Merge branch 'charlesmchen/refineViewModelDiffs'

Signal/src/ViewControllers/ColorPickerViewController.swift

@@ -340,6 +340,7 @@ private class MockConversationViewItem: NSObject, ConversationViewItem {
     var hasBodyTextActionContent: Bool = false
     var hasMediaActionContent: Bool = false
     var mediaAlbumItems: [ConversationMediaAlbumItem]?
+    var hasCachedLayoutState: Bool = false
 
     override init() {
         super.init()

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m

@@ -577,7 +577,6 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
         case OWSMessageCellType_Unknown:
         case OWSMessageCellType_TextMessage:
         case OWSMessageCellType_OversizeTextMessage:
-            return NO;
         case OWSMessageCellType_Audio:
         case OWSMessageCellType_GenericAttachment:
         case OWSMessageCellType_DownloadingAttachment:
@@ -588,6 +587,21 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
     }
 }
 
+- (BOOL)hasBodyMediaView {
+    switch (self.cellType) {
+        case OWSMessageCellType_Unknown:
+        case OWSMessageCellType_TextMessage:
+        case OWSMessageCellType_OversizeTextMessage:
+            return NO;
+        case OWSMessageCellType_Audio:
+        case OWSMessageCellType_GenericAttachment:
+        case OWSMessageCellType_DownloadingAttachment:
+        case OWSMessageCellType_ContactShare:
+        case OWSMessageCellType_MediaAlbum:
+            return YES;
+    }
+}
+
 - (BOOL)hasFullWidthMediaView
 {
     return (self.hasBodyMediaWithThumbnail || self.cellType == OWSMessageCellType_ContactShare
@@ -601,8 +615,14 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
 
 - (BOOL)hasBottomFooter
 {
-    BOOL shouldFooterOverlayMedia = (self.canFooterOverlayMedia && !self.hasBodyText);
+    BOOL shouldFooterOverlayMedia = (self.canFooterOverlayMedia && self.hasBodyMediaView && !self.hasBodyText);
-    return !self.viewItem.shouldHideFooter && !shouldFooterOverlayMedia;
+    if (self.viewItem.shouldHideFooter) {
+        return NO;
+    } else if (shouldFooterOverlayMedia) {
+        return NO;
+    } else {
+        return YES;
+    }
 }
 
 - (BOOL)insertAnyTextViewsIntoStackView:(NSArray<UIView *> *)textViews

Signal/src/ViewControllers/ConversationView/ConversationViewItem.h

@@ -91,6 +91,8 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType);
 
 - (void)clearCachedLayoutState;
 
+@property (nonatomic, readonly) BOOL hasCachedLayoutState;
+
 #pragma mark - Audio Playback
 
 @property (nonatomic, weak) OWSAudioMessageView *lastAudioMessageView;

Signal/src/ViewControllers/ConversationView/ConversationViewItem.m

@@ -286,6 +286,10 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     self.cachedCellSize = nil;
 }
 
+- (BOOL)hasCachedLayoutState {
+    return self.cachedCellSize != nil;
+}
+
 - (CGSize)cellSize
 {
     OWSAssertIsOnMainThread();

Signal/src/ViewControllers/ConversationView/ConversationViewModel.m

@@ -569,7 +569,6 @@ static const int kYapDatabaseRangeMinLength = 0;
     // reloadViewItems.
     BOOL hasMalformedRowChange = NO;
     NSMutableSet<NSString *> *updatedItemSet = [NSMutableSet new];
-    NSMutableSet<NSString *> *updatedNeighborItemSet = [NSMutableSet new];
     for (YapDatabaseViewRowChange *rowChange in rowChanges) {
         switch (rowChange.type) {
             case YapDatabaseViewChangeUpdate: {
@@ -579,17 +578,10 @@ static const int kYapDatabaseRangeMinLength = 0;
                     if (viewItem) {
                         [self reloadInteractionForViewItem:viewItem];
                         [updatedItemSet addObject:viewItem.itemId];
-                        if (rowChange.changes == YapDatabaseViewChangedDependency) {
-                            [updatedNeighborItemSet addObject:viewItem.itemId];
-                        }
                     } else {
                         OWSLogError(@"Update is missing view item");
                         hasMalformedRowChange = YES;
                     }
-                } else if (rowChange.indexPath && rowChange.originalIndex < self.viewItems.count) {
-                    // Do nothing, this is a pseudo-update generated due to
-                    // setCellDrawingDependencyOffsets.
-                    OWSAssertDebug(rowChange.changes == YapDatabaseViewChangedDependency);
                 } else {
                     OWSFailDebug(@"Update is missing collection key");
                     hasMalformedRowChange = YES;
@@ -634,9 +626,7 @@ static const int kYapDatabaseRangeMinLength = 0;
 
     OWSLogVerbose(@"self.viewItems.count: %zd -> %zd", oldItemIdList.count, self.viewItems.count);
 
-    [self updateViewWithOldItemIdList:oldItemIdList
+    [self updateViewWithOldItemIdList:oldItemIdList updatedItemSet:updatedItemSet];
-                       updatedItemSet:updatedItemSet
-               updatedNeighborItemSet:updatedNeighborItemSet];
 }
 
 // A simpler version of the update logic we use when
@@ -662,15 +652,13 @@ static const int kYapDatabaseRangeMinLength = 0;
 
     OWSLogVerbose(@"self.viewItems.count: %zd -> %zd", oldItemIdList.count, self.viewItems.count);
 
-    [self updateViewWithOldItemIdList:oldItemIdList updatedItemSet:[NSSet set] updatedNeighborItemSet:nil];
+    [self updateViewWithOldItemIdList:oldItemIdList updatedItemSet:[NSSet set]];
 }
 
 - (void)updateViewWithOldItemIdList:(NSArray<NSString *> *)oldItemIdList
-                     updatedItemSet:(NSSet<NSString *> *)updatedItemSet
+                     updatedItemSet:(NSSet<NSString *> *)updatedItemSetParam {
-             updatedNeighborItemSet:(nullable NSMutableSet<NSString *> *)updatedNeighborItemSet
-{
     OWSAssertDebug(oldItemIdList);
-    OWSAssertDebug(updatedItemSet);
+    OWSAssertDebug(updatedItemSetParam);
 
     if (!self.delegate.isObservingVMUpdates) {
         OWSLogVerbose(@"Skipping VM update.");
@@ -771,6 +759,44 @@ static const int kYapDatabaseRangeMinLength = 0;
         return [self.delegate conversationViewModelDidUpdate:ConversationUpdate.reloadUpdate];
     }
 
+    // In addition to "update" items from the database change notification,
+    // we may need to update other items.  One example is neighbors of modified
+    // cells. Another is cells whose appearance has changed due to the passage
+    // of time.  We detect "dirty" items by whether or not they have cached layout
+    // state, since that is cleared whenever we change the properties of the
+    // item that affect its appearance.
+    //
+    // This replaces the setCellDrawingDependencyOffsets/
+    // YapDatabaseViewChangedDependency logic offered by YDB mappings,
+    // which only reflects changes in the data store, not at the view
+    // level.
+    NSMutableSet<NSString *> *updatedItemSet = [updatedItemSetParam mutableCopy];
+    NSMutableSet<NSString *> *updatedNeighborItemSet = [NSMutableSet new];
+    for (NSString *itemId in newItemIdSet) {
+        if (![oldItemIdSet containsObject:itemId]) {
+            continue;
+        }
+        if ([insertedItemIdSet containsObject:itemId] || [updatedItemSet containsObject:itemId]) {
+            continue;
+        }
+        OWSAssertDebug(![deletedItemIdSet containsObject:itemId]);
+
+        NSUInteger newIndex = [newItemIdList indexOfObject:itemId];
+        if (newIndex == NSNotFound) {
+            OWSFailDebug(@"Can't find index of holdover view item.");
+            return [self.delegate conversationViewModelDidUpdate:ConversationUpdate.reloadUpdate];
+        }
+        id<ConversationViewItem> _Nullable viewItem = newViewItemMap[itemId];
+        if (!viewItem) {
+            OWSFailDebug(@"Can't find holdover view item.");
+            return [self.delegate conversationViewModelDidUpdate:ConversationUpdate.reloadUpdate];
+        }
+        if (!viewItem.hasCachedLayoutState) {
+            [updatedItemSet addObject:itemId];
+            [updatedNeighborItemSet addObject:itemId];
+        }
+    }
+
     // 3. Updates.
     //
     // NOTE: Order doesn't matter.
@@ -867,16 +893,6 @@ static const int kYapDatabaseRangeMinLength = 0;
             [[YapDatabaseViewMappings alloc] initWithGroups:@[] view:TSMessageDatabaseViewExtensionName];
     }
 
-    // Cells' appearance can depend on adjacent cells in both directions.
-    //
-    // TODO: We could do the same thing in our logic to generate "update items"
-    //       in updateViewWithOldItemIdList.
-    [self.messageMappings setCellDrawingDependencyOffsets:[NSSet setWithArray:@[
-        @(-1),
-        @(+1),
-    ]]
-                                                 forGroup:self.thread.uniqueId];
-
     [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
         [self.messageMappings updateWithTransaction:transaction];
     }];