Reduce relayout and reload churn; respond to dynamic type changes.

// FREEBIE

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

@@ -125,6 +125,8 @@ NS_ASSUME_NONNULL_BEGIN
     [self.bubbleImageView autoPinToSuperviewEdges];
 
     self.textView = [UITextView new];
+    // Honor dynamic type in the message bodies.
+    self.textView.font = [self textMessageFont];
     self.textView.font = [UIFont ows_regularFontWithSize:16.f];
     self.textView.backgroundColor = [UIColor clearColor];
     self.textView.opaque = NO;
@@ -167,6 +169,11 @@ NS_ASSUME_NONNULL_BEGIN
     return NSStringFromClass([self class]);
 }
 
+- (UIFont *)textMessageFont
+{
+    return [UIFont ows_dynamicTypeBodyFont];
+}
+
 - (OWSMessageCellType)cellType
 {
     return self.viewItem.messageCellType;
@@ -543,6 +550,7 @@ NS_ASSUME_NONNULL_BEGIN
     self.textView.text = self.textMessage;
     UIColor *textColor = [self textColor];
     self.textView.textColor = textColor;
+    self.textView.font = [self textMessageFont];
 
     // Don't link outgoing messages that haven't been sent yet, as
     // this interferes with "tap to retry".
@@ -738,6 +746,7 @@ NS_ASSUME_NONNULL_BEGIN
             const int maxTextWidth = (int)floor(maxMessageWidth - (leftMargin + rightMargin));
 
             self.textView.text = self.textMessage;
+            self.textView.font = [self textMessageFont];
             CGSize textSize = [self.textView sizeThatFits:CGSizeMake(maxTextWidth, CGFLOAT_MAX)];
             cellSize = CGSizeMake((CGFloat)ceil(textSize.width + leftMargin + rightMargin),
                 (CGFloat)ceil(textSize.height + textVMargin * 2));

Signal/src/ViewControllers/ConversationView/ConversationInputToolbar.h

@@ -49,6 +49,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (nullable NSString *)textInputPrimaryLanguage;
 
+- (void)updateFontSizes;
+
 #pragma mark - Voice Memo
 
 - (void)showVoiceMemoUI;

Signal/src/ViewControllers/ConversationView/ConversationInputToolbar.m

@@ -83,6 +83,7 @@ static void *kConversationInputTextViewObservingContext = &kConversationInputTex
 
     _inputTextView = [ConversationInputTextView new];
     self.inputTextView.textViewToolbarDelegate = self;
+    self.inputTextView.font = [UIFont ows_dynamicTypeBodyFont];
     [self.contentView addSubview:self.inputTextView];
 
     // We want to be permissive about taps on the send and attachment buttons,
@@ -151,6 +152,13 @@ static void *kConversationInputTextViewObservingContext = &kConversationInputTex
     [self ensureContentConstraints];
 }
 
+- (void)updateFontSizes
+{
+    self.inputTextView.font = [UIFont ows_dynamicTypeBodyFont];
+
+    [self ensureContentConstraints];
+}
+
 - (void)setInputTextViewDelegate:(id<ConversationInputTextViewDelegate>)value
 {
     OWSAssert(self.inputTextView);

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -329,8 +329,11 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
             [self setNavigationTitle];
         }
 
-        // Reload all cells.
-        [self resetContentAndLayout];
+        if (self.isGroupConversation) {
+            // Reload all cells if this is a group conversation,
+            // since we may need to update the sender names on the messages.
+            [self resetContentAndLayout];
+        }
     }
 }
 
@@ -633,10 +636,8 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
 - (void)resetContentAndLayout
 {
     // Avoid layout corrupt issues and out-of-date message subtitles.
-    [self.collectionView.collectionViewLayout
-        invalidateLayoutWithContext:[JSQMessagesCollectionViewFlowLayoutInvalidationContext context]];
+    [self.collectionView.collectionViewLayout invalidateLayout];
     [self.collectionView reloadData];
-
     // TODO: Should we evacuate cached cell sizes here?
 }
 
@@ -1377,9 +1378,14 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
  */
 - (void)didChangePreferredContentSize:(NSNotification *)notification
 {
-    //    [self.collectionView.collectionViewLayout setMessageBubbleFont:[UIFont ows_dynamicTypeBodyFont]];
+    DDLogInfo(@"%@ didChangePreferredContentSize", self.tag);
+
+    // Evacuate cached cell sizes.
+    for (ConversationViewItem *viewItem in self.viewItems) {
+        [viewItem clearCachedLayoutState];
+    }
     [self resetContentAndLayout];
-    //    [self reloadInputToolbarSizeIfNeeded];
+    [self.inputToolbar updateFontSizes];
 }
 
 #pragma mark - Actions
@@ -3579,7 +3585,6 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     [groupMemberIds addObject:[TSAccountManager localNumber]];
     groupModel.groupMemberIds = [NSMutableArray arrayWithArray:[groupMemberIds allObjects]];
     [self updateGroupModelTo:groupModel successCompletion:nil];
-    [self resetContentAndLayout];
 }
 
 - (void)popAllConversationSettingsViews
@@ -3668,20 +3673,12 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
         [self toggleDefaultKeyboard];
     }
     [self clearDraft];
-    [self finishSendingMessage];
+    [self.inputToolbar clearTextMessage];
     if (didAddToProfileWhitelist) {
         [self ensureDynamicInteractions];
     }
 }
 
-- (void)finishSendingMessage
-{
-    [self.inputToolbar clearTextMessage];
-    [self.collectionView.collectionViewLayout
-        invalidateLayoutWithContext:[JSQMessagesCollectionViewFlowLayoutInvalidationContext context]];
-    [self.collectionView reloadData];
-}
-
 - (void)voiceMemoGestureDidStart
 {
     OWSAssert([NSThread isMainThread]);