#import "ASImageNode.h"

#import <tgmath.h>

#import "_ASDisplayLayer.h"

#import "ASAssert.h"

#import "ASDimension.h"

#import "ASDisplayNode+Subclasses.h"

#import "ASDisplayNodeInternal.h"

#import "ASDisplayNodeExtras.h"

#import "ASDisplayNode+Beta.h"

#import "ASLayout.h"

#import "ASTextNode.h"

#import "ASImageNode+AnimatedImagePrivate.h"

#import "ASImageNode+CGExtras.h"

#import "AsyncDisplayKit+Debug.h"

#import "ASInternalHelpers.h"

#import "ASEqualityHelpers.h"

#import "ASEqualityHashHelpers.h"

#import "ASWeakMap.h"

#include <functional>

struct ASImageNodeDrawParameters {

BOOL opaque;

CGRect bounds;

CGFloat contentsScale;

UIColor *backgroundColor;

UIViewContentMode contentMode;

BOOL cropEnabled;

BOOL forceUpscaling;

CGSize forcedSize;

CGRect cropRect;

CGRect cropDisplayBounds;

asimagenode_modification_block_t imageModificationBlock;

};

@interface ASImageNodeContentsKey : NSObject {}

@property (nonatomic, strong) UIImage *image;

@property CGSize backingSize;

@property CGRect imageDrawRect;

@property BOOL isOpaque;

@property (nonatomic, strong) UIColor *backgroundColor;

@property (nonatomic, copy) ASDisplayNodeContextModifier preContextBlock;

@property (nonatomic, copy) ASDisplayNodeContextModifier postContextBlock;

@property (nonatomic, copy) asimagenode_modification_block_t imageModificationBlock;

@implementation ASImageNodeContentsKey

- (BOOL)isEqual:(id)object

{

if (self == object) {

return YES;

}

// Optimization opportunity: The `isKindOfClass` call here could be avoided by not using the NSObject `isEqual:`

// convention and instead using a custom comparison function that assumes all items are heterogeneous.

// However, profiling shows that our entire `isKindOfClass` expression is only ~1/40th of the total

// overheard of our caching, so it's likely not high-impact.

if ([object isKindOfClass:[ASImageNodeContentsKey class]]) {

ASImageNodeContentsKey *other = (ASImageNodeContentsKey *)object;

return [_image isEqual:other.image]

&& CGSizeEqualToSize(_backingSize, other.backingSize)

&& CGRectEqualToRect(_imageDrawRect, other.imageDrawRect)

&& _isOpaque == other.isOpaque

&& [_backgroundColor isEqual:other.backgroundColor]

&& _preContextBlock == other.preContextBlock

&& _postContextBlock == other.postContextBlock

&& _imageModificationBlock == other.imageModificationBlock;

} else {

return NO;

}

}

- (NSUInteger)hash

{

NSUInteger subhashes[] = {

// Profiling shows that the work done in UIImage's `hash` is on the order of 0.005ms on an A5 processor

// and isn't proportional to the size of the image.

[_image hash],

// TODO: Hashing the floats in a CGRect or CGSize is tricky. Equality of floats is

// fuzzy, but it's a 100% requirement that two equal values must produce an identical hash value.

// Until there's a robust solution for hashing floats, leave all float values out of the hash.

// This may lead to a greater number of isEqual comparisons but does not comprimise correctness.

//AS::hash<CGRect>()(_backingSize),

//AS::hash<CGRect>()(_imageDrawRect),

AS::hash<BOOL>()(_isOpaque),

[_backgroundColor hash],

AS::hash<void *>()((void*)_preContextBlock),

AS::hash<void *>()((void*)_postContextBlock),

AS::hash<void *>()((void*)_imageModificationBlock),

};

return ASIntegerArrayHash(subhashes, sizeof(subhashes) / sizeof(subhashes[0]));

}

@implementation ASImageNode

{

UIImage *_image;

ASWeakMapEntry *_weakCacheEntry; // Holds a reference that keeps our contents in cache.

void (^_displayCompletionBlock)(BOOL canceled);

// Drawing

ASImageNodeDrawParameters _drawParameter;

ASTextNode *_debugLabelNode;

// Cropping.

BOOL _cropEnabled; // Defaults to YES.

BOOL _forceUpscaling; //Defaults to NO.

CGSize _forcedSize; //Defaults to CGSizeZero, indicating no forced size.

CGRect _cropRect; // Defaults to CGRectMake(0.5, 0.5, 0, 0)

CGRect _cropDisplayBounds; // Defaults to CGRectNull

}

@synthesize image = _image;

@synthesize imageModificationBlock = _imageModificationBlock;

#pragma mark - NSObject

+ (void)initialize

{

[super initialize];

if (self != [ASImageNode class]) {

// Prevent custom drawing in subclasses

ASDisplayNodeAssert(!ASSubclassOverridesClassSelector([ASImageNode class], self, @selector(displayWithParameters:isCancelled:)), @"Subclass %@ must not override displayWithParameters:isCancelled: method. Custom drawing in %@ subclass is not supported.", NSStringFromClass(self), NSStringFromClass([ASImageNode class]));

}

}

- (instancetype)init

{

if (!(self = [super init]))

return nil;

// TODO can this be removed?

self.contentsScale = ASScreenScale();

self.contentMode = UIViewContentModeScaleAspectFill;

self.opaque = NO;

// If no backgroundColor is set to the image node and it's a subview of UITableViewCell, UITableView is setting

// the opaque value of all subviews to YES if highlighting / selection is happening and does not set it back to the

// initial value. With setting a explicit backgroundColor we can prevent that change.

self.backgroundColor = [UIColor clearColor];

_cropEnabled = YES;

_forceUpscaling = NO;

_cropRect = CGRectMake(0.5, 0.5, 0, 0);

_cropDisplayBounds = CGRectNull;

_placeholderColor = ASDisplayNodeDefaultPlaceholderColor();

_animatedImageRunLoopMode = ASAnimatedImageDefaultRunLoopMode;

return self;

}

- (void)dealloc

{

// Invalidate all components around animated images

[self invalidateAnimatedImage];

}

#pragma mark - Layout and Sizing

- (CGSize)calculateSizeThatFits:(CGSize)constrainedSize

{

ASDN::MutexLocker l(__instanceLock__);

if (_image == nil) {

return constrainedSize;

}

return _image.size;

}

#pragma mark - Setter / Getter

- (void)setImage:(UIImage *)image

{

ASDN::MutexLocker l(__instanceLock__);

if (!ASObjectIsEqual(_image, image)) {

_image = image;

[self invalidateCalculatedLayout];

if (image) {

[self setNeedsDisplay];

if ([ASImageNode shouldShowImageScalingOverlay] && _debugLabelNode == nil) {

ASPerformBlockOnMainThread(^{

_debugLabelNode = [[ASTextNode alloc] init];

_debugLabelNode.layerBacked = YES;

[self addSubnode:_debugLabelNode];

});

}

} else {

self.contents = nil;

}

}

}

- (UIImage *)image

{

ASDN::MutexLocker l(__instanceLock__);

return _image;

}

- (void)setPlaceholderColor:(UIColor *)placeholderColor

{

_placeholderColor = placeholderColor;

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

self.placeholderEnabled = placeholderColor != nil;

}

#pragma mark - Drawing

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

{

ASDN::MutexLocker l(__instanceLock__);

_drawParameter = {

.bounds = self.bounds,

.opaque = self.opaque,

.contentsScale = _contentsScaleForDisplay,

.backgroundColor = self.backgroundColor,

.contentMode = self.contentMode,

.cropEnabled = _cropEnabled,

.forceUpscaling = _forceUpscaling,

.forcedSize = _forcedSize,

.cropRect = _cropRect,

.cropDisplayBounds = _cropDisplayBounds,

.imageModificationBlock = _imageModificationBlock

};

return nil;

}

- (NSDictionary *)debugLabelAttributes

{

return @{

NSFontAttributeName: [UIFont systemFontOfSize:15.0],

NSForegroundColorAttributeName: [UIColor redColor]

};

}

- (UIImage *)displayWithParameters:(id<NSObject> *)parameter isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled

{

UIImage *image = self.image;

if (image == nil) {

return nil;

}

CGRect drawParameterBounds = CGRectZero;

BOOL forceUpscaling = NO;

CGSize forcedSize = CGSizeZero;

BOOL cropEnabled = YES;

BOOL isOpaque = NO;

UIColor *backgroundColor = nil;

UIViewContentMode contentMode = UIViewContentModeScaleAspectFill;

CGFloat contentsScale = 0.0;

CGRect cropDisplayBounds = CGRectZero;

CGRect cropRect = CGRectZero;

asimagenode_modification_block_t imageModificationBlock;

{

ASDN::MutexLocker l(__instanceLock__);

ASImageNodeDrawParameters drawParameter = _drawParameter;

drawParameterBounds = drawParameter.bounds;

forceUpscaling = drawParameter.forceUpscaling;

forcedSize = drawParameter.forcedSize;

cropEnabled = drawParameter.cropEnabled;

isOpaque = drawParameter.opaque;

backgroundColor = drawParameter.backgroundColor;

contentMode = drawParameter.contentMode;

contentsScale = drawParameter.contentsScale;

cropDisplayBounds = drawParameter.cropDisplayBounds;

cropRect = drawParameter.cropRect;

imageModificationBlock = drawParameter.imageModificationBlock;

}

BOOL hasValidCropBounds = cropEnabled && !CGRectIsEmpty(cropDisplayBounds);

CGRect bounds = (hasValidCropBounds ? cropDisplayBounds : drawParameterBounds);

ASDisplayNodeContextModifier preContextBlock = self.willDisplayNodeContentWithRenderingContext;

ASDisplayNodeContextModifier postContextBlock = self.didDisplayNodeContentWithRenderingContext;

ASDisplayNodeAssert(contentsScale > 0, @"invalid contentsScale at display time");

// if the image is resizable, bail early since the image has likely already been configured

BOOL stretchable = !UIEdgeInsetsEqualToEdgeInsets(image.capInsets, UIEdgeInsetsZero);

if (stretchable) {

if (imageModificationBlock != NULL) {

image = imageModificationBlock(image);

}

return image;

}

CGSize imageSize = image.size;

CGSize imageSizeInPixels = CGSizeMake(imageSize.width * image.scale, imageSize.height * image.scale);

CGSize boundsSizeInPixels = CGSizeMake(std::floor(bounds.size.width * contentsScale), std::floor(bounds.size.height * contentsScale));

if (_debugLabelNode) {

CGFloat pixelCountRatio = (imageSizeInPixels.width * imageSizeInPixels.height) / (boundsSizeInPixels.width * boundsSizeInPixels.height);

if (pixelCountRatio != 1.0) {

NSString *scaleString = [NSString stringWithFormat:@"%.2fx", pixelCountRatio];

_debugLabelNode.attributedText = [[NSAttributedString alloc] initWithString:scaleString attributes:[self debugLabelAttributes]];

_debugLabelNode.hidden = NO;

[self setNeedsLayout];

} else {

_debugLabelNode.hidden = YES;

_debugLabelNode.attributedText = nil;

}

}

BOOL contentModeSupported = contentMode == UIViewContentModeScaleAspectFill ||

contentMode == UIViewContentModeScaleAspectFit ||

contentMode == UIViewContentModeCenter;

CGSize backingSize = CGSizeZero;

CGRect imageDrawRect = CGRectZero;

if (boundsSizeInPixels.width * contentsScale < 1.0f || boundsSizeInPixels.height * contentsScale < 1.0f ||

imageSizeInPixels.width < 1.0f || imageSizeInPixels.height < 1.0f) {

return nil;

}

// If we're not supposed to do any cropping, just decode image at original size

if (!cropEnabled || !contentModeSupported || stretchable) {

backingSize = imageSizeInPixels;

imageDrawRect = (CGRect){.size = backingSize};

} else {

if (CGSizeEqualToSize(CGSizeZero, forcedSize) == NO) {

//scale forced size

forcedSize.width *= contentsScale;

forcedSize.height *= contentsScale;

}

ASCroppedImageBackingSizeAndDrawRectInBounds(imageSizeInPixels,

boundsSizeInPixels,

contentMode,

cropRect,

forceUpscaling,

forcedSize,

&backingSize,

&imageDrawRect);

}

if (backingSize.width <= 0.0f || backingSize.height <= 0.0f ||

imageDrawRect.size.width <= 0.0f || imageDrawRect.size.height <= 0.0f) {

return nil;

}

ASImageNodeContentsKey *contentsKey = [[ASImageNodeContentsKey alloc] init];

contentsKey.image = image;

contentsKey.backingSize = backingSize;

contentsKey.imageDrawRect = imageDrawRect;

contentsKey.isOpaque = isOpaque;

contentsKey.backgroundColor = backgroundColor;

contentsKey.preContextBlock = preContextBlock;

contentsKey.postContextBlock = postContextBlock;

contentsKey.imageModificationBlock = imageModificationBlock;

if (isCancelled()) {

return nil;

}

ASWeakMapEntry<UIImage *> *entry = [self.class contentsForkey:contentsKey isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled];

if (entry == nil) { // If nil, we were cancelled.

return nil;

}

_weakCacheEntry = entry; // Retain so that the entry remains in the weak cache

return entry.value;

}

static ASWeakMap<ASImageNodeContentsKey *, UIImage *> *cache = nil;

static ASDN::Mutex cacheLock;

+ (ASWeakMapEntry *)contentsForkey:(ASImageNodeContentsKey *)key isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled

{

{

ASDN::MutexLocker l(cacheLock);

if (!cache) {

cache = [[ASWeakMap alloc] init];

}

ASWeakMapEntry *entry = [cache entryForKey:key];

if (entry != nil) {

// cache hit

return entry;

}

}

// cache miss

UIImage *contents = [self createContentsForkey:key isCancelled:isCancelled];

if (contents == nil) { // If nil, we were cancelled

return nil;

}

{

ASDN::MutexLocker l(cacheLock);

return [cache setObject:contents forKey:key];

}

}

+ (UIImage *)createContentsForkey:(ASImageNodeContentsKey *)key isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled

{

// The following `UIGraphicsBeginImageContextWithOptions` call will sometimes take take longer than 5ms on an

// A5 processor for a 400x800 backingSize.

// Check for cancellation before we call it.

if (isCancelled()) {

return nil;

}

// Use contentsScale of 1.0 and do the contentsScale handling in boundsSizeInPixels so ASCroppedImageBackingSizeAndDrawRectInBounds

// will do its rounding on pixel instead of point boundaries

UIGraphicsBeginImageContextWithOptions(key.backingSize, key.isOpaque, 1.0);

BOOL contextIsClean = YES;

CGContextRef context = UIGraphicsGetCurrentContext();

if (context && key.preContextBlock) {

key.preContextBlock(context);

contextIsClean = NO;

}

// if view is opaque, fill the context with background color

if (key.isOpaque && key.backgroundColor) {

[key.backgroundColor setFill];

UIRectFill({ .size = key.backingSize });

contextIsClean = NO;

}

// iOS 9 appears to contain a thread safety regression when drawing the same CGImageRef on

// multiple threads concurrently. In fact, instead of crashing, it appears to deadlock.

// The issue is present in Mac OS X El Capitan and has been seen hanging Pro apps like Adobe Premiere,

// as well as iOS games, and a small number of ASDK apps that provide the same image reference

// to many separate ASImageNodes. A workaround is to set .displaysAsynchronously = NO for the nodes

// that may get the same pointer for a given UI asset image, etc.

// FIXME: We should replace @synchronized here, probably using a global, locked NSMutableSet, and

// only if the object already exists in the set we should create a semaphore to signal waiting threads

// upon removal of the object from the set when the operation completes.

// Another option is to have ASDisplayNode+AsyncDisplay coordinate these cases, and share the decoded buffer.

// Details tracked in https://github.com/facebook/AsyncDisplayKit/issues/1068

UIImage *image = key.image;

BOOL canUseCopy = (contextIsClean || ASImageAlphaInfoIsOpaque(CGImageGetAlphaInfo(image.CGImage)));

CGBlendMode blendMode = canUseCopy ? kCGBlendModeCopy : kCGBlendModeNormal;

@synchronized(image) {

[image drawInRect:key.imageDrawRect blendMode:blendMode alpha:1];

}

if (context && key.postContextBlock) {

key.postContextBlock(context);

}

// The following `UIGraphicsGetImageFromCurrentImageContext` call will commonly take more than 20ms on an

// A5 processor. Check for cancellation before we call it.

if (isCancelled()) {

UIGraphicsEndImageContext();

return nil;

}

UIImage *result = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

if (key.imageModificationBlock != NULL) {

result = key.imageModificationBlock(result);

}

return result;

}

- (void)displayDidFinish

{

[super displayDidFinish];

__instanceLock__.lock();

void (^displayCompletionBlock)(BOOL canceled) = _displayCompletionBlock;

UIImage *image = _image;

__instanceLock__.unlock();

// If we've got a block to perform after displaying, do it.

if (image && displayCompletionBlock) {

displayCompletionBlock(NO);

__instanceLock__.lock();

_displayCompletionBlock = nil;

__instanceLock__.unlock();

}

}

- (void)setNeedsDisplayWithCompletion:(void (^ _Nullable)(BOOL canceled))displayCompletionBlock

{

if (self.displaySuspended) {

if (displayCompletionBlock)

displayCompletionBlock(YES);

return;

}

// Stash the block and call-site queue. We'll invoke it in -displayDidFinish.

ASDN::MutexLocker l(__instanceLock__);

if (_displayCompletionBlock != displayCompletionBlock) {

_displayCompletionBlock = [displayCompletionBlock copy];

}

[self setNeedsDisplay];

}

#pragma mark Interface State

- (void)clearContents

{

[super clearContents];

_weakCacheEntry = nil; // release contents from the cache.

}

#pragma mark - Cropping

- (BOOL)isCropEnabled

{

ASDN::MutexLocker l(__instanceLock__);

return _cropEnabled;

}

- (void)setCropEnabled:(BOOL)cropEnabled

{

[self setCropEnabled:cropEnabled recropImmediately:NO inBounds:self.bounds];

}

- (void)setCropEnabled:(BOOL)cropEnabled recropImmediately:(BOOL)recropImmediately inBounds:(CGRect)cropBounds

{

ASDN::MutexLocker l(__instanceLock__);

if (_cropEnabled == cropEnabled)

return;

_cropEnabled = cropEnabled;

_cropDisplayBounds = cropBounds;

// If we have an image to display, display it, respecting our recrop flag.

if (self.image)

{

ASPerformBlockOnMainThread(^{

if (recropImmediately)

[self displayImmediately];

else

[self setNeedsDisplay];

});

}

}

- (CGRect)cropRect

{

ASDN::MutexLocker l(__instanceLock__);

return _cropRect;

}

- (void)setCropRect:(CGRect)cropRect

{

ASDN::MutexLocker l(__instanceLock__);

if (CGRectEqualToRect(_cropRect, cropRect))

return;

_cropRect = cropRect;

// TODO: this logic needs to be updated to respect cropRect.

CGSize boundsSize = self.bounds.size;

CGSize imageSize = self.image.size;

BOOL isCroppingImage = ((boundsSize.width < imageSize.width) || (boundsSize.height < imageSize.height));

// Re-display if we need to.

ASPerformBlockOnMainThread(^{

if (self.nodeLoaded && self.contentMode == UIViewContentModeScaleAspectFill && isCroppingImage)

[self setNeedsDisplay];

});

}

- (BOOL)forceUpscaling

{

ASDN::MutexLocker l(__instanceLock__);

return _forceUpscaling;

}

- (void)setForceUpscaling:(BOOL)forceUpscaling

{

ASDN::MutexLocker l(__instanceLock__);

_forceUpscaling = forceUpscaling;

}

- (CGSize)forcedSize

{

ASDN::MutexLocker l(__instanceLock__);

return _forcedSize;

}

- (void)setForcedSize:(CGSize)forcedSize

{

ASDN::MutexLocker l(__instanceLock__);

_forcedSize = forcedSize;

}

- (asimagenode_modification_block_t)imageModificationBlock

{

ASDN::MutexLocker l(__instanceLock__);

return _imageModificationBlock;

}

- (void)setImageModificationBlock:(asimagenode_modification_block_t)imageModificationBlock

{

ASDN::MutexLocker l(__instanceLock__);

_imageModificationBlock = imageModificationBlock;

}

#pragma mark - Debug

- (void)layout

{

[super layout];

if (_debugLabelNode) {

CGSize boundsSize = self.bounds.size;

CGSize debugLabelSize = [_debugLabelNode layoutThatFits:ASSizeRangeMake(CGSizeZero, boundsSize)].size;

CGPoint debugLabelOrigin = CGPointMake(boundsSize.width - debugLabelSize.width,

boundsSize.height - debugLabelSize.height);

_debugLabelNode.frame = (CGRect) {debugLabelOrigin, debugLabelSize};

}

}

#pragma mark - Extras

extern asimagenode_modification_block_t ASImageNodeRoundBorderModificationBlock(CGFloat borderWidth, UIColor *borderColor)

{

return ^(UIImage *originalImage) {

UIGraphicsBeginImageContextWithOptions(originalImage.size, NO, originalImage.scale);

UIBezierPath *roundOutline = [UIBezierPath bezierPathWithOvalInRect:(CGRect){CGPointZero, originalImage.size}];

// Make the image round

[roundOutline addClip];

// Draw the original image

[originalImage drawAtPoint:CGPointZero blendMode:kCGBlendModeCopy alpha:1];

// Draw a border on top.

if (borderWidth > 0.0) {

[borderColor setStroke];

[roundOutline setLineWidth:borderWidth];

[roundOutline stroke];

}

UIImage *modifiedImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return modifiedImage;

};

}

extern asimagenode_modification_block_t ASImageNodeTintColorModificationBlock(UIColor *color)

{

return ^(UIImage *originalImage) {

UIGraphicsBeginImageContextWithOptions(originalImage.size, NO, originalImage.scale);

// Set color and render template

[color setFill];

UIImage *templateImage = [originalImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];

[templateImage drawAtPoint:CGPointZero blendMode:kCGBlendModeCopy alpha:1];

UIImage *modifiedImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

// if the original image was stretchy, keep it stretchy

if (!UIEdgeInsetsEqualToEdgeInsets(originalImage.capInsets, UIEdgeInsetsZero)) {

modifiedImage = [modifiedImage resizableImageWithCapInsets:originalImage.capInsets resizingMode:originalImage.resizingMode];

}

return modifiedImage;

};

}