Use two columns for trending links/accounts on wide screens

Tusker/Extensions/NSCollectionLayoutSection+Readable.swift

@@ -13,33 +13,39 @@ 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
+        guard let maximumReadableWidth = environment.maximumReadableWidth else {
-        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 - maximumReadableWidth) / 2)
-        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
     }
     
 }
+
+extension NSCollectionLayoutEnvironment {
+    var maximumReadableWidth: CGFloat? {
+        switch traitCollection.preferredContentSizeCategory {
+        case .extraSmall:
+            return 560
+        case .small:
+            return 600
+        case .medium:
+            return 632
+        case .large:
+            return 664
+        case .extraLarge:
+            return 744
+        case .extraExtraLarge:
+            return 816
+        case .extraExtraExtraLarge:
+            return 896
+        case .accessibilityMedium:
+            return 1096
+        default:
+            // greater accessibility sizes don't have a limit
+            return nil
+        }
+    }
+}

Tusker/Screens/Explore/SuggestedProfilesViewController.swift

@@ -46,9 +46,17 @@ class SuggestedProfilesViewController: UIViewController, CollectionViewControlle
                 
             case .accounts:
                 let size = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .estimated(280))
-                let item = NSCollectionLayoutItem(layoutSize: size)
+                let group: NSCollectionLayoutGroup
-                let item2 = NSCollectionLayoutItem(layoutSize: size)
+                if let maximumReadableWidth = environment.maximumReadableWidth,
-                let group = NSCollectionLayoutGroup.vertical(layoutSize: size, subitems: [item, item2])
+                   environment.container.contentSize.width >= maximumReadableWidth {
+                    let width = (environment.container.contentSize.width - 48) / 2
+                    group = .horizontal(layoutSize: size, subitems: [
+                        NSCollectionLayoutItem(layoutSize: .init(widthDimension: .absolute(width), heightDimension: .estimated(280))),
+                        NSCollectionLayoutItem(layoutSize: .init(widthDimension: .absolute(width), heightDimension: .estimated(280))),
+                    ])
+                } else {
+                    group = .vertical(layoutSize: size, subitems: [NSCollectionLayoutItem(layoutSize: size)])
+                }
                 group.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16)
                 group.interItemSpacing = .fixed(16)
                 let section = NSCollectionLayoutSection(group: group)

Tusker/Screens/Explore/TrendingLinksViewController.swift

@@ -50,9 +50,17 @@ class TrendingLinksViewController: UIViewController, CollectionViewController {
                 
             case .links:
                 let size = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .estimated(280))
-                let item = NSCollectionLayoutItem(layoutSize: size)
+                let group: NSCollectionLayoutGroup
-                let item2 = NSCollectionLayoutItem(layoutSize: size)
+                if let maximumReadableWidth = environment.maximumReadableWidth,
-                let group = NSCollectionLayoutGroup.vertical(layoutSize: size, subitems: [item, item2])
+                   environment.container.contentSize.width >= maximumReadableWidth {
+                    let width = (environment.container.contentSize.width - 48) / 2
+                    group = .horizontal(layoutSize: size, subitems: [
+                        NSCollectionLayoutItem(layoutSize: .init(widthDimension: .absolute(width), heightDimension: .estimated(280))),
+                        NSCollectionLayoutItem(layoutSize: .init(widthDimension: .absolute(width), heightDimension: .estimated(280))),
+                    ])
+                } else {
+                    group = .vertical(layoutSize: size, subitems: [NSCollectionLayoutItem(layoutSize: size)])
+                }
                 group.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16)
                 group.interItemSpacing = .fixed(16)
                 let section = NSCollectionLayoutSection(group: group)