react-native/Libraries/Image/RCTNetworkImageView.m

162 lines
4.8 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 "RCTNetworkImageView.h"
#import "RCTConvert.h"
#import "RCTGIFImage.h"
#import "RCTImageDownloader.h"
#import "RCTUtils.h"
#import "UIView+React.h"
@implementation RCTNetworkImageView
{
BOOL _deferred;
NSURL *_imageURL;
NSURL *_deferredImageURL;
NSUInteger _deferSentinel;
RCTImageDownloader *_imageDownloader;
id _downloadToken;
}
- (instancetype)initWithFrame:(CGRect)frame imageDownloader:(RCTImageDownloader *)imageDownloader
{
if ((self = [super initWithFrame:frame])) {
_deferSentinel = 0;
_imageDownloader = imageDownloader;
self.userInteractionEnabled = NO;
}
return self;
}
- (NSURL *)imageURL
{
// We clear our imageURL when we are not in a window for a while,
// to make sure we don't consume network resources while offscreen.
// However we don't want to expose this hackery externally.
return _deferred ? _deferredImageURL : _imageURL;
}
- (void)setBackgroundColor:(UIColor *)backgroundColor
{
super.backgroundColor = backgroundColor;
[self _updateImage];
}
- (void)reactSetFrame:(CGRect)frame
{
[super reactSetFrame:frame];
[self _updateImage];
}
- (void)_updateImage
{
[self setImageURL:_imageURL resetToDefaultImageWhileLoading:NO];
}
- (void)setImageURL:(NSURL *)imageURL resetToDefaultImageWhileLoading:(BOOL)reset
{
if (![_imageURL isEqual:imageURL] && _downloadToken) {
[_imageDownloader cancelDownload:_downloadToken];
_downloadToken = nil;
}
_imageURL = imageURL;
if (_deferred) {
_deferredImageURL = imageURL;
} else {
if (!imageURL) {
self.layer.contents = nil;
return;
}
if (reset) {
self.layer.contentsScale = _defaultImage.scale;
self.layer.contents = (__bridge id)_defaultImage.CGImage;
self.layer.minificationFilter = kCAFilterTrilinear;
self.layer.magnificationFilter = kCAFilterTrilinear;
}
if ([imageURL.pathExtension caseInsensitiveCompare:@"gif"] == NSOrderedSame) {
_downloadToken = [_imageDownloader downloadDataForURL:imageURL block:^(NSData *data, NSError *error) {
if (data) {
dispatch_async(dispatch_get_main_queue(), ^{
if (imageURL != self.imageURL) {
// Image has changed
return;
}
CAKeyframeAnimation *animation = RCTGIFImageWithData(data);
self.layer.contentsScale = 1.0;
self.layer.minificationFilter = kCAFilterLinear;
self.layer.magnificationFilter = kCAFilterLinear;
[self.layer addAnimation:animation forKey:@"contents"];
});
} else if (error) {
RCTLogWarn(@"Unable to download image data. Error: %@", error);
}
}];
} else {
_downloadToken = [_imageDownloader downloadImageForURL:imageURL size:self.bounds.size scale:RCTScreenScale() resizeMode:self.contentMode backgroundColor:self.backgroundColor block:^(UIImage *image, NSError *error) {
if (image) {
dispatch_async(dispatch_get_main_queue(), ^{
if (imageURL != self.imageURL) {
// Image has changed
return;
}
[self.layer removeAnimationForKey:@"contents"];
self.layer.contentsScale = image.scale;
self.layer.contents = (__bridge id)image.CGImage;
});
} else if (error) {
RCTLogWarn(@"Unable to download image. Error: %@", error);
}
}];
}
}
}
- (void)setImageURL:(NSURL *)imageURL
{
[self setImageURL:imageURL resetToDefaultImageWhileLoading:YES];
}
- (void)willMoveToWindow:(UIWindow *)newWindow
{
[super willMoveToWindow:newWindow];
if (newWindow != nil && _deferredImageURL) {
// Immediately exit deferred mode and restore the imageURL that we saved when we went offscreen.
[self setImageURL:_deferredImageURL resetToDefaultImageWhileLoading:YES];
_deferredImageURL = nil;
}
}
- (void)_enterDeferredModeIfNeededForSentinel:(NSUInteger)sentinel
{
if (self.window == nil && _deferSentinel == sentinel) {
_deferred = YES;
[_imageDownloader cancelDownload:_downloadToken];
_downloadToken = nil;
_deferredImageURL = _imageURL;
_imageURL = nil;
}
}
- (void)didMoveToWindow
{
[super didMoveToWindow];
if (self.window == nil) {
__weak RCTNetworkImageView *weakSelf = self;
NSUInteger sentinelAtDispatchTime = ++_deferSentinel;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC), dispatch_get_main_queue(), ^(void){
[weakSelf _enterDeferredModeIfNeededForSentinel:sentinelAtDispatchTime];
});
}
}
@end