Optimize scrolling slightly. jessesquires#1058.

JSQMessagesViewController/Controllers/JSQMessagesViewController.m

@@ -540,11 +540,7 @@ - (UICollectionViewCell *)collectionView:(JSQMessagesCollectionView *)collection
         cell.messageBubbleTopLabel.textInsets = UIEdgeInsetsMake(0.0f, bubbleTopLabelInset, 0.0f, 0.0f);
     }
 
-    cell.textView.dataDetectorTypes = UIDataDetectorTypeAll;
-
     cell.backgroundColor = [UIColor clearColor];
-    cell.layer.rasterizationScale = [UIScreen mainScreen].scale;
-    cell.layer.shouldRasterize = YES;
 
     return cell;
 }

JSQMessagesViewController/Factories/JSQMessagesTimestampFormatter.m

@@ -20,7 +20,9 @@
 
 @interface JSQMessagesTimestampFormatter ()
 
+// Separate formatters for the Date & Time parts for performance reasons
 @property (strong, nonatomic, readwrite) NSDateFormatter *dateFormatter;
+@property (strong, nonatomic, readwrite) NSDateFormatter *timeFormatter;
 
 @end
 
@@ -50,6 +52,9 @@ - (instancetype)init
         [_dateFormatter setLocale:[NSLocale currentLocale]];
         [_dateFormatter setDoesRelativeDateFormatting:YES];
 
+        _timeFormatter = [[NSDateFormatter alloc] init];
+        [_timeFormatter setLocale:[NSLocale currentLocale]];
+
         UIColor *color = [UIColor lightGrayColor];
 
         NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
@@ -69,6 +74,7 @@ - (instancetype)init
 - (void)dealloc
 {
     _dateFormatter = nil;
+    _timeFormatter = nil;
     _dateTextAttributes = nil;
     _timeTextAttributes = nil;
 }
@@ -81,9 +87,10 @@ - (NSString *)timestampForDate:(NSDate *)date
         return nil;
     }
 
-    [self.dateFormatter setDateStyle:NSDateFormatterMediumStyle];
-    [self.dateFormatter setTimeStyle:NSDateFormatterShortStyle];
-    return [self.dateFormatter stringFromDate:date];
+    NSString *relativeDate = [self relativeDateForDate:date];
+    NSString *time = [self timeForDate:date];
+
+    return [NSString stringWithFormat:@"%@ %@", relativeDate, time];
 }
 
 - (NSAttributedString *)attributedTimestampForDate:(NSDate *)date
@@ -112,9 +119,9 @@ - (NSString *)timeForDate:(NSDate *)date
         return nil;
     }
 
-    [self.dateFormatter setDateStyle:NSDateFormatterNoStyle];
-    [self.dateFormatter setTimeStyle:NSDateFormatterShortStyle];
-    return [self.dateFormatter stringFromDate:date];
+    [self.timeFormatter setDateStyle:NSDateFormatterNoStyle];
+    [self.timeFormatter setTimeStyle:NSDateFormatterShortStyle];
+    return [self.timeFormatter stringFromDate:date];
 }
 
 - (NSString *)relativeDateForDate:(NSDate *)date
@@ -128,4 +135,4 @@ - (NSString *)relativeDateForDate:(NSDate *)date
     return [self.dateFormatter stringFromDate:date];
 }
 
-@end
+@end

JSQMessagesViewController/Views/JSQMessagesCellTextView.m

@@ -18,7 +18,9 @@
 
 #import "JSQMessagesCellTextView.h"
 
-@implementation JSQMessagesCellTextView
+@implementation JSQMessagesCellTextView {
+    BOOL _hasText;
+}
 
 - (void)awakeFromNib
 {
@@ -31,7 +33,7 @@ - (void)awakeFromNib
     self.dataDetectorTypes = UIDataDetectorTypeNone;
     self.showsHorizontalScrollIndicator = NO;
     self.showsVerticalScrollIndicator = NO;
-    self.scrollEnabled = NO;
+    //self.scrollEnabled = NO;
     self.backgroundColor = [UIColor clearColor];
     self.contentInset = UIEdgeInsetsZero;
     self.scrollIndicatorInsets = UIEdgeInsetsZero;
@@ -45,14 +47,40 @@ - (void)awakeFromNib
     self.textContainer.lineFragmentPadding = 0;
 }
 
-- (void)setText:(NSString *)text {
-    [super setText:text];
+// In prepareForReuse we would set the text to nil,
+// and then we would set the text to the correct value.
+// This dance takes time, especially with data detectors in place.
+// We make sure that the outside can see the correct values and we do layout.
+- (void)setText:(NSString *)text
+{
     if (text) {
+        [super setText:text];
+    }
+    _hasText = !!text.length;
+    [self setNeedsLayout];
+}
+
+- (NSString *)text
+{
+    return (_hasText) ?  [super text] :  nil;
+}
+
+- (void)setAttributedText:(NSAttributedString *)attributedText
+{
+    if (attributedText) {
         NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
         paragraphStyle.lineSpacing = self.font.pointSize * self.lineHeightFactor;
         NSDictionary *attrsDictionary = @{ NSFontAttributeName: self.font, NSParagraphStyleAttributeName: paragraphStyle};
-        self.attributedText = [[NSAttributedString alloc] initWithString:text attributes:attrsDictionary];
+        attributedText = [[NSAttributedString alloc] initWithString:attributedText.string attributes:attrsDictionary];
+        [super setAttributedText:attributedText];
     }
+    _hasText = !!attributedText.length;
+    [self setNeedsLayout];
+}
+
+- (NSAttributedString *)attributedText
+{
+    return (_hasText) ? [super attributedText] : nil;
 }
 
 - (void)setSelectedRange:(NSRange)selectedRange