Track 'persisted' viewItems separately

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -702,7 +702,7 @@ typedef enum : NSUInteger {
 
 - (NSArray<id<ConversationViewItem>> *)viewItems
 {
-    return self.conversationViewModel.viewItems;
+    return self.conversationViewModel.allViewItems;
 }
 
 - (ThreadDynamicInteractions *)dynamicInteractions

Signal/src/ViewControllers/ConversationView/ConversationViewModel.h

@@ -80,7 +80,7 @@ typedef NS_ENUM(NSUInteger, ConversationUpdateItemType) {
 
 @interface ConversationViewModel : NSObject
 
-@property (nonatomic, readonly) NSArray<id<ConversationViewItem>> *viewItems;
+@property (nonatomic, readonly) NSArray<id<ConversationViewItem>> *allViewItems;
 @property (nonatomic, nullable) NSString *focusMessageIdOnOpen;
 @property (nonatomic, readonly, nullable) ThreadDynamicInteractions *dynamicInteractions;
 

Signal/src/ViewControllers/ConversationView/ConversationViewModel.m

@@ -154,7 +154,7 @@ static const int kYapDatabaseRangeMinLength = 0;
 // * If we do the third step, we must call resetContentAndLayout afterward.
 @property (nonatomic) YapDatabaseViewMappings *messageMappings;
 
-@property (nonatomic) NSArray<id<ConversationViewItem>> *viewItems;
+@property (nonatomic) NSArray<id<ConversationViewItem>> *allViewItems;
 @property (nonatomic) NSMutableDictionary<NSString *, id<ConversationViewItem>> *viewItemCache;
 
 @property (nonatomic) NSUInteger lastRangeLength;
@@ -165,6 +165,7 @@ static const int kYapDatabaseRangeMinLength = 0;
 
 @property (nonatomic, nullable) ConversationProfileState *conversationProfileState;
 @property (nonatomic) BOOL hasTooManyOutgoingMessagesToBlockCached;
+@property (nonatomic) NSArray<id<ConversationViewItem>> *persistedViewItems;
 
 @end
 
@@ -489,7 +490,7 @@ static const int kYapDatabaseRangeMinLength = 0;
 
 - (nullable id<ConversationViewItem>)viewItemForUnreadMessagesIndicator
 {
-    for (id<ConversationViewItem> viewItem in self.viewItems) {
+    for (id<ConversationViewItem> viewItem in self.allViewItems) {
         if (viewItem.unreadIndicator) {
             return viewItem;
         }
@@ -596,7 +597,7 @@ static const int kYapDatabaseRangeMinLength = 0;
     }
 
     NSMutableArray<NSString *> *oldItemIdList = [NSMutableArray new];
-    for (id<ConversationViewItem> viewItem in self.viewItems) {
+    for (id<ConversationViewItem> viewItem in self.allViewItems) {
         [oldItemIdList addObject:viewItem.itemId];
     }
 
@@ -659,7 +660,7 @@ static const int kYapDatabaseRangeMinLength = 0;
         return;
     }
 
-    OWSLogVerbose(@"self.viewItems.count: %zd -> %zd", oldItemIdList.count, self.viewItems.count);
+    OWSLogVerbose(@"self.viewItems.count: %zd -> %zd", oldItemIdList.count, self.allViewItems.count);
 
     [self updateViewWithOldItemIdList:oldItemIdList updatedItemSet:updatedItemSet];
 }
@@ -673,7 +674,7 @@ static const int kYapDatabaseRangeMinLength = 0;
     OWSLogVerbose(@"");
 
     NSMutableArray<NSString *> *oldItemIdList = [NSMutableArray new];
-    for (id<ConversationViewItem> viewItem in self.viewItems) {
+    for (id<ConversationViewItem> viewItem in self.allViewItems) {
         [oldItemIdList addObject:viewItem.itemId];
     }
 
@@ -685,7 +686,7 @@ static const int kYapDatabaseRangeMinLength = 0;
         return;
     }
 
-    OWSLogVerbose(@"self.viewItems.count: %zd -> %zd", oldItemIdList.count, self.viewItems.count);
+    OWSLogVerbose(@"self.viewItems.count: %zd -> %zd", oldItemIdList.count, self.allViewItems.count);
 
     [self updateViewWithOldItemIdList:oldItemIdList updatedItemSet:[NSSet set]];
 }
@@ -710,7 +711,7 @@ static const int kYapDatabaseRangeMinLength = 0;
 
     NSMutableArray<NSString *> *newItemIdList = [NSMutableArray new];
     NSMutableDictionary<NSString *, id<ConversationViewItem>> *newViewItemMap = [NSMutableDictionary new];
-    for (id<ConversationViewItem> viewItem in self.viewItems) {
+    for (id<ConversationViewItem> viewItem in self.allViewItems) {
         [newItemIdList addObject:viewItem.itemId];
         newViewItemMap[viewItem.itemId] = viewItem;
     }
@@ -1150,6 +1151,32 @@ static const int kYapDatabaseRangeMinLength = 0;
     return offersMessage;
 }
 
+
+- (id<ConversationViewItem>)addViewItemWithInteraction:(TSInteraction *)interaction
+                                     conversationStyle:(ConversationStyle *)conversationStyle
+                                         isGroupThread:(BOOL)isGroupThread
+                                           transaction:(YapDatabaseReadTransaction *)transaction
+                                         viewItemCache:
+                                             (NSMutableDictionary<NSString *, id<ConversationViewItem>> *)viewItemCache
+                                           toViewItems:(NSMutableArray<id<ConversationViewItem>> *)viewItems
+{
+    OWSAssertDebug(interaction.uniqueId.length > 0);
+
+    id<ConversationViewItem> _Nullable viewItem = self.viewItemCache[interaction.uniqueId];
+    if (!viewItem) {
+        viewItem = [[ConversationInteractionViewItem alloc] initWithInteraction:interaction
+                                                                  isGroupThread:isGroupThread
+                                                                    transaction:transaction
+                                                              conversationStyle:conversationStyle];
+    }
+    [viewItems addObject:viewItem];
+    OWSAssertDebug(
+        !viewItemCache[interaction.uniqueId] || [interaction isKindOfClass:[OWSTypingIndicatorInteraction class]]);
+    viewItemCache[interaction.uniqueId] = viewItem;
+
+    return viewItem;
+}
+
 // This is a key method.  It builds or rebuilds the list of
 // cell view models.
 //
@@ -1166,20 +1193,14 @@ static const int kYapDatabaseRangeMinLength = 0;
     [self ensureConversationProfileState];
 
     __block BOOL hasError = NO;
-    id<ConversationViewItem> (^tryToAddViewItem)(TSInteraction *, YapDatabaseReadTransaction *) = ^(TSInteraction *interaction, YapDatabaseReadTransaction *transaction) {
+    id<ConversationViewItem> (^tryToAddViewItem)(TSInteraction *, YapDatabaseReadTransaction *)
-        OWSAssertDebug(interaction.uniqueId.length > 0);
+        = ^(TSInteraction *interaction, YapDatabaseReadTransaction *transaction) {
-
+              return [self addViewItemWithInteraction:interaction
-        id<ConversationViewItem> _Nullable viewItem = self.viewItemCache[interaction.uniqueId];
+                                    conversationStyle:conversationStyle
-        if (!viewItem) {
-            viewItem = [[ConversationInteractionViewItem alloc] initWithInteraction:interaction
                                         isGroupThread:isGroupThread
                                           transaction:transaction
-                                                                  conversationStyle:conversationStyle];
+                                        viewItemCache:viewItemCache
-        }
+                                          toViewItems:viewItems];
-        [viewItems addObject:viewItem];
-        OWSAssertDebug(!viewItemCache[interaction.uniqueId]);
-        viewItemCache[interaction.uniqueId] = viewItem;
-        return viewItem;
           };
 
     [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
@@ -1242,17 +1263,6 @@ static const int kYapDatabaseRangeMinLength = 0;
         return [left.interaction compareForSorting:right.interaction];
     }];
 
-    if (self.typingIndicatorsSender) {
-        [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
-            id<ConversationViewItem> _Nullable lastViewItem = viewItems.lastObject;
-            uint64_t typingIndicatorTimestamp = (lastViewItem ? lastViewItem.interaction.timestamp + 1 : 1);
-            TSInteraction *interaction =
-            [[OWSTypingIndicatorInteraction alloc] initWithThread:self.thread
-                                                        timestamp:typingIndicatorTimestamp
-                                                      recipientId:self.typingIndicatorsSender];
-            tryToAddViewItem(interaction, transaction);
-        }];
-    }
     // Flag to ensure that we only increment once per launch.
     if (hasError) {
         OWSLogWarn(@"incrementing version of: %@", TSMessageDatabaseViewExtensionName);
@@ -1260,13 +1270,36 @@ static const int kYapDatabaseRangeMinLength = 0;
     }
 
     self.viewItemCache = viewItemCache;
-    self.viewItems = [self prepareViewItemsForDisplay:viewItems];
+    self.persistedViewItems = [viewItems copy];
+    self.allViewItems = [self prepareViewItemsForDisplay:viewItems];
 
     return !hasError;
 }
 
-- (NSArray<id<ConversationViewItem>> *)prepareViewItemsForDisplay:(NSArray<id<ConversationViewItem>> *)viewItems
+- (NSArray<id<ConversationViewItem>> *)prepareViewItemsForDisplay:(NSArray<id<ConversationViewItem>> *)viewItemsArg
 {
+    NSArray<id<ConversationViewItem>> *viewItems = viewItemsArg;
+    if (self.typingIndicatorsSender) {
+        NSMutableArray<id<ConversationViewItem>> *mutableViewItems = [viewItems mutableCopy];
+        [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+            id<ConversationViewItem> _Nullable lastViewItem = viewItems.lastObject;
+            uint64_t typingIndicatorTimestamp = (lastViewItem ? lastViewItem.interaction.timestamp + 1 : 1);
+            TSInteraction *interaction =
+                [[OWSTypingIndicatorInteraction alloc] initWithThread:self.thread
+                                                            timestamp:typingIndicatorTimestamp
+                                                          recipientId:self.typingIndicatorsSender];
+
+            [self addViewItemWithInteraction:interaction
+                           conversationStyle:self.delegate.conversationStyle
+                               isGroupThread:self.thread.isGroupThread
+                                 transaction:transaction
+                               viewItemCache:self.viewItemCache
+                                 toViewItems:mutableViewItems];
+
+        }];
+        viewItems = [mutableViewItems copy];
+    }
+
     // Update the "break" properties (shouldShowDate and unreadIndicator) of the view items.
     BOOL shouldShowDateOnNextViewItem = YES;
     uint64_t previousViewItemTimestamp = 0;
@@ -1509,14 +1542,15 @@ static const int kYapDatabaseRangeMinLength = 0;
                                                    conversationStyle:self.delegate.conversationStyle];
     }];
 
-    ConversationUpdateItem *updateItem = [[ConversationUpdateItem alloc] initWithUpdateItemType:ConversationUpdateItemType_Insert
+    ConversationUpdateItem *updateItem =
+        [[ConversationUpdateItem alloc] initWithUpdateItemType:ConversationUpdateItemType_Insert
                                                       oldIndex:0
-                                                                                       newIndex:self.viewItems.count
+                                                      newIndex:self.persistedViewItems.count
                                                       viewItem:viewItem];
 
-    NSMutableArray<id <ConversationViewItem>> *viewItems = [self.viewItems mutableCopy];
+    NSMutableArray<id<ConversationViewItem>> *viewItems = [self.persistedViewItems mutableCopy];
     [viewItems addObject:viewItem];
-    self.viewItems = [self prepareViewItemsForDisplay:viewItems];
+    self.allViewItems = [self prepareViewItemsForDisplay:viewItems];
     ConversationUpdate *conversationUpdate = [[ConversationUpdate alloc] initWithConversationUpdateType:ConversationUpdateType_Diff
                                                                                             updateItems:@[updateItem]
                                                                                    shouldAnimateUpdates:NO];
@@ -1666,7 +1700,7 @@ static const int kYapDatabaseRangeMinLength = 0;
         OWSFailDebug(@"Could not locate view item for quoted reply.");
         return nil;
     }
-    NSUInteger viewItemIndex = [self.viewItems indexOfObject:viewItem];
+    NSUInteger viewItemIndex = [self.allViewItems indexOfObject:viewItem];
     if (viewItemIndex == NSNotFound) {
         OWSFailDebug(@"Could not locate view item index for quoted reply.");
         return nil;
@@ -1718,7 +1752,7 @@ static const int kYapDatabaseRangeMinLength = 0;
 
     // Update the view items if necessary.
     // We don't have to do this if they haven't been configured yet.
-    if (didChange && self.viewItems != nil) {
+    if (didChange && self.allViewItems != nil) {
         [self updateForTransientItems];
     }
 }