#import "ASTextKitRenderer.h"

#import "ASAssert.h"

#import "ASTextKitContext.h"

#import "ASTextKitShadower.h"

#import "ASTextKitTailTruncater.h"

#import "ASTextKitFontSizeAdjuster.h"

#import "ASTextKitTruncating.h"

#define LOG(...)

static NSCharacterSet *_defaultAvoidTruncationCharacterSet()

{

static NSCharacterSet *truncationCharacterSet;

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

NSMutableCharacterSet *mutableCharacterSet = [[NSMutableCharacterSet alloc] init];

[mutableCharacterSet formUnionWithCharacterSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

[mutableCharacterSet addCharactersInString:@".,!?:;"];

truncationCharacterSet = mutableCharacterSet;

});

return truncationCharacterSet;

}

@implementation ASTextKitRenderer {

CGSize _calculatedSize;

BOOL _sizeIsCalculated;

}

@synthesize attributes = _attributes, context = _context, shadower = _shadower, truncater = _truncater, fontSizeAdjuster = _fontSizeAdjuster;

#pragma mark - Initialization

- (instancetype)initWithTextKitAttributes:(const ASTextKitAttributes &)attributes

constrainedSize:(const CGSize)constrainedSize

{

if (self = [super init]) {

_constrainedSize = constrainedSize;

_attributes = attributes;

_sizeIsCalculated = NO;

}

return self;

}

- (ASTextKitShadower *)shadower

{

if (!_shadower) {

ASTextKitAttributes attributes = _attributes;

_shadower = [[ASTextKitShadower alloc] initWithShadowOffset:attributes.shadowOffset

shadowColor:attributes.shadowColor

shadowOpacity:attributes.shadowOpacity

shadowRadius:attributes.shadowRadius];

}

return _shadower;

}

- (ASTextKitTailTruncater *)truncater

{

if (!_truncater) {

ASTextKitAttributes attributes = _attributes;

NSCharacterSet *avoidTailTruncationSet = attributes.avoidTailTruncationSet ? : _defaultAvoidTruncationCharacterSet();

_truncater = [[ASTextKitTailTruncater alloc] initWithContext:[self context]

truncationAttributedString:attributes.truncationAttributedString

avoidTailTruncationSet:avoidTailTruncationSet];

}

return _truncater;

}

- (ASTextKitFontSizeAdjuster *)fontSizeAdjuster

{

if (!_fontSizeAdjuster) {

ASTextKitAttributes attributes = _attributes;

// We must inset the constrained size by the size of the shadower.

CGSize shadowConstrainedSize = [[self shadower] insetSizeWithConstrainedSize:_constrainedSize];

_fontSizeAdjuster = [[ASTextKitFontSizeAdjuster alloc] initWithContext:[self context]

minimumScaleFactor:attributes.minimumScaleFactor

constrainedSize:shadowConstrainedSize];

}

return _fontSizeAdjuster;

}

- (ASTextKitContext *)context

{

if (!_context) {

ASTextKitAttributes attributes = _attributes;

// We must inset the constrained size by the size of the shadower.

CGSize shadowConstrainedSize = [[self shadower] insetSizeWithConstrainedSize:_constrainedSize];

_context = [[ASTextKitContext alloc] initWithAttributedString:attributes.attributedString

lineBreakMode:attributes.lineBreakMode

maximumNumberOfLines:attributes.maximumNumberOfLines

exclusionPaths:attributes.exclusionPaths

constrainedSize:shadowConstrainedSize

layoutManagerFactory:attributes.layoutManagerFactory

layoutManagerDelegate:attributes.layoutManagerDelegate];

}

return _context;

}

#pragma mark - Sizing

- (CGSize)size

{

if (!_sizeIsCalculated) {

[self _calculateSize];

_sizeIsCalculated = YES;

}

return _calculatedSize;

}

- (void)setConstrainedSize:(CGSize)constrainedSize

{

if (!CGSizeEqualToSize(constrainedSize, _constrainedSize)) {

_sizeIsCalculated = NO;

_constrainedSize = constrainedSize;

// If the context isn't created yet, it will be initialized with the appropriate size when next accessed.

if (_context || _fontSizeAdjuster) {

// If we're updating an existing context, make sure to use the same inset logic used during initialization.

// This codepath allows us to reuse the

CGSize shadowConstrainedSize = [[self shadower] insetSizeWithConstrainedSize:constrainedSize];

if (_context) _context.constrainedSize = shadowConstrainedSize;

if (_fontSizeAdjuster) _fontSizeAdjuster.constrainedSize = shadowConstrainedSize;

}

}

}

- (void)_calculateSize

{

[self truncater];

if (_attributes.minimumScaleFactor < 1 && _attributes.minimumScaleFactor > 0) {

[[self fontSizeAdjuster] adjustFontSize];

}

// Force glyph generation and layout, which may not have happened yet (and isn't triggered by

// -usedRectForTextContainer:).

[[self context] performBlockWithLockedTextKitComponents:^(NSLayoutManager *layoutManager, NSTextStorage *textStorage, NSTextContainer *textContainer) {

[layoutManager ensureLayoutForTextContainer:textContainer];

}];

CGRect constrainedRect = {CGPointZero, _constrainedSize};

__block CGRect boundingRect;

[[self context] performBlockWithLockedTextKitComponents:^(NSLayoutManager *layoutManager, NSTextStorage *textStorage, NSTextContainer *textContainer) {

boundingRect = [layoutManager usedRectForTextContainer:textContainer];

}];

// TextKit often returns incorrect glyph bounding rects in the horizontal direction, so we clip to our bounding rect

// to make sure our width calculations aren't being offset by glyphs going beyond the constrained rect.

boundingRect = CGRectIntersection(boundingRect, {.size = constrainedRect.size});

_calculatedSize = [_shadower outsetSizeWithInsetSize:boundingRect.size];

}

#pragma mark - Drawing

- (void)drawInContext:(CGContextRef)context bounds:(CGRect)bounds;

{

// We add an assertion so we can track the rare conditions where a graphics context is not present

ASDisplayNodeAssertNotNil(context, @"This is no good without a context.");

CGRect shadowInsetBounds = [[self shadower] insetRectWithConstrainedRect:bounds];

CGContextSaveGState(context);

[[self shadower] setShadowInContext:context];

UIGraphicsPushContext(context);

LOG(@"%@, shadowInsetBounds = %@",self, NSStringFromCGRect(shadowInsetBounds));

[[self context] performBlockWithLockedTextKitComponents:^(NSLayoutManager *layoutManager, NSTextStorage *textStorage, NSTextContainer *textContainer) {

LOG(@"usedRect: %@", NSStringFromCGRect([layoutManager usedRectForTextContainer:textContainer]));

NSRange glyphRange = [layoutManager glyphRangeForTextContainer:textContainer];

LOG(@"boundingRect: %@", NSStringFromCGRect([layoutManager boundingRectForGlyphRange:glyphRange inTextContainer:textContainer]));

[layoutManager drawBackgroundForGlyphRange:glyphRange atPoint:shadowInsetBounds.origin];

[layoutManager drawGlyphsForGlyphRange:glyphRange atPoint:shadowInsetBounds.origin];

}];

UIGraphicsPopContext();

CGContextRestoreGState(context);

}

#pragma mark - String Ranges

- (NSUInteger)lineCount

{

__block NSUInteger lineCount = 0;

[[self context] performBlockWithLockedTextKitComponents:^(NSLayoutManager *layoutManager, NSTextStorage *textStorage, NSTextContainer *textContainer) {

for (NSRange lineRange = { 0, 0 }; NSMaxRange(lineRange) < [layoutManager numberOfGlyphs]; lineCount++) {

[layoutManager lineFragmentRectForGlyphAtIndex:NSMaxRange(lineRange) effectiveRange:&lineRange];

}

}];

return lineCount;

}

- (std::vector<NSRange>)visibleRanges

{

return [self truncater].visibleRanges;

}