Clean up ahead of PR.

// FREEBIE

Signal/src/ViewControllers/ConversationView/ConversationViewItem.m

@@ -217,6 +217,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - View State
 
+// TODO: Now that we're caching the displayable text on the view items,
+//       I don't think we need this cache any more.
 - (NSCache *)displayableTextCache
 {
     static NSCache *cache = nil;
@@ -285,7 +287,6 @@ NS_ASSUME_NONNULL_BEGIN
     TSMessage *interaction = (TSMessage *)self.interaction;
     if (interaction.body.length > 0) {
         self.messageCellType = OWSMessageCellType_TextMessage;
-        // TODO: This can be expensive.  Should we cache it on the view item?
         self.textMessage = [self displayableTextForText:interaction.body interactionId:interaction.uniqueId];
         return;
     } else {
@@ -297,7 +298,6 @@ NS_ASSUME_NONNULL_BEGIN
 
                 if ([attachment.contentType isEqualToString:OWSMimeTypeOversizeTextMessage]) {
                     self.messageCellType = OWSMessageCellType_OversizeTextMessage;
-                    // TODO: This can be expensive.  Should we cache it on the view item?
                     self.textMessage = [self displayableTextForAttachmentStream:self.attachmentStream
                                                                   interactionId:interaction.uniqueId];
                     return;

Signal/src/ViewControllers/ConversationView/ConversationViewLayout.h

@@ -5,6 +5,7 @@
 NS_ASSUME_NONNULL_BEGIN
 
 typedef NS_ENUM(NSInteger, ConversationViewLayoutAlignment) {
+    // We use incoming/outgoing, not left/right to support RTL.
     ConversationViewLayoutAlignment_Incoming,
     ConversationViewLayoutAlignment_Outgoing,
     ConversationViewLayoutAlignment_FullWidth,
@@ -29,6 +30,8 @@ typedef NS_ENUM(NSInteger, ConversationViewLayoutAlignment) {
 
 #pragma mark -
 
+// A new lean and efficient layout for conversation view designed to
+// handle our edge cases (e.g. full-width unread indicators, etc.).
 @interface ConversationViewLayout : UICollectionViewLayout
 
 @property (nonatomic, weak) id<ConversationViewLayoutDelegate> delegate;

Signal/src/ViewControllers/ConversationView/ConversationViewLayout.m

@@ -12,11 +12,11 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic) CGSize contentSize;
 @property (nonatomic, readonly) NSMutableDictionary<NSNumber *, UICollectionViewLayoutAttributes *> *itemAttributesMap;
 
-// This may be redundant with logic in UICollectionViewLayout, but
+// This dirty flag may be redundant with logic in UICollectionViewLayout,
-// it can't hurt and it ensures that we can safely & cheaply call
+// but it can't hurt and it ensures that we can safely & cheaply call
-// prepareLayout from view logic to ensure that we always have a
+// prepareLayout from view logic to ensure that we always have a¸valid
-// valid layout without incurring any of the (great) expense of
+// layout without incurring any of the (great) expense of performing an
-// performing an unnecessary layout pass.
+// unnecessary layout pass.
 @property (nonatomic) BOOL hasLayout;
 
 @end

Signal/src/ViewControllers/HomeViewController.m

@@ -270,11 +270,6 @@ typedef NS_ENUM(NSInteger, CellState) { kArchiveState, kInboxState };
     }
 
     [self updateBarButtonItems];
-
-    dispatch_async(dispatch_get_main_queue(), ^{
-        TSThread *thread = [self threadForIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
-        [self presentThread:thread keyboardOnViewAppearing:NO callOnViewAppearing:NO];
-    });
 }
 
 - (void)updateBarButtonItems