//

// ASTextKitCoreTextAdditions.h

// 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 <Foundation/Foundation.h>

#import <UIKit/UIKit.h>

#import <AsyncDisplayKit/ASBaseDefines.h>

NS_ASSUME_NONNULL_BEGIN

ASDISPLAYNODE_EXTERN_C_BEGIN

/**

@abstract Returns whether a given attribute is an unsupported Core Text attribute.

@param attributeName The name of the attribute

@discussion The following Core Text attributes are not supported on NSAttributedString, and thus will not be preserved during the conversion:

- kCTForegroundColorFromContextAttributeName

- kCTSuperscriptAttributeName

- kCTGlyphInfoAttributeName

- kCTCharacterShapeAttributeName

- kCTLanguageAttributeName

- kCTRunDelegateAttributeName

- kCTBaselineClassAttributeName

- kCTBaselineInfoAttributeName

- kCTBaselineReferenceInfoAttributeName

- kCTWritingDirectionAttributeName

- kCTUnderlineColorAttributeName

@result Whether attributeName is an unsupported Core Text attribute.

*/

BOOL ASAttributeWithNameIsUnsupportedCoreTextAttribute(NSString *attributeName);

/**

@abstract Returns an attributes dictionary for use by NSAttributedString, given a dictionary of Core Text attributes.

@param coreTextAttributes An NSDictionary whose keys are CFAttributedStringRef attributes.

@discussion The following Core Text attributes are not supported on NSAttributedString, and thus will not be preserved during the conversion:

- kCTForegroundColorFromContextAttributeName

- kCTSuperscriptAttributeName

- kCTGlyphInfoAttributeName

- kCTCharacterShapeAttributeName

- kCTLanguageAttributeName

- kCTRunDelegateAttributeName

- kCTBaselineClassAttributeName

- kCTBaselineInfoAttributeName

- kCTBaselineReferenceInfoAttributeName

- kCTWritingDirectionAttributeName

- kCTUnderlineColorAttributeName

@result An NSDictionary of attributes for use by NSAttributedString.

*/

extern NSDictionary *NSAttributedStringAttributesForCoreTextAttributes(NSDictionary *coreTextAttributes);

/**

@abstract Returns an NSAttributedString whose Core Text attributes have been converted, where possible, to NSAttributedString attributes.

@param dirtyAttributedString An NSAttributedString that may contain Core Text attributes.

@result An NSAttributedString that's preserved as many CFAttributedString attributes as possible.

*/

extern NSAttributedString *ASCleanseAttributedStringOfCoreTextAttributes(NSAttributedString *dirtyAttributedString);

ASDISPLAYNODE_EXTERN_C_END

#pragma mark -

#pragma mark -

@interface NSParagraphStyle (ASTextKitCoreTextAdditions)

/**

@abstract Returns an NSParagraphStyle initialized with the paragraph specifiers from the given CTParagraphStyleRef.

@param coreTextParagraphStyle A Core Text paragraph style.

@discussion It is important to note that not all CTParagraphStyle specifiers are supported by NSParagraphStyle, and consequently, this is a lossy conversion. Notably, the following specifiers will not preserved:

- kCTParagraphStyleSpecifierTabStops

- kCTParagraphStyleSpecifierDefaultTabInterval

- kCTParagraphStyleSpecifierMaximumLineSpacing

- kCTParagraphStyleSpecifierMinimumLineSpacing

- kCTParagraphStyleSpecifierLineSpacingAdjustment

- kCTParagraphStyleSpecifierLineBoundsOptions

@result An NSParagraphStyle initialized with as many of the paragraph specifiers from `coreTextParagraphStyle` as possible.

*/

+ (instancetype)paragraphStyleWithCTParagraphStyle:(CTParagraphStyleRef)coreTextParagraphStyle;

@end

NS_ASSUME_NONNULL_END