[ASTextKitFontSizeAdjuster] Replace use of boundingRectWithSize:optio…

…ns:context: with boundingRectForGlyphRange: inTextContainer: (#251) * [ASTextKitFontSizeAdjuster] Replace use of boundingRectWithSize:options:context: with boundingRectForGlyphRange: inTextContainer: `boundingRectWithSize:options:context:` started returning different values for the same strings between iOS 10.2 and iOS 10.3. Switching to using `NSLayoutManager`’s `boundingRectForGlyphRange: inTextContainer:` fixed this. It also makes sure we are consistent with what `ASTextKitTailTruncater` uses. * updated changelog
TextureGroup · May 11, 2017 · 002f470 · 002f470
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## master
 
 * Add your own contributions to the next release on the line below this with your name.
+- [ASTextKitFontSizeAdjuster] [Ricky Cancro] Replace use of NSAttributedString's boundingRectWithSize:options:context: with NSLayoutManager's boundingRectForGlyphRange:inTextContainer:
 - Add support for IGListKit post-removal-of-IGListSectionType, in preparation for IGListKit 3.0.0 release. [Adlai Holler](https://github.com/Adlai-Holler) [#49](https://github.com/TextureGroup/Texture/pull/49)
 - Fix `__has_include` check in ASLog.h [Philipp Smorygo]([email protected])
 - Fix potential deadlock in ASControlNode [Garrett Moon](https://github.com/garrettmoon)

diff --git a/Source/TextKit/ASTextKitFontSizeAdjuster.mm b/Source/TextKit/ASTextKitFontSizeAdjuster.mm
@@ -21,23 +21,30 @@
 #import <tgmath.h>
 #import <mutex>
 
-#import <AsyncDisplayKit/ASTextKitContext.h>
 #import <AsyncDisplayKit/ASLayoutManager.h>
+#import <AsyncDisplayKit/ASTextKitContext.h>
+#import <AsyncDisplayKit/ASThread.h>
 
 //#define LOG(...) NSLog(__VA_ARGS__)
 #define LOG(...)
 
+@interface ASTextKitFontSizeAdjuster()
+@property (nonatomic, strong, readonly) NSLayoutManager *sizingLayoutManager;
+@property (nonatomic, strong, readonly) NSTextContainer *sizingTextContainer;
+@end
+
 @implementation ASTextKitFontSizeAdjuster
 {
   __weak ASTextKitContext *_context;
   ASTextKitAttributes _attributes;
-  std::mutex _textKitMutex;
   BOOL _measured;
   CGFloat _scaleFactor;
-  NSLayoutManager *_sizingLayoutManager;
-  NSTextContainer *_sizingTextContainer;
+  ASDN::Mutex __instanceLock__;
 }
 
+@synthesize sizingLayoutManager = _sizingLayoutManager;
+@synthesize sizingTextContainer = _sizingTextContainer;
+
 - (instancetype)initWithContext:(ASTextKitContext *)context
                 constrainedSize:(CGSize)constrainedSize
               textKitAttributes:(const ASTextKitAttributes &)textComponentAttributes;
@@ -94,38 +101,61 @@ + (void)adjustFontSizeForAttributeString:(NSMutableAttributedString *)attrString
 
 - (NSUInteger)lineCountForString:(NSAttributedString *)attributedString
 {
-    NSUInteger lineCount = 0;
-
-    static std::mutex __static_mutex;
-    std::lock_guard<std::mutex> l(__static_mutex);
+  NSUInteger lineCount = 0;
+
+  NSLayoutManager *sizingLayoutManager = [self sizingLayoutManager];
+  NSTextContainer *sizingTextContainer = [self sizingTextContainer];
+
+  NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedString];
+  [textStorage addLayoutManager:sizingLayoutManager];
+
+  [sizingLayoutManager ensureLayoutForTextContainer:sizingTextContainer];
+  for (NSRange lineRange = { 0, 0 }; NSMaxRange(lineRange) < [sizingLayoutManager numberOfGlyphs] && lineCount <= _attributes.maximumNumberOfLines; lineCount++) {
+    [sizingLayoutManager lineFragmentRectForGlyphAtIndex:NSMaxRange(lineRange) effectiveRange:&lineRange];
+  }
+
+  [textStorage removeLayoutManager:sizingLayoutManager];
+  return lineCount;
+}
+
+- (CGSize)boundingBoxForString:(NSAttributedString *)attributedString
+{
+  NSLayoutManager *sizingLayoutManager = [self sizingLayoutManager];
+  NSTextContainer *sizingTextContainer = [self sizingTextContainer];
+
+  NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedString];
+  [textStorage addLayoutManager:sizingLayoutManager];
+
+  [sizingLayoutManager ensureLayoutForTextContainer:sizingTextContainer];
+  CGRect textRect = [sizingLayoutManager boundingRectForGlyphRange:NSMakeRange(0, [textStorage length])
+                                                   inTextContainer:sizingTextContainer];
+  [textStorage removeLayoutManager:sizingLayoutManager];
+  return textRect.size;
+}
+
+- (NSLayoutManager *)sizingLayoutManager
+{
+  ASDN::MutexLocker l(__instanceLock__);
+  if (_sizingLayoutManager == nil) {
+    _sizingLayoutManager = [[ASLayoutManager alloc] init];
+    _sizingLayoutManager.usesFontLeading = NO;
 
-    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:attributedString];
-    if (_sizingLayoutManager == nil) {
-        _sizingLayoutManager = [[ASLayoutManager alloc] init]; 
-        _sizingLayoutManager.usesFontLeading = NO;
-    }
-    [textStorage addLayoutManager:_sizingLayoutManager];
     if (_sizingTextContainer == nil) {
-        // make this text container unbounded in height so that the layout manager will compute the total
-        // number of lines and not stop counting when height runs out.
-        _sizingTextContainer = [[NSTextContainer alloc] initWithSize:CGSizeMake(_constrainedSize.width, CGFLOAT_MAX)];
-        _sizingTextContainer.lineFragmentPadding = 0;
-
-        // use 0 regardless of what is in the attributes so that we get an accurate line count
-        _sizingTextContainer.maximumNumberOfLines = 0;
-        [_sizingLayoutManager addTextContainer:_sizingTextContainer];
-    }
-
-    _sizingTextContainer.lineBreakMode = _attributes.lineBreakMode;
-    _sizingTextContainer.exclusionPaths = _attributes.exclusionPaths;
-
-
-    for (NSRange lineRange = { 0, 0 }; NSMaxRange(lineRange) < [_sizingLayoutManager numberOfGlyphs] && lineCount <= _attributes.maximumNumberOfLines; lineCount++) {
-        [_sizingLayoutManager lineFragmentRectForGlyphAtIndex:NSMaxRange(lineRange) effectiveRange:&lineRange];
+      // make this text container unbounded in height so that the layout manager will compute the total
+      // number of lines and not stop counting when height runs out.
+      _sizingTextContainer = [[NSTextContainer alloc] initWithSize:CGSizeMake(_constrainedSize.width, CGFLOAT_MAX)];
+      _sizingTextContainer.lineFragmentPadding = 0;
+
+      // use 0 regardless of what is in the attributes so that we get an accurate line count
+      _sizingTextContainer.maximumNumberOfLines = 0;
+
+      _sizingTextContainer.lineBreakMode = _attributes.lineBreakMode;
+      _sizingTextContainer.exclusionPaths = _attributes.exclusionPaths;
     }
-
-    [textStorage removeLayoutManager:_sizingLayoutManager];
-    return lineCount;
+    [_sizingLayoutManager addTextContainer:_sizingTextContainer];
+  }
+
+  return _sizingLayoutManager;
 }
 
 - (CGFloat)scaleFactor
@@ -202,7 +232,7 @@ - (CGFloat)scaleFactor
         // if max lines still doesn't fit, continue without checking that we fit in the constrained height
         if (maxLinesFits == YES && heightFits == NO) {
           // max lines fit so make sure that we fit in the constrained height.
-          CGSize stringSize = [scaledString boundingRectWithSize:CGSizeMake(_constrainedSize.width, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin context:nil].size;
+          CGSize stringSize = [self boundingBoxForString:scaledString];
           heightFits = (stringSize.height <= _constrainedSize.height);
         }
       }