#import "ASTextNode.h"

#import <AsyncDisplayKit/_ASDisplayLayer.h>

#import <AsyncDisplayKit/ASAssert.h>

#import <AsyncDisplayKit/ASDisplayNode+Subclasses.h>

#import <AsyncDisplayKit/ASHighlightOverlayLayer.h>

#import <AsyncDisplayKit/ASTextNodeCoreTextAdditions.h>

#import <AsyncDisplayKit/ASTextNodeTextKitHelpers.h>

#import <AsyncDisplayKit/ASDisplayNodeExtras.h>

#import "ASTextNodeRenderer.h"

#import "ASTextNodeShadower.h"

static const NSTimeInterval ASTextNodeHighlightFadeOutDuration = 0.15;

static const NSTimeInterval ASTextNodeHighlightFadeInDuration = 0.1;

static const CGFloat ASTextNodeHighlightLightOpacity = 0.11;

static const CGFloat ASTextNodeHighlightDarkOpacity = 0.22;

static NSString *ASTextNodeTruncationTokenAttributeName = @"ASTextNodeTruncationAttribute";

@interface ASTextNodeDrawParameters : NSObject

- (instancetype)initWithRenderer:(ASTextNodeRenderer *)renderer

shadower:(ASTextNodeShadower *)shadower

textOrigin:(CGPoint)textOrigin

backgroundColor:(CGColorRef)backgroundColor;

@property (nonatomic, strong, readonly) ASTextNodeRenderer *renderer;

@property (nonatomic, strong, readonly) ASTextNodeShadower *shadower;

@property (nonatomic, assign, readonly) CGPoint textOrigin;

@property (nonatomic, assign, readonly) CGColorRef backgroundColor;

@implementation ASTextNodeDrawParameters

- (instancetype)initWithRenderer:(ASTextNodeRenderer *)renderer

shadower:(ASTextNodeShadower *)shadower

textOrigin:(CGPoint)textOrigin

backgroundColor:(CGColorRef)backgroundColor

{

if (self = [super init]) {

_renderer = renderer;

_shadower = shadower;

_textOrigin = textOrigin;

_backgroundColor = CGColorRetain(backgroundColor);

}

return self;

}

- (void)dealloc

{

CGColorRelease(_backgroundColor);

}

ASDISPLAYNODE_INLINE CGFloat ceilPixelValueForScale(CGFloat f, CGFloat scale)

{

// Round up to device pixel (.5 on retina)

return ceilf(f * scale) / scale;

}

ASDISPLAYNODE_INLINE CGFloat ceilPixelValue(CGFloat f)

{

return ceilPixelValueForScale(f, [UIScreen mainScreen].scale);

}

@interface ASTextNode () <UIGestureRecognizerDelegate>

@implementation ASTextNode {

CGSize _shadowOffset;

CGColorRef _shadowColor;

CGFloat _shadowOpacity;

CGFloat _shadowRadius;

NSAttributedString *_composedTruncationString;

NSString *_highlightedLinkAttributeName;

id _highlightedLinkAttributeValue;

NSRange _highlightRange;

ASHighlightOverlayLayer *_activeHighlightLayer;

ASDN::Mutex _rendererLock;

CGSize _constrainedSize;

ASTextNodeRenderer *_renderer;

ASTextNodeShadower *_shadower;

UILongPressGestureRecognizer *_longPressGestureRecognizer;

}

#pragma mark - NSObject

- (instancetype)init

{

if (self = [super init]) {

// Load default values from superclass.

_shadowOffset = [super shadowOffset];

CGColorRef superColor = [super shadowColor];

if (superColor != NULL) {

_shadowColor = CGColorRetain(superColor);

}

_shadowOpacity = [super shadowOpacity];

_shadowRadius = [super shadowRadius];

// Disable user interaction for text node by default.

self.userInteractionEnabled = NO;

self.needsDisplayOnBoundsChange = YES;

_truncationMode = NSLineBreakByWordWrapping;

_truncationAttributedString = [[NSAttributedString alloc] initWithString:NSLocalizedString(@"\u2026", @"Default truncation string")];

// The common case is for a text node to be non-opaque and blended over some background.

self.opaque = NO;

self.backgroundColor = [UIColor clearColor];

self.linkAttributeNames = @[ NSLinkAttributeName ];

// Accessibility

self.isAccessibilityElement = YES;

self.accessibilityTraits = UIAccessibilityTraitStaticText;

_constrainedSize = CGSizeMake(-INFINITY, -INFINITY);

// Placeholders

self.placeholderEnabled = YES;

_placeholderColor = ASDisplayNodeDefaultPlaceholderColor();

_placeholderInsets = UIEdgeInsetsMake(1.0, 0.0, 1.0, 0.0);

}

return self;

}

- (void)dealloc

{

if (_shadowColor != NULL) {

CGColorRelease(_shadowColor);

}

if (_longPressGestureRecognizer) {

_longPressGestureRecognizer.delegate = nil;

[_longPressGestureRecognizer removeTarget:nil action:NULL];

[self.view removeGestureRecognizer:_longPressGestureRecognizer];

}

}

- (NSString *)description

{

NSString *plainString = [[_attributedString string] stringByTrimmingCharactersInSet:[NSCharacterSet newlineCharacterSet]];

NSString *truncationString = [_composedTruncationString string];

if (plainString.length > 50)

plainString = [[plainString substringToIndex:50] stringByAppendingString:@"\u2026"];

return [NSString stringWithFormat:@"<%@: %p; text = \"%@\"; truncation string = \"%@\"; frame = %@>", self.class, self, plainString, truncationString, self.nodeLoaded ? NSStringFromCGRect(self.layer.frame) : nil];

}

#pragma mark - ASDisplayNode

- (CGSize)calculateSizeThatFits:(CGSize)constrainedSize

{

ASDisplayNodeAssert(constrainedSize.width >= 0, @"Constrained width for text (%f) is too narrow", constrainedSize.width);

ASDisplayNodeAssert(constrainedSize.height >= 0, @"Constrained height for text (%f) is too short", constrainedSize.height);

// The supplied constrainedSize should include room for shadowPadding.

// Inset the constrainedSize by the shadow padding to get the size available for text.

UIEdgeInsets shadowPadding = [[self _shadower] shadowPadding];

// Invert the negative values of shadow padding to get a positive inset

UIEdgeInsets shadowPaddingOutset = ASDNEdgeInsetsInvert(shadowPadding);

// Inset the padded constrainedSize to get the remaining size available for text

CGRect constrainedRect = CGRect{CGPointZero, constrainedSize};

CGSize constrainedSizeForText = UIEdgeInsetsInsetRect(constrainedRect, shadowPaddingOutset).size;

ASDisplayNodeAssert(constrainedSizeForText.width >= 0, @"Constrained width for text (%f) after subtracting shadow padding (%@) is too narrow", constrainedSizeForText.width, NSStringFromUIEdgeInsets(shadowPadding));

ASDisplayNodeAssert(constrainedSizeForText.height >= 0, @"Constrained height for text (%f) after subtracting shadow padding (%@) is too short", constrainedSizeForText.height, NSStringFromUIEdgeInsets(shadowPadding));

_constrainedSize = constrainedSizeForText;

[self _invalidateRenderer];

[self setNeedsDisplay];

CGSize rendererSize = [[self _renderer] size];

// Add shadow padding back

CGSize renderSizePlusShadowPadding = UIEdgeInsetsInsetRect(CGRect{CGPointZero, rendererSize}, shadowPadding).size;

ASDisplayNodeAssert(renderSizePlusShadowPadding.width >= 0, @"Calculated width for text with shadow padding (%f) is too narrow", constrainedSizeForText.width);

ASDisplayNodeAssert(renderSizePlusShadowPadding.height >= 0, @"Calculated height for text with shadow padding (%f) is too short", constrainedSizeForText.height);

return CGSizeMake(fminf(ceilPixelValue(renderSizePlusShadowPadding.width), constrainedSize.width),

fminf(ceilPixelValue(renderSizePlusShadowPadding.height), constrainedSize.height));

}

- (void)displayDidFinish

{

[super displayDidFinish];

// We invalidate our renderer here to clear the very high memory cost of

// keeping this around. _invalidateRenderer will dealloc this onto a bg

// thread resulting in less stutters on the main thread than if it were

// to be deallocated in dealloc. This is also helpful in opportunistically

// reducing memory consumption and reducing the overall footprint of the app.

[self _invalidateRenderer];

}

- (void)reclaimMemory

{

// We discard the backing store and renderer to prevent the very large

// memory overhead of maintaining these for all text nodes. They can be

// regenerated when layout is necessary.

[super reclaimMemory]; // ASDisplayNode will set layer.contents = nil

[self _invalidateRenderer];

}

- (void)didLoad

{

[super didLoad];

// If we are view-backed, support gesture interaction.

if (!self.isLayerBacked) {

_longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(_handleLongPress:)];

_longPressGestureRecognizer.delegate = self;

[self.view addGestureRecognizer:_longPressGestureRecognizer];

}

}

#pragma mark - Renderer Management

- (ASTextNodeRenderer *)_renderer

{

ASDN::MutexLocker l(_rendererLock);

if (_renderer == nil) {

CGSize constrainedSize = _constrainedSize.width != -INFINITY ? _constrainedSize : self.bounds.size;

_renderer = [[ASTextNodeRenderer alloc] initWithAttributedString:_attributedString

truncationString:_composedTruncationString

truncationMode:_truncationMode

constrainedSize:constrainedSize];

}

return _renderer;

}

- (void)_invalidateRenderer

{

ASDN::MutexLocker l(_rendererLock);

if (_renderer) {

// Destruction of the layout managers/containers/text storage is quite

// expensive, and can take some time, so we dispatch onto a bg queue to

// actually dealloc.

__block ASTextNodeRenderer *renderer = _renderer;

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

renderer = nil;

});

}

_renderer = nil;

}

#pragma mark - Shadow Drawer Management

- (ASTextNodeShadower *)_shadower

{

if (_shadower == nil) {

_shadower = [[ASTextNodeShadower alloc] initWithShadowOffset:_shadowOffset

shadowColor:_shadowColor

shadowOpacity:_shadowOpacity

shadowRadius:_shadowRadius];

}

return _shadower;

}

- (void)_invalidateShadower

{

_shadower = nil;

}

#pragma mark - Modifying User Text

- (void)setAttributedString:(NSAttributedString *)attributedString {

if (attributedString == _attributedString) {

return;

}

if (attributedString == nil) {

attributedString = [[NSAttributedString alloc] initWithString:@"" attributes:nil];

}

_attributedString = ASCleanseAttributedStringOfCoreTextAttributes(attributedString);

// We need an entirely new renderer

[self _invalidateRenderer];

// Tell the display node superclasses that the cached sizes are incorrect now

[self invalidateCalculatedSize];

[self setNeedsDisplay];

self.accessibilityLabel = _attributedString.string;

if (_attributedString.length == 0) {

// We're not an accessibility element by default if there is no string.

self.isAccessibilityElement = NO;

} else {

self.isAccessibilityElement = YES;

}

}

#pragma mark - Drawing

+ (void)drawRect:(CGRect)bounds withParameters:(ASTextNodeDrawParameters *)parameters isCancelled:(asdisplaynode_iscancelled_block_t)isCancelledBlock isRasterizing:(BOOL)isRasterizing

{

CGContextRef context = UIGraphicsGetCurrentContext();

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

CGContextSaveGState(context);

// Fill background

if (!isRasterizing) {

CGColorRef backgroundColor = parameters.backgroundColor;

if (backgroundColor) {

CGContextSetFillColorWithColor(context, backgroundColor);

CGContextSetBlendMode(context, kCGBlendModeCopy);

// outset the background fill to cover fractional errors when drawing at a

// small contentsScale.

CGContextFillRect(context, CGRectInset(bounds, -2, -2));

CGContextSetBlendMode(context, kCGBlendModeNormal);

}

}

// Draw shadow

[parameters.shadower setShadowInContext:context];

// Draw text

bounds.origin = parameters.textOrigin;

[parameters.renderer drawInRect:bounds isRasterizing:isRasterizing];

CGContextRestoreGState(context);

}

- (NSObject *)drawParametersForAsyncLayer:(_ASDisplayLayer *)layer

{

// Offset the text origin by any shadow padding

UIEdgeInsets shadowPadding = [self shadowPadding];

CGPoint textOrigin = CGPointMake(self.bounds.origin.x - shadowPadding.left, self.bounds.origin.y - shadowPadding.top);

return [[ASTextNodeDrawParameters alloc] initWithRenderer:[self _renderer]

shadower:[self _shadower]

textOrigin:textOrigin

backgroundColor:self.backgroundColor.CGColor];

}

#pragma mark - Attributes

- (id)linkAttributeValueAtPoint:(CGPoint)point

attributeName:(out NSString **)attributeNameOut

range:(out NSRange *)rangeOut

{

return [self _linkAttributeValueAtPoint:point

attributeName:attributeNameOut

range:rangeOut

inAdditionalTruncationMessage:NULL];

}

- (id)_linkAttributeValueAtPoint:(CGPoint)point

attributeName:(out NSString **)attributeNameOut

range:(out NSRange *)rangeOut

inAdditionalTruncationMessage:(out BOOL *)inAdditionalTruncationMessageOut

{

ASTextNodeRenderer *renderer = [self _renderer];

NSRange visibleRange = [renderer visibleRange];

NSAttributedString *attributedString = _attributedString;

// Check in a 9-point region around the actual touch point so we make sure

// we get the best attribute for the touch.

__block CGFloat minimumGlyphDistance = CGFLOAT_MAX;

// Final output vars

__block id linkAttributeValue = nil;

__block NSString *linkAttributeName = nil;

__block BOOL inTruncationMessage = NO;

[renderer enumerateTextIndexesAtPosition:point usingBlock:^(NSUInteger characterIndex, CGRect glyphBoundingRect, BOOL *stop) {

CGPoint glyphLocation = CGPointMake(CGRectGetMidX(glyphBoundingRect), CGRectGetMidY(glyphBoundingRect));

CGFloat currentDistance = sqrtf(powf(point.x - glyphLocation.x, 2.f) + powf(point.y - glyphLocation.y, 2.f));

if (currentDistance >= minimumGlyphDistance) {

// If the distance computed from the touch to the glyph location is

// not the minimum among the located link attributes, we can just skip

// to the next location.

return;

}

// Check if it's outside the visible range, if so, then we mark this touch

// as inside the truncation message, because in at least one of the touch

// points it was.

if (!(NSLocationInRange(characterIndex, visibleRange))) {

inTruncationMessage = YES;

}

if (inAdditionalTruncationMessageOut != NULL) {

*inAdditionalTruncationMessageOut = inTruncationMessage;

}

// Short circuit here if it's just in the truncation message. Since the

// truncation message may be beyond the scope of the actual input string,

// we have to make sure that we don't start asking for attributes on it.

if (inTruncationMessage) {

return;

}

for (NSString *attributeName in _linkAttributeNames) {

NSRange range;

id value = [attributedString attribute:attributeName atIndex:characterIndex longestEffectiveRange:&range inRange:visibleRange];

NSString *name = attributeName;

if (value == nil || name == nil) {

// Didn't find anything

continue;

}

// Check if delegate implements optional method, if not assume NO.

// Should the text be highlightable/touchable?

if (![_delegate respondsToSelector:@selector(textNode:shouldHighlightLinkAttribute:value:atPoint:)] ||

![_delegate textNode:self shouldHighlightLinkAttribute:name value:value atPoint:point]) {

value = nil;

name = nil;

}

if (value != nil || name != nil) {

// We found a minimum glyph distance link attribute, so set the min

// distance, and the out params.

minimumGlyphDistance = currentDistance;

if (rangeOut != NULL && value != nil) {

*rangeOut = range;

// Limit to only the visible range, because the attributed string will

// return values outside the visible range.

if (NSMaxRange(*rangeOut) > NSMaxRange(visibleRange)) {

(*rangeOut).length = MAX(NSMaxRange(visibleRange) - (*rangeOut).location, 0);

}

}

if (attributeNameOut != NULL) {

*attributeNameOut = name;

}

// Set the values for the next iteration

linkAttributeValue = value;

linkAttributeName = name;

break;

}

}

}];

return linkAttributeValue;

}

#pragma mark - UIGestureRecognizerDelegate

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer

{

if (gestureRecognizer == _longPressGestureRecognizer) {

// Don't allow long press on truncation message

if ([self _pendingTruncationTap]) {

return NO;

}

// Ask our delegate if a long-press on an attribute is relevant

if ([self.delegate respondsToSelector:@selector(textNode:shouldLongPressLinkAttribute:value:atPoint:)]) {

return [self.delegate textNode:self

shouldLongPressLinkAttribute:_highlightedLinkAttributeName

value:_highlightedLinkAttributeValue

atPoint:[gestureRecognizer locationInView:self.view]];

}

// Otherwise we are good to go.

return YES;

}

if (([self _pendingLinkTap] || [self _pendingTruncationTap])

&& [gestureRecognizer isKindOfClass:[UITapGestureRecognizer class]]

&& CGRectContainsPoint(self.view.bounds, [gestureRecognizer locationInView:self.view])) {

return NO;

}

return [super gestureRecognizerShouldBegin:gestureRecognizer];

}

#pragma mark - Highlighting

- (NSRange)highlightRange

{

return _highlightRange;

}

- (void)setHighlightRange:(NSRange)highlightRange

{

[self setHighlightRange:highlightRange animated:NO];

}

- (void)setHighlightRange:(NSRange)highlightRange animated:(BOOL)animated

{

[self _setHighlightRange:highlightRange forAttributeName:nil value:nil animated:animated];

}

- (void)_setHighlightRange:(NSRange)highlightRange forAttributeName:(NSString *)highlightedAttributeName value:(id)highlightedAttributeValue animated:(BOOL)animated

{

ASDisplayNodeAssertMainThread();

_highlightedLinkAttributeName = highlightedAttributeName;

_highlightedLinkAttributeValue = highlightedAttributeValue;

if (!NSEqualRanges(highlightRange, _highlightRange) && ((0 != highlightRange.length) || (0 != _highlightRange.length))) {

_highlightRange = highlightRange;

if (_activeHighlightLayer) {

if (animated) {

__unsafe_unretained CALayer *weakHighlightLayer = _activeHighlightLayer;

_activeHighlightLayer = nil;

weakHighlightLayer.opacity = 0.0;

CFTimeInterval beginTime = CACurrentMediaTime();

CABasicAnimation *possibleFadeIn = (CABasicAnimation *)[weakHighlightLayer animationForKey:@"opacity"];

if (possibleFadeIn) {

// Calculate when we should begin fading out based on the end of the fade in animation,

// Also check to make sure that the new begin time hasn't already passed

CGFloat newBeginTime = (possibleFadeIn.beginTime + possibleFadeIn.duration);

if (newBeginTime > beginTime) {

beginTime = newBeginTime;

}

}

CABasicAnimation *fadeOut = [CABasicAnimation animationWithKeyPath:@"opacity"];

fadeOut.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

fadeOut.fromValue = possibleFadeIn.toValue ?: @(((CALayer *)weakHighlightLayer.presentationLayer).opacity);

fadeOut.toValue = @0.0;

fadeOut.fillMode = kCAFillModeBoth;

fadeOut.duration = ASTextNodeHighlightFadeOutDuration;

fadeOut.beginTime = beginTime;

dispatch_block_t prev = [CATransaction completionBlock];

[CATransaction setCompletionBlock:^{

[weakHighlightLayer removeFromSuperlayer];

}];

[weakHighlightLayer addAnimation:fadeOut forKey:fadeOut.keyPath];

[CATransaction setCompletionBlock:prev];

} else {

[_activeHighlightLayer removeFromSuperlayer];

_activeHighlightLayer = nil;

}

}

if (0 != highlightRange.length) {

// Find layer in hierarchy that allows us to draw highlighting on.

CALayer *highlightTargetLayer = self.layer;

while (highlightTargetLayer != nil) {

if (highlightTargetLayer.as_allowsHighlightDrawing) {

break;

}

highlightTargetLayer = highlightTargetLayer.superlayer;

}

if (highlightTargetLayer != nil) {

NSArray *highlightRects = [[self _renderer] rectsForTextRange:highlightRange measureOption:ASTextNodeRendererMeasureOptionBlock];

NSMutableArray *converted = [NSMutableArray arrayWithCapacity:highlightRects.count];

for (NSValue *rectValue in highlightRects) {

CGRect rendererRect = [[self class] _adjustRendererRect:rectValue.CGRectValue forShadowPadding:_shadower.shadowPadding];

CGRect highlightedRect = [self.layer convertRect:rendererRect toLayer:highlightTargetLayer];

// We set our overlay layer's frame to the bounds of the highlight target layer.

// Offset highlight rects to avoid double-counting target layer's bounds.origin.

highlightedRect.origin.x -= highlightTargetLayer.bounds.origin.x;

highlightedRect.origin.y -= highlightTargetLayer.bounds.origin.y;

[converted addObject:[NSValue valueWithCGRect:highlightedRect]];

}

ASHighlightOverlayLayer *overlayLayer = [[ASHighlightOverlayLayer alloc] initWithRects:converted];

overlayLayer.highlightColor = [[self class] _highlightColorForStyle:self.highlightStyle];

overlayLayer.frame = highlightTargetLayer.bounds;

overlayLayer.masksToBounds = NO;

overlayLayer.opacity = [[self class] _highlightOpacityForStyle:self.highlightStyle];

[highlightTargetLayer addSublayer:overlayLayer];

if (animated) {

CABasicAnimation *fadeIn = [CABasicAnimation animationWithKeyPath:@"opacity"];

fadeIn.fromValue = @0.0;

fadeIn.toValue = @(overlayLayer.opacity);

fadeIn.duration = ASTextNodeHighlightFadeInDuration;

fadeIn.beginTime = CACurrentMediaTime();

[overlayLayer addAnimation:fadeIn forKey:fadeIn.keyPath];

}

[overlayLayer setNeedsDisplay];

_activeHighlightLayer = overlayLayer;

}

}

}

}

- (void)_clearHighlightIfNecessary

{

if ([self _pendingLinkTap] || [self _pendingTruncationTap]) {

[self setHighlightRange:NSMakeRange(0, 0) animated:YES];

}

}

+ (CGColorRef)_highlightColorForStyle:(ASTextNodeHighlightStyle)style

{

return [UIColor colorWithWhite:(style == ASTextNodeHighlightStyleLight ? 0.0 : 1.0) alpha:1.0].CGColor;

}

+ (CGFloat)_highlightOpacityForStyle:(ASTextNodeHighlightStyle)style

{

return (style == ASTextNodeHighlightStyleLight) ? ASTextNodeHighlightLightOpacity : ASTextNodeHighlightDarkOpacity;

}

#pragma mark - Text rects

+ (CGRect)_adjustRendererRect:(CGRect)rendererRect forShadowPadding:(UIEdgeInsets)shadowPadding

{

rendererRect.origin.x -= shadowPadding.left;

rendererRect.origin.y -= shadowPadding.top;

return rendererRect;

}

- (NSArray *)_rectsForTextRange:(NSRange)textRange measureOption:(ASTextNodeRendererMeasureOption)measureOption

{

NSArray *rects = [[self _renderer] rectsForTextRange:textRange measureOption:measureOption];

NSMutableArray *adjustedRects = [NSMutableArray array];

for (NSValue *rectValue in rects) {

CGRect rect = [rectValue CGRectValue];

rect = [self.class _adjustRendererRect:rect forShadowPadding:self.shadowPadding];

NSValue *adjustedRectValue = [NSValue valueWithCGRect:rect];

[adjustedRects addObject:adjustedRectValue];

}

return adjustedRects;

}

- (NSArray *)rectsForTextRange:(NSRange)textRange

{

return [self _rectsForTextRange:textRange measureOption:ASTextNodeRendererMeasureOptionCapHeight];

}

- (NSArray *)highlightRectsForTextRange:(NSRange)textRange

{

return [self _rectsForTextRange:textRange measureOption:ASTextNodeRendererMeasureOptionBlock];

}

- (CGRect)trailingRect

{

CGRect rect = [[self _renderer] trailingRect];

return [self.class _adjustRendererRect:rect forShadowPadding:self.shadowPadding];

}

- (CGRect)frameForTextRange:(NSRange)textRange

{

CGRect frame = [[self _renderer] frameForTextRange:textRange];

return [self.class _adjustRendererRect:frame forShadowPadding:self.shadowPadding];

}

#pragma mark - Placeholders

- (void)setPlaceholderColor:(UIColor *)placeholderColor

{

_placeholderColor = placeholderColor;

// prevent placeholders if we don't have a color

self.placeholderEnabled = placeholderColor != nil;

}

- (UIImage *)placeholderImage

{

CGSize size = self.calculatedSize;

UIGraphicsBeginImageContext(size);

[self.placeholderColor setFill];

ASTextNodeRenderer *renderer = [self _renderer];

NSRange textRange = [renderer visibleRange];

// cap height is both faster and creates less subpixel blending

NSArray *lineRects = [self _rectsForTextRange:textRange measureOption:ASTextNodeRendererMeasureOptionLineHeight];

// fill each line with the placeholder color

for (NSValue *rectValue in lineRects) {

CGRect lineRect = [rectValue CGRectValue];

CGRect fillBounds = UIEdgeInsetsInsetRect(lineRect, self.placeholderInsets);

if (fillBounds.size.width > 0.0 && fillBounds.size.height > 0.0) {

UIRectFill(fillBounds);

}

}

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}

#pragma mark - Touch Handling

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

[super touchesBegan:touches withEvent:event];

ASDisplayNodeAssertMainThread();

UITouch *touch = [touches anyObject];

UIView *view = touch.view;

CGPoint point = [touch locationInView:view];

point = [self.view convertPoint:point fromView:view];

NSRange range = NSMakeRange(0, 0);

NSString *linkAttributeName = nil;

BOOL inAdditionalTruncationMessage = NO;

id linkAttributeValue = [self _linkAttributeValueAtPoint:point

attributeName:&linkAttributeName

range:&range

inAdditionalTruncationMessage:&inAdditionalTruncationMessage];

NSUInteger lastCharIndex = NSIntegerMax;

BOOL linkCrossesVisibleRange = (lastCharIndex > range.location) && (lastCharIndex < NSMaxRange(range) - 1);

if (inAdditionalTruncationMessage) {

NSRange truncationMessageRange = [self _additionalTruncationMessageRangeWithVisibleRange:[[self _renderer] visibleRange]];

[self _setHighlightRange:truncationMessageRange forAttributeName:ASTextNodeTruncationTokenAttributeName value:nil animated:YES];

} else if (range.length && !linkCrossesVisibleRange && linkAttributeValue != nil && linkAttributeName != nil) {

[self _setHighlightRange:range forAttributeName:linkAttributeName value:linkAttributeValue animated:YES];

}

}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event

{

[super touchesCancelled:touches withEvent:event];

[self _clearHighlightIfNecessary];

}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

{

[super touchesEnded:touches withEvent:event];

if ([self _pendingLinkTap] && [_delegate respondsToSelector:@selector(textNode:tappedLinkAttribute:value:atPoint:textRange:)]) {

CGPoint point = [[touches anyObject] locationInView:self.view];

[_delegate textNode:self tappedLinkAttribute:_highlightedLinkAttributeName value:_highlightedLinkAttributeValue atPoint:point textRange:_highlightRange];

}

if ([self _pendingTruncationTap]) {

if ([_delegate respondsToSelector:@selector(textNodeTappedTruncationToken:)]) {

[_delegate textNodeTappedTruncationToken:self];

}

}

[self _clearHighlightIfNecessary];

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

{

[super touchesMoved:touches withEvent:event];

[self _clearHighlightIfNecessary];

}

- (void)_handleLongPress:(UILongPressGestureRecognizer *)longPressRecognizer

{

// Respond to long-press when it begins, not when it ends.

if (longPressRecognizer.state == UIGestureRecognizerStateBegan) {

if ([self.delegate respondsToSelector:@selector(textNode:longPressedLinkAttribute:value:atPoint:textRange:)]) {

CGPoint touchPoint = [_longPressGestureRecognizer locationInView:self.view];

[self.delegate textNode:self longPressedLinkAttribute:_highlightedLinkAttributeName value:_highlightedLinkAttributeValue atPoint:touchPoint textRange:_highlightRange];

}

}

}

- (BOOL)_pendingLinkTap

{

return (_highlightedLinkAttributeValue != nil && ![self _pendingTruncationTap]) && _delegate != nil;

}

- (BOOL)_pendingTruncationTap

{

return [_highlightedLinkAttributeName isEqualToString:ASTextNodeTruncationTokenAttributeName];

}

#pragma mark - Shadow Properties

- (CGColorRef)shadowColor

{

return _shadowColor;

}

- (void)setShadowColor:(CGColorRef)shadowColor

{

if (_shadowColor != shadowColor) {

if (shadowColor != NULL) {

CGColorRetain(shadowColor);

}

_shadowColor = shadowColor;

[self _invalidateShadower];

[self setNeedsDisplay];

}

}

- (CGSize)shadowOffset

{

return _shadowOffset;

}

- (void)setShadowOffset:(CGSize)shadowOffset

{

if (!CGSizeEqualToSize(_shadowOffset, shadowOffset)) {

_shadowOffset = shadowOffset;

[self _invalidateShadower];

[self setNeedsDisplay];

}

}

- (CGFloat)shadowOpacity

{

return _shadowOpacity;

}

- (void)setShadowOpacity:(CGFloat)shadowOpacity

{

if (_shadowOpacity != shadowOpacity) {

_shadowOpacity = shadowOpacity;

[self _invalidateShadower];

[self setNeedsDisplay];

}

}

- (CGFloat)shadowRadius

{

return _shadowRadius;

}

- (void)setShadowRadius:(CGFloat)shadowRadius

{

if (_shadowRadius != shadowRadius) {

_shadowRadius = shadowRadius;

[self _invalidateShadower];

[self setNeedsDisplay];

}

}

- (UIEdgeInsets)shadowPadding

{

return [[self _shadower] shadowPadding];

}

#pragma mark - Truncation Message

- (void)setTruncationAttributedString:(NSAttributedString *)truncationAttributedString

{

// No-op if they're exactly equal (avoid redrawing)

if (_truncationAttributedString == truncationAttributedString) {

return;

}

if (![_truncationAttributedString isEqual:truncationAttributedString]) {

_truncationAttributedString = [truncationAttributedString copy];

[self _invalidateTruncationString];

}

}

- (void)setAdditionalTruncationMessage:(NSAttributedString *)additionalTruncationMessage

{

// Short circuit if we're setting to nil (prevent redrawing when we don't need to)

if (_additionalTruncationMessage == additionalTruncationMessage) {

return;

}

if (![_additionalTruncationMessage isEqual:additionalTruncationMessage]) {

_additionalTruncationMessage = [additionalTruncationMessage copy];

[self _invalidateTruncationString];

}

}

- (void)setTruncationMode:(NSLineBreakMode)truncationMode

{

if (_truncationMode != truncationMode) {

_truncationMode = truncationMode;

[self _invalidateRenderer];

[self setNeedsDisplay];

}

}

- (BOOL)isTruncated

{

return [[self _renderer] truncationStringCharacterRange].location != NSNotFound;

}

- (NSUInteger)lineCount

{

return [[self _renderer] lineCount];

}

#pragma mark - Truncation Message

- (void)_invalidateTruncationString

{

_composedTruncationString = [self _prepareTruncationStringForDrawing:[self _composedTruncationString]];

[self _invalidateRenderer];

[self setNeedsDisplay];

}

- (NSRange)_additionalTruncationMessageRangeWithVisibleRange:(NSRange)visibleRange

{

// Check if we even have an additional truncation message.

if (!_additionalTruncationMessage) {

return NSMakeRange(NSNotFound, 0);

}

// Character location of the unicode ellipsis (the first index after the visible range)

NSInteger truncationTokenIndex = NSMaxRange(visibleRange);

NSUInteger additionalTruncationMessageLength = _additionalTruncationMessage.length;

// We get the location of the truncation token, then add the length of the

// truncation attributed string +1 for the space between.

NSRange range = NSMakeRange(truncationTokenIndex + _truncationAttributedString.length + 1, additionalTruncationMessageLength);

return range;

}

- (NSAttributedString *)_composedTruncationString

{

// Short circuit if we only have one or the other.

if (!_additionalTruncationMessage) {

return _truncationAttributedString;

}

if (!_truncationAttributedString) {

return _additionalTruncationMessage;

}

// If we've reached this point, both _additionalTruncationMessage and

// _truncationAttributedString are present. Compose them.

NSMutableAttributedString *newComposedTruncationString = [[NSMutableAttributedString alloc] initWithAttributedString:_truncationAttributedString];

[newComposedTruncationString replaceCharactersInRange:NSMakeRange(newComposedTruncationString.length, 0) withString:@" "];

[newComposedTruncationString appendAttributedString:_additionalTruncationMessage];

return newComposedTruncationString;

}

- (NSAttributedString *)_prepareTruncationStringForDrawing:(NSAttributedString *)truncationString

{

truncationString = ASCleanseAttributedStringOfCoreTextAttributes(truncationString);

NSMutableAttributedString *truncationMutableString = [truncationString mutableCopy];

// Grab the attributes from the full string

if (_attributedString.length > 0) {

NSAttributedString *originalString = _attributedString;

NSInteger originalStringLength = _attributedString.length;

// Add any of the original string's attributes to the truncation string,

// but don't overwrite any of the truncation string's attributes

NSDictionary *originalStringAttributes = [originalString attributesAtIndex:originalStringLength-1 effectiveRange:NULL];

[truncationString enumerateAttributesInRange:NSMakeRange(0, truncationString.length) options:0 usingBlock:

^(NSDictionary *attributes, NSRange range, BOOL *stop) {

NSMutableDictionary *futureTruncationAttributes = [NSMutableDictionary dictionaryWithDictionary:originalStringAttributes];

[futureTruncationAttributes addEntriesFromDictionary:attributes];

[truncationMutableString setAttributes:futureTruncationAttributes range:range];

}];

}

return truncationMutableString;

}