Revert "Issue1176 improve ios marker performance by X100 (react-native-maps#1187)"

This reverts commit b908c08.

Author: christopherdro

lib/ios/AirGoogleMaps/AIRGoogleMapMarker.m

@@ -12,7 +12,6 @@
 #import "AIRGMSMarker.h"
 #import "AIRGoogleMapCallout.h"
 #import "DummyView.h"
-#import "GlobalVars.h"
 
 CGRect unionRect(CGRect a, CGRect b) {
   return CGRectMake(
@@ -37,7 +36,6 @@ - (instancetype)init
   if ((self = [super init])) {
     _realMarker = [[AIRGMSMarker alloc] init];
     _realMarker.fakeMarker = self;
-    _realMarker.appearAnimation = kGMSMarkerAnimationPop;
   }
   return self;
 }
@@ -94,18 +92,6 @@ - (void)insertReactSubview:(id<RCTComponent>)subview atIndex:(NSInteger)atIndex
   [super insertReactSubview:(UIView*)dummySubview atIndex:atIndex];
 }
 
-- (void)setIcon:(UIImage*)image {
-  CGImageRef cgref = [image CGImage];
-  CIImage *cim = [image CIImage];
-  
-  if (cim == nil && cgref == NULL) {
-    // image does not contain image data
-    _realMarker.icon = [GMSMarker markerImageWithColor:UIColor.blueColor];
-  } else {
-    _realMarker.icon = image;
-  }
-}
-
 - (void)removeReactSubview:(id<RCTComponent>)dummySubview {
   UIView* subview = ((DummyView*)dummySubview).view;
 
@@ -202,8 +188,70 @@ - (void)setOpacity:(double)opacity
 
 - (void)setImageSrc:(NSString *)imageSrc
 {
-  UIImage * image = [[GlobalVars sharedInstance] getSharedUIImage:imageSrc];
-  [self setIcon:image];
+  _imageSrc = imageSrc;
+
+  if (_reloadImageCancellationBlock) {
+    _reloadImageCancellationBlock();
+    _reloadImageCancellationBlock = nil;
+  }
+
+  if (!_imageSrc) {
+    if (_iconImageView) [_iconImageView removeFromSuperview];
+    return;
+  }
+
+  if (!_iconImageView) {
+    // prevent glitch with marker (cf. https://github.com/airbnb/react-native-maps/issues/738)
+    UIImageView *empyImageView = [[UIImageView alloc] init];
+    _iconImageView = empyImageView;
+    [self iconViewInsertSubview:_iconImageView atIndex:0];
+  }
+
+  _reloadImageCancellationBlock = [_bridge.imageLoader loadImageWithURLRequest:[RCTConvert NSURLRequest:_imageSrc]
+                                                                          size:self.bounds.size
+                                                                         scale:RCTScreenScale()
+                                                                       clipped:YES
+                                                                    resizeMode:RCTResizeModeCenter
+                                                                 progressBlock:nil
+                                                              partialLoadBlock:nil
+                                                               completionBlock:^(NSError *error, UIImage *image) {
+                                                                 if (error) {
+                                                                   // TODO(lmr): do something with the error?
+                                                                   NSLog(@"%@", error);
+                                                                 }
+                                                                 dispatch_async(dispatch_get_main_queue(), ^{
+
+                                                                   // TODO(gil): This way allows different image sizes
+                                                                   if (_iconImageView) [_iconImageView removeFromSuperview];
+
+                                                                   // ... but this way is more efficient?
+//                                                                   if (_iconImageView) {
+//                                                                     [_iconImageView setImage:image];
+//                                                                     return;
+//                                                                   }
+
+                                                                   UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
+
+                                                                   // TODO: w,h or pixel density could be a prop.
+                                                                   float density = 1;
+                                                                   float w = image.size.width/density;
+                                                                   float h = image.size.height/density;
+                                                                   CGRect bounds = CGRectMake(0, 0, w, h);
+
+                                                                   imageView.contentMode = UIViewContentModeScaleAspectFit;
+                                                                   [imageView setFrame:bounds];
+
+                                                                   // NOTE: sizeToFit doesn't work instead. Not sure why.
+                                                                   // TODO: Doing it this way is not ideal because it causes things to reshuffle
+                                                                   //       when the image loads IF the image is larger than the UIView.
+                                                                   //       Shouldn't required images have size info automatically via RN?
+                                                                   CGRect selfBounds = unionRect(bounds, self.bounds);
+                                                                   [self setFrame:selfBounds];
+
+                                                                   _iconImageView = imageView;
+                                                                   [self iconViewInsertSubview:imageView atIndex:0];
+                                                                 });
+                                                               }];
 }
 
 - (void)setTitle:(NSString *)title {