react-native/Libraries/Image/RCTImageLoader.m

281 lines
10 KiB
Objective-C

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import "RCTImageLoader.h"
#import <AssetsLibrary/AssetsLibrary.h>
#import <Photos/PHAsset.h>
#import <Photos/PHFetchResult.h>
#import <Photos/PHImageManager.h>
#import <UIKit/UIKit.h>
#import "RCTBridge.h"
#import "RCTConvert.h"
#import "RCTDefines.h"
#import "RCTGIFImage.h"
#import "RCTImageDownloader.h"
#import "RCTImageStoreManager.h"
#import "RCTImageUtils.h"
#import "RCTLog.h"
#import "RCTUtils.h"
static void RCTDispatchCallbackOnMainQueue(void (^callback)(NSError *, id), NSError *error, UIImage *image)
{
if ([NSThread isMainThread]) {
callback(error, image);
} else {
dispatch_async(dispatch_get_main_queue(), ^{
callback(error, image);
});
}
}
static dispatch_queue_t RCTImageLoaderQueue(void)
{
static dispatch_queue_t queue = NULL;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
queue = dispatch_queue_create("com.facebook.rctImageLoader", DISPATCH_QUEUE_SERIAL);
});
return queue;
}
@implementation RCTImageLoader
{
ALAssetsLibrary *_assetsLibrary;
}
@synthesize bridge = _bridge;
RCT_EXPORT_MODULE()
- (RCTImageLoaderCancellationBlock)loadImageWithTag:(NSString *)imageTag
callback:(RCTImageLoaderCompletionBlock)callback
{
return [self loadImageWithTag:imageTag
size:CGSizeZero
scale:1
resizeMode:UIViewContentModeScaleToFill
progressBlock:nil
completionBlock:callback];
}
// Why use a custom scaling method? Greater efficiency, reduced memory overhead:
// http://www.mindsea.com/2012/12/downscaling-huge-alassets-without-fear-of-sigkill
static UIImage *RCTScaledImageForAsset(ALAssetRepresentation *representation,
CGSize size, CGFloat scale,
UIViewContentMode resizeMode,
NSError **error)
{
NSUInteger length = (NSUInteger)representation.size;
NSMutableData *data = [NSMutableData dataWithLength:length];
if (![representation getBytes:data.mutableBytes
fromOffset:0
length:length
error:error]) {
return nil;
}
CGSize sourceSize = representation.dimensions;
CGSize targetSize = RCTTargetSize(sourceSize, representation.scale,
size, scale, resizeMode, NO);
NSDictionary *options = @{
(id)kCGImageSourceShouldAllowFloat: @YES,
(id)kCGImageSourceCreateThumbnailWithTransform: @YES,
(id)kCGImageSourceCreateThumbnailFromImageAlways: @YES,
(id)kCGImageSourceThumbnailMaxPixelSize: @(MAX(targetSize.width, targetSize.height) * scale)
};
CGImageSourceRef sourceRef = CGImageSourceCreateWithData((__bridge CFDataRef)data, nil);
CGImageRef imageRef = CGImageSourceCreateThumbnailAtIndex(sourceRef, 0, (__bridge CFDictionaryRef)options);
if (sourceRef) {
CFRelease(sourceRef);
}
if (imageRef) {
UIImage *image = [UIImage imageWithCGImage:imageRef scale:scale
orientation:UIImageOrientationUp];
CGImageRelease(imageRef);
return image;
}
return nil;
}
- (ALAssetsLibrary *)assetsLibrary
{
if (!_assetsLibrary) {
_assetsLibrary = [[ALAssetsLibrary alloc] init];
}
return _assetsLibrary;
}
- (RCTImageLoaderCancellationBlock)loadImageWithTag:(NSString *)imageTag
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(UIViewContentMode)resizeMode
progressBlock:(RCTImageLoaderProgressBlock)progressBlock
completionBlock:(RCTImageLoaderCompletionBlock)completionBlock
{
if ([imageTag hasPrefix:@"assets-library://"]) {
[[self assetsLibrary] assetForURL:[RCTConvert NSURL:imageTag] resultBlock:^(ALAsset *asset) {
if (asset) {
// ALAssetLibrary API is async and will be multi-threaded. Loading a few full
// resolution images at once will spike the memory up to store the image data,
// and might trigger memory warnings and/or OOM crashes.
// To improve this, process the loaded asset in a serial queue.
dispatch_async(RCTImageLoaderQueue(), ^{
// Also make sure the image is released immediately after it's used so it
// doesn't spike the memory up during the process.
@autoreleasepool {
BOOL useMaximumSize = CGSizeEqualToSize(size, CGSizeZero);
ALAssetRepresentation *representation = [asset defaultRepresentation];
UIImage *image;
NSError *error = nil;
if (useMaximumSize) {
image = [UIImage imageWithCGImage:representation.fullResolutionImage
scale:scale
orientation:(UIImageOrientation)representation.orientation];
} else {
image = RCTScaledImageForAsset(representation, size, scale, resizeMode, &error);
}
RCTDispatchCallbackOnMainQueue(completionBlock, error, image);
}
});
} else {
NSString *errorText = [NSString stringWithFormat:@"Failed to load asset at URL %@ with no error message.", imageTag];
NSError *error = RCTErrorWithMessage(errorText);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
}
} failureBlock:^(NSError *loadError) {
NSString *errorText = [NSString stringWithFormat:@"Failed to load asset at URL %@.\niOS Error: %@", imageTag, loadError];
NSError *error = RCTErrorWithMessage(errorText);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
}];
return ^{};
} else if ([imageTag hasPrefix:@"ph://"]) {
// Using PhotoKit for iOS 8+
// The 'ph://' prefix is used by FBMediaKit to differentiate between
// assets-library. It is prepended to the local ID so that it is in the
// form of an, NSURL which is what assets-library uses.
NSString *phAssetID = [imageTag substringFromIndex:[@"ph://" length]];
PHFetchResult *results = [PHAsset fetchAssetsWithLocalIdentifiers:@[phAssetID] options:nil];
if (results.count == 0) {
NSString *errorText = [NSString stringWithFormat:@"Failed to fetch PHAsset with local identifier %@ with no error message.", phAssetID];
NSError *error = RCTErrorWithMessage(errorText);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
return ^{};
}
PHAsset *asset = [results firstObject];
PHImageRequestOptions *imageOptions = [[PHImageRequestOptions alloc] init];
BOOL useMaximumSize = CGSizeEqualToSize(size, CGSizeZero);
CGSize targetSize;
if ( useMaximumSize ){
targetSize = PHImageManagerMaximumSize;
imageOptions.resizeMode = PHImageRequestOptionsResizeModeNone;
} else {
targetSize = size;
imageOptions.resizeMode = PHImageRequestOptionsResizeModeFast;
}
PHImageContentMode contentMode = PHImageContentModeAspectFill;
if (resizeMode == UIViewContentModeScaleAspectFit) {
contentMode = PHImageContentModeAspectFit;
}
[[PHImageManager defaultManager] requestImageForAsset:asset targetSize:targetSize contentMode:contentMode options:imageOptions resultHandler:^(UIImage *result, NSDictionary *info) {
if (result) {
RCTDispatchCallbackOnMainQueue(completionBlock, nil, result);
} else {
NSString *errorText = [NSString stringWithFormat:@"Failed to load PHAsset with local identifier %@ with no error message.", phAssetID];
NSError *error = RCTErrorWithMessage(errorText);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
return;
}
}];
return ^{};
} else if ([imageTag hasPrefix:@"http"]) {
NSURL *url = [RCTConvert NSURL:imageTag];
if (!url) {
NSString *errorMessage = [NSString stringWithFormat:@"Invalid URL: %@", imageTag];
RCTDispatchCallbackOnMainQueue(completionBlock, RCTErrorWithMessage(errorMessage), nil);
return ^{};
}
return [_bridge.imageDownloader downloadImageForURL:url size:size scale:scale resizeMode:resizeMode progressBlock:progressBlock completionBlock:^(NSError *error, id image) {
RCTDispatchCallbackOnMainQueue(completionBlock, error, image);
}];
} else if ([imageTag hasPrefix:@"rct-image-store://"]) {
[_bridge.imageStoreManager getImageForTag:imageTag withBlock:^(UIImage *image) {
if (image) {
RCTDispatchCallbackOnMainQueue(completionBlock, nil, image);
} else {
NSString *errorMessage = [NSString stringWithFormat:@"Unable to load image from image store: %@", imageTag];
NSError *error = RCTErrorWithMessage(errorMessage);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
}
}];
return ^{};
} else if ([imageTag.lowercaseString hasSuffix:@".gif"]) {
id image = RCTGIFImageWithFileURL([RCTConvert NSURL:imageTag]);
if (image) {
RCTDispatchCallbackOnMainQueue(completionBlock, nil, image);
} else {
NSString *errorMessage = [NSString stringWithFormat:@"Unable to load GIF image: %@", imageTag];
NSError *error = RCTErrorWithMessage(errorMessage);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
}
return ^{};
} else {
UIImage *image = [RCTConvert UIImage:imageTag];
if (image) {
RCTDispatchCallbackOnMainQueue(completionBlock, nil, image);
} else {
NSString *errorMessage = [NSString stringWithFormat:@"Unrecognized tag protocol: %@", imageTag];
NSError *error = RCTErrorWithMessage(errorMessage);
RCTDispatchCallbackOnMainQueue(completionBlock, error, nil);
}
return ^{};
}
}
+ (BOOL)isAssetLibraryImage:(NSString *)imageTag
{
return [imageTag hasPrefix:@"assets-library://"] || [imageTag hasPrefix:@"ph://"];
}
+ (BOOL)isRemoteImage:(NSString *)imageTag
{
return [imageTag hasPrefix:@"http://"] || [imageTag hasPrefix:@"https://"];
}
@end
@implementation RCTBridge (RCTImageLoader)
- (RCTImageLoader *)imageLoader
{
return self.modules[RCTBridgeModuleNameForClass([RCTImageLoader class])];
}
- (ALAssetsLibrary *)assetsLibrary
{
return [self.imageLoader assetsLibrary];
}
@end