//

// ASTextKitCoreTextAdditions.m

// AsyncDisplayKit

//

// Copyright (c) 2014-present, Facebook, Inc. All rights reserved.

// This source code is licensed under the BSD-style license found in the

// LICENSE file in the root directory of this source tree. An additional grant

// of patent rights can be found in the PATENTS file in the same directory.

//

#import <AsyncDisplayKit/ASTextKitCoreTextAdditions.h>

#import <CoreText/CTFont.h>

#import <CoreText/CTStringAttributes.h>

#import <AsyncDisplayKit/ASAssert.h>

#pragma mark - Public

BOOL ASAttributeWithNameIsUnsupportedCoreTextAttribute(NSString *attributeName)

{

static NSSet *coreTextAttributes;

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

coreTextAttributes = [NSSet setWithObjects:(__bridge id)kCTForegroundColorAttributeName,

kCTForegroundColorFromContextAttributeName,

kCTForegroundColorAttributeName,

kCTStrokeColorAttributeName,

kCTUnderlineStyleAttributeName,

kCTVerticalFormsAttributeName,

kCTRunDelegateAttributeName,

kCTBaselineClassAttributeName,

kCTBaselineInfoAttributeName,

kCTBaselineReferenceInfoAttributeName,

kCTUnderlineColorAttributeName,

nil];

});

return [coreTextAttributes containsObject:attributeName];

}

NSDictionary *NSAttributedStringAttributesForCoreTextAttributes(NSDictionary *coreTextAttributes)

{

NSMutableDictionary *cleanAttributes = [[NSMutableDictionary alloc] initWithCapacity:coreTextAttributes.count];

[coreTextAttributes enumerateKeysAndObjectsUsingBlock:^(NSString *coreTextKey, id coreTextValue, BOOL *stop) {

// The following attributes are not supported on NSAttributedString. Should they become available, we should add them.

/*

kCTForegroundColorFromContextAttributeName

kCTSuperscriptAttributeName

kCTGlyphInfoAttributeName

kCTCharacterShapeAttributeName

kCTLanguageAttributeName

kCTRunDelegateAttributeName

kCTBaselineClassAttributeName

kCTBaselineInfoAttributeName

kCTBaselineReferenceInfoAttributeName

kCTWritingDirectionAttributeName

kCTUnderlineColorAttributeName

*/

// Conversely, the following attributes are not supported on CFAttributedString. Should they become available, we should add them.

/*

NSStrikethroughStyleAttributeName

NSShadowAttributeName

NSBackgroundColorAttributeName

*/

// kCTFontAttributeName -> NSFontAttributeName

if ([coreTextKey isEqualToString:(NSString *)kCTFontAttributeName]) {

CTFontRef coreTextFont = (__bridge CTFontRef)coreTextValue;

NSString *fontName = (__bridge_transfer NSString *)CTFontCopyPostScriptName(coreTextFont);

CGFloat fontSize = CTFontGetSize(coreTextFont);

UIFont *font = [UIFont fontWithName:fontName size:fontSize];

ASDisplayNodeCAssertNotNil(font, @"unable to load font %@ with size %f", fontName, fontSize);

if (font == nil) {

// Gracefully fail if we were unable to load the font.

font = [UIFont systemFontOfSize:fontSize];

}

cleanAttributes[NSFontAttributeName] = font;

}

// kCTKernAttributeName -> NSKernAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTKernAttributeName]) {

cleanAttributes[NSKernAttributeName] = (NSNumber *)coreTextValue;

}

// kCTLigatureAttributeName -> NSLigatureAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTLigatureAttributeName]) {

cleanAttributes[NSLigatureAttributeName] = (NSNumber *)coreTextValue;

}

// kCTForegroundColorAttributeName -> NSForegroundColorAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTForegroundColorAttributeName]) {

cleanAttributes[NSForegroundColorAttributeName] = [UIColor colorWithCGColor:(CGColorRef)coreTextValue];

}

// kCTParagraphStyleAttributeName -> NSParagraphStyleAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTParagraphStyleAttributeName] && ![coreTextValue isKindOfClass:[NSParagraphStyle class]]) {

cleanAttributes[NSParagraphStyleAttributeName] = [NSParagraphStyle paragraphStyleWithCTParagraphStyle:(CTParagraphStyleRef)coreTextValue];

}

// kCTStrokeWidthAttributeName -> NSStrokeWidthAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTStrokeWidthAttributeName]) {

cleanAttributes[NSStrokeWidthAttributeName] = (NSNumber *)coreTextValue;

}

// kCTStrokeColorAttributeName -> NSStrokeColorAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTStrokeColorAttributeName]) {

cleanAttributes[NSStrokeColorAttributeName] = [UIColor colorWithCGColor:(CGColorRef)coreTextValue];

}

// kCTUnderlineStyleAttributeName -> NSUnderlineStyleAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTUnderlineStyleAttributeName]) {

cleanAttributes[NSUnderlineStyleAttributeName] = (NSNumber *)coreTextValue;

}

// kCTVerticalFormsAttributeName -> NSVerticalGlyphFormAttributeName

else if ([coreTextKey isEqualToString:(NSString *)kCTVerticalFormsAttributeName]) {

BOOL flag = (BOOL)CFBooleanGetValue((CFBooleanRef)coreTextValue);

cleanAttributes[NSVerticalGlyphFormAttributeName] = @((int)flag); // NSVerticalGlyphFormAttributeName is documented to be an NSNumber with an integer that's either 0 or 1.

}

// Don't filter out any internal text attributes

else if (!ASAttributeWithNameIsUnsupportedCoreTextAttribute(coreTextKey)){

cleanAttributes[coreTextKey] = coreTextValue;

}

}];

return cleanAttributes;

}

NSAttributedString *ASCleanseAttributedStringOfCoreTextAttributes(NSAttributedString *dirtyAttributedString)

{

if (!dirtyAttributedString)

return nil;

// First see if there are any core text attributes on the string

__block BOOL containsCoreTextAttributes = NO;

[dirtyAttributedString enumerateAttributesInRange:NSMakeRange(0, dirtyAttributedString.length)

options:0

usingBlock:^(NSDictionary *dirtyAttributes, NSRange range, BOOL *stop) {

[dirtyAttributes enumerateKeysAndObjectsUsingBlock:^(NSString *coreTextKey, id coreTextValue, BOOL *innerStop) {

if (ASAttributeWithNameIsUnsupportedCoreTextAttribute(coreTextKey)) {

containsCoreTextAttributes = YES;

*innerStop = YES;

}

}];

*stop = containsCoreTextAttributes;

}];

if (containsCoreTextAttributes) {

NSString *plainString = dirtyAttributedString.string;

NSMutableAttributedString *cleanAttributedString = [[NSMutableAttributedString alloc] initWithString:plainString];

// Iterate over all of the attributes, cleaning them as appropriate and applying them as we go.

[dirtyAttributedString enumerateAttributesInRange:NSMakeRange(0, plainString.length)

options:0

usingBlock:^(NSDictionary *dirtyAttributes, NSRange range, BOOL *stop) {

[cleanAttributedString addAttributes:NSAttributedStringAttributesForCoreTextAttributes(dirtyAttributes) range:range];

}];

return cleanAttributedString;

} else {

return [dirtyAttributedString copy];

}

}

#pragma mark -

#pragma mark -

@implementation NSParagraphStyle (ASTextKitCoreTextAdditions)

+ (instancetype)paragraphStyleWithCTParagraphStyle:(CTParagraphStyleRef)coreTextParagraphStyle;

{

NSMutableParagraphStyle *newParagraphStyle = [[NSMutableParagraphStyle alloc] init];

if (!coreTextParagraphStyle)

return newParagraphStyle;

// The following paragraph style specifiers are not supported on NSParagraphStyle. Should they become available, we should add them.

/*

kCTParagraphStyleSpecifierTabStops

kCTParagraphStyleSpecifierDefaultTabInterval

kCTParagraphStyleSpecifierMaximumLineSpacing

kCTParagraphStyleSpecifierMinimumLineSpacing

kCTParagraphStyleSpecifierLineSpacingAdjustment

kCTParagraphStyleSpecifierLineBoundsOptions

*/

// Conversely, the following paragraph styles are not supported on CTParagraphStyle. Should they become available, we should add them.

/*

hyphenationFactor

*/

// kCTParagraphStyleSpecifierAlignment -> alignment

CTTextAlignment coreTextAlignment;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierAlignment, sizeof(coreTextAlignment), &coreTextAlignment))

newParagraphStyle.alignment = NSTextAlignmentFromCTTextAlignment(coreTextAlignment);

// kCTParagraphStyleSpecifierFirstLineHeadIndent -> firstLineHeadIndent

CGFloat firstLineHeadIndent;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierFirstLineHeadIndent, sizeof(firstLineHeadIndent), &firstLineHeadIndent))

newParagraphStyle.firstLineHeadIndent = firstLineHeadIndent;

// kCTParagraphStyleSpecifierHeadIndent -> headIndent

CGFloat headIndent;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierHeadIndent, sizeof(headIndent), &headIndent))

newParagraphStyle.headIndent = headIndent;

// kCTParagraphStyleSpecifierTailIndent -> tailIndent

CGFloat tailIndent;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierTailIndent, sizeof(tailIndent), &tailIndent))

newParagraphStyle.tailIndent = tailIndent;

// kCTParagraphStyleSpecifierLineBreakMode -> lineBreakMode

CTLineBreakMode coreTextLineBreakMode;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierLineBreakMode, sizeof(coreTextLineBreakMode), &coreTextLineBreakMode))

newParagraphStyle.lineBreakMode = (NSLineBreakMode)coreTextLineBreakMode; // They're the same enum.

// kCTParagraphStyleSpecifierLineHeightMultiple -> lineHeightMultiple

CGFloat lineHeightMultiple;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierLineHeightMultiple, sizeof(lineHeightMultiple), &lineHeightMultiple))

newParagraphStyle.lineHeightMultiple = lineHeightMultiple;

// kCTParagraphStyleSpecifierMaximumLineHeight -> maximumLineHeight

CGFloat maximumLineHeight;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierMaximumLineHeight, sizeof(maximumLineHeight), &maximumLineHeight))

newParagraphStyle.maximumLineHeight = maximumLineHeight;

// kCTParagraphStyleSpecifierMinimumLineHeight -> minimumLineHeight

CGFloat minimumLineHeight;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierMinimumLineHeight, sizeof(minimumLineHeight), &minimumLineHeight))

newParagraphStyle.minimumLineHeight = minimumLineHeight;

// 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;

#pragma clang diagnostic pop

// kCTParagraphStyleSpecifierParagraphSpacing -> paragraphSpacing

CGFloat paragraphSpacing;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierParagraphSpacing, sizeof(paragraphSpacing), &paragraphSpacing))

newParagraphStyle.paragraphSpacing = paragraphSpacing;

// kCTParagraphStyleSpecifierParagraphSpacingBefore -> paragraphSpacingBefore

CGFloat paragraphSpacingBefore;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierParagraphSpacingBefore, sizeof(paragraphSpacingBefore), &paragraphSpacingBefore))

newParagraphStyle.paragraphSpacingBefore = paragraphSpacingBefore;

// kCTParagraphStyleSpecifierBaseWritingDirection -> baseWritingDirection

CTWritingDirection coreTextBaseWritingDirection;

if (CTParagraphStyleGetValueForSpecifier(coreTextParagraphStyle, kCTParagraphStyleSpecifierBaseWritingDirection, sizeof(coreTextBaseWritingDirection), &coreTextBaseWritingDirection))

newParagraphStyle.baseWritingDirection = (NSWritingDirection)coreTextBaseWritingDirection; // They're the same enum.

return newParagraphStyle;

}

@end