanelState = .hidden
             let position: FloatingPanelPosition = .bottom
         }
@@ -245,19 +239,19 @@ class LayoutTests: XCTestCase {
         var next: CGFloat
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: -100.0,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: -100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos - 100.0)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: hiddenPos - fullPos + 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, hiddenPos + 100.0)
@@ -267,12 +261,10 @@ class LayoutTests: XCTestCase {
 
     func test_updateInteractiveEdgeConstraintWithHidden_bottomEdge() {
         class FloatingPanelLayout2Positions: FloatingPanelLayout {
-            var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring]  {
-                [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: 18.0, edge: .bottom, referenceGuide: .safeArea),
-                    .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .top, referenceGuide: .superview),
-                ]
-            }
+            let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: 18.0, edge: .bottom, referenceGuide: .safeArea),
+                .hidden: FloatingPanelLayoutAnchor(absoluteInset: 0, edge: .top, referenceGuide: .superview),
+            ]
             let initialState: FloatingPanelState = .hidden
             let position: FloatingPanelPosition = .top
         }
@@ -288,19 +280,19 @@ class LayoutTests: XCTestCase {
         var next: CGFloat
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: 100.0,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos + 100.0)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: hiddenPos - fullPos + 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, hiddenPos + 100.0)
@@ -310,12 +302,10 @@ class LayoutTests: XCTestCase {
 
     func test_updateInteractiveTopConstraintWithMinusInsets() {
         class FloatingPanelLayoutMinusInsets: FloatingPanelLayout {
-            var anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring]  {
-                [
-                    .full: FloatingPanelLayoutAnchor(absoluteInset: -200, edge: .top, referenceGuide: .safeArea),
-                    .tip: FloatingPanelLayoutAnchor(absoluteInset: -200, edge: .bottom, referenceGuide: .safeArea),
-                ]
-            }
+            let anchors: [FloatingPanelState: FloatingPanelLayoutAnchoring] = [
+                .full: FloatingPanelLayoutAnchor(absoluteInset: -200, edge: .top, referenceGuide: .safeArea),
+                .tip: FloatingPanelLayoutAnchor(absoluteInset: -200, edge: .bottom, referenceGuide: .safeArea),
+            ]
             let initialState: FloatingPanelState = .full
             let position: FloatingPanelPosition = .bottom
         }
@@ -328,19 +318,19 @@ class LayoutTests: XCTestCase {
 
         var next: CGFloat
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: -100.0,
-                                                                        overflow: false,
+                                                                        scrollingContent: true,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: -100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, fullPos - 100)
 
         fpc.floatingPanel.layoutAdapter.updateInteractiveEdgeConstraint(diff: tipPos - fullPos + 100.0,
-                                                                        overflow: true,
+                                                                        scrollingContent: false,
                                                                         allowsRubberBanding: fpc.floatingPanel.behaviorAdapter.allowsRubberBanding(for:))
         next = fpc.surfaceLocation.y
         XCTAssertEqual(next, tipPos + 100)

Tests/SurfaceViewTests.swift

@@ -228,4 +228,88 @@ class SurfaceViewTests: XCTestCase {
         XCTAssert(surface.containerView.layer.borderColor == UIColor.red.cgColor)
         XCTAssert(surface.containerView.layer.borderWidth == 3.0)
     }
+
+    func test_surfaceView_grabberArea() {
+        let sv = SurfaceView()
+        sv.bounds  = .init(x: 0, y: 0, width: 375, height: 500)
+        sv.grabberAreaOffset = 44.0
+        // Top
+        do {
+            sv.position = .top
+            XCTAssertEqual(sv.grabberAreaFrame,
+                           .init(x: 0,
+                                 y: sv.bounds.height - sv.grabberAreaOffset,
+                                 width: sv.bounds.width,
+                                 height: sv.grabberAreaOffset))
+        }
+        // Bottom
+        do {
+            sv.position = .bottom
+            XCTAssertEqual(sv.grabberAreaFrame,
+                           .init(x: 0,
+                                 y: 0,
+                                 width: sv.bounds.width,
+                                 height: sv.grabberAreaOffset))
+        }
+        // Left
+        do {
+            sv.position = .left
+            XCTAssertEqual(sv.grabberAreaFrame,
+                           .init(x: sv.bounds.width - sv.grabberAreaOffset,
+                                 y: 0,
+                                 width: sv.grabberAreaOffset,
+                                 height: sv.bounds.height))
+        }
+        // Right
+        do {
+            sv.position = .right
+            XCTAssertEqual(sv.grabberAreaFrame,
+                           .init(x: 0,
+                                 y: 0,
+                                 width: sv.grabberAreaOffset,
+                                 height: sv.bounds.height))
+        }
+    }
+
+    func test_surfaceView_grabberAreaDetection() {
+        let sv = SurfaceView()
+        sv.bounds  = .init(x: 0, y: 0, width: 375, height: 500)
+        // Top
+        do {
+            sv.position = .top
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: 0, y: sv.bounds.height)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width / 2, y: sv.bounds.height)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width / 2, y: sv.bounds.height + 2)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: -2, y: sv.bounds.height)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: -2, y: -2)))
+        }
+        // Bottom
+        do {
+            sv.position = .bottom
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: 0, y: 0)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width / 2, y: 0)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width / 2, y: -2)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: -2, y: 0)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: -2, y: -2)))
+        }
+        // Left
+        do {
+            sv.position = .left
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width, y: 0)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width, y: sv.bounds.height / 2)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: sv.bounds.width + 2, y: sv.bounds.height / 2)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: sv.bounds.width, y: -2)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: -2, y: -2)))
+        }
+        // Right
+        do {
+            sv.position = .right
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: 0, y: 0)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: 0, y: sv.bounds.height / 2)))
+            XCTAssertTrue(sv.grabberAreaContains(.init(x: -2, y: sv.bounds.height / 2)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: 0, y: -2)))
+            XCTAssertFalse(sv.grabberAreaContains(.init(x: -2, y: -2)))
+        }
+    }
+
 }

Tests/TestSupports.swift

@@ -77,3 +77,25 @@ class FloatingPanelProjectableBehavior: FloatingPanelBehavior {
         return true
     }
 }
+
+class MockTransitionCoordinator: NSObject, UIViewControllerTransitionCoordinator {
+    func animate(alongsideTransition animation: ((UIViewControllerTransitionCoordinatorContext) -> Void)?, completion: ((UIViewControllerTransitionCoordinatorContext) -> Void)? = nil) -> Bool { true }
+    func animateAlongsideTransition(in view: UIView?, animation: ((UIViewControllerTransitionCoordinatorContext) -> Void)?, completion: ((UIViewControllerTransitionCoordinatorContext) -> Void)? = nil) -> Bool { true }
+    func notifyWhenInteractionEnds(_ handler: @escaping (UIViewControllerTransitionCoordinatorContext) -> Void) {}
+    func notifyWhenInteractionChanges(_ handler: @escaping (UIViewControllerTransitionCoordinatorContext) -> Void) {}
+    var isAnimated: Bool = false
+    var presentationStyle: UIModalPresentationStyle = .fullScreen
+    var initiallyInteractive: Bool = false
+    var isInterruptible: Bool = false
+    var isInteractive: Bool = false
+    var isCancelled: Bool = false
+    var transitionDuration: TimeInterval = 0.25
+    var percentComplete: CGFloat = 0
+    var completionVelocity: CGFloat = 0
+    var completionCurve: UIView.AnimationCurve = .easeInOut
+    func viewController(forKey key: UITransitionContextViewControllerKey) -> UIViewController? { nil }
+    func view(forKey key: UITransitionContextViewKey) -> UIView? { nil }
+    var containerView: UIView { UIView() }
+    var targetTransform: CGAffineTransform = .identity
+}
+