Use browser-style navigation bars on iPad

Tusker.xcodeproj/project.pbxproj

@@ -88,6 +88,7 @@
 		D63661C02381C144004B9E16 /* PreferencesNavigationController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D63661BF2381C144004B9E16 /* PreferencesNavigationController.swift */; };
 		D6370B9C24421FF30092A7FF /* Tusker.xcdatamodeld in Sources */ = {isa = PBXBuildFile; fileRef = D6370B9A24421FF30092A7FF /* Tusker.xcdatamodeld */; };
 		D63A8D0B2561C27F00D9DFFF /* ProfileStatusesViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D63A8D0A2561C27F00D9DFFF /* ProfileStatusesViewController.swift */; };
+		D63D8DF42850FE7A008D95E1 /* ViewTags.swift in Sources */ = {isa = PBXBuildFile; fileRef = D63D8DF32850FE7A008D95E1 /* ViewTags.swift */; };
 		D63F9C6E241D2D85004C03CF /* CompositionAttachment.swift in Sources */ = {isa = PBXBuildFile; fileRef = D63F9C6D241D2D85004C03CF /* CompositionAttachment.swift */; };
 		D6403CC224A6B72D00E81C55 /* VisualEffectImageButton.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6403CC124A6B72D00E81C55 /* VisualEffectImageButton.swift */; };
 		D640D76922BAF5E6004FBE69 /* DomainBlocks.plist in Resources */ = {isa = PBXBuildFile; fileRef = D640D76822BAF5E6004FBE69 /* DomainBlocks.plist */; };
@@ -434,6 +435,7 @@
 		D63661BF2381C144004B9E16 /* PreferencesNavigationController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesNavigationController.swift; sourceTree = "<group>"; };
 		D6370B9B24421FF30092A7FF /* Tusker.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = Tusker.xcdatamodel; sourceTree = "<group>"; };
 		D63A8D0A2561C27F00D9DFFF /* ProfileStatusesViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ProfileStatusesViewController.swift; sourceTree = "<group>"; };
+		D63D8DF32850FE7A008D95E1 /* ViewTags.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ViewTags.swift; sourceTree = "<group>"; };
 		D63F9C6D241D2D85004C03CF /* CompositionAttachment.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CompositionAttachment.swift; sourceTree = "<group>"; };
 		D6403CC124A6B72D00E81C55 /* VisualEffectImageButton.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VisualEffectImageButton.swift; sourceTree = "<group>"; };
 		D640D76822BAF5E6004FBE69 /* DomainBlocks.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = DomainBlocks.plist; sourceTree = "<group>"; };
@@ -1372,6 +1374,7 @@
 				D6C693EE216192C2007D6A6D /* TuskerNavigationDelegate.swift */,
 				D6DFC69F242C4CCC00ACC392 /* WeakArray.swift */,
 				D62E9988279DB2D100C26176 /* InstanceFeatures.swift */,
+				D63D8DF32850FE7A008D95E1 /* ViewTags.swift */,
 				D6D4DDD6212518A200E1C4BB /* Assets.xcassets */,
 				D6AEBB3F2321640F00E5038B /* Activities */,
 				D6F1F84E2193B9BE00F5FE67 /* Caching */,
@@ -1821,6 +1824,7 @@
 				D681E4D5246E2BC30053414F /* UnmuteConversationActivity.swift in Sources */,
 				D6B4A4FF2506B81A000C81C1 /* AccountDisplayNameLabel.swift in Sources */,
 				D6C143E025354E34007DC240 /* EmojiPickerCollectionViewController.swift in Sources */,
+				D63D8DF42850FE7A008D95E1 /* ViewTags.swift in Sources */,
 				D6B053A623BD2D0C00A066FA /* AssetCollectionViewController.swift in Sources */,
 				D67B506D250B291200FAECFB /* BlurHashDecode.swift in Sources */,
 				D62275A024F1677200B82A16 /* ComposeHostingController.swift in Sources */,

Tusker/Screens/Compose/ComposeHostingController.swift

@@ -15,9 +15,6 @@ protocol ComposeHostingControllerDelegate: AnyObject {
     func dismissCompose(mode: ComposeUIState.DismissMode) -> Bool
 }
 
-private let VISIBILITY_BAR_BUTTON_TAG = 42001
-private let LOCAL_ONLY_BAR_BUTTON_TAG = 42002
-
 class ComposeHostingController: UIHostingController<ComposeContainerView> {
     
     weak var delegate: ComposeHostingControllerDelegate?
@@ -135,12 +132,12 @@ class ComposeHostingController: UIHostingController<ComposeContainerView> {
         items.append(UIBarButtonItem(title: "CW", style: .plain, target: self, action: #selector(cwButtonPressed)))
         
         let visibilityItem = UIBarButtonItem(image: nil, style: .plain, target: nil, action: nil)
-        visibilityItem.tag = VISIBILITY_BAR_BUTTON_TAG
+        visibilityItem.tag = ViewTags.composeVisibilityBarButton
         items.append(visibilityItem)
         
         if mastodonController.instanceFeatures.localOnlyPosts {
             let item = UIBarButtonItem(image: nil, style: .plain, target: nil, action: nil)
-            item.tag = LOCAL_ONLY_BAR_BUTTON_TAG
+            item.tag = ViewTags.composeLocalOnlyBarButton
             items.append(item)
             localOnlyChanged(draft.localOnly)
         }
@@ -243,7 +240,7 @@ class ComposeHostingController: UIHostingController<ComposeContainerView> {
     
     private func visibilityChanged(_ newVisibility: Status.Visibility) {
         for toolbar in [mainToolbar, inputAccessoryToolbar] {
-            guard let item = toolbar?.items?.first(where: { $0.tag == VISIBILITY_BAR_BUTTON_TAG }) else {
+            guard let item = toolbar?.items?.first(where: { $0.tag == ViewTags.composeVisibilityBarButton }) else {
                 continue
             }
             item.image = UIImage(systemName: newVisibility.imageName)
@@ -260,7 +257,7 @@ class ComposeHostingController: UIHostingController<ComposeContainerView> {
     
     private func localOnlyChanged(_ localOnly: Bool) {
         for toolbar in [mainToolbar, inputAccessoryToolbar] {
-            guard let item = toolbar?.items?.first(where: { $0.tag == LOCAL_ONLY_BAR_BUTTON_TAG }) else {
+            guard let item = toolbar?.items?.first(where: { $0.tag == ViewTags.composeLocalOnlyBarButton }) else {
                 continue
             }
             if localOnly {

Tusker/Screens/Main/MainSplitViewController.swift

@@ -46,7 +46,9 @@ class MainSplitViewController: UISplitViewController {
         setViewController(sidebar, for: .primary)
         primaryBackgroundStyle = .sidebar
 
-        setViewController(EnhancedNavigationViewController(), for: .secondary)
+        let secondaryNav = EnhancedNavigationViewController()
+        secondaryNav.useBrowserStyleNavigation = true
+        setViewController(secondaryNav, for: .secondary)
         // don't unnecesarily construct a content VC unless the we're in actually split mode
         // when we change from compact -> split for the first time, the VC will be transferred anyways
         if traitCollection.horizontalSizeClass != .compact {

Tusker/Screens/Main/MainTabBarViewController.swift

@@ -141,7 +141,9 @@ class MainTabBarViewController: UITabBarController, UITabBarControllerDelegate {
         if let vc = vc as? UINavigationController {
             return vc
         } else {
-            return EnhancedNavigationViewController(rootViewController: vc)
+            let nav = EnhancedNavigationViewController(rootViewController: vc)
+            nav.useBrowserStyleNavigation = true
+            return nav
         }
     }
     

Tusker/Screens/Utilities/EnhancedNavigationViewController.swift

@@ -10,42 +10,68 @@ import UIKit
 
 class EnhancedNavigationViewController: UINavigationController {
     
+    var useBrowserStyleNavigation = false
+    
     var poppedViewControllers = [UIViewController]()
     var skipResetPoppedOnNextPush = false
     
     private var interactivePushTransition: InteractivePushTransition!
     
+    override var viewControllers: [UIViewController] {
+        didSet {
+            poppedViewControllers = []
+            for vc in viewControllers {
+                configureNavItem(vc.navigationItem)
+            }
+            updateTopNavItemState()
+        }
+    }
+    
     override func viewDidLoad() {
         super.viewDidLoad()
 
         self.interactivePushTransition = InteractivePushTransition(navigationController: self)
+        
+        if let topViewController {
+            configureNavItem(topViewController.navigationItem)
+            updateTopNavItemState()
+        }
     }
     
     override func popViewController(animated: Bool) -> UIViewController? {
-        if let popped = super.popViewController(animated: animated) {
+        let popped = performAfterAnimating(block: {
+            super.popViewController(animated: animated)
+        }, after: {
+            self.updateTopNavItemState()
+        }, animated: animated)
+        if let popped {
             poppedViewControllers.insert(popped, at: 0)
-            return popped
-        } else {
-            return nil
         }
+        return popped
     }
     
     override func popToRootViewController(animated: Bool) -> [UIViewController]? {
-        if let popped = super.popToRootViewController(animated: animated) {
+        let popped = performAfterAnimating(block: {
+            super.popToRootViewController(animated: animated)
+        }, after: {
+            self.updateTopNavItemState()
+        }, animated: animated)
+        if let popped {
             poppedViewControllers = popped
-            return popped
-        } else {
-            return nil
         }
+        return popped
     }
     
     override func popToViewController(_ viewController: UIViewController, animated: Bool) -> [UIViewController]? {
-        if let popped = super.popToViewController(viewController, animated: animated) {
+        let popped = performAfterAnimating(block: {
+            super.popToViewController(viewController, animated: animated)
+        }, after: {
+            self.updateTopNavItemState()
+        }, animated: animated)
+        if let popped {
             poppedViewControllers.insert(contentsOf: popped, at: 0)
-            return popped
-        } else {
-            return nil
         }
+        return popped
     }
     
     override func pushViewController(_ viewController: UIViewController, animated: Bool) {
@@ -54,7 +80,43 @@ class EnhancedNavigationViewController: UINavigationController {
         } else {
             self.poppedViewControllers = []
         }
+        
+        configureNavItem(viewController.navigationItem)
+        
         super.pushViewController(viewController, animated: animated)
+        
+        updateTopNavItemState()
+    }
+    
+    func pushPoppedViewController() {
+        guard !poppedViewControllers.isEmpty else {
+            return
+        }
+        skipResetPoppedOnNextPush = true
+        pushViewController(poppedViewControllers.removeFirst(), animated: true)
+    }
+    
+    func pushToPoppedViewController(_ target: UIViewController) {
+        guard poppedViewControllers.contains(target) else {
+            return
+        }
+        var toInsert: [UIViewController] = []
+        while true {
+            let vc = poppedViewControllers.removeFirst()
+            if vc == target {
+                break
+            } else {
+                toInsert.append(vc)
+            }
+        }
+        // match the system behavior when popping multiple by animated-ly pushing the final destination one,
+        // and then intersiting the intermediary ones before it, as if they'd all been pushed together
+        performAfterAnimating(block: {
+            pushViewController(target, animated: true)
+        }, after: {
+            self.viewControllers.insert(contentsOf: toInsert, at: self.viewControllers.count - 1)
+            self.updateTopNavItemState()
+        }, animated: true)
     }
     
     func onWillShow() {
@@ -73,6 +135,92 @@ class EnhancedNavigationViewController: UINavigationController {
         })
     }
     
+    private func configureNavItem(_ navItem: UINavigationItem) {
+        guard useBrowserStyleNavigation,
+              UIDevice.current.userInterfaceIdiom != .phone else {
+            return
+        }
+        navItem.style = .browser
+        navItem.hidesBackButton = true
+        if let titleView = navItem.titleView,
+           titleView.tag != ViewTags.navEmptyTitleView {
+            // blergh, i don't like changing this out from under some other view controller
+            // we use an empty view because otherwise the title label displays in addition to the new title view bar button item
+            navItem.titleView = UIView()
+            navItem.titleView?.tag = ViewTags.navEmptyTitleView
+            // TODO: centerItemGroups don't animate out during nav transitions, the just (dis)appear abruptly
+            navItem.centerItemGroups = [
+                .fixedGroup(items: [UIBarButtonItem(customView: titleView)])
+            ]
+        }
+        let back = UIBarButtonItem(image: UIImage(systemName: "chevron.backward"), style: .plain, target: self, action: #selector(goBack))
+        back.tag = ViewTags.navBackBarButton
+        back.menu = UIMenu(children: [
+            UIDeferredMenuElement({ [unowned self] completion in
+                completion(self.viewControllers.dropLast(1).reversed().map { vc in
+                    UIAction(title: vc.navigationItem.title ?? "Back") { [weak self] _ in
+                        _ = self?.popToViewController(vc, animated: true)
+                    }
+                })
+            })
+        ])
+        let forward = UIBarButtonItem(image: UIImage(systemName: "chevron.forward"), style: .plain, target: self, action: #selector(goForward))
+        forward.tag = ViewTags.navForwardBarButton
+        forward.menu = UIMenu(children: [
+            UIDeferredMenuElement.uncached({ [unowned self] completion in
+                completion(poppedViewControllers.map { vc in
+                    UIAction(title: vc.navigationItem.title ?? "Forward") { [weak self] _ in
+                        self?.pushToPoppedViewController(vc)
+                    }
+                })
+            })
+        ])
+        navItem.leadingItemGroups = [
+            .fixedGroup(items: [
+                back,
+                forward,
+            ])
+        ]
+    }
+    
+    private func updateTopNavItemState() {
+        guard useBrowserStyleNavigation,
+              UIDevice.current.userInterfaceIdiom != .phone,
+              let vc = topViewController,
+              let group = vc.navigationItem.leadingItemGroups.first,
+              group.barButtonItems.count == 2,
+              group.barButtonItems[0].tag == ViewTags.navBackBarButton,
+              group.barButtonItems[1].tag == ViewTags.navForwardBarButton else {
+            return
+        }
+        group.barButtonItems[0].isEnabled = viewControllers.count > 1
+        group.barButtonItems[1].isEnabled = !poppedViewControllers.isEmpty
+    }
+    
+    private func performAfterAnimating<R>(block: () -> R, after: @escaping () -> Void, animated: Bool) -> R {
+        if animated {
+            CATransaction.begin()
+            let result = block()
+            CATransaction.setCompletionBlock {
+                after()
+            }
+            CATransaction.commit()
+            return result
+        } else {
+            let result = block()
+            after()
+            return result
+        }
+    }
+    
+    @objc private func goBack() {
+        _ = popViewController(animated: true)
+    }
+    
+    @objc private func goForward() {
+        pushPoppedViewController()
+    }
+
 }
 
 extension EnhancedNavigationViewController: BackgroundableViewController {

Tusker/Screens/Utilities/SegmentedPageViewController.swift

@@ -24,6 +24,12 @@ class SegmentedPageViewController: UIPageViewController, UIPageViewControllerDel
         super.init(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
 
         self.delegate = self
+        
+        // this needs to happen in init because EnhancedNavigationViewController expects to be able to look at the titleView
+        // before the view has necessarily loaded
+        segmentedControl = UISegmentedControl(items: titles)
+        segmentedControl.addTarget(self, action: #selector(segmentedControlChanged), for: .valueChanged)
+        navigationItem.titleView = segmentedControl
     }
     
     required init?(coder: NSCoder) {
@@ -35,10 +41,6 @@ class SegmentedPageViewController: UIPageViewController, UIPageViewControllerDel
         
         view.backgroundColor = .systemBackground
         
-        segmentedControl = UISegmentedControl(items: titles)
-        segmentedControl.addTarget(self, action: #selector(segmentedControlChanged), for: .valueChanged)
-        navigationItem.titleView = segmentedControl
-        
         segmentedControl.selectedSegmentIndex = 0
         selectPage(at: 0, animated: false)
         

Tusker/ViewTags.swift

@@ -0,0 +1,19 @@
+//
+//  ViewTags.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 6/8/22.
+//  Copyright © 2022 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+
+struct ViewTags {
+    private init() {}
+    
+    static let composeVisibilityBarButton = 42001
+    static let composeLocalOnlyBarButton = 42002
+    static let navBackBarButton = 42003
+    static let navForwardBarButton = 42004
+    static let navEmptyTitleView = 42005
+}