Ensure gallery is GC'd

// FREEBIE

Signal/src/ViewControllers/MediaGalleryViewController.swift

@@ -158,7 +158,6 @@ protocol MediaGalleryDataSource: class {
     func galleryItem(before currentItem: MediaGalleryItem) -> MediaGalleryItem?
     func galleryItem(after currentItem: MediaGalleryItem) -> MediaGalleryItem?
 
-    // TODO this doesn't seem very "data-source"
     func showAllMedia(focusedItem: MediaGalleryItem)
     func dismissSelf(animated isAnimated: Bool, completion: (() -> Void)?)
 }
@@ -177,6 +176,10 @@ class MediaGalleryViewController: UINavigationController, MediaGalleryDataSource
     // we start with a small range size for quick loading.
     private let fetchRangeSize: UInt = 10
 
+    deinit {
+        Logger.debug("\(logTag) deinit")
+    }
+
     convenience init(thread: TSThread, uiDatabaseConnection: YapDatabaseConnection) {
         self.init(thread: thread, uiDatabaseConnection: uiDatabaseConnection, includeGallery: true)
     }

Signal/src/ViewControllers/MediaPageViewController.swift

@@ -35,7 +35,7 @@ public struct MediaGalleryPage: Equatable {
 
 class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate, MediaDetailViewControllerDelegate {
 
-    let mediaGalleryDataSource: MediaGalleryDataSource
+    private weak var mediaGalleryDataSource: MediaGalleryDataSource?
 
     private var cachedPages: [MediaGalleryPage] = []
     private var initialPage: MediaGalleryPage!
@@ -181,7 +181,11 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
     public func didPressAllMediaButton(sender: Any) {
         Logger.debug("\(logTag) in \(#function)")
 
-        self.mediaGalleryDataSource.showAllMedia(focusedItem: currentItem)
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            return
+        }
+        mediaGalleryDataSource.showAllMedia(focusedItem: currentItem)
     }
 
     @objc
@@ -344,6 +348,11 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
             return cachedPage.viewController
         }
 
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            return nil
+        }
+
         guard let previousItem: MediaGalleryItem = mediaGalleryDataSource.galleryItem(before: currentPage.galleryItem) else {
             return nil
         }
@@ -370,6 +379,11 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
             return cachedPage.viewController
         }
 
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            return nil
+        }
+
         guard let nextItem: MediaGalleryItem = mediaGalleryDataSource.galleryItem(after: currentPage.galleryItem) else {
             return nil
         }
@@ -406,7 +420,15 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
     public func dismissSelf(animated isAnimated: Bool, completion: (() -> Void)? = nil) {
         // Swapping mediaView for presentationView will be perceptible if we're not zoomed out all the way.
         currentPage.viewController.zoomOut(animated: true)
-        self.mediaGalleryDataSource.dismissSelf(animated: isAnimated, completion: completion)
+
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            self.presentingViewController?.dismiss(animated: true)
+
+            return
+        }
+
+        mediaGalleryDataSource.dismissSelf(animated: isAnimated, completion: completion)
     }
 
     public func mediaDetailViewController(_ mediaDetailViewController: MediaDetailViewController, isPlayingVideo: Bool) {

Signal/src/ViewControllers/MediaTileViewController.swift

@@ -10,13 +10,20 @@ public protocol MediaTileViewControllerDelegate: class {
 
 public class MediaTileViewController: UICollectionViewController, MediaGalleryCellDelegate {
 
-    // TODO weak?
+    private weak var mediaGalleryDataSource: MediaGalleryDataSource?
-    private var mediaGalleryDataSource: MediaGalleryDataSource
 
     private var galleryItems: [GalleryDate: [MediaGalleryItem]] {
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            return [:]
+        }
         return mediaGalleryDataSource.sections
     }
     private var galleryDates: [GalleryDate] {
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            return []
+        }
         return mediaGalleryDataSource.sectionDates
     }
     public var focusedItem: MediaGalleryItem?
@@ -25,6 +32,10 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
 
     public weak var delegate: MediaTileViewControllerDelegate?
 
+    deinit {
+        Logger.debug("\(logTag) deinit")
+    }
+
     init(mediaGalleryDataSource: MediaGalleryDataSource, uiDatabaseConnection: YapDatabaseConnection) {
 
         self.mediaGalleryDataSource = mediaGalleryDataSource
@@ -250,10 +261,18 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
         switch section {
         case kLoadOlderSectionIdx:
             // Show "loading older..." iff there is still older data to be fetched
-            return self.mediaGalleryDataSource.hasFetchedOldest ? CGSize.zero : CGSize(width: 0, height: 100)
+            guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+                owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+                return CGSize.zero
+            }
+            return mediaGalleryDataSource.hasFetchedOldest ? CGSize.zero : CGSize(width: 0, height: 100)
         case kLoadNewerSectionIdx:
             // Show "loading newer..." iff there is still more recent data to be fetched
-            return self.mediaGalleryDataSource.hasFetchedMostRecent ? CGSize.zero : CGSize(width: 0, height: 100)
+            guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+                owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+                return CGSize.zero
+            }
+            return mediaGalleryDataSource.hasFetchedMostRecent ? CGSize.zero : CGSize(width: 0, height: 100)
         default:
             return CGSize(width: 0, height: kHeaderHeight)
         }
@@ -305,6 +324,11 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
             return
         }
 
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            return
+        }
+
         let contentOffsetY = collectionView.contentOffset.y
         let oldContentHeight = collectionView.contentSize.height
 
@@ -326,7 +350,7 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
             let scrollDistanceToBottom = oldContentHeight - contentOffsetY
 
             collectionView.performBatchUpdates({
-                self.mediaGalleryDataSource.ensureGalleryItemsLoaded(.before, item: oldestLoadedItem, amount: self.kMediaTileViewLoadBatchSize) { addedSections, addedItems in
+                mediaGalleryDataSource.ensureGalleryItemsLoaded(.before, item: oldestLoadedItem, amount: self.kMediaTileViewLoadBatchSize) { addedSections, addedItems in
                     Logger.debug("\(self.logTag) in \(#function) insertingSections: \(addedSections) items: \(addedItems)")
 
                     collectionView.insertSections(addedSections)
@@ -357,13 +381,8 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
 
             isFetchingMoreData = true
             collectionView.performBatchUpdates({
-                self.mediaGalleryDataSource.ensureGalleryItemsLoaded(.after, item: mostRecentLoadedItem, amount: self.kMediaTileViewLoadBatchSize) { addedSections, addedItems in
+                mediaGalleryDataSource.ensureGalleryItemsLoaded(.after, item: mostRecentLoadedItem, amount: self.kMediaTileViewLoadBatchSize) { addedSections, addedItems in
-                    guard let collectionView = self.collectionView else {
-                        Logger.debug("\(self.logTag) in \(#function) collectionView was unexpectedly nil")
-                        return
-                    }
                     Logger.debug("\(self.logTag) in \(#function) insertingSections: \(addedSections), items: \(addedItems)")
-
                     collectionView.insertSections(addedSections)
                     collectionView.insertItems(at: addedItems)
                 }