Fix Delete

from conversation settings > tile > tap for details > delete

TODO:

- Don't dismiss pager, show next item
- dismiss pager if deleting last media

// FREEBIE

Signal/src/ViewControllers/MediaDetailViewController.h

@@ -17,7 +17,9 @@ typedef NS_OPTIONS(NSInteger, MediaGalleryOption) {
 
 @protocol MediaDetailViewControllerDelegate <NSObject>
 
-- (void)dismissSelfAnimated:(BOOL)isAnimated completion:(void (^_Nullable)(void))completionBlock;
+- (void)mediaDetailViewController:(MediaDetailViewController *)mediaDetailViewController
+    requestDeleteConversationViewItem:(ConversationViewItem *)conversationViewItem;
+
 - (void)mediaDetailViewController:(MediaDetailViewController *)mediaDetailViewController
                    isPlayingVideo:(BOOL)isPlayingVideo;
 

Signal/src/ViewControllers/MediaDetailViewController.m

@@ -411,35 +411,27 @@ NS_ASSUME_NONNULL_BEGIN
         [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];
 
     [actionSheet
-        addAction:[UIAlertAction actionWithTitle:NSLocalizedString(@"TXT_DELETE_TITLE", nil)
-                                           style:UIAlertActionStyleDestructive
-                                         handler:^(UIAlertAction *action) {
-                                             OWSAssert([self.presentingViewController
-                                                 isKindOfClass:[UINavigationController class]]);
-                                             UINavigationController *navController
-                                                 = (UINavigationController *)self.presentingViewController;
+        addAction:[UIAlertAction
+                      actionWithTitle:NSLocalizedString(@"TXT_DELETE_TITLE", nil)
+                                style:UIAlertActionStyleDestructive
+                              handler:^(UIAlertAction *action) {
+                                  [self.delegate mediaDetailViewController:self
+                                         requestDeleteConversationViewItem:self.viewItem];
 
-                                             if ([navController.topViewController
-                                                     isKindOfClass:[ConversationViewController class]]) {
-                                                 [self.delegate dismissSelfAnimated:YES
-                                                                         completion:^{
-                                                                             [self.viewItem deleteAction];
-                                                                         }];
-                                             } else if ([navController.topViewController
-                                                            isKindOfClass:[MessageDetailViewController class]]) {
-                                                 [self.delegate dismissSelfAnimated:YES
-                                                                         completion:^{
-                                                                             [self.viewItem deleteAction];
-                                                                         }];
-                                                 [navController popViewControllerAnimated:YES];
-                                             } else {
-                                                 OWSFail(@"Unexpected presentation context.");
-                                                 [self.delegate dismissSelfAnimated:YES
-                                                                         completion:^{
-                                                                             [self.viewItem deleteAction];
-                                                                         }];
-                                             }
-                                         }]];
+                                  // TODO maybe this would be more straight forward if the MessageDetailVC was the
+                                  // deleteDelegate
+                                  if ([self.presentingViewController isKindOfClass:[UINavigationController class]]) {
+                                      UINavigationController *navController
+                                          = (UINavigationController *)self.presentingViewController;
+                                      if ([navController.topViewController
+                                              isKindOfClass:[MessageDetailViewController class]]) {
+                                          MessageDetailViewController *messageDetailViewController
+                                              = (MessageDetailViewController *)navController.topViewController;
+                                          messageDetailViewController.wasDeleted = YES;
+                                          [navController popViewControllerAnimated:YES];
+                                      }
+                                  }
+                              }]];
 
     [actionSheet addAction:[OWSAlerts cancelAction]];
 

Signal/src/ViewControllers/MediaGalleryViewController.swift

@@ -175,6 +175,8 @@ protocol MediaGalleryDataSource: class {
 
     func showAllMedia(focusedItem: MediaGalleryItem)
     func dismissMediaDetailViewController(_ mediaDetailViewController: MediaPageViewController, animated isAnimated: Bool, completion: (() -> Void)?)
+
+    func delete(message: TSMessage)
 }
 
 class MediaGalleryViewController: UINavigationController, MediaGalleryDataSource, MediaTileViewControllerDelegate {
@@ -182,6 +184,7 @@ class MediaGalleryViewController: UINavigationController, MediaGalleryDataSource
     private var pageViewController: MediaPageViewController?
 
     private let uiDatabaseConnection: YapDatabaseConnection
+    private let editingDatabaseConnection: YapDatabaseConnection
     private let mediaGalleryFinder: OWSMediaGalleryFinder
 
     private var initialDetailItem: MediaGalleryItem?
@@ -199,6 +202,9 @@ class MediaGalleryViewController: UINavigationController, MediaGalleryDataSource
         self.thread = thread
         assert(uiDatabaseConnection.isInLongLivedReadTransaction())
         self.uiDatabaseConnection = uiDatabaseConnection
+
+        self.editingDatabaseConnection = OWSPrimaryStorage.shared().newDatabaseConnection()
+
         self.options = options
         self.mediaGalleryFinder = OWSMediaGalleryFinder(thread: thread)
 
@@ -631,6 +637,12 @@ class MediaGalleryViewController: UINavigationController, MediaGalleryDataSource
                 Logger.debug("\(self.logTag) in \(#function) fetching set: \(unfetchedSet)")
                 let nsRange: NSRange = NSRange(location: unfetchedSet.min()!, length: unfetchedSet.count)
                 self.mediaGalleryFinder.enumerateMediaMessages(range: nsRange, transaction: transaction) { (message: TSMessage) in
+
+                    guard !self.deletedMessages.contains(message) else {
+                        Logger.debug("\(self.logTag) skipping \(message) which has been deleted.")
+                        return
+                    }
+
                     guard let item: MediaGalleryItem = self.buildGalleryItem(message: message, transaction: transaction) else {
                         owsFail("\(self.logTag) in \(#function) unexpectedly failed to buildGalleryItem")
                         return
@@ -700,6 +712,65 @@ class MediaGalleryViewController: UINavigationController, MediaGalleryDataSource
         }
     }
 
+    var deletedMessages: Set<TSMessage> = Set()
+    func delete(message: TSMessage) {
+        Logger.info("\(logTag) in \(#function) with message: \(String(describing: message.uniqueId)) attachmentId: \(String(describing: message.attachmentIds.firstObject))")
+
+        // TODO put this somewhere reasonable...
+        self.mediaTileViewController.collectionView!.layoutIfNeeded()
+
+        self.editingDatabaseConnection.asyncReadWrite { transaction in
+            message.remove(with: transaction)
+        }
+
+        self.deletedMessages.insert(message)
+
+        var deletedSections: IndexSet = IndexSet()
+        var deletedIndexPaths: [IndexPath] = []
+
+        guard let itemIndex = galleryItems.index(where: { $0.message == message }) else {
+            owsFail("\(logTag) in \(#function) removing unknown item.")
+            return
+        }
+        let item: MediaGalleryItem = galleryItems[itemIndex]
+
+        self.galleryItems.remove(at: itemIndex)
+
+        guard let sectionIndex = sectionDates.index(where: { $0 == item.galleryDate }) else {
+            owsFail("\(logTag) in \(#function) item with unknown date.")
+            return
+        }
+
+        guard var sectionItems = self.sections[item.galleryDate] else {
+            owsFail("\(logTag) in \(#function) item with unknown section")
+            return
+        }
+
+        if sectionItems == [item] {
+            // Last item in section. Delete section.
+            self.sections[item.galleryDate] = nil
+            self.sectionDates.remove(at: sectionIndex)
+
+            deletedSections.insert(sectionIndex + 1)
+            deletedIndexPaths.append(IndexPath(row: 0, section: sectionIndex + 1))
+        } else {
+            guard let sectionRowIndex = sectionItems.index(of: item) else {
+                owsFail("\(logTag) in \(#function) item with unknown sectionRowIndex")
+                return
+            }
+
+            sectionItems.remove(at: sectionRowIndex)
+            self.sections[item.galleryDate] = sectionItems
+
+            deletedIndexPaths.append(IndexPath(row: sectionRowIndex, section: sectionIndex + 1))
+        }
+
+        // TODO? notify pager view
+
+        // notify tile view    
+        self.mediaTileViewController.updatedDataSource(deletedSections: deletedSections, deletedItems: deletedIndexPaths)
+    }
+
     let kGallerySwipeLoadBatchSize: UInt = 5
 
     internal func galleryItem(after currentItem: MediaGalleryItem) -> MediaGalleryItem? {

Signal/src/ViewControllers/MediaPageViewController.swift

@@ -440,8 +440,6 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
         return viewController
     }
 
-    // MARK: MediaDetailViewControllerDelegate
-
     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.
         // currentVC
@@ -457,6 +455,28 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
         mediaGalleryDataSource.dismissMediaDetailViewController(self, animated: isAnimated, completion: completion)
     }
 
+    // MARK: MediaDetailViewControllerDelegate
+
+    public func mediaDetailViewController(_ mediaDetailViewController: MediaDetailViewController, requestDelete conversationViewItem: ConversationViewItem) {
+        guard let mediaGalleryDataSource = self.mediaGalleryDataSource else {
+            owsFail("\(logTag) in \(#function) mediaGalleryDataSource was unexpectedly nil")
+            self.presentingViewController?.dismiss(animated: true)
+
+            return
+        }
+
+        guard let message = conversationViewItem.interaction as? TSMessage else {
+            owsFail("\(logTag) in \(#function) unexpected interaction: \(type(of: conversationViewItem))")
+            self.presentingViewController?.dismiss(animated: true)
+
+            return
+        }
+
+        dismissSelf(animated: true) {
+            mediaGalleryDataSource.delete(message: message)
+        }
+    }
+
     public func mediaDetailViewController(_ mediaDetailViewController: MediaDetailViewController, isPlayingVideo: Bool) {
         guard mediaDetailViewController == currentViewController else {
             Logger.verbose("\(logTag) in \(#function) ignoring stale delegate.")

Signal/src/ViewControllers/MediaTileViewController.swift

@@ -145,6 +145,19 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryCe
 
     // MARK: UIColletionViewDataSource
 
+    public func updatedDataSource(deletedSections: IndexSet, deletedItems: [IndexPath]) {
+        guard let collectionView = self.collectionView else {
+            owsFail("\(logTag) in \(#function) collectionView was unexpetedly nil")
+            return
+        }
+
+        // If collectionView hasn't been laid out yet, it won't have the sections/rows to remove.
+        collectionView.performBatchUpdates({
+            collectionView.deleteSections(deletedSections)
+            collectionView.deleteItems(at: deletedItems)
+        })
+    }
+
     override public func numberOfSections(in collectionView: UICollectionView) -> Int {
         guard galleryDates.count > 0 else {
             // empty gallery

Signal/src/ViewControllers/MessageDetailViewController.swift

@@ -29,6 +29,7 @@ class MessageDetailViewController: OWSViewController, UIScrollViewDelegate, Medi
     let mode: MessageMetadataViewMode
     let viewItem: ConversationViewItem
     var message: TSMessage
+    var wasDeleted: Bool = false
 
     var mediaMessageView: MediaMessageView?
 
@@ -622,6 +623,10 @@ class MessageDetailViewController: OWSViewController, UIScrollViewDelegate, Medi
 
         updateDBConnectionAndMessageToLatest()
 
+        guard !wasDeleted else {
+            // Item was deleted. Don't bother re-rendering, it will fail and we'll soon be dismissed.
+            return
+        }
         updateContent()
     }