Extract most Gallery functionality from the gallery NavigationController.

By not overriding the initializer for an OWSNavigationController subclass,
we can use the dynamic disaptch intialization chain.

The root difficulty here is that super.init(navBarClass:) wants to call
self.init(nibNam)

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -2051,12 +2051,12 @@ typedef enum : NSUInteger {
     }
     TSMessage *mediaMessage = (TSMessage *)viewItem.interaction;
 
-    MediaGalleryViewController *vc = [[MediaGalleryViewController alloc]
-              initWithThread:self.thread
-        uiDatabaseConnection:self.uiDatabaseConnection
-                     options:MediaGalleryOptionSliderEnabled | MediaGalleryOptionShowAllMediaButton];
+    MediaGallery *mediaGallery =
+        [[MediaGallery alloc] initWithThread:self.thread
+                        uiDatabaseConnection:self.uiDatabaseConnection
+                                     options:MediaGalleryOptionSliderEnabled | MediaGalleryOptionShowAllMediaButton];
 
-    [vc presentDetailViewFromViewController:self mediaMessage:mediaMessage replacingView:imageView];
+    [mediaGallery presentDetailViewFromViewController:self mediaMessage:mediaMessage replacingView:imageView];
 }
 
 - (void)didTapVideoViewItem:(id<ConversationViewItem>)viewItem
@@ -2080,12 +2080,12 @@ typedef enum : NSUInteger {
     }
     TSMessage *mediaMessage = (TSMessage *)viewItem.interaction;
 
-    MediaGalleryViewController *vc = [[MediaGalleryViewController alloc]
-              initWithThread:self.thread
-        uiDatabaseConnection:self.uiDatabaseConnection
-                     options:MediaGalleryOptionSliderEnabled | MediaGalleryOptionShowAllMediaButton];
+    MediaGallery *mediaGallery =
+        [[MediaGallery alloc] initWithThread:self.thread
+                        uiDatabaseConnection:self.uiDatabaseConnection
+                                     options:MediaGalleryOptionSliderEnabled | MediaGalleryOptionShowAllMediaButton];
 
-    [vc presentDetailViewFromViewController:self mediaMessage:mediaMessage replacingView:imageView];
+    [mediaGallery presentDetailViewFromViewController:self mediaMessage:mediaMessage replacingView:imageView];
 }
 
 - (void)didTapAudioViewItem:(id<ConversationViewItem>)viewItem attachmentStream:(TSAttachmentStream *)attachmentStream

Signal/src/ViewControllers/MediaGalleryViewController.swift

@@ -168,44 +168,7 @@ protocol MediaGalleryDataSourceDelegate: class {
     func mediaGalleryDataSource(_ mediaGalleryDataSource: MediaGalleryDataSource, deletedSections: IndexSet, deletedItems: [IndexPath])
 }
 
-@objc
-class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSource, MediaTileViewControllerDelegate {
-
-    private var pageViewController: MediaPageViewController?
-
-    private let uiDatabaseConnection: YapDatabaseConnection
-    private let editingDatabaseConnection: YapDatabaseConnection
-    private let mediaGalleryFinder: OWSMediaGalleryFinder
-
-    private var initialDetailItem: MediaGalleryItem?
-    private let thread: TSThread
-    private let options: MediaGalleryOption
-
-    // we start with a small range size for quick loading.
-    private let fetchRangeSize: UInt = 10
-
-    deinit {
-        Logger.debug("deinit")
-    }
-
-    @objc
-    init(thread: TSThread, uiDatabaseConnection: YapDatabaseConnection, options: MediaGalleryOption = []) {
-        self.thread = thread
-        assert(uiDatabaseConnection.isInLongLivedReadTransaction())
-        self.uiDatabaseConnection = uiDatabaseConnection
-
-        self.editingDatabaseConnection = OWSPrimaryStorage.shared().newDatabaseConnection()
-
-        self.options = options
-        self.mediaGalleryFinder = OWSMediaGalleryFinder(thread: thread)
-        super.init(nibName: nil, bundle: nil)
-        self.setValue(OWSNavigationBar(), forKey: "navigationBar")
-        super.setupNavbar()
-    }
-
-    required init?(coder aDecoder: NSCoder) {
-        notImplemented()
-    }
+class MediaGalleryNavigationController: OWSNavigationController {
 
     // MARK: View LifeCycle
 
@@ -215,6 +178,9 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         UIViewController.attemptRotationToDeviceOrientation()
     }
 
+    var presentationView: UIImageView!
+    var retainUntilDismissed: MediaGallery?
+
     // HACK: Though we don't have an input accessory view, the VC we are presented above (ConversationVC) does.
     // If the app is backgrounded and then foregrounded, when OWSWindowManager calls mainWindow.makeKeyAndVisible
     // the ConversationVC's inputAccessoryView will appear *above* us unless we'd previously become first responder.
@@ -256,6 +222,52 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         presentationView.contentMode = .scaleAspectFit
     }
 
+    // MARK: Orientation
+
+    public override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
+        return .allButUpsideDown
+    }
+}
+
+@objc
+class MediaGallery: NSObject, MediaGalleryDataSource, MediaTileViewControllerDelegate {
+
+    @objc
+    weak public var navigationController: MediaGalleryNavigationController!
+
+    private var pageViewController: MediaPageViewController?
+
+    private let uiDatabaseConnection: YapDatabaseConnection
+    private let editingDatabaseConnection: YapDatabaseConnection
+    private let mediaGalleryFinder: OWSMediaGalleryFinder
+
+    private var initialDetailItem: MediaGalleryItem?
+    private let thread: TSThread
+    private let options: MediaGalleryOption
+
+    // we start with a small range size for quick loading.
+    private let fetchRangeSize: UInt = 10
+
+    deinit {
+        Logger.debug("")
+    }
+
+    @objc
+    init(thread: TSThread, uiDatabaseConnection: YapDatabaseConnection, options: MediaGalleryOption = []) {
+        self.thread = thread
+        assert(uiDatabaseConnection.isInLongLivedReadTransaction())
+        self.uiDatabaseConnection = uiDatabaseConnection
+
+        self.editingDatabaseConnection = OWSPrimaryStorage.shared().newDatabaseConnection()
+
+        self.options = options
+        self.mediaGalleryFinder = OWSMediaGalleryFinder(thread: thread)
+        let navController = MediaGalleryNavigationController()
+        self.navigationController = navController
+        super.init()
+        navController.retainUntilDismissed = self
+    }
+
     // MARK: Present/Dismiss
 
     private var currentItem: MediaGalleryItem {
@@ -263,7 +275,6 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
     }
 
     private var replacingView: UIView?
-    private var presentationView: UIImageView!
     private var presentationViewConstraints: [NSLayoutConstraint] = []
 
     // TODO rename to replacingOriginRect
@@ -294,7 +305,7 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         self.addDataSourceDelegate(pageViewController)
 
         self.pageViewController = pageViewController
-        self.setViewControllers([pageViewController], animated: false)
+        navigationController.setViewControllers([pageViewController], animated: false)
 
         self.replacingView = replacingView
 
@@ -302,13 +313,13 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         self.originRect = convertedRect
 
         // loadView hasn't necessarily been called yet.
-        self.loadViewIfNeeded()
+        navigationController.loadViewIfNeeded()
 
-        self.presentationView.image = initialDetailItem.attachmentStream.thumbnailImageLarge(success: { [weak self] (image) in
+        navigationController.presentationView.image = initialDetailItem.attachmentStream.thumbnailImageLarge(success: { [weak self] (image) in
             guard let strongSelf = self else {
                 return
             }
-            strongSelf.presentationView.image = image
+            strongSelf.navigationController.presentationView.image = image
             }, failure: {
                 Logger.warn("Could not load presentation image.")
         })
@@ -316,8 +327,8 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         self.applyInitialMediaViewConstraints()
 
         // Restore presentationView.alpha in case a previous dismiss left us in a bad state.
-        self.setNavigationBarHidden(false, animated: false)
-        self.presentationView.alpha = 1
+        navigationController.setNavigationBarHidden(false, animated: false)
+        navigationController.presentationView.alpha = 1
 
         // We want to animate the tapped media from it's position in the previous VC
         // to it's resting place in the center of this view controller.
@@ -330,7 +341,7 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         // 2. For Video views, the AVPlayerLayer content does not scale with the presentation animation. So you instead get a full scale
         //    video, wherein only the cropping is animated.
         // Using a simple image view allows us to address both these problems relatively easily.
-        self.view.alpha = 0.0
+        navigationController.view.alpha = 0.0
 
         guard let detailView = pageViewController.view else {
             owsFailDebug("detailView was unexpectedly nil")
@@ -339,23 +350,23 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
 
         // At this point our media view should be overlayed perfectly
         // by our presentationView. Swapping them out should be imperceptible.
-        self.presentationView.isHidden = false
+        navigationController.presentationView.isHidden = false
         // We don't hide the pageViewController entirely - e.g. we want the toolbars to fade in.
         pageViewController.currentViewController.view.isHidden = true
         detailView.backgroundColor = .clear
-        self.view.backgroundColor = .clear
+        navigationController.view.backgroundColor = .clear
 
-        self.presentationView.layer.cornerRadius = kOWSMessageCellCornerRadius_Small
+        navigationController.presentationView.layer.cornerRadius = kOWSMessageCellCornerRadius_Small
 
-        fromViewController.present(self, animated: false) {
+        fromViewController.present(navigationController, animated: false) {
 
             // 1. Fade in the entire view.
             UIView.animate(withDuration: 0.1) {
                 self.replacingView?.alpha = 0.0
-                self.view.alpha = 1.0
+                self.navigationController.view.alpha = 1.0
             }
 
-            self.presentationView.superview?.layoutIfNeeded()
+            self.navigationController.presentationView.superview?.layoutIfNeeded()
             self.applyFinalMediaViewConstraints()
 
             // 2. Animate imageView from it's initial position, which should match where it was
@@ -366,20 +377,20 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
                            options: .curveEaseOut,
                            animations: {
 
-                            self.presentationView.layer.cornerRadius = 0
-                            self.presentationView.superview?.layoutIfNeeded()
+                            self.navigationController.presentationView.layer.cornerRadius = 0
+                            self.navigationController.presentationView.superview?.layoutIfNeeded()
 
                             // fade out content behind the pageViewController
                             // and behind the presentation view
-                            self.view.backgroundColor = Theme.backgroundColor
+                            self.navigationController.view.backgroundColor = Theme.backgroundColor
             },
                            completion: { (_: Bool) in
                             // At this point our presentation view should be overlayed perfectly
                             // with our media view. Swapping them out should be imperceptible.
                             pageViewController.currentViewController.view.isHidden = false
-                            self.presentationView.isHidden = true
+                            self.navigationController.presentationView.isHidden = true
 
-                            self.view.isUserInteractionEnabled = true
+                            self.navigationController.view.isUserInteractionEnabled = true
 
                             pageViewController.wasPresented()
 
@@ -390,7 +401,7 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
                             //
                             // We don't need to do this when pushing VCs onto the SignalsNavigationController - only when
                             // presenting directly from ConversationVC.
-                            _ = self.becomeFirstResponder()
+                            _ = self.navigationController.becomeFirstResponder()
             })
         }
     }
@@ -426,7 +437,7 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         } else {
             // If from conversation view
             mediaTileViewController.focusedItem = focusedItem
-            self.pushViewController(mediaTileViewController, animated: true)
+            navigationController.pushViewController(mediaTileViewController, animated: true)
         }
     }
 
@@ -459,7 +470,7 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
 
             guard let pageViewController = self.pageViewController else {
                 owsFailDebug("pageViewController was unexpectedly nil")
-                self.dismiss(animated: true)
+                self.navigationController.dismiss(animated: true)
 
                 return
             }
@@ -468,32 +479,32 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
             pageViewController.willBePresentedAgain()
 
             // TODO fancy zoom animation
-            self.popViewController(animated: true)
+            self.navigationController.popViewController(animated: true)
         }
     }
 
     public func dismissMediaDetailViewController(_ mediaPageViewController: MediaPageViewController, animated isAnimated: Bool, completion: (() -> Void)?) {
-        self.view.isUserInteractionEnabled = false
+        navigationController.view.isUserInteractionEnabled = false
         UIApplication.shared.isStatusBarHidden = false
 
         guard let detailView = mediaPageViewController.view else {
             owsFailDebug("detailView was unexpectedly nil")
-            self.presentingViewController?.dismiss(animated: false, completion: completion)
+            self.navigationController.presentingViewController?.dismiss(animated: false, completion: completion)
             return
         }
 
         mediaPageViewController.currentViewController.view.isHidden = true
-        self.presentationView.isHidden = false
+        navigationController.presentationView.isHidden = false
 
         // Move the presentationView back to it's initial position, i.e. where
         // it sits on the screen in the conversation view.
         let changedItems = currentItem != self.initialDetailItem
         if changedItems {
-            self.presentationView.image = currentItem.attachmentStream.thumbnailImageLarge(success: { [weak self] (image) in
+            navigationController.presentationView.image = currentItem.attachmentStream.thumbnailImageLarge(success: { [weak self] (image) in
                 guard let strongSelf = self else {
                     return
                 }
-                strongSelf.presentationView.image = image
+                strongSelf.navigationController.presentationView.image = image
                 }, failure: {
                     Logger.warn("Could not load presentation image.")
             })
@@ -508,14 +519,14 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
                            options: .curveEaseOut,
                            animations: {
                             // Move back over it's original location
-                            self.presentationView.superview?.layoutIfNeeded()
+                            self.navigationController.presentationView.superview?.layoutIfNeeded()
 
                             detailView.alpha = 0
 
                             if changedItems {
-                                self.presentationView.alpha = 0
+                                self.navigationController.presentationView.alpha = 0
                             } else {
-                                self.presentationView.layer.cornerRadius = kOWSMessageCellCornerRadius_Small
+                                self.navigationController.presentationView.layer.cornerRadius = kOWSMessageCellCornerRadius_Small
                             }
             },
                            completion: { (_: Bool) in
@@ -532,24 +543,24 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
                            animations: {
                             guard let replacingView = self.replacingView else {
                                 owsFailDebug("replacingView was unexpectedly nil")
-                                self.presentingViewController?.dismiss(animated: false, completion: completion)
+                                self.navigationController.presentingViewController?.dismiss(animated: false, completion: completion)
                                 return
                             }
                             // fade out content and toolbars
-                            self.view.alpha = 0.0
+                            self.navigationController.view.alpha = 0.0
                             replacingView.alpha = 1.0
             },
                            completion: { (_: Bool) in
-                            self.presentingViewController?.dismiss(animated: false, completion: completion)
+                            self.navigationController.presentingViewController?.dismiss(animated: false, completion: completion)
             })
         } else {
             guard let replacingView = self.replacingView else {
                 owsFailDebug("replacingView was unexpectedly nil")
-                self.presentingViewController?.dismiss(animated: false, completion: completion)
+                navigationController.presentingViewController?.dismiss(animated: false, completion: completion)
                 return
             }
             replacingView.alpha = 1.0
-            self.presentingViewController?.dismiss(animated: false, completion: completion)
+            navigationController.presentingViewController?.dismiss(animated: false, completion: completion)
         }
     }
 
@@ -564,17 +575,17 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
             return
         }
 
-        guard let presentationSuperview = self.presentationView.superview else {
+        guard let presentationSuperview = navigationController.presentationView.superview else {
             owsFailDebug("presentationView.superview was unexpectedly nil")
             return
         }
 
         let convertedRect: CGRect = presentationSuperview.convert(originRect, from: UIApplication.shared.keyWindow)
 
-        self.presentationViewConstraints += self.presentationView.autoSetDimensions(to: convertedRect.size)
+        self.presentationViewConstraints += navigationController.presentationView.autoSetDimensions(to: convertedRect.size)
         self.presentationViewConstraints += [
-            self.presentationView.autoPinEdge(toSuperviewEdge: .top, withInset: convertedRect.origin.y),
-            self.presentationView.autoPinEdge(toSuperviewEdge: .left, withInset: convertedRect.origin.x)
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .top, withInset: convertedRect.origin.y),
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .left, withInset: convertedRect.origin.x)
         ]
     }
 
@@ -585,10 +596,10 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         }
 
         self.presentationViewConstraints = [
-            self.presentationView.autoPinEdge(toSuperviewEdge: .leading),
-            self.presentationView.autoPinEdge(toSuperviewEdge: .top),
-            self.presentationView.autoPinEdge(toSuperviewEdge: .trailing),
-            self.presentationView.autoPinEdge(toSuperviewEdge: .bottom)
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .leading),
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .top),
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .trailing),
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .bottom)
         ]
     }
 
@@ -599,9 +610,9 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         }
 
         self.presentationViewConstraints += [
-            self.presentationView.autoPinEdge(toSuperviewEdge: .leading),
-            self.presentationView.autoPinEdge(toSuperviewEdge: .trailing),
-            self.presentationView.autoPinEdge(.top, to: .bottom, of: self.view)
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .leading),
+            navigationController.presentationView.autoPinEdge(toSuperviewEdge: .trailing),
+            navigationController.presentationView.autoPinEdge(.top, to: .bottom, of: self.navigationController.view)
         ]
     }
 
@@ -918,10 +929,4 @@ class MediaGalleryViewController: OWSNavigationController, MediaGalleryDataSourc
         }
         return Int(count) - deletedMessages.count
     }
-
-    // MARK: Orientation
-
-    public override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
-        return .allButUpsideDown
-    }
 }

Signal/src/ViewControllers/MessageDetailViewController.swift

@@ -615,17 +615,17 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
     // MARK: OWSMessageBubbleViewDelegate
 
     func didTapImageViewItem(_ viewItem: ConversationViewItem, attachmentStream: TSAttachmentStream, imageView: UIView) {
-        let mediaGalleryViewController = MediaGalleryViewController(thread: self.thread, uiDatabaseConnection: self.uiDatabaseConnection)
+        let mediaGallery = MediaGallery(thread: self.thread, uiDatabaseConnection: self.uiDatabaseConnection)
 
-        mediaGalleryViewController.addDataSourceDelegate(self)
-        mediaGalleryViewController.presentDetailView(fromViewController: self, mediaMessage: self.message, replacingView: imageView)
+        mediaGallery.addDataSourceDelegate(self)
+        mediaGallery.presentDetailView(fromViewController: self, mediaMessage: self.message, replacingView: imageView)
     }
 
     func didTapVideoViewItem(_ viewItem: ConversationViewItem, attachmentStream: TSAttachmentStream, imageView: UIView) {
-        let mediaGalleryViewController = MediaGalleryViewController(thread: self.thread, uiDatabaseConnection: self.uiDatabaseConnection)
+        let mediaGallery = MediaGallery(thread: self.thread, uiDatabaseConnection: self.uiDatabaseConnection)
 
-        mediaGalleryViewController.addDataSourceDelegate(self)
-        mediaGalleryViewController.presentDetailView(fromViewController: self, mediaMessage: self.message, replacingView: imageView)
+        mediaGallery.addDataSourceDelegate(self)
+        mediaGallery.presentDetailView(fromViewController: self, mediaMessage: self.message, replacingView: imageView)
     }
 
     func didTapContactShare(_ viewItem: ConversationViewItem) {

Signal/src/ViewControllers/ThreadSettings/OWSConversationSettingsViewController.m

@@ -54,7 +54,7 @@ const CGFloat kIconViewLength = 24;
 
 @property (nonatomic) NSArray<NSNumber *> *disappearingMessagesDurations;
 @property (nonatomic) OWSDisappearingMessagesConfiguration *disappearingMessagesConfiguration;
-@property (nullable, nonatomic) MediaGalleryViewController *mediaGalleryViewController;
+@property (nullable, nonatomic) MediaGalleryNavigationController *mediaGalleryViewController;
 @property (nonatomic, readonly) TSAccountManager *accountManager;
 @property (nonatomic, readonly) OWSContactsManager *contactsManager;
 @property (nonatomic, readonly) OWSMessageSender *messageSender;
@@ -1273,19 +1273,18 @@ const CGFloat kIconViewLength = 24;
 
 - (void)showMediaGallery
 {
-    OWSLogDebug(@"in showMediaGallery");
+    OWSLogDebug(@"");
 
-    MediaGalleryViewController *vc =
-        [[MediaGalleryViewController alloc] initWithThread:self.thread
-                                      uiDatabaseConnection:self.uiDatabaseConnection
-                                                   options:MediaGalleryOptionSliderEnabled];
+    MediaGallery *mediaGallery = [[MediaGallery alloc] initWithThread:self.thread
+                                                 uiDatabaseConnection:self.uiDatabaseConnection
+                                                              options:MediaGalleryOptionSliderEnabled];
 
     // although we don't present the mediaGalleryViewController directly, we need to maintain a strong
     // reference to it until we're dismissed.
-    self.mediaGalleryViewController = vc;
+    self.mediaGalleryViewController = mediaGallery.navigationController;
 
     OWSAssertDebug([self.navigationController isKindOfClass:[OWSNavigationController class]]);
-    [vc pushTileViewFromNavController:(OWSNavigationController *)self.navigationController];
+    [mediaGallery pushTileViewFromNavController:(OWSNavigationController *)self.navigationController];
 }
 #pragma mark - Notifications
 

SignalMessaging/ViewControllers/OWSNavigationController.h

@@ -23,9 +23,6 @@ NS_ASSUME_NONNULL_BEGIN
 // unsaved changes.
 @interface OWSNavigationController : UINavigationController
 
-- (instancetype)init;
-- (void)setupNavbar;
-
 @end
 
 NS_ASSUME_NONNULL_END