Return to conversation after deleting long text

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -141,6 +141,7 @@ typedef enum : NSUInteger {
     ConversationViewLayoutDelegate,
     ConversationViewCellDelegate,
     ConversationInputTextViewDelegate,
+    LongTextViewDelegate,
     MessageActionsDelegate,
     MessageDetailViewDelegate,
     MenuActionsViewControllerDelegate,
@@ -1956,6 +1957,14 @@ typedef enum : NSUInteger {
     [self.navigationController popToViewController:self animated:YES];
 }
 
+#pragma mark - LongTextViewDelegate
+
+- (void)longTextViewMessageWasDeleted:(LongTextViewController *)longTextViewController
+{
+    OWSLogInfo(@"");
+    [self.navigationController popToViewController:self animated:YES];
+}
+
 #pragma mark - MenuActionsViewControllerDelegate
 
 - (void)menuActionsDidHide:(MenuActionsViewController *)menuActionsViewController
@@ -2256,8 +2265,9 @@ typedef enum : NSUInteger {
     OWSAssertDebug(conversationItem);
     OWSAssertDebug([conversationItem.interaction isKindOfClass:[TSMessage class]]);
 
-    LongTextViewController *view = [[LongTextViewController alloc] initWithViewItem:conversationItem];
+    LongTextViewController *viewController = [[LongTextViewController alloc] initWithViewItem:conversationItem];
-    [self.navigationController pushViewController:view animated:YES];
+    viewController.delegate = self;
+    [self.navigationController pushViewController:viewController animated:YES];
 }
 
 - (void)didTapContactShareViewItem:(id<ConversationViewItem>)conversationItem

Signal/src/ViewControllers/LongTextViewController.swift

@@ -1,15 +1,30 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
 import Foundation
 import SignalServiceKit
 import SignalMessaging
 
+@objc
+public protocol LongTextViewDelegate {
+    @objc
+    func longTextViewMessageWasDeleted(_ longTextViewController: LongTextViewController)
+}
+
 @objc
 public class LongTextViewController: OWSViewController {
 
-    // MARK: Properties
+    // MARK: - Dependencies
+
+    var uiDatabaseConnection: YapDatabaseConnection {
+        return OWSPrimaryStorage.shared().uiDatabaseConnection
+    }
+
+    // MARK: - Properties
+
+    @objc
+    weak var delegate: LongTextViewDelegate?
 
     let viewItem: ConversationViewItem
 
@@ -55,6 +70,54 @@ public class LongTextViewController: OWSViewController {
         createViews()
 
         self.messageTextView.contentOffset = CGPoint(x: 0, y: self.messageTextView.contentInset.top)
+
+        NotificationCenter.default.addObserver(self,
+                                               selector: #selector(uiDatabaseDidUpdate),
+                                               name: .OWSUIDatabaseConnectionDidUpdate,
+                                               object: OWSPrimaryStorage.shared().dbNotificationObject)
+    }
+
+    // MARK: - DB
+
+    @objc internal func uiDatabaseDidUpdate(notification: NSNotification) {
+        AssertIsOnMainThread()
+
+        guard let notifications = notification.userInfo?[OWSUIDatabaseConnectionNotificationsKey] as? [Notification] else {
+            owsFailDebug("notifications was unexpectedly nil")
+            return
+        }
+
+        guard let uniqueId = self.viewItem.interaction.uniqueId else {
+            Logger.error("Message is missing uniqueId.")
+            return
+        }
+
+        guard self.uiDatabaseConnection.hasChange(forKey: uniqueId,
+                                                  inCollection: TSInteraction.collection(),
+                                                  in: notifications) else {
+                                                    Logger.debug("No relevant changes.")
+                                                    return
+        }
+
+        do {
+            try uiDatabaseConnection.read { transaction in
+                guard TSInteraction.fetch(uniqueId: uniqueId, transaction: transaction) != nil else {
+                    Logger.error("Message was deleted")
+                    throw LongTextViewError.messageWasDeleted
+                }
+            }
+        } catch LongTextViewError.messageWasDeleted {
+            DispatchQueue.main.async {
+                self.delegate?.longTextViewMessageWasDeleted(self)
+            }
+        } catch {
+            owsFailDebug("unexpected error: \(error)")
+
+        }
+    }
+
+    enum LongTextViewError: Error {
+        case messageWasDeleted
     }
 
     // MARK: - Create Views

Signal/src/ViewControllers/MessageDetailViewController.swift

@@ -90,7 +90,7 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
         contactShareViewHelper.delegate = self
 
         do {
-            try updateDBConnectionAndMessageToLatest()
+            try updateMessageToLatest()
         } catch DetailViewError.messageWasDeleted {
             self.delegate?.detailViewMessageWasDeleted(self)
         } catch {
@@ -543,7 +543,7 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
     }
 
     // This method should be called after self.databaseConnection.beginLongLivedReadTransaction().
-    private func updateDBConnectionAndMessageToLatest() throws {
+    private func updateMessageToLatest() throws {
 
         AssertIsOnMainThread()
 
@@ -589,7 +589,7 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
         }
 
         do {
-            try updateDBConnectionAndMessageToLatest()
+            try updateMessageToLatest()
         } catch DetailViewError.messageWasDeleted {
             DispatchQueue.main.async {
                 self.delegate?.detailViewMessageWasDeleted(self)
@@ -723,6 +723,7 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
         }
 
         let viewController = LongTextViewController(viewItem: viewItem)
+        viewController.delegate = self
         navigationController.pushViewController(viewController, animated: true)
     }
 
@@ -789,3 +790,9 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
         self.dismiss(animated: true)
     }
 }
+
+extension MessageDetailViewController: LongTextViewDelegate {
+    func longTextViewMessageWasDeleted(_ longTextViewController: LongTextViewController) {
+        self.delegate?.detailViewMessageWasDeleted(self)
+    }
+}