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

* Issue1176 attempt to fix UI lag success by re-using UIImage

* Now use NSMutableDictionary instead of single UIImage

* appearAnimation happen at init rather than setIcon

* Init NSMutableDictionary

* Remove reference to other app

Author: ericapply

lib/ios/AirGoogleMaps/AIRGoogleMapMarker.m

@@ -12,6 +12,7 @@
 #import "AIRGMSMarker.h"
 #import "AIRGoogleMapCallout.h"
 #import "DummyView.h"
+#import "GlobalVars.h"
 
 CGRect unionRect(CGRect a, CGRect b) {
   return CGRectMake(
@@ -36,6 +37,7 @@ - (instancetype)init
   if ((self = [super init])) {
     _realMarker = [[AIRGMSMarker alloc] init];
     _realMarker.fakeMarker = self;
+    _realMarker.appearAnimation = kGMSMarkerAnimationPop;
   }
   return self;
 }
@@ -92,6 +94,18 @@ - (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;
 
@@ -188,70 +202,8 @@ - (void)setOpacity:(double)opacity
 
 - (void)setImageSrc:(NSString *)imageSrc
 {
-  _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];
-                                                                 });
-                                                               }];
+  UIImage * image = [[GlobalVars sharedInstance] getSharedUIImage:imageSrc];
+  [self setIcon:image];
 }
 
 - (void)setTitle:(NSString *)title {

lib/ios/AirGoogleMaps/GlobalVars.h

@@ -0,0 +1,22 @@
+//
+//  GlobalVars.h
+//
+//  Created by Eric Kim on 2017-04-04.
+//  Copyright © 2017 Apply Digital. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+@interface GlobalVars : NSObject
+{
+  NSMutableDictionary *dict;
+}
+
++ (GlobalVars *)sharedInstance;
+
+- (UIImage *)getSharedUIImage:(NSString *)imageSrc;
+
+@property(strong, nonatomic, readwrite) NSMutableDictionary *dict;
+
+@end

lib/ios/AirGoogleMaps/GlobalVars.m

@@ -0,0 +1,54 @@
+//
+//  GlobalVars.m
+//
+//  Created by Eric Kim on 2017-04-04.
+//  Copyright © 2017 Apply Digital. All rights reserved.
+//
+
+#import "GlobalVars.h"
+
+@implementation GlobalVars
+
+@synthesize dict = _dict;
+
++ (GlobalVars *)sharedInstance {
+  static dispatch_once_t onceToken;
+  static GlobalVars *instance = nil;
+  dispatch_once(&onceToken, ^{
+    instance = [[GlobalVars alloc] init];
+  });
+  return instance;
+}
+
+- (UIImage *)getSharedUIImage:(NSString *)imageSrc {
+  
+  UIImage* cachedImage = dict[imageSrc];
+  
+  CGImageRef cgref = [cachedImage CGImage];
+  CIImage *cim = [cachedImage CIImage];
+  
+  if (cim == nil && cgref == NULL) {
+    UIImage *newImage;
+    if ([imageSrc hasPrefix:@"http://"] || [imageSrc hasPrefix:@"https://"]){
+      NSURL *url = [NSURL URLWithString:imageSrc];
+      NSData *data = [NSData dataWithContentsOfURL:url];
+      newImage = [UIImage imageWithData:data scale:[UIScreen mainScreen].scale];
+    } else {
+      newImage = [UIImage imageWithContentsOfFile:imageSrc];
+    }
+    dict[imageSrc] = newImage;
+    return newImage;
+  } else {
+    return cachedImage;
+  }
+}
+
+- (id)init {
+  self = [super init];
+  if (self) {
+    dict = [[NSMutableDictionary alloc] init];
+  }
+  return self;
+}
+
+@end