#import <AsyncDisplayKit/ASTextKitComponents.h>

#import "ASTextKitContext.h"

#import <AsyncDisplayKit/ASAssert.h>

#import <AsyncDisplayKit/ASMainThreadDeallocation.h>

#import <tgmath.h>

@implementation ASCustomTextContainer

- (instancetype)initWithSize:(CGSize)size textStorage:(NSTextStorage *)textStorage {

self = [super initWithSize:size];

if (self != nil) {

}

return self;

}

- (BOOL)isSimpleRectangularTextContainer {

return false;

}

- (CGRect)lineFragmentRectForProposedRect:(CGRect)proposedRect atIndex:(NSUInteger)characterIndex writingDirection:(NSWritingDirection)baseWritingDirection remainingRect:(nullable CGRect *)remainingRect {

CGRect result = [super lineFragmentRectForProposedRect:proposedRect atIndex:characterIndex writingDirection:baseWritingDirection remainingRect:remainingRect];

NSTextStorage *textStorage = self.layoutManager.textStorage;

if (textStorage != nil) {

NSString *string = textStorage.string;

int index = (int)characterIndex;

if (index >= 0 && index < string.length) {

NSDictionary *attributes = [textStorage attributesAtIndex:index effectiveRange:nil];

NSObject *blockQuote = attributes[@"Attribute__Blockquote"];

if (blockQuote != nil) {

bool isFirstLine = false;

if (index == 0) {

isFirstLine = true;

} else {

NSDictionary *previousAttributes = [textStorage attributesAtIndex:index - 1 effectiveRange:nil];

NSObject *previousBlockQuote = previousAttributes[@"Attribute__Blockquote"];

if (previousBlockQuote == nil) {

isFirstLine = true;

} else if (![blockQuote isEqual:previousBlockQuote]) {

isFirstLine = true;

}

}

if (isFirstLine) {

result.size.width -= 100.0f;

}

}

}

}

return result;

}

@interface ASCustomLayoutManager : NSLayoutManager

@implementation ASCustomLayoutManager

- (void)showCGGlyphs:(const CGGlyph *)glyphs positions:(const CGPoint *)positions count:(NSUInteger)glyphCount font:(UIFont *)font matrix:(CGAffineTransform)textMatrix attributes:(NSDictionary<NSAttributedStringKey,id> *)attributes inContext:(CGContextRef)graphicsContext {

for (NSUInteger i = 0; i < glyphCount; i++) {

if (attributes[@"Attribute__CustomEmoji"] != nil) {

continue;

}

[super showCGGlyphs:&glyphs[i] positions:&positions[i] count:1 font:font matrix:textMatrix attributes:attributes inContext:graphicsContext];

}

}

- (void)drawGlyphsForGlyphRange:(NSRange)glyphsToShow atPoint:(CGPoint)origin {

[super drawGlyphsForGlyphRange:glyphsToShow atPoint:origin];

}

@interface ASTextKitComponentsTextView () {

// Prevent UITextView from updating contentOffset while deallocating: https://github.com/TextureGroup/Texture/issues/860

BOOL _deallocating;

}

@property CGRect threadSafeBounds;

@implementation ASTextKitComponentsTextView

- (instancetype)initWithFrame:(CGRect)frame textContainer:(NSTextContainer *)textContainer

{

self = [super initWithFrame:frame textContainer:textContainer];

if (self) {

_threadSafeBounds = self.bounds;

_deallocating = NO;

}

return self;

}

- (void)dealloc

{

_deallocating = YES;

}

- (void)setFrame:(CGRect)frame

{

ASDisplayNodeAssertMainThread();

[super setFrame:frame];

self.threadSafeBounds = self.bounds;

}

- (void)setBounds:(CGRect)bounds

{

ASDisplayNodeAssertMainThread();

[super setBounds:bounds];

self.threadSafeBounds = bounds;

}

- (void)setContentOffset:(CGPoint)contentOffset

{

if (_deallocating) {

return;

}

[super setContentOffset:contentOffset];

}

@interface ASTextKitComponents ()

@property (nonatomic) NSTextStorage *textStorage;

@property (nonatomic) NSTextContainer *textContainer;

@property (nonatomic) NSLayoutManager *layoutManager;

@implementation ASTextKitComponents

#pragma mark - Class

+ (instancetype)componentsWithAttributedSeedString:(NSAttributedString *)attributedSeedString

textContainerSize:(CGSize)textContainerSize NS_RETURNS_RETAINED

{

NSTextStorage *textStorage = attributedSeedString ? [[NSTextStorage alloc] initWithAttributedString:attributedSeedString] : [[NSTextStorage alloc] init];

return [self componentsWithTextStorage:textStorage

textContainerSize:textContainerSize

layoutManager:[[ASCustomLayoutManager alloc] init]];

}

+ (instancetype)componentsWithTextStorage:(NSTextStorage *)textStorage

textContainerSize:(CGSize)textContainerSize

layoutManager:(NSLayoutManager *)layoutManager NS_RETURNS_RETAINED

{

ASTextKitComponents *components = [[self alloc] init];

components.textStorage = textStorage;

components.layoutManager = layoutManager;

[components.textStorage addLayoutManager:components.layoutManager];

components.textContainer = [[ASCustomTextContainer alloc] initWithSize:textContainerSize textStorage:textStorage];

components.textContainer.lineFragmentPadding = 0.0; // We want the text laid out up to the very edges of the text-view.

[components.layoutManager addTextContainer:components.textContainer];

return components;

}

+ (BOOL)needsMainThreadDeallocation

{

return YES;

}

#pragma mark - Lifecycle

- (void)dealloc

{

// Nil out all delegates to prevent crash

if (_textView) {

ASDisplayNodeAssertMainThread();

_textView.delegate = nil;

}

_layoutManager.delegate = nil;

}

#pragma mark - Sizing

- (CGSize)sizeForConstrainedWidth:(CGFloat)constrainedWidth

{

ASTextKitComponents *components = self;

// If our text-view's width is already the constrained width, we can use our existing TextKit stack for this sizing calculation.

// Otherwise, we create a temporary stack to size for `constrainedWidth`.

UIEdgeInsets additionalInsets = UIEdgeInsetsZero;

if (CGRectGetWidth(components.textView.threadSafeBounds) != constrainedWidth) {

additionalInsets = self.textView.textContainerInset;

components = [ASTextKitComponents componentsWithAttributedSeedString:components.textStorage textContainerSize:CGSizeMake(constrainedWidth - additionalInsets.left - additionalInsets.right, CGFLOAT_MAX)];

}

// Force glyph generation and layout, which may not have happened yet (and isn't triggered by -usedRectForTextContainer:).

[components.layoutManager ensureLayoutForTextContainer:components.textContainer];

CGSize textSize = [components.layoutManager usedRectForTextContainer:components.textContainer].size;

return textSize;

}

- (CGSize)sizeForConstrainedWidth:(CGFloat)constrainedWidth

forMaxNumberOfLines:(NSInteger)maxNumberOfLines

{

if (maxNumberOfLines == 0) {

return [self sizeForConstrainedWidth:constrainedWidth];

}

ASTextKitComponents *components = self;

// Always use temporary stack in case of threading issues

components = [ASTextKitComponents componentsWithAttributedSeedString:components.textStorage textContainerSize:CGSizeMake(constrainedWidth, CGFLOAT_MAX)];

// Force glyph generation and layout, which may not have happened yet (and isn't triggered by - usedRectForTextContainer:).

[components.layoutManager ensureLayoutForTextContainer:components.textContainer];

CGFloat width = [components.layoutManager usedRectForTextContainer:components.textContainer].size.width;

// Calculate height based on line fragments

// Based on calculating number of lines from: http://asciiwwdc.com/2013/sessions/220

NSRange glyphRange, lineRange = NSMakeRange(0, 0);

CGRect rect = CGRectZero;

CGFloat height = 0;

CGFloat lastOriginY = -1.0;

NSUInteger numberOfLines = 0;

glyphRange = [components.layoutManager glyphRangeForTextContainer:components.textContainer];

while (lineRange.location < NSMaxRange(glyphRange)) {

rect = [components.layoutManager lineFragmentRectForGlyphAtIndex:lineRange.location

effectiveRange:&lineRange];

if (CGRectGetMinY(rect) > lastOriginY) {

++numberOfLines;

if (numberOfLines == maxNumberOfLines) {

height = rect.origin.y + rect.size.height;

break;

}

}

lastOriginY = CGRectGetMinY(rect);

lineRange.location = NSMaxRange(lineRange);

}

CGFloat fragmentHeight = rect.origin.y + rect.size.height;

CGFloat finalHeight = std::ceil(std::fmax(height, fragmentHeight));

CGSize size = CGSizeMake(width, finalHeight);

return size;

}