clean up from PR jessesquires#644 code review

shaolinjr · Dec 19, 2014 · 697c839 · 697c839
1 parent d6c9dd0
commit 697c839
Showing 1 changed file with 9 additions and 10 deletions.
diff --git a/JSQMessagesViewController/Controllers/JSQMessagesViewController.m b/JSQMessagesViewController/Controllers/JSQMessagesViewController.m
@@ -370,20 +370,19 @@ - (void)scrollToBottomAnimated:(BOOL)animated
         return;
     }
 
-    // if last object is huge, use UICollectionViewScrollPositionBottom for better appearance
-    // else use Top
-    NSInteger finalRow = MAX(0, [self.collectionView numberOfItemsInSection:0] - 1);
-    NSIndexPath *finalIndexPath = [NSIndexPath indexPathForItem:finalRow
-                                                      inSection:0];
+    //  workaround for really long messages not scrolling
+    //  if last message is too long, use scroll position bottom for better appearance, else use top
+    //  possibly a UIKit bug, see #480 on GitHub
+    NSUInteger finalRow = MAX(0, [self.collectionView numberOfItemsInSection:0] - 1);
+    NSIndexPath *finalIndexPath = [NSIndexPath indexPathForItem:finalRow inSection:0];
     CGSize finalCellSize = [self.collectionView.collectionViewLayout sizeForItemAtIndexPath:finalIndexPath];
 
-    CGFloat maxHeight = CGRectGetHeight(self.collectionView.bounds) - self.collectionView.contentInset.top - CGRectGetHeight(self.inputToolbar.bounds);
+    CGFloat maxHeightForVisibleMessage = CGRectGetHeight(self.collectionView.bounds) - self.collectionView.contentInset.top - CGRectGetHeight(self.inputToolbar.bounds);
 
-    BOOL hugeCell = (maxHeight < finalCellSize.height);
-    UICollectionViewScrollPosition position = (hugeCell) ? UICollectionViewScrollPositionBottom : UICollectionViewScrollPositionTop;
+    UICollectionViewScrollPosition scrollPosition = (finalCellSize.height > maxHeightForVisibleMessage) ? UICollectionViewScrollPositionBottom : UICollectionViewScrollPositionTop;
 
-    [self.collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:items - 1 inSection:0]
-                                atScrollPosition:position
+    [self.collectionView scrollToItemAtIndexPath:finalIndexPath
+                                atScrollPosition:scrollPosition
                                         animated:animated];
 }