Improve readable-width content inset behavior

Tusker.xcodeproj/project.pbxproj

@@ -286,6 +286,7 @@
 		D6CA6ED229EF6091003EC5DF /* TuskerPreferences in Frameworks */ = {isa = PBXBuildFile; productRef = D6CA6ED129EF6091003EC5DF /* TuskerPreferences */; };
 		D6CA8CDA2962231F0050C433 /* ArrayUniqueTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6CA8CD92962231F0050C433 /* ArrayUniqueTests.swift */; };
 		D6CA8CDE296387310050C433 /* SaveToPhotosActivity.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6CA8CDD296387310050C433 /* SaveToPhotosActivity.swift */; };
+		D6CF5B832AC65DDF00F15D83 /* NSCollectionLayoutSection+Readable.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6CF5B822AC65DDF00F15D83 /* NSCollectionLayoutSection+Readable.swift */; };
 		D6D12B2F2925D66500D528E1 /* TimelineGapCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6D12B2E2925D66500D528E1 /* TimelineGapCollectionViewCell.swift */; };
 		D6D12B56292D57E800D528E1 /* AccountCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6D12B55292D57E800D528E1 /* AccountCollectionViewCell.swift */; };
 		D6D12B58292D5B2C00D528E1 /* StatusActionAccountListCollectionViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6D12B57292D5B2C00D528E1 /* StatusActionAccountListCollectionViewController.swift */; };
@@ -685,6 +686,7 @@
 		D6CA6ED029EF6060003EC5DF /* TuskerPreferences */ = {isa = PBXFileReference; lastKnownFileType = wrapper; name = TuskerPreferences; path = Packages/TuskerPreferences; sourceTree = "<group>"; };
 		D6CA8CD92962231F0050C433 /* ArrayUniqueTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ArrayUniqueTests.swift; sourceTree = "<group>"; };
 		D6CA8CDD296387310050C433 /* SaveToPhotosActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SaveToPhotosActivity.swift; sourceTree = "<group>"; };
+		D6CF5B822AC65DDF00F15D83 /* NSCollectionLayoutSection+Readable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NSCollectionLayoutSection+Readable.swift"; sourceTree = "<group>"; };
 		D6D12B2E2925D66500D528E1 /* TimelineGapCollectionViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TimelineGapCollectionViewCell.swift; sourceTree = "<group>"; };
 		D6D12B55292D57E800D528E1 /* AccountCollectionViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AccountCollectionViewCell.swift; sourceTree = "<group>"; };
 		D6D12B57292D5B2C00D528E1 /* StatusActionAccountListCollectionViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusActionAccountListCollectionViewController.swift; sourceTree = "<group>"; };
@@ -1245,6 +1247,7 @@
 				D61F75AC293AF39000C0B37F /* Filter+Helpers.swift */,
 				D6C3F5162991C1A00009FCFF /* View+AppListStyle.swift */,
 				D691771029A2B76A0054D7EF /* MainActor+Unsafe.swift */,
+				D6CF5B822AC65DDF00F15D83 /* NSCollectionLayoutSection+Readable.swift */,
 			);
 			path = Extensions;
 			sourceTree = "<group>";
@@ -2218,6 +2221,7 @@
 				D6C3F5172991C1A00009FCFF /* View+AppListStyle.swift in Sources */,
 				D65B4B6A297777D900DABDFB /* StatusNotFoundView.swift in Sources */,
 				D6412B0924B0291E00F5412E /* MyProfileViewController.swift in Sources */,
+				D6CF5B832AC65DDF00F15D83 /* NSCollectionLayoutSection+Readable.swift in Sources */,
 				D601FA5D297B2E6F00A8E8B5 /* ConversationCollectionViewController.swift in Sources */,
 				D6D12B56292D57E800D528E1 /* AccountCollectionViewCell.swift in Sources */,
 				D60088F22980DAA0005B4D00 /* TipJarView.swift in Sources */,

Tusker/Extensions/NSCollectionLayoutSection+Readable.swift

@@ -0,0 +1,45 @@
+//
+//  NSCollectionLayoutSection+Readable.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 9/28/23.
+//  Copyright © 2023 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+
+extension NSCollectionLayoutSection {
+    
+    // The .readableContent insets reference has a bunch of weird behavior,
+    // so just calculate the content inset ourselves.
+    func readableContentInset(in environment: NSCollectionLayoutEnvironment) {
+        let maxWidth: CGFloat
+        switch environment.traitCollection.preferredContentSizeCategory {
+        case .extraSmall:
+            maxWidth = 560
+        case .small:
+            maxWidth = 600
+        case .medium:
+            maxWidth = 632
+        case .large:
+            maxWidth = 664
+        case .extraLarge:
+            maxWidth = 744
+        case .extraExtraLarge:
+            maxWidth = 816
+        case .extraExtraExtraLarge:
+            maxWidth = 896
+        case .accessibilityMedium:
+            maxWidth = 1096
+        default:
+            // greater accessibility sizes don't have a limit
+            return
+        }
+        
+        let inset = max(0, (environment.container.contentSize.width - maxWidth) / 2)
+        // make sure not to overwrite the vertical insets, which are non-zero for grouped styles
+        contentInsets.leading = inset
+        contentInsets.trailing = inset
+    }
+    
+}

Tusker/Screens/Account Follows/AccountFollowsListViewController.swift

@@ -56,9 +56,7 @@ class AccountFollowsListViewController: UIViewController, CollectionViewControll
         }
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         view = UICollectionView(frame: .zero, collectionViewLayout: layout)

Tusker/Screens/Account List/AccountListViewController.swift

@@ -35,9 +35,7 @@ class AccountListViewController: UIViewController, CollectionViewController {
         config.backgroundColor = .appGroupedBackground
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         view = UICollectionView(frame: .zero, collectionViewLayout: layout)

Tusker/Screens/Conversation/ConversationCollectionViewController.swift

@@ -59,10 +59,12 @@ class ConversationCollectionViewController: UIViewController, CollectionViewCont
             config.bottomSeparatorInsets = TimelineStatusCollectionViewCell.separatorInsets
             return config
         }
-        // we're not using contenetInsetsReference = .readableContent here because it always insets the cells even if
+        let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
-        // the collection view's actual width is narrow enough to fit in the readable width, resulting in a bit of the
+            let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-        // background color always peeking through the edges
+            section.readableContentInset(in: environment)
-        let layout = UICollectionViewCompositionalLayout.list(using: config)
+            return section
+        }
+        viewRespectsSystemMinimumLayoutMargins = false
         view = UICollectionView(frame: .zero, collectionViewLayout: layout)
         // something about the autoresizing mask breaks resizing the vc
         view.translatesAutoresizingMaskIntoConstraints = false

Tusker/Screens/Explore/TrendingStatusesViewController.swift

@@ -62,9 +62,7 @@ class TrendingStatusesViewController: UIViewController, CollectionViewController
         }
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         view = UICollectionView(frame: .zero, collectionViewLayout: layout)

Tusker/Screens/Local Predicate Statuses List/LocalPredicateStatusesViewController.swift

@@ -68,9 +68,7 @@ class LocalPredicateStatusesViewController: UIViewController, CollectionViewCont
         }
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         view = UICollectionView(frame: .zero, collectionViewLayout: layout)

Tusker/Screens/Notifications/NotificationsCollectionViewController.swift

@@ -93,9 +93,7 @@ class NotificationsCollectionViewController: UIViewController, TimelineLikeColle
         }
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)

Tusker/Screens/Profile/ProfileStatusesViewController.swift

@@ -91,9 +91,7 @@ class ProfileStatusesViewController: UIViewController, TimelineLikeCollectionVie
                 return .list(using: config, layoutEnvironment: environment)
             } else {
                 let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-                if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+                section.readableContentInset(in: environment)
-                    section.contentInsetsReference = .readableContent
-                }
                 return section
             }
         }

Tusker/Screens/Status Action Account List/StatusActionAccountListCollectionViewController.swift

@@ -60,6 +60,7 @@ class StatusActionAccountListCollectionViewController: UIViewController, Collect
             return config
         }
         let layout = UICollectionViewCompositionalLayout { [unowned self] sectionIndex, environment in
+            let section: NSCollectionLayoutSection
             switch dataSource.sectionIdentifier(for: sectionIndex)! {
             case .status:
                 var config = UICollectionLayoutListConfiguration(appearance: .grouped)
@@ -71,14 +72,12 @@ class StatusActionAccountListCollectionViewController: UIViewController, Collect
                 config.trailingSwipeActionsConfigurationProvider = { [unowned self] in
                     (collectionView.cellForItem(at: $0) as? TimelineStatusCollectionViewCell)?.trailingSwipeActions()
                 }
-                let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
+                section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-                if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
-                    section.contentInsetsReference = .readableContent
-                }
-                return section
             case .accounts:
-                return NSCollectionLayoutSection.list(using: accountsConfig, layoutEnvironment: environment)
+                section = NSCollectionLayoutSection.list(using: accountsConfig, layoutEnvironment: environment)
             }
+            section.readableContentInset(in: environment)
+            return section
         }
         view = UICollectionView(frame: .zero, collectionViewLayout: layout)
         collectionView.delegate = self

Tusker/Screens/Status Edit History/StatusEditHistoryViewController.swift

@@ -54,9 +54,7 @@ class StatusEditHistoryViewController: UIViewController, CollectionViewControlle
         }
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -109,12 +109,10 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
             }
             return config
         }
-        // just setting layout.configuration.contentInsetsReference doesn't work with UICollectionViewCompositionalLayout.list
+        // Use the sectionProvider closure, because the content inset depends on the environment.
         let layout = UICollectionViewCompositionalLayout { sectionIndex, environment in
             let section = NSCollectionLayoutSection.list(using: config, layoutEnvironment: environment)
-            if UIDevice.current.userInterfaceIdiom == .pad || UIDevice.current.userInterfaceIdiom == .mac {
+            section.readableContentInset(in: environment)
-                section.contentInsetsReference = .readableContent
-            }
             return section
         }
         collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)