chore: update sidebar color and Detail placeholder background color

Mastodon.xcodeproj/project.pbxproj

@@ -575,6 +575,7 @@
 		DBF156DF2701B17600EC00B7 /* SidebarAddAccountCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = DBF156DE2701B17600EC00B7 /* SidebarAddAccountCollectionViewCell.swift */; };
 		DBF156E22702DA6900EC00B7 /* UIStatusBarManager+HandleTapAction.m in Sources */ = {isa = PBXBuildFile; fileRef = DBF156E12702DA6900EC00B7 /* UIStatusBarManager+HandleTapAction.m */; };
 		DBF156E42702DB3F00EC00B7 /* HandleTapAction.swift in Sources */ = {isa = PBXBuildFile; fileRef = DBF156E32702DB3F00EC00B7 /* HandleTapAction.swift */; };
+		DBF1572F27046F1A00EC00B7 /* SecondaryPlaceholderViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = DBF1572E27046F1A00EC00B7 /* SecondaryPlaceholderViewController.swift */; };
 		DBF1D24E269DAF5D00C1C08A /* SearchDetailViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = DBF1D24D269DAF5D00C1C08A /* SearchDetailViewController.swift */; };
 		DBF1D251269DB01200C1C08A /* SearchHistoryViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = DBF1D250269DB01200C1C08A /* SearchHistoryViewController.swift */; };
 		DBF1D257269DBAC600C1C08A /* SearchDetailViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = DBF1D256269DBAC600C1C08A /* SearchDetailViewModel.swift */; };
@@ -1360,6 +1361,7 @@
 		DBF156E02702DA6800EC00B7 /* Mastodon-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "Mastodon-Bridging-Header.h"; sourceTree = "<group>"; };
 		DBF156E12702DA6900EC00B7 /* UIStatusBarManager+HandleTapAction.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "UIStatusBarManager+HandleTapAction.m"; sourceTree = "<group>"; };
 		DBF156E32702DB3F00EC00B7 /* HandleTapAction.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HandleTapAction.swift; sourceTree = "<group>"; };
+		DBF1572E27046F1A00EC00B7 /* SecondaryPlaceholderViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SecondaryPlaceholderViewController.swift; sourceTree = "<group>"; };
 		DBF1D24D269DAF5D00C1C08A /* SearchDetailViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SearchDetailViewController.swift; sourceTree = "<group>"; };
 		DBF1D250269DB01200C1C08A /* SearchHistoryViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SearchHistoryViewController.swift; sourceTree = "<group>"; };
 		DBF1D256269DBAC600C1C08A /* SearchDetailViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SearchDetailViewModel.swift; sourceTree = "<group>"; };
@@ -2554,6 +2556,7 @@
 				DB0EF72C26FDB1D600347686 /* View */,
 				DB852D1826FAEB6B00FC9D81 /* SidebarViewController.swift */,
 				DB852D1E26FB037800FC9D81 /* SidebarViewModel.swift */,
+				DBF1572E27046F1A00EC00B7 /* SecondaryPlaceholderViewController.swift */,
 			);
 			path = Sidebar;
 			sourceTree = "<group>";
@@ -3972,6 +3975,7 @@
 				DB36679F268ABAF20027D07F /* ComposeStatusAttachmentSection.swift in Sources */,
 				2DA7D04425CA52B200804E11 /* TimelineLoaderTableViewCell.swift in Sources */,
 				DB87D44B2609C11900D12C0D /* PollOptionView.swift in Sources */,
+				DBF1572F27046F1A00EC00B7 /* SecondaryPlaceholderViewController.swift in Sources */,
 				DB03F7F32689AEA3007B274C /* ComposeRepliedToStatusContentTableViewCell.swift in Sources */,
 				2D4AD8A826316D3500613EFC /* SelectedAccountItem.swift in Sources */,
 				DBE3CDFB261C6CA500430CC6 /* FavoriteViewModel.swift in Sources */,

Mastodon/Scene/Root/RootSplitViewController.swift

@@ -63,7 +63,7 @@ final class RootSplitViewController: UISplitViewController, NeedsDependency {
         
         setViewController(sidebarViewController, for: .primary)
         setViewController(supplementaryViewControllers[0], for: .supplementary)
-        setViewController(UIViewController(), for: .secondary)
+        setViewController(SecondaryPlaceholderViewController(), for: .secondary)
         setViewController(mainTabBarController, for: .compact)
     }
     

Mastodon/Scene/Root/Sidebar/SecondaryPlaceholderViewController.swift

@@ -0,0 +1,36 @@
+//
+//  SecondaryPlaceholderViewController.swift
+//  Mastodon
+//
+//  Created by Cirno MainasuK on 2021-9-29.
+//
+
+import UIKit
+import Combine
+
+final class SecondaryPlaceholderViewController: UIViewController {
+    var disposeBag = Set<AnyCancellable>()
+}
+
+extension SecondaryPlaceholderViewController {
+    
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        
+        setupBackground(theme: ThemeService.shared.currentTheme.value)
+        ThemeService.shared.currentTheme
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] theme in
+                guard let self = self else { return }
+                self.setupBackground(theme: theme)
+            }
+            .store(in: &disposeBag)
+    }
+    
+}
+
+extension SecondaryPlaceholderViewController {
+    private func setupBackground(theme: Theme) {
+        view.backgroundColor = theme.secondarySystemBackgroundColor
+    }
+}

Mastodon/Scene/Root/Sidebar/SidebarViewController.swift

@@ -35,6 +35,7 @@ final class SidebarViewController: UIViewController, NeedsDependency {
     static func createLayout() -> UICollectionViewLayout {
         let layout = UICollectionViewCompositionalLayout() { (sectionIndex, layoutEnvironment) -> NSCollectionLayoutSection? in
             var configuration = UICollectionLayoutListConfiguration(appearance: .sidebar)
+            configuration.backgroundColor = .clear
             if sectionIndex == SidebarViewModel.Section.tab.rawValue {
                 // with indentation
                 configuration.headerMode = .none
@@ -103,16 +104,23 @@ extension SidebarViewController {
     }
     
     private func setupBackground(theme: Theme) {
+        let color: UIColor = theme.sidebarBackgroundColor
         let barAppearance = UINavigationBarAppearance()
         barAppearance.configureWithOpaqueBackground()
-        barAppearance.backgroundColor = theme.sidebarBackgroundColor
+        barAppearance.backgroundColor = color
         barAppearance.shadowColor = .clear
         barAppearance.shadowImage = UIImage()   // remove separator line
         navigationItem.standardAppearance = barAppearance
         navigationItem.compactAppearance = barAppearance
         navigationItem.scrollEdgeAppearance = barAppearance
+        if #available(iOS 15.0, *) {
+            navigationItem.compactScrollEdgeAppearance = barAppearance
+        } else {
+            // Fallback on earlier versions
+        }
         
-        view.backgroundColor = theme.sidebarBackgroundColor
+        view.backgroundColor = color
+        collectionView.backgroundColor = color
     }
     
 }

Mastodon/Service/ThemeService/ThemeService+Appearance.swift

@@ -24,6 +24,9 @@ extension ThemeService {
         UINavigationBar.appearance().standardAppearance = appearance
         UINavigationBar.appearance().compactAppearance = appearance
         UINavigationBar.appearance().scrollEdgeAppearance = appearance
+        if #available(iOS 15.0, *) {
+            UINavigationBar.appearance().compactScrollEdgeAppearance = appearance
+        }
 
         // set tab bar appearance
         let tabBarAppearance = UITabBarAppearance()