swift api compatibility

YYText/Component/YYTextContainerView.h

@@ -17,6 +17,8 @@
 #import "YYTextLayout.h"
 #endif
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  A simple view to diaplay `YYTextLayout`.
 
@@ -29,23 +31,25 @@
 @interface YYTextContainerView : UIView
 
 /// First responder's aciton will forward to this view.
-@property (nonatomic, weak) UIView *hostView;
+@property (nullable, nonatomic, weak) UIView *hostView;
 
 /// Debug option for layout debug. Set this property will let the view redraw it's contents.
-@property (nonatomic, copy) YYTextDebugOption *debugOption;
+@property (nullable, nonatomic, copy) YYTextDebugOption *debugOption;
 
 /// Text vertical alignment.
-@property (nonatomic, assign) YYTextVerticalAlignment textVerticalAlignment;
+@property (nonatomic) YYTextVerticalAlignment textVerticalAlignment;
 
 /// Text layout. Set this property will let the view redraw it's contents.
-@property (nonatomic, strong) YYTextLayout *layout;
+@property (nullable, nonatomic, strong) YYTextLayout *layout;
 
 /// The contents fade animation duration when the layout's contents changed. Default is 0 (no animation).
-@property (nonatomic, assign) NSTimeInterval contentsFadeDuration;
+@property (nonatomic) NSTimeInterval contentsFadeDuration;
 
 /// Convenience method to set `layout` and `contentsFadeDuration`.
 /// @param layout  Same as `layout` property.
 /// @param fadeDuration  Same as `contentsFadeDuration` property.
-- (void)setLayout:(YYTextLayout *)layout withFadeDuration:(NSTimeInterval)fadeDuration;
+- (void)setLayout:(nullable YYTextLayout *)layout withFadeDuration:(NSTimeInterval)fadeDuration;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextDebugOption.h

@@ -13,6 +13,8 @@
 
 @class YYTextDebugOption;
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  The YYTextDebugTarget protocol defines the method a debug target should implement.
  A debug target can be add to the global container to receive the shared debug
@@ -28,7 +30,7 @@
  
  @param option  The shared debug option.
  */
-- (void)setDebugOption:(YYTextDebugOption *)option;
+- (void)setDebugOption:(nullable YYTextDebugOption *)option;
 @end
 
 
@@ -37,17 +39,17 @@
  The debug option for YYText.
  */
 @interface YYTextDebugOption : NSObject <NSCopying>
-@property (nonatomic, strong) UIColor *baselineColor;      ///< baseline color
-@property (nonatomic, strong) UIColor *CTFrameBorderColor; ///< CTFrame path border color
-@property (nonatomic, strong) UIColor *CTFrameFillColor;   ///< CTFrame path fill color
-@property (nonatomic, strong) UIColor *CTLineBorderColor;  ///< CTLine bounds border color
-@property (nonatomic, strong) UIColor *CTLineFillColor;    ///< CTLine bounds fill color
-@property (nonatomic, strong) UIColor *CTLineNumberColor;  ///< CTLine line number color
-@property (nonatomic, strong) UIColor *CTRunBorderColor;   ///< CTRun bounds border color
-@property (nonatomic, strong) UIColor *CTRunFillColor;     ///< CTRun bounds fill color
-@property (nonatomic, strong) UIColor *CTRunNumberColor;   ///< CTRun number color
-@property (nonatomic, strong) UIColor *CGGlyphBorderColor; ///< CGGlyph bounds border color
-@property (nonatomic, strong) UIColor *CGGlyphFillColor;   ///< CGGlyph bounds fill color
+@property (nullable, nonatomic, strong) UIColor *baselineColor;      ///< baseline color
+@property (nullable, nonatomic, strong) UIColor *CTFrameBorderColor; ///< CTFrame path border color
+@property (nullable, nonatomic, strong) UIColor *CTFrameFillColor;   ///< CTFrame path fill color
+@property (nullable, nonatomic, strong) UIColor *CTLineBorderColor;  ///< CTLine bounds border color
+@property (nullable, nonatomic, strong) UIColor *CTLineFillColor;    ///< CTLine bounds fill color
+@property (nullable, nonatomic, strong) UIColor *CTLineNumberColor;  ///< CTLine line number color
+@property (nullable, nonatomic, strong) UIColor *CTRunBorderColor;   ///< CTRun bounds border color
+@property (nullable, nonatomic, strong) UIColor *CTRunFillColor;     ///< CTRun bounds fill color
+@property (nullable, nonatomic, strong) UIColor *CTRunNumberColor;   ///< CTRun number color
+@property (nullable, nonatomic, strong) UIColor *CGGlyphBorderColor; ///< CGGlyph bounds border color
+@property (nullable, nonatomic, strong) UIColor *CGGlyphFillColor;   ///< CGGlyph bounds fill color
 
 - (BOOL)needDrawDebug; ///< `YES`: at least one debug color is visible. `NO`: all debug color is invisible/nil.
 - (void)clear; ///< Set all debug color to nil.
@@ -75,7 +77,7 @@
  
  @return The shared debug option, default is nil.
  */
-+ (YYTextDebugOption *)sharedDebugOption;
++ (nullable YYTextDebugOption *)sharedDebugOption;
 
 /**
  Set a debug option as shared debug option.
@@ -86,6 +88,8 @@
  
  @param option  A new debug option (nil is valid).
  */
-+ (void)setSharedDebugOption:(YYTextDebugOption *)option;
++ (void)setSharedDebugOption:(nullable YYTextDebugOption *)option;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextEffectWindow.h

@@ -19,6 +19,8 @@
 #import "YYTextSelectionView.h"
 #endif
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  A window to display magnifier and extra contents for text view.
  
@@ -28,7 +30,7 @@
 @interface YYTextEffectWindow : UIWindow
 
 /// Returns the shared instance (returns nil in App Extension).
-+ (instancetype)sharedWindow;
++ (nullable instancetype)sharedWindow;
 
 /// Show the magnifier in this window with a 'popup' animation. @param mag A magnifier.
 - (void)showMagnifier:(YYTextMagnifier *)mag;
@@ -46,3 +48,5 @@
 - (void)hideSelectionDot:(YYTextSelectionView *)selection;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextInput.h

@@ -11,6 +11,8 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  Text position affinity. For example, the offset appears after the last
  character on a line is backward affinity, before the first character on
@@ -81,3 +83,5 @@ typedef NS_ENUM(NSInteger, YYTextAffinity) {
 @property (nonatomic, readwrite) BOOL isVertical;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextKeyboardManager.h

@@ -11,6 +11,8 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  System keyboard transition information.
  Use -[YYTextKeyboardManager convertRect:toView:] to convert frame to specified view.
@@ -49,13 +51,13 @@ typedef struct {
 + (instancetype)new UNAVAILABLE_ATTRIBUTE;
 
 /// Get the default manager (returns nil in App Extension).
-+ (instancetype)defaultManager;
++ (nullable instancetype)defaultManager;
 
 /// Get the keyboard window. nil if there's no keyboard window.
-@property (nonatomic, readonly) UIWindow *keyboardWindow;
+@property (nullable, nonatomic, readonly) UIWindow *keyboardWindow;
 
 /// Get the keyboard view. nil if there's no keyboard view.
-@property (nonatomic, readonly) UIView *keyboardView;
+@property (nullable, nonatomic, readonly) UIView *keyboardView;
 
 /// Whether the keyboard is visible.
 @property (nonatomic, readonly, getter=isKeyboardVisible) BOOL keyboardVisible;
@@ -89,6 +91,8 @@ typedef struct {
  @param view A specified view or window (pass nil to convert for main window).
  @return The converted rect in specifeid view.
  */
-- (CGRect)convertRect:(CGRect)rect toView:(UIView *)view;
+- (CGRect)convertRect:(CGRect)rect toView:(nullable UIView *)view;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextLayout.h

@@ -23,6 +23,12 @@
 #endif
 
 @protocol YYTextLinePositionModifier;
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ The max text container size in layout.
+ */
 extern const CGSize YYTextContainerMaxSize;
 
 /**
@@ -59,43 +65,43 @@ extern const CGSize YYTextContainerMaxSize;
 + (instancetype)containerWithSize:(CGSize)size insets:(UIEdgeInsets)insets;
 
 /// Creates a container with the specified path. @param size The path.
-+ (instancetype)containerWithPath:(UIBezierPath *)path;
++ (instancetype)containerWithPath:(nullable UIBezierPath *)path;
 
 /// The constrained size. (if the size is larger than YYTextContainerMaxSize, it will be clipped)
-@property (assign) CGSize size;
+@property CGSize size;
 
 /// The insets for constrained size. The inset value should not be negative. Default is UIEdgeInsetsZero.
-@property (assign) UIEdgeInsets insets;
+@property UIEdgeInsets insets;
 
 /// Custom constrained path. Set this property to ignore `size` and `insets`. Default is nil.
-@property (copy) UIBezierPath *path;
+@property (nullable, copy) UIBezierPath *path;
 
 /// An array of `UIBezierPath` for path exclusion. Default is nil.
-@property (copy) NSArray *exclusionPaths;
+@property (nullable, copy) NSArray<UIBezierPath *> *exclusionPaths;
 
 /// Path line width. Default is 0;
-@property (assign) CGFloat pathLineWidth;
+@property CGFloat pathLineWidth;
 
 /// YES:(PathFillEvenOdd) Text is filled in the area that would be painted if the path were given to CGContextEOFillPath.
 /// NO: (PathFillWindingNumber) Text is fill in the area that would be painted if the path were given to CGContextFillPath.
 /// Default is YES;
-@property (assign, getter=isPathFillEvenOdd) BOOL pathFillEvenOdd;
+@property (getter=isPathFillEvenOdd) BOOL pathFillEvenOdd;
 
 /// Whether the text is vertical form (may used for CJK text layout). Default is NO.
-@property (assign, getter=isVerticalForm) BOOL verticalForm;
+@property (getter=isVerticalForm) BOOL verticalForm;
 
 /// Maximum number of rows, 0 means no limit. Default is 0.
-@property (assign) NSUInteger maximumNumberOfRows;
+@property NSUInteger maximumNumberOfRows;
 
 /// The line truncation type, default is none.
-@property (assign) YYTextTruncationType truncationType;
+@property YYTextTruncationType truncationType;
 
 /// The truncation token. If nil, the layout will use "…" instead. Default is nil.
-@property (copy) NSAttributedString *truncationToken;
+@property (nullable, copy) NSAttributedString *truncationToken;
 
 /// This modifier is applied to the lines before the layout is completed,
 /// give you a chance to modify the line position. Default is nil.
-@property (copy) id<YYTextLinePositionModifier> linePositionModifier;
+@property (nullable, copy) id<YYTextLinePositionModifier> linePositionModifier;
 @end
 
 
@@ -111,7 +117,7 @@ extern const CGSize YYTextContainerMaxSize;
  @param text      The full text.
  @param container The layout container.
  */
-- (void)modifyLines:(NSArray *)lines fromText:(NSAttributedString *)text inContainer:(YYTextContainer *)container;
+- (void)modifyLines:(NSArray<YYTextLine *> *)lines fromText:(NSAttributedString *)text inContainer:(YYTextContainer *)container;
 @end
 
 
@@ -157,7 +163,7 @@ extern const CGSize YYTextContainerMaxSize;
  @param text The text (if nil, returns nil).
  @return A new layout, or nil when an error occurs.
 */
-+ (YYTextLayout *)layoutWithContainerSize:(CGSize)size text:(NSAttributedString *)text;
++ (nullable YYTextLayout *)layoutWithContainerSize:(CGSize)size text:(NSAttributedString *)text;
 
 /**
  Generate a layout with the given container and text.
@@ -166,7 +172,7 @@ extern const CGSize YYTextContainerMaxSize;
  @param text      The text (if nil, returns nil).
  @return A new layout, or nil when an error occurs.
  */
-+ (YYTextLayout *)layoutWithContainer:(YYTextContainer *)container text:(NSAttributedString *)text;
++ (nullable YYTextLayout *)layoutWithContainer:(YYTextContainer *)container text:(NSAttributedString *)text;
 
 /**
  Generate a layout with the given container and text.
@@ -177,7 +183,7 @@ extern const CGSize YYTextContainerMaxSize;
     length of the range is 0, it means the length is no limit.
  @return A new layout, or nil when an error occurs.
  */
-+ (YYTextLayout *)layoutWithContainer:(YYTextContainer *)container text:(NSAttributedString *)text range:(NSRange)range;
++ (nullable YYTextLayout *)layoutWithContainer:(YYTextContainer *)container text:(NSAttributedString *)text range:(NSRange)range;
 
 /**
  Generate layouts with the given containers and text.
@@ -187,7 +193,8 @@ extern const CGSize YYTextContainerMaxSize;
  @return An array of YYTextLayout object (the count is same as containers),
     or nil when an error occurs.
  */
-+ (NSArray *)layoutWithContainers:(NSArray *)containers text:(NSAttributedString *)text;
++ (nullable NSArray<YYTextLayout *> *)layoutWithContainers:(NSArray<YYTextContainer *> *)containers
+                                                      text:(NSAttributedString *)text;
 
 /**
  Generate layouts with the given containers and text.
@@ -199,7 +206,9 @@ extern const CGSize YYTextContainerMaxSize;
  @return An array of YYTextLayout object (the count is same as containers),
     or nil when an error occurs.
  */
-+ (NSArray *)layoutWithContainers:(NSArray *)containers text:(NSAttributedString *)text range:(NSRange)range;
++ (nullable NSArray<YYTextLayout *> *)layoutWithContainers:(NSArray<YYTextContainer *> *)containers
+                                                      text:(NSAttributedString *)text
+                                                     range:(NSRange)range;
 
 - (instancetype)init UNAVAILABLE_ATTRIBUTE;
 + (instancetype)new UNAVAILABLE_ATTRIBUTE;
@@ -210,31 +219,56 @@ extern const CGSize YYTextContainerMaxSize;
 /// @name Text layout attributes
 ///=============================================================================
 
-@property (nonatomic, readonly) YYTextContainer *container;    ///< The text container
-@property (nonatomic, readonly) NSAttributedString *text;      ///< The full text
-@property (nonatomic, readonly) NSRange range;                 ///< The text range in full text
-@property (nonatomic, readonly) CTFramesetterRef frameSetter;  ///< CTFrameSetter
-@property (nonatomic, readonly) CTFrameRef frame;              ///< CTFrame
-@property (nonatomic, readonly) NSArray *lines;                ///< Array of `YYTextLine`, no truncated
-@property (nonatomic, readonly) YYTextLine *truncatedLine;     ///< YYTextLine with truncated token, or nil
-@property (nonatomic, readonly) NSArray *attachments;          ///< Array of `YYTextAttachment`
-@property (nonatomic, readonly) NSArray *attachmentRanges;     ///< Array of NSRange(wrapped by NSValue) in text
-@property (nonatomic, readonly) NSArray *attachmentRects;      ///< Array of CGRect(wrapped by NSValue) in container
-@property (nonatomic, readonly) NSSet *attachmentContentsSet;  ///< Set of Attachment (UIImage/UIView/CALayer)
-@property (nonatomic, readonly) NSUInteger rowCount;           ///< Number of rows
-@property (nonatomic, readonly) NSRange visibleRange;          ///< Visible text range
-@property (nonatomic, readonly) CGRect textBoundingRect;       ///< Bounding rect (glyphs)
-@property (nonatomic, readonly) CGSize textBoundingSize;       ///< Bounding size (glyphs and insets, ceil to pixel)
-@property (nonatomic, readonly) BOOL containsHighlight;        ///< Has highlight attribute
-@property (nonatomic, readonly) BOOL needDrawBlockBorder;      ///< Has block border attribute
-@property (nonatomic, readonly) BOOL needDrawBackgroundBorder; ///< Has background border attribute
-@property (nonatomic, readonly) BOOL needDrawShadow;           ///< Has shadow attribute
-@property (nonatomic, readonly) BOOL needDrawUnderline;        ///< Has underline attribute
-@property (nonatomic, readonly) BOOL needDrawText;             ///< Has visible text
-@property (nonatomic, readonly) BOOL needDrawAttachment;       ///< Has attachment attribute
-@property (nonatomic, readonly) BOOL needDrawInnerShadow;      ///< Has inner shadow attribute
-@property (nonatomic, readonly) BOOL needDrawStrikethrough;    ///< Has strickthrough attribute
-@property (nonatomic, readonly) BOOL needDrawBorder;           ///< Has border attribute
+///< The text container
+@property (nonatomic, strong, readonly) YYTextContainer *container;
+///< The full text
+@property (nonatomic, strong, readonly) NSAttributedString *text;
+///< The text range in full text
+@property (nonatomic, readonly) NSRange range;
+///< CTFrameSetter
+@property (nonatomic, readonly) CTFramesetterRef frameSetter;
+///< CTFrame
+@property (nonatomic, readonly) CTFrameRef frame;
+///< Array of `YYTextLine`, no truncated
+@property (nonatomic, strong, readonly) NSArray<YYTextLine *> *lines;
+///< YYTextLine with truncated token, or nil
+@property (nullable, nonatomic, strong, readonly) YYTextLine *truncatedLine;
+///< Array of `YYTextAttachment`
+@property (nullable, nonatomic, strong, readonly) NSArray<YYTextAttachment *> *attachments;
+///< Array of NSRange(wrapped by NSValue) in text
+@property (nullable, nonatomic, strong, readonly) NSArray<NSValue *> *attachmentRanges;
+///< Array of CGRect(wrapped by NSValue) in container
+@property (nullable, nonatomic, strong, readonly) NSArray<NSValue *> *attachmentRects;
+///< Set of Attachment (UIImage/UIView/CALayer)
+@property (nullable, nonatomic, strong, readonly) NSSet *attachmentContentsSet;
+///< Number of rows
+@property (nonatomic, readonly) NSUInteger rowCount;
+///< Visible text range
+@property (nonatomic, readonly) NSRange visibleRange;
+///< Bounding rect (glyphs)
+@property (nonatomic, readonly) CGRect textBoundingRect;
+///< Bounding size (glyphs and insets, ceil to pixel)
+@property (nonatomic, readonly) CGSize textBoundingSize;
+///< Has highlight attribute
+@property (nonatomic, readonly) BOOL containsHighlight;
+///< Has block border attribute
+@property (nonatomic, readonly) BOOL needDrawBlockBorder;
+///< Has background border attribute
+@property (nonatomic, readonly) BOOL needDrawBackgroundBorder;
+///< Has shadow attribute
+@property (nonatomic, readonly) BOOL needDrawShadow;
+///< Has underline attribute
+@property (nonatomic, readonly) BOOL needDrawUnderline;
+///< Has visible text
+@property (nonatomic, readonly) BOOL needDrawText;
+///< Has attachment attribute
+@property (nonatomic, readonly) BOOL needDrawAttachment;
+///< Has inner shadow attribute
+@property (nonatomic, readonly) BOOL needDrawInnerShadow;
+///< Has strickthrough attribute
+@property (nonatomic, readonly) BOOL needDrawStrikethrough;
+///< Has border attribute
+@property (nonatomic, readonly) BOOL needDrawBorder;
 
 
 #pragma mark - Query information from text layout
@@ -318,7 +352,7 @@ extern const CGSize YYTextContainerMaxSize;
  @param point  A point in the container.
  @return A text position, or nil if not found.
  */
-- (YYTextPosition *)closestPositionToPoint:(CGPoint)point;
+- (nullable YYTextPosition *)closestPositionToPoint:(CGPoint)point;
 
 /**
  Returns the new position when moving selection grabber in text view.
@@ -332,9 +366,9 @@ extern const CGSize YYTextContainerMaxSize;
  
  @return A text position, or nil if not found.
  */
-- (YYTextPosition *)positionForPoint:(CGPoint)point
-                         oldPosition:(YYTextPosition *)oldPosition
-                       otherPosition:(YYTextPosition *)otherPosition;
+- (nullable YYTextPosition *)positionForPoint:(CGPoint)point
+                                  oldPosition:(YYTextPosition *)oldPosition
+                                otherPosition:(YYTextPosition *)otherPosition;
 
 /**
  Returns the character or range of characters that is at a given point in the container.
@@ -347,7 +381,7 @@ extern const CGSize YYTextContainerMaxSize;
  @return An object representing a range that encloses a character (or characters) 
  at point. Or nil if not found.
  */
-- (YYTextRange *)textRangeAtPoint:(CGPoint)point;
+- (nullable YYTextRange *)textRangeAtPoint:(CGPoint)point;
 
 /**
  Returns the closest character or range of characters that is at a given point in 
@@ -360,7 +394,7 @@ extern const CGSize YYTextContainerMaxSize;
  @return An object representing a range that encloses a character (or characters)
  at point. Or nil if not found.
  */
-- (YYTextRange *)closestTextRangeAtPoint:(CGPoint)point;
+- (nullable YYTextRange *)closestTextRangeAtPoint:(CGPoint)point;
 
 /**
  If the position is inside an emoji, composed character sequences, line break '\\r\\n'
@@ -371,7 +405,7 @@ extern const CGSize YYTextContainerMaxSize;
  
  @return A text-range object that extend the position. Or nil if an error occurs
  */
-- (YYTextRange *)textRangeByExtendingPosition:(YYTextPosition *)position;
+- (nullable YYTextRange *)textRangeByExtendingPosition:(YYTextPosition *)position;
 
 /**
  Returns a text range at a given offset in a specified direction from another 
@@ -384,9 +418,9 @@ extern const CGSize YYTextContainerMaxSize;
  @return A text-range object that represents the distance from position to the
  farthest extent in direction. Or nil if an error occurs.
  */
-- (YYTextRange *)textRangeByExtendingPosition:(YYTextPosition *)position
-                                  inDirection:(UITextLayoutDirection)direction
-                                       offset:(NSInteger)offset;
+- (nullable YYTextRange *)textRangeByExtendingPosition:(YYTextPosition *)position
+                                           inDirection:(UITextLayoutDirection)direction
+                                                offset:(NSInteger)offset;
 
 /**
  Returns the line index for a given text position.
@@ -446,7 +480,7 @@ extern const CGSize YYTextContainerMaxSize;
  @return An array of `YYTextSelectionRect` objects that encompass the selection.
  If not found, the array is empty.
  */
-- (NSArray *)selectionRectsForRange:(YYTextRange *)range;
+- (NSArray<YYTextSelectionRect *> *)selectionRectsForRange:(YYTextRange *)range;
 
 /**
  Returns an array of selection rects corresponding to the range of text.
@@ -455,7 +489,7 @@ extern const CGSize YYTextContainerMaxSize;
  @return An array of `YYTextSelectionRect` objects that encompass the selection.
  If not found, the array is empty.
  */
-- (NSArray *)selectionRectsWithoutStartAndEndForRange:(YYTextRange *)range;
+- (NSArray<YYTextSelectionRect *> *)selectionRectsWithoutStartAndEndForRange:(YYTextRange *)range;
 
 /**
  Returns the start and end selection rects corresponding to the range of text.
@@ -465,7 +499,7 @@ extern const CGSize YYTextContainerMaxSize;
  @return An array of `YYTextSelectionRect` objects contains the start and end to
  the selection. If not found, the array is empty.
  */
-- (NSArray *)selectionRectsWithOnlyStartAndEndForRange:(YYTextRange *)range;
+- (NSArray<YYTextSelectionRect *> *)selectionRectsWithOnlyStartAndEndForRange:(YYTextRange *)range;
 
 
 #pragma mark - Draw text layout
@@ -494,13 +528,13 @@ extern const CGSize YYTextContainerMaxSize;
                     If it returns YES, the further draw progress will be canceled.
                     Pass nil to ignore this feature.
  */
-- (void)drawInContext:(CGContextRef)context
+- (void)drawInContext:(nullable CGContextRef)context
                  size:(CGSize)size
                 point:(CGPoint)point
-                 view:(UIView *)view
-                layer:(CALayer *)layer
-                debug:(YYTextDebugOption *)debug
-               cancel:(BOOL (^)(void))cancel;
+                 view:(nullable UIView *)view
+                layer:(nullable CALayer *)layer
+                debug:(nullable YYTextDebugOption *)debug
+               cancel:(nullable BOOL (^)(void))cancel;
 
 /**
  Draw the layout text and image (without view or layer attachments).
@@ -511,7 +545,7 @@ extern const CGSize YYTextContainerMaxSize;
  @param size    The context size.
  @param debug   The debug option. Pass nil to avoid debug drawing.
  */
-- (void)drawInContext:(CGContextRef)context size:(CGSize)size debug:(YYTextDebugOption *)debug;
+- (void)drawInContext:(nullable CGContextRef)context size:(CGSize)size debug:(nullable YYTextDebugOption *)debug;
 
 /**
  Show view and layer attachments.
@@ -521,7 +555,7 @@ extern const CGSize YYTextContainerMaxSize;
  @param view  The attachment views will add to this view.
  @param layer The attachment layers will add to this layer.
  */
-- (void)addAttachmentToView:(UIView *)view layer:(CALayer *)layer;
+- (void)addAttachmentToView:(nullable UIView *)view layer:(nullable CALayer *)layer;
 
 /**
  Remove attachment views and layers from their super container.
@@ -531,3 +565,5 @@ extern const CGSize YYTextContainerMaxSize;
 - (void)removeAttachmentFromViewAndLayer;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextLine.h

@@ -18,6 +18,10 @@
 #import "YYTextAttribute.h"
 #endif
 
+@class YYTextRunGlyphRange;
+
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  A text line object wrapped `CTLineRef`, see `YYTextLayout` for more.
  */
@@ -25,9 +29,9 @@
 
 + (instancetype)lineWithCTLine:(CTLineRef)CTLine position:(CGPoint)position vertical:(BOOL)isVertical;
 
-@property (nonatomic, assign) NSUInteger index;     ///< line index
-@property (nonatomic, assign) NSUInteger row;       ///< line row
-@property (nonatomic, strong) NSArray *verticalRotateRange; ///< Run rotate range Array<Array<YYTextRunGlyphRange>>
+@property (nonatomic) NSUInteger index;     ///< line index
+@property (nonatomic) NSUInteger row;       ///< line row
+@property (nullable, nonatomic, strong) NSArray<NSArray<YYTextRunGlyphRange *> *> *verticalRotateRange; ///< Run rotate range
 
 @property (nonatomic, readonly) CTLineRef CTLine;   ///< CoreText line
 @property (nonatomic, readonly) NSRange range;      ///< string range
@@ -42,16 +46,16 @@
 @property (nonatomic, readonly) CGFloat left;       ///< bounds.origin.x
 @property (nonatomic, readonly) CGFloat right;      ///< bounds.origin.x + bounds.size.width
 
-@property (nonatomic, assign)   CGPoint position;   ///< baseline position
+@property (nonatomic)   CGPoint position;   ///< baseline position
 @property (nonatomic, readonly) CGFloat ascent;     ///< line ascent
 @property (nonatomic, readonly) CGFloat descent;    ///< line descent
 @property (nonatomic, readonly) CGFloat leading;    ///< line leading
 @property (nonatomic, readonly) CGFloat lineWidth;  ///< line width
 @property (nonatomic, readonly) CGFloat trailingWhitespaceWidth;
 
-@property (nonatomic, readonly) NSArray *attachments;      ///< YYTextAttachment
-@property (nonatomic, readonly) NSArray *attachmentRanges; ///< NSRange(NSValue)
-@property (nonatomic, readonly) NSArray *attachmentRects;  ///< CGRect(NSValue)
+@property (nonatomic, readonly) NSArray<YYTextAttachment *> *attachments; ///< YYTextAttachment
+@property (nonatomic, readonly) NSArray<NSValue *> *attachmentRanges;     ///< NSRange(NSValue)
+@property (nonatomic, readonly) NSArray<NSValue *> *attachmentRects;      ///< CGRect(NSValue)
 
 @end
 
@@ -72,9 +76,9 @@ typedef NS_ENUM(NSUInteger, YYTextRunGlyphDrawMode) {
  A range in CTRun, used for vertical form.
  */
 @interface YYTextRunGlyphRange : NSObject
-@property (nonatomic, assign) NSRange glyphRangeInRun;
-@property (nonatomic, assign) YYTextRunGlyphDrawMode drawMode;
+@property (nonatomic) NSRange glyphRangeInRun;
+@property (nonatomic) YYTextRunGlyphDrawMode drawMode;
 + (instancetype)rangeWithRange:(NSRange)range drawMode:(YYTextRunGlyphDrawMode)mode;
 @end
 
-
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextMagnifier.h

@@ -17,6 +17,8 @@
 #import "YYTextAttribute.h"
 #endif
 
+NS_ASSUME_NONNULL_BEGIN
+
 /// Magnifier type
 typedef NS_ENUM(NSInteger, YYTextMagnifierType) {
     YYTextMagnifierTypeCaret,  ///< Circular magnifier
@@ -34,16 +36,18 @@ typedef NS_ENUM(NSInteger, YYTextMagnifierType) {
 /// Create a mangifier with the specified type. @param type The magnifier type.
 + (id)magnifierWithType:(YYTextMagnifierType)type;
 
-@property (nonatomic, readonly) YYTextMagnifierType type; ///< Type of magnifier
-@property (nonatomic, readonly) CGSize fitSize;           ///< The 'best' size for magnifier view.
-@property (nonatomic, readonly) CGSize snapshotSize;      ///< The 'best' snapshot image size for magnifier.
-@property (nonatomic, strong) UIImage *snapshot;          ///< The image in magnifier (readwrite).
+@property (nonatomic, readonly) YYTextMagnifierType type;  ///< Type of magnifier
+@property (nonatomic, readonly) CGSize fitSize;            ///< The 'best' size for magnifier view.
+@property (nonatomic, readonly) CGSize snapshotSize;       ///< The 'best' snapshot image size for magnifier.
+@property (nullable, nonatomic, strong) UIImage *snapshot; ///< The image in magnifier (readwrite).
 
-@property (nonatomic, weak) UIView *hostView;             ///< The coordinate based view.
-@property (nonatomic, assign) CGPoint hostCaptureCenter;  ///< The snapshot capture center in `hostView`.
-@property (nonatomic, assign) CGPoint hostPopoverCenter;  ///< The popover center in `hostView`.
-@property (nonatomic, assign) BOOL hostVerticalForm;      ///< The host view is vertical form.
-@property (nonatomic, assign) BOOL captureDisabled;       ///< A hint for `YYTextEffectWindow` to disable capture.
-@property (nonatomic, assign) BOOL captureFadeAnimation;  ///< Show fade animation when the snapshot image changed.
+@property (nullable, nonatomic, weak) UIView *hostView;   ///< The coordinate based view.
+@property (nonatomic) CGPoint hostCaptureCenter;          ///< The snapshot capture center in `hostView`.
+@property (nonatomic) CGPoint hostPopoverCenter;          ///< The popover center in `hostView`.
+@property (nonatomic) BOOL hostVerticalForm;              ///< The host view is vertical form.
+@property (nonatomic) BOOL captureDisabled;               ///< A hint for `YYTextEffectWindow` to disable capture.
+@property (nonatomic) BOOL captureFadeAnimation;          ///< Show fade animation when the snapshot image changed.
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Component/YYTextSelectionView.h

@@ -19,6 +19,8 @@
 #import "YYTextInput.h"
 #endif
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  A single dot view. The frame should be foursquare.
  Change the background color for display.
@@ -39,8 +41,8 @@
 @interface YYSelectionGrabber : UIView
 
 @property (nonatomic, readonly) YYSelectionGrabberDot *dot; ///< the dot view
-@property (nonatomic, assign) YYTextDirection dotDirection; ///< don't support composite direction
-@property (nonatomic, strong) UIColor *color; ///< tint color, default is nil
+@property (nonatomic) YYTextDirection dotDirection;         ///< don't support composite direction
+@property (nullable, nonatomic, strong) UIColor *color;     ///< tint color, default is nil
 
 @end
 
@@ -52,14 +54,14 @@
  */
 @interface YYTextSelectionView : UIView
 
-@property (nonatomic, weak) UIView *hostView; ///< the holder view
-@property (nonatomic, strong) UIColor *color; ///< the tint color
-@property (nonatomic, assign, getter = isCaretBlinks) BOOL caretBlinks; ///< whether the caret is blinks
-@property (nonatomic, assign, getter = isCaretVisible) BOOL caretVisible; ///< whether the caret is visible
-@property (nonatomic, assign, getter = isVerticalForm) BOOL verticalForm; ///< weather the text view is vertical form
+@property (nullable, nonatomic, weak) UIView *hostView; ///< the holder view
+@property (nullable, nonatomic, strong) UIColor *color; ///< the tint color
+@property (nonatomic, getter = isCaretBlinks) BOOL caretBlinks; ///< whether the caret is blinks
+@property (nonatomic, getter = isCaretVisible) BOOL caretVisible; ///< whether the caret is visible
+@property (nonatomic, getter = isVerticalForm) BOOL verticalForm; ///< weather the text view is vertical form
 
-@property (nonatomic, assign) CGRect caretRect; ///< caret rect (width==0 or height==0)
-@property (nonatomic, copy) NSArray *selectionRects; ///<  array of YYTextSelectionRect, default is nil
+@property (nonatomic) CGRect caretRect; ///< caret rect (width==0 or height==0)
+@property (nullable, nonatomic, copy) NSArray<YYTextSelectionRect *> *selectionRects; ///< default is nil
 
 @property (nonatomic, readonly) UIView *caretView;
 @property (nonatomic, readonly) YYSelectionGrabber *startGrabber;
@@ -72,3 +74,5 @@
 - (BOOL)isSelectionRectsContainsPoint:(CGPoint)point;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/String/YYTextArchiver.h

@@ -11,6 +11,8 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  A subclass of `NSKeyedArchiver` which implement `NSKeyedArchiverDelegate` protocol.
  
@@ -26,4 +28,6 @@
  `YYTextArchiver` or `NSKeyedArchiver`.
  */
 @interface YYTextUnarchiver : NSKeyedUnarchiver <NSKeyedUnarchiverDelegate>
-@end
+@end
+
+NS_ASSUME_NONNULL_END

YYText/String/YYTextAttribute.h

@@ -11,6 +11,7 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - Enum Define
 
@@ -171,9 +172,9 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  It may used for copy/paste plain text from attributed string.
  Example: If :) is replace by a custom emoji (such as😊), the backed string can be set to @":)".
  */
-@interface YYTextBackedString : NSObject <NSCoding,NSCopying>
-+ (instancetype)stringWithString:(NSString *)string;
-@property (nonatomic, copy) NSString *string; ///< backed string
+@interface YYTextBackedString : NSObject <NSCoding, NSCopying>
++ (instancetype)stringWithString:(nullable NSString *)string;
+@property (nullable, nonatomic, copy) NSString *string; ///< backed string
 @end
 
 
@@ -188,7 +189,7 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  */
 @interface YYTextBinding : NSObject <NSCoding, NSCopying>
 + (instancetype)bindingWithDeleteConfirm:(BOOL)deleteConfirm;
-@property (nonatomic, assign) BOOL deleteConfirm; ///< confirm the range when delete in YYTextView
+@property (nonatomic) BOOL deleteConfirm; ///< confirm the range when delete in YYTextView
 @end
 
 
@@ -200,13 +201,13 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  It's similar to `NSShadow`, but offers more options.
  */
 @interface YYTextShadow : NSObject <NSCoding, NSCopying>
-+ (instancetype)shadowWithColor:(UIColor *)color offset:(CGSize)offset radius:(CGFloat)radius;
++ (instancetype)shadowWithColor:(nullable UIColor *)color offset:(CGSize)offset radius:(CGFloat)radius;
 
-@property (nonatomic, strong) UIColor *color;           ///< shadow color
-@property (nonatomic, assign) CGSize offset;            ///< shadow offset
-@property (nonatomic, assign) CGFloat radius;           ///< shadow blur radius
-@property (nonatomic, assign) CGBlendMode blendMode;    ///< shadow blend mode
-@property (nonatomic, strong) YYTextShadow *subShadow;  ///< a sub shadow which will be added above the parent shadow
+@property (nullable, nonatomic, strong) UIColor *color; ///< shadow color
+@property (nonatomic) CGSize offset;                    ///< shadow offset
+@property (nonatomic) CGFloat radius;                   ///< shadow blur radius
+@property (nonatomic) CGBlendMode blendMode;            ///< shadow blend mode
+@property (nullable, nonatomic, strong) YYTextShadow *subShadow;  ///< a sub shadow which will be added above the parent shadow
 
 + (instancetype)shadowWithNSShadow:(NSShadow *)nsShadow; ///< convert NSShadow to YYTextShadow
 - (NSShadow *)nsShadow; ///< convert YYTextShadow to NSShadow
@@ -223,11 +224,11 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  */
 @interface YYTextDecoration : NSObject <NSCoding, NSCopying>
 + (instancetype)decorationWithStyle:(YYTextLineStyle)style;
-+ (instancetype)decorationWithStyle:(YYTextLineStyle)style width:(NSNumber *)width color:(UIColor *)color;
-@property (nonatomic, assign) YYTextLineStyle style; ///< line style
-@property (nonatomic, strong) NSNumber *width;       ///< line width (nil means automatic width)
-@property (nonatomic, strong) UIColor *color;        ///< line color (nil means automatic color)
-@property (nonatomic, strong) YYTextShadow *shadow;  ///< line shadow
++ (instancetype)decorationWithStyle:(YYTextLineStyle)style width:(nullable NSNumber *)width color:(nullable UIColor *)color;
+@property (nonatomic) YYTextLineStyle style;                   ///< line style
+@property (nullable, nonatomic, strong) NSNumber *width;       ///< line width (nil means automatic width)
+@property (nullable, nonatomic, strong) UIColor *color;        ///< line color (nil means automatic color)
+@property (nullable, nonatomic, strong) YYTextShadow *shadow;  ///< line shadow
 @end
 
 
@@ -245,16 +246,16 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
     ╰──────╯
  */
 @interface YYTextBorder : NSObject <NSCoding, NSCopying>
-+ (instancetype)borderWithLineStyle:(YYTextLineStyle)lineStyle lineWidth:(CGFloat)width strokeColor:(UIColor *)color;
-+ (instancetype)borderWithFillColor:(UIColor *)color cornerRadius:(CGFloat)cornerRadius;
-@property (nonatomic, assign) YYTextLineStyle lineStyle; ///< border line style
-@property (nonatomic, assign) CGFloat strokeWidth;       ///< border line width
-@property (nonatomic, strong) UIColor *strokeColor;      ///< border line color
-@property (nonatomic, assign) CGLineJoin lineJoin;       ///< border line join
-@property (nonatomic, assign) UIEdgeInsets insets;       ///< border insets for text bounds
-@property (nonatomic, assign) CGFloat cornerRadius;      ///< border corder radius
-@property (nonatomic, strong) YYTextShadow *shadow;      ///< border shadow
-@property (nonatomic, strong) UIColor *fillColor;        ///< inner fill color
++ (instancetype)borderWithLineStyle:(YYTextLineStyle)lineStyle lineWidth:(CGFloat)width strokeColor:(nullable UIColor *)color;
++ (instancetype)borderWithFillColor:(nullable UIColor *)color cornerRadius:(CGFloat)cornerRadius;
+@property (nonatomic) YYTextLineStyle lineStyle;              ///< border line style
+@property (nonatomic) CGFloat strokeWidth;                    ///< border line width
+@property (nullable, nonatomic, strong) UIColor *strokeColor; ///< border line color
+@property (nonatomic) CGLineJoin lineJoin;                    ///< border line join
+@property (nonatomic) UIEdgeInsets insets;                    ///< border insets for text bounds
+@property (nonatomic) CGFloat cornerRadius;                   ///< border corder radius
+@property (nullable, nonatomic, strong) YYTextShadow *shadow; ///< border shadow
+@property (nullable, nonatomic, strong) UIColor *fillColor;   ///< inner fill color
 @end
 
 
@@ -269,11 +270,11 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  then it will be added to the text container's view or layer.
  */
 @interface YYTextAttachment : NSObject<NSCoding, NSCopying>
-+ (instancetype)attachmentWithContent:(id)content;
-@property (nonatomic, strong) id content;                    ///< Supported type: UIImage, UIView, CALayer
-@property (nonatomic, assign) UIViewContentMode contentMode; ///< Content display mode.
-@property (nonatomic, assign) UIEdgeInsets contentInsets;    ///< The insets when drawing content.
-@property (nonatomic, strong) NSDictionary *userInfo;        ///< The user information dictionary.
++ (instancetype)attachmentWithContent:(nullable id)content;
+@property (nullable, nonatomic, strong) id content;             ///< Supported type: UIImage, UIView, CALayer
+@property (nonatomic) UIViewContentMode contentMode;            ///< Content display mode.
+@property (nonatomic) UIEdgeInsets contentInsets;               ///< The insets when drawing content.
+@property (nullable, nonatomic, strong) NSDictionary *userInfo; ///< The user information dictionary.
 @end
 
 
@@ -294,7 +295,7 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  Key:   Same as CoreText/YYText Attribute Name.
  Value: Modify attribute value when highlight (NSNull for remove attribute).
  */
-@property (nonatomic, copy) NSDictionary *attributes;
+@property (nullable, nonatomic, copy) NSDictionary<NSString *, id> *attributes;
 
 /**
  Creates a highlight object with specified attributes.
@@ -302,44 +303,45 @@ typedef void(^YYTextAction)(UIView *containerView, NSAttributedString *text, NSR
  @param attributes The attributes which will replace original attributes when highlight,
         If the value is NSNull, it will removed when highlight.
  */
-+ (instancetype)highlightWithAttributes:(NSDictionary *)attributes;
++ (instancetype)highlightWithAttributes:(nullable NSDictionary<NSString *, id> *)attributes;
 
 /**
  Convenience methods to create a default highlight with the specifeid background color.
  
  @param color The background border color.
  */
-+ (instancetype)highlightWithBackgroundColor:(UIColor *)color;
++ (instancetype)highlightWithBackgroundColor:(nullable UIColor *)color;
 
 // Convenience methods below to set the `attributes`.
-- (void)setFont:(UIFont *)font;
-- (void)setColor:(UIColor *)color;
-- (void)setStrokeWidth:(NSNumber *)width;
-- (void)setStrokeColor:(UIColor *)color;
-- (void)setShadow:(YYTextShadow *)shadow;
-- (void)setInnerShadow:(YYTextShadow *)shadow;
-- (void)setUnderline:(YYTextDecoration *)underline;
-- (void)setStrikethrough:(YYTextDecoration *)strikethrough;
-- (void)setBackgroundBorder:(YYTextBorder *)border;
-- (void)setBorder:(YYTextBorder *)border;
-- (void)setAttachment:(YYTextAttachment *)attachment;
+- (void)setFont:(nullable UIFont *)font;
+- (void)setColor:(nullable UIColor *)color;
+- (void)setStrokeWidth:(nullable NSNumber *)width;
+- (void)setStrokeColor:(nullable UIColor *)color;
+- (void)setShadow:(nullable YYTextShadow *)shadow;
+- (void)setInnerShadow:(nullable YYTextShadow *)shadow;
+- (void)setUnderline:(nullable YYTextDecoration *)underline;
+- (void)setStrikethrough:(nullable YYTextDecoration *)strikethrough;
+- (void)setBackgroundBorder:(nullable YYTextBorder *)border;
+- (void)setBorder:(nullable YYTextBorder *)border;
+- (void)setAttachment:(nullable YYTextAttachment *)attachment;
 
 /**
  The user information dictionary, default is nil.
  */
-@property (nonatomic, copy) NSDictionary *userInfo;
+@property (nullable, nonatomic, copy) NSDictionary *userInfo;
 
 /**
  Tap action when user tap the highlight, default is nil.
  If the value is nil, YYTextView or YYLabel will ask it's delegate to deal with tap action.
  */
-@property (nonatomic, copy) YYTextAction tapAction;
+@property (nullable, nonatomic, copy) YYTextAction tapAction;
 
 /**
  Long press action when user long press the highlight, default is nil.
  If the value is nil, YYTextView or YYLabel will ask it's delegate to deal with long press action.
  */
-@property (nonatomic, copy) YYTextAction longPressAction;
+@property (nullable, nonatomic, copy) YYTextAction longPressAction;
 
 @end
 
+NS_ASSUME_NONNULL_END

YYText/String/YYTextParser.h

@@ -11,6 +11,8 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  The YYTextParser protocol declares the required method for YYTextView and YYLabel
  to modify the text during editing.
@@ -32,7 +34,7 @@
  
  @return If the 'text' is modified in this method, returns `YES`, otherwise returns `NO`.
  */
-- (BOOL)parseText:(NSMutableAttributedString *)text selectedRange:(NSRangePointer)selectedRange;
+- (BOOL)parseText:(nullable NSMutableAttributedString *)text selectedRange:(nullable NSRangePointer)selectedRange;
 @end
 
 
@@ -52,15 +54,15 @@
  Or you can use lex/yacc to generate your custom parser.
  */
 @interface YYTextSimpleMarkdownParser : NSObject <YYTextParser>
-@property (nonatomic, assign) CGFloat fontSize;         ///< default is 14
-@property (nonatomic, assign) CGFloat headerFontSize;   ///< default is 20
+@property (nonatomic) CGFloat fontSize;         ///< default is 14
+@property (nonatomic) CGFloat headerFontSize;   ///< default is 20
 
-@property (nonatomic, strong) UIColor *textColor;
-@property (nonatomic, strong) UIColor *controlTextColor;
-@property (nonatomic, strong) UIColor *headerTextColor;
-@property (nonatomic, strong) UIColor *inlineTextColor;
-@property (nonatomic, strong) UIColor *codeTextColor;
-@property (nonatomic, strong) UIColor *linkTextColor;
+@property (nullable, nonatomic, strong) UIColor *textColor;
+@property (nullable, nonatomic, strong) UIColor *controlTextColor;
+@property (nullable, nonatomic, strong) UIColor *headerTextColor;
+@property (nullable, nonatomic, strong) UIColor *inlineTextColor;
+@property (nullable, nonatomic, strong) UIColor *codeTextColor;
+@property (nullable, nonatomic, strong) UIColor *linkTextColor;
 
 - (void)setColorWithBrightTheme; ///< reset the color properties to pre-defined value.
 - (void)setColorWithDarkTheme;   ///< reset the color properties to pre-defined value.
@@ -83,5 +85,7 @@
  The key is a specified plain string, such as @":smile:".
  The value is a UIImage which will replace the specified plain string in text.
  */
-@property (copy) NSDictionary *emoticonMapper;
+@property (nullable, copy) NSDictionary<NSString *, __kindof UIImage *> *emoticonMapper;
 @end
+
+NS_ASSUME_NONNULL_END

YYText/String/YYTextRubyAnnotation.h

@@ -12,6 +12,8 @@
 #import <UIKit/UIKit.h>
 #import <CoreText/CoreText.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  Wrapper for CTRubyAnnotationRef.
  
@@ -29,29 +31,29 @@
 @interface YYTextRubyAnnotation : NSObject <NSCopying, NSCoding>
 
 /// Specifies how the ruby text and the base text should be aligned relative to each other.
-@property (nonatomic, assign) CTRubyAlignment alignment;
+@property (nonatomic) CTRubyAlignment alignment;
 
 /// Specifies how the ruby text can overhang adjacent characters.
-@property (nonatomic, assign) CTRubyOverhang overhang;
+@property (nonatomic) CTRubyOverhang overhang;
 
 /// Specifies the size of the annotation text as a percent of the size of the base text.
-@property (nonatomic, assign) CGFloat sizeFactor;
+@property (nonatomic) CGFloat sizeFactor;
 
 
 /// The ruby text is positioned before the base text;
 /// i.e. above horizontal text and to the right of vertical text.
-@property (nonatomic, copy) NSString *textBefore;
+@property (nullable, nonatomic, copy) NSString *textBefore;
 
 /// The ruby text is positioned after the base text;
 /// i.e. below horizontal text and to the left of vertical text.
-@property (nonatomic, copy) NSString *textAfter;
+@property (nullable, nonatomic, copy) NSString *textAfter;
 
 /// The ruby text is positioned to the right of the base text whether it is horizontal or vertical.
 /// This is the way that Bopomofo annotations are attached to Chinese text in Taiwan.
-@property (nonatomic, copy) NSString *textInterCharacter;
+@property (nullable, nonatomic, copy) NSString *textInterCharacter;
 
 /// The ruby text follows the base text with no special styling.
-@property (nonatomic, copy) NSString *textInline;
+@property (nullable, nonatomic, copy) NSString *textInline;
 
 
 /**
@@ -69,6 +71,8 @@
  @return A new CTRuby object, or NULL when an error occurs.
  The returned value should be release after used.
  */
-- (CTRubyAnnotationRef)CTRubyAnnotation CF_RETURNS_RETAINED NS_AVAILABLE_IOS(8_0);
+- (nullable CTRubyAnnotationRef)CTRubyAnnotation CF_RETURNS_RETAINED NS_AVAILABLE_IOS(8_0);
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/String/YYTextRunDelegate.h

@@ -12,6 +12,8 @@
 #import <UIKit/UIKit.h>
 #import <CoreText/CoreText.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  Wrapper for CTRunDelegateRef.
  
@@ -39,26 +41,28 @@
  
  @return The CTRunDelegate object.
  */
-- (CTRunDelegateRef)CTRunDelegate CF_RETURNS_RETAINED;
+- (nullable CTRunDelegateRef)CTRunDelegate CF_RETURNS_RETAINED;
 
 /**
  Additional information about the the run delegate.
  */
-@property (nonatomic, strong) NSDictionary *userInfo;
+@property (nullable, nonatomic, strong) NSDictionary *userInfo;
 
 /**
  The typographic ascent of glyphs in the run.
  */
-@property (nonatomic, assign) CGFloat ascent;
+@property (nonatomic) CGFloat ascent;
 
 /**
  The typographic descent of glyphs in the run.
  */
-@property (nonatomic, assign) CGFloat descent;
+@property (nonatomic) CGFloat descent;
 
 /**
  The typographic width of glyphs in the run.
  */
-@property (nonatomic, assign) CGFloat width;
+@property (nonatomic) CGFloat width;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Utility/NSParagraphStyle+YYText.h

@@ -11,6 +11,8 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  Provides extensions for `NSParagraphStyle` to work with CoreText.
  */
@@ -23,11 +25,13 @@
  
  @return a new NSParagraphStyle
  */
-+ (NSParagraphStyle *)yy_styleWithCTStyle:(CTParagraphStyleRef)CTStyle;
++ (nullable NSParagraphStyle *)yy_styleWithCTStyle:(CTParagraphStyleRef)CTStyle;
 
 /**
  Creates and returns a CoreText Paragraph Style. (need call CFRelease() after used)
  */
-- (CTParagraphStyleRef)yy_CTStyle CF_RETURNS_RETAINED;
+- (nullable CTParagraphStyleRef)yy_CTStyle CF_RETURNS_RETAINED;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Utility/UIPasteboard+YYText.h

@@ -11,21 +11,23 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  Extend UIPasteboard to support image and attributed string.
  */
 @interface UIPasteboard (YYText)
 
-@property (nonatomic, copy) NSData *yy_PNGData;    ///< PNG file data
-@property (nonatomic, copy) NSData *yy_JPEGData;   ///< JPEG file data
-@property (nonatomic, copy) NSData *yy_GIFData;    ///< GIF file data
-@property (nonatomic, copy) NSData *yy_WEBPData;   ///< WebP file data
-@property (nonatomic, copy) NSData *yy_ImageData;  ///< image file data
+@property (nullable, nonatomic, copy) NSData *yy_PNGData;    ///< PNG file data
+@property (nullable, nonatomic, copy) NSData *yy_JPEGData;   ///< JPEG file data
+@property (nullable, nonatomic, copy) NSData *yy_GIFData;    ///< GIF file data
+@property (nullable, nonatomic, copy) NSData *yy_WEBPData;   ///< WebP file data
+@property (nullable, nonatomic, copy) NSData *yy_ImageData;  ///< image file data
 
 /// Attributed string,
 /// Set this attributed will also set the string property which is copy from the attributed string.
 /// If the attributed string contains one or more image, it will also set the `images` property.
-@property (nonatomic, copy) NSAttributedString *yy_AttributedString;
+@property (nullable, nonatomic, copy) NSAttributedString *yy_AttributedString;
 
 @end
 
@@ -35,3 +37,5 @@ UIKIT_EXTERN NSString *const YYTextPasteboardTypeAttributedString;
 
 /// The UTI Type identifying WebP data in pasteboard.
 UIKIT_EXTERN NSString *const YYTextUTTypeWEBP;
+
+NS_ASSUME_NONNULL_END

YYText/Utility/UIView+YYText.h

@@ -11,6 +11,8 @@
 
 #import <UIKit/UIKit.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  Provides extensions for `UIView`.
  */
@@ -19,7 +21,7 @@
 /**
  Returns the view's view controller (may be nil).
  */
-@property (nonatomic, readonly) UIViewController *yy_viewController;
+@property (nullable, nonatomic, readonly) UIViewController *yy_viewController;
 
 /**
  Returns the visible alpha on screen, taking into account superview and window.
@@ -66,3 +68,5 @@
 - (CGRect)yy_convertRect:(CGRect)rect fromViewOrWindow:(UIView *)view;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Utility/YYTextAsyncLayer.h

@@ -14,6 +14,7 @@
 
 @class YYTextAsyncLayerDisplayTask;
 
+NS_ASSUME_NONNULL_BEGIN
 
 /**
  The YYTextAsyncLayer class is a subclass of CALayer used for render contents asynchronously.
@@ -49,7 +50,7 @@
  
  @param layer  The layer.
  */
-@property (nonatomic, copy) void (^willDisplay)(CALayer *layer);
+@property (nullable, nonatomic, copy) void (^willDisplay)(CALayer *layer);
 
 /**
  This block is called to draw the layer's contents.
@@ -62,7 +63,7 @@
  @param isCancelled  If this block returns `YES`, the method should cancel the
  drawing process and return as quickly as possible.
  */
-@property (nonatomic, copy) void (^display)(CGContextRef context, CGSize size, BOOL(^isCancelled)(void));
+@property (nullable, nonatomic, copy) void (^display)(CGContextRef context, CGSize size, BOOL(^isCancelled)(void));
 
 /**
  This block will be called after the asynchronous drawing finished.
@@ -71,6 +72,8 @@
  @param layer  The layer.
  @param finished  If the draw process is cancelled, it's `NO`, otherwise it's `YES`;
  */
-@property (nonatomic, copy) void (^didDisplay)(CALayer *layer, BOOL finished);
+@property (nullable, nonatomic, copy) void (^didDisplay)(CALayer *layer, BOOL finished);
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Utility/YYTextTransaction.h

@@ -11,6 +11,8 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  YYTextTransaction let you perform a selector once before current runloop sleep.
  */
@@ -36,3 +38,5 @@
 - (void)commit;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/Utility/YYTextUtilities.h

@@ -22,6 +22,7 @@
 #define YYTEXT_SWAP(_a_, _b_)  do { __typeof__(_a_) _tmp_ = (_a_); (_a_) = (_b_); (_b_) = _tmp_; } while (0)
 #endif
 
+NS_ASSUME_NONNULL_BEGIN
 
 /**
  Whether the character is 'line break char':
@@ -56,7 +57,7 @@ static inline BOOL YYTextIsLinebreakChar(unichar c) {
  @param str A string
  @return YES or NO.
  */
-static inline BOOL YYTextIsLinebreakString(NSString *str) {
+static inline BOOL YYTextIsLinebreakString( NSString * _Nullable str) {
     if (str.length > 2 || str.length == 0) return NO;
     if (str.length == 1) {
         unichar c = [str characterAtIndex:0];
@@ -72,7 +73,7 @@ static inline BOOL YYTextIsLinebreakString(NSString *str) {
  @param str  A string.
  @return The length of the tail line break: 0, 1 or 2.
  */
-static inline NSUInteger YYTextLinebreakTailLength(NSString *str) {
+static inline NSUInteger YYTextLinebreakTailLength(NSString * _Nullable str) {
     if (str.length >= 2) {
         unichar c2 = [str characterAtIndex:str.length - 1];
         if (YYTextIsLinebreakChar(c2)) {
@@ -519,17 +520,17 @@ static inline UIEdgeInsets YYTextUIEdgeInsetPixelCeil(UIEdgeInsets insets) {
 
 
 
-static inline UIFont * YYTextFontWithBold(UIFont *font) {
+static inline  UIFont * _Nullable YYTextFontWithBold(UIFont *font) {
     if (![font respondsToSelector:@selector(fontDescriptor)]) return font;
     return [UIFont fontWithDescriptor:[font.fontDescriptor fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitBold] size:font.pointSize];
 }
 
-static inline UIFont * YYTextFontWithItalic(UIFont *font) {
+static inline UIFont * _Nullable YYTextFontWithItalic(UIFont *font) {
     if (![font respondsToSelector:@selector(fontDescriptor)]) return font;
     return [UIFont fontWithDescriptor:[font.fontDescriptor fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitItalic] size:font.pointSize];
 }
 
-static inline UIFont * YYTextFontWithBoldItalic(UIFont *font) {
+static inline UIFont * _Nullable YYTextFontWithBoldItalic(UIFont *font) {
     if (![font respondsToSelector:@selector(fontDescriptor)]) return font;
     return [UIFont fontWithDescriptor:[font.fontDescriptor fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitBold | UIFontDescriptorTraitItalic] size:font.pointSize];
 }
@@ -557,4 +558,6 @@ static inline CFRange YYTextCFRangeFromNSRange(NSRange range) {
 BOOL YYTextIsAppExtension();
 
 /// Returns nil in App Extension.
-UIApplication *YYTextSharedApplication();
+UIApplication * _Nullable YYTextSharedApplication();
+
+NS_ASSUME_NONNULL_END

YYText/Utility/YYTextWeakProxy.h

@@ -11,6 +11,8 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  A proxy used to hold a weak object.
  It can be used to avoid retain cycles, such as the target in NSTimer or CADisplayLink.
@@ -34,7 +36,7 @@
 /**
  The proxy target.
  */
-@property (nonatomic, weak, readonly) id target;
+@property (nullable, nonatomic, weak, readonly) id target;
 
 /**
  Creates a new weak proxy for target.
@@ -55,3 +57,5 @@
 + (instancetype)proxyWithTarget:(id)target;
 
 @end
+
+NS_ASSUME_NONNULL_END

YYText/YYLabel.h

@@ -21,6 +21,8 @@
 #import "YYTextAttribute.h"
 #endif
 
+NS_ASSUME_NONNULL_BEGIN
+
 #if !TARGET_INTERFACE_BUILDER
 
 /**
@@ -158,7 +160,7 @@
  An array of UIBezierPath objects representing the exclusion paths inside the
  receiver's bounding rectangle. Default value is nil.
  */
-@property (nullable, nonatomic, copy) NSArray *exclusionPaths;
+@property (nullable, nonatomic, copy) NSArray<UIBezierPath *> *exclusionPaths;
 
 /**
  The inset of the text container's layout area within the text view's content area.
@@ -359,7 +361,7 @@ IB_DESIGNABLE
 @property (nullable, nonatomic, strong) id<YYTextParser> textParser;
 @property (nullable, nonatomic, strong) YYTextLayout *textLayout;
 @property (nullable, nonatomic, copy) UIBezierPath *textContainerPath;
-@property (nullable, nonatomic, copy) NSArray *exclusionPaths;
+@property (nullable, nonatomic, copy) NSArray<UIBezierPath*> *exclusionPaths;
 @property (nonatomic) UIEdgeInsets textContainerInset;
 @property (nullable, nonatomic, copy) id<YYTextLinePositionModifier> linePositionModifier;
 @property (nonnull, nonatomic, copy) YYTextDebugOption *debugOption;
@@ -372,3 +374,5 @@ IB_DESIGNABLE
 @property (nonatomic) BOOL ignoreCommonProperties;
 @end
 #endif // !TARGET_INTERFACE_BUILDER
+
+NS_ASSUME_NONNULL_END

YYText/YYTextView.h

@@ -21,10 +21,10 @@
 #import "YYTextAttribute.h"
 #endif
 
-NS_ASSUME_NONNULL_BEGIN
-
 @class YYTextView;
 
+NS_ASSUME_NONNULL_BEGIN
+
 /**
  The YYTextViewDelegate protocol defines a set of optional methods you can use
  to receive editing-related messages for YYTextView objects. 
@@ -127,20 +127,20 @@ NS_ASSUME_NONNULL_BEGIN
  When a range of text is detected by the `dataDetectorTypes`, this value would be
  used to modify the original attributes in the range.
  */
-@property (nullable, nonatomic, copy) NSDictionary *linkTextAttributes;
+@property (nullable, nonatomic, copy) NSDictionary<NSString *, id> *linkTextAttributes;
 
 /**
  The attributes to apply to links at highlight state. Default is a gray border.
  When a range of text is detected by the `dataDetectorTypes` and the range was touched by user,
  this value would be used to modify the original attributes in the range.
  */
-@property (nullable, nonatomic, copy) NSDictionary *highlightTextAttributes;
+@property (nullable, nonatomic, copy) NSDictionary<NSString *, id> *highlightTextAttributes;
 
 /**
  The attributes to apply to new text being entered by the user.
  When the text view's selection changes, this value is reset automatically.
  */
-@property (nullable, nonatomic, copy) NSDictionary *typingAttributes;
+@property (nullable, nonatomic, copy) NSDictionary<NSString *, id> *typingAttributes;
 
 /**
  The styled text displayed by the text view.
@@ -219,7 +219,7 @@ NS_ASSUME_NONNULL_BEGIN
  An array of UIBezierPath objects representing the exclusion paths inside the 
  receiver's bounding rectangle. Default value is nil.
  */
-@property (nullable, nonatomic, copy) NSArray *exclusionPaths;
+@property (nullable, nonatomic, copy) NSArray<UIBezierPath *> *exclusionPaths;
 
 /**
  Whether the receiver's layout orientation is vertical form. Default is NO.