[ASTextKitCoreTextAdditions] Adds mappings for kCTParagraphStyleSpeci…

…fierMinimumLineSpacing, kCTParagraphStyleSpecifierMaximumLineSpacing, kCTParagraphStyleSpecifierLineSpacingAdjustment when mapping CTParagraphStyle onto NSParagraphStyle [ASTextNode] Uses CoreText-cleansed attributed string when assigning ascender/descender to avoid crash when a CTParagraphStyle is passed as an attribute
TextureGroup · Jan 6, 2018 · 8eb2dbe · 8eb2dbe
1 parent bf9aa78
commit 8eb2dbe
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Showing 2 changed files with 27 additions and 10 deletions.
diff --git a/Source/ASTextNode.mm b/Source/ASTextNode.mm
@@ -447,10 +447,10 @@ - (void)setAttributedText:(NSAttributedString *)attributedText
   // Since truncation text matches style of attributedText, invalidate it now.
   [self _invalidateTruncationText];
 
-  NSUInteger length = attributedText.length;
+  NSUInteger length = _attributedText.length;
   if (length > 0) {
-    self.style.ascender = [[self class] ascenderWithAttributedString:attributedText];
-    self.style.descender = [[attributedText attribute:NSFontAttributeName atIndex:attributedText.length - 1 effectiveRange:NULL] descender];
+    self.style.ascender = [[self class] ascenderWithAttributedString:_attributedText];
+    self.style.descender = [[_attributedText attribute:NSFontAttributeName atIndex:length - 1 effectiveRange:NULL] descender];
   }
 
   // Tell the display node superclasses that the cached layout is incorrect now
@@ -461,7 +461,7 @@ - (void)setAttributedText:(NSAttributedString *)attributedText
 
 
   // Accessiblity
-  self.accessibilityLabel = attributedText.string;
+  self.accessibilityLabel = _attributedText.string;
   self.isAccessibilityElement = (length != 0); // We're an accessibility element by default if there is a string.
 }
 

diff --git a/Source/TextKit/ASTextKitCoreTextAdditions.m b/Source/TextKit/ASTextKitCoreTextAdditions.m
@@ -39,6 +39,7 @@ BOOL ASAttributeWithNameIsUnsupportedCoreTextAttribute(NSString *attributeName)
                           kCTBaselineInfoAttributeName,
                           kCTBaselineReferenceInfoAttributeName,
                           kCTUnderlineColorAttributeName,
+                          kCTParagraphStyleAttributeName,
                           nil];
   });
   return [coreTextAttributes containsObject:attributeName];
@@ -227,17 +228,33 @@ + (instancetype)paragraphStyleWithCTParagraphStyle:(CTParagraphStyleRef)coreText
   CGFloat minimumLineHeight;
   if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierMinimumLineHeight, sizeof(minimumLineHeight), &minimumLineHeight))
     newParagraphStyle.minimumLineHeight = minimumLineHeight;
-
+
+  CGFloat lineSpacing = 0;
 #if TARGET_OS_IOS
-  // kCTParagraphStyleSpecifierLineSpacing -> lineSpacing
-  // Note that kCTParagraphStyleSpecifierLineSpacing is deprecated and will die soon. We should not be using it.
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
-    CGFloat lineSpacing;
-    if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierLineSpacing, sizeof(lineSpacing), &lineSpacing))
-        newParagraphStyle.lineSpacing = lineSpacing;
+  // kCTParagraphStyleSpecifierLineSpacing -> lineSpacing
+  // Note that kCTParagraphStyleSpecifierLineSpacing is deprecated and will die soon. We should not be using it.
+  if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierLineSpacing, sizeof(lineSpacing), &lineSpacing))
+    newParagraphStyle.lineSpacing = lineSpacing;
 #pragma clang diagnostic pop
 #endif
+
+  // Attempt to weakly map the following onto -[NSParagraphStyle lineSpacing]:
+  //   - kCTParagraphStyleSpecifierMinimumLineSpacing
+  //   - kCTParagraphStyleSpecifierMaximumLineSpacing
+  //   - kCTParagraphStyleSpecifierLineSpacingAdjustment
+  if (fabs(lineSpacing) <= FLT_EPSILON &&
+      CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierMinimumLineSpacing, sizeof(lineSpacing), &lineSpacing))
+    newParagraphStyle.lineSpacing = lineSpacing;
+
+  if (fabs(lineSpacing) <= FLT_EPSILON &&
+      CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierMaximumLineSpacing, sizeof(lineSpacing), &lineSpacing))
+    newParagraphStyle.lineSpacing = lineSpacing;
+
+  if (fabs(lineSpacing) <= FLT_EPSILON &&
+      CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierLineSpacingAdjustment, sizeof(lineSpacing), &lineSpacing))
+    newParagraphStyle.lineSpacing = lineSpacing;
 
   // kCTParagraphStyleSpecifierParagraphSpacing -> paragraphSpacing
   CGFloat paragraphSpacing;