fixes https://github.com/ProjectSeptemberInc/gl-react-native/issues/142

example/ios/GLImage.m

+
+#import <React/RCTBridge.h>
+#import <React/RCTImageLoader.h>
+#import <React/RCTLog.h>
+#import <React/RCTUtils.h>
+#import "GLImage.h"
+#import "GLImageData.h"
+#import "GLTexture.h"
+
+@implementation GLImage
+{
+  RCTBridge *_bridge; // React's bridge allow to access the imageLoader
+  UIImage *_image; // The currently loaded image (nil if no image fully loaded yet)
+  GLImageData *_data; // Cache of the data related to this image (computed by getImageData)
+  GLTexture *_texture; // Cache of the texture
+  void (^_onload)(void); // called everytime an image loads
+  RCTImageLoaderCancellationBlock _loading; // the current loading cancellation function
+}
+
+- (instancetype)initWithBridge:(RCTBridge *)bridge withOnLoad:(void (^)(void))onload
+{
+  if ((self = [super init])) {
+    _bridge = bridge;
+    _onload = onload;
+    _image = nil;
+    _loading = nil;
+    _texture = [[GLTexture alloc] init];
+  }
+  return self;
+}
+
+- (void)dealloc
+{
+  [self clearImage];
+  if (_loading) _loading();
+  _onload = nil;
+  _loading = nil;
+  _bridge = nil;
+  _texture = nil;
+}
+
+RCT_NOT_IMPLEMENTED(-init)
+
+- (void) clearImage
+{
+  _image = nil;
+  _data = nil;
+}
+
+- (GLTexture *) getTexture
+{
+  if (_image) {
+    if (!_data) {
+        _data = [GLImageData genPixelsWithImage:_image];
+    }
+    [_texture setPixels:_data];
+  }
+  else {
+      [_texture setPixels:nil];
+  }
+  return _texture;
+}
+
+- (void)setSource:(RCTImageSource *)source
+{
+  if (![source isEqual:_source]) {
+    _source = source;
+    [self reloadImage];
+  }
+}
+
+- (void)reloadImage
+{
+  RCTImageSource *source = _source;
+  if (_loading) _loading();
+  _loading = nil;
+  if (!source) {
+    [self clearImage];
+  }
+  else {
+    // Load the image (without resizing it)
+    __weak GLImage *weakSelf = self;
+    _loading = [_bridge.imageLoader loadImageWithURLRequest:source.request
+                                       size:CGSizeZero
+                                      scale:0
+                                      clipped:YES
+                                 resizeMode:RCTResizeModeStretch
+                              progressBlock:nil
+                              partialLoadBlock:nil
+                            completionBlock:^(NSError *error, UIImage *loadedImage) {
+                              GLImage *strongSelf = weakSelf;
+                              void (^setImageBlock)(UIImage *) = ^(UIImage *image) {
+                                if (![source isEqual:strongSelf.source]) {
+                                  // Bail out if source has changed since we started loading
+                                  return;
+                                }
+                                strongSelf.image = [UIImage imageWithCGImage:image.CGImage];
+                                dispatch_async(dispatch_get_main_queue(), ^{
+                                  if (_onload) _onload();
+                                });
+                              };
+
+                              _loading = nil;
+                              [self clearImage];
+                              if (error) {
+                                NSLog(@"Image failed to load: %@", error);
+                              } else {
+                                if ([NSThread isMainThread]) {
+                                  setImageBlock(loadedImage);
+                                } else {
+                                  RCTUnsafeExecuteOnMainQueueSync(^{
+                                    setImageBlock(loadedImage);
+                                  });
+                                }
+                              }
+                            }];
+  }
+}
+
+
+@end