Fix transparent topBar background color transition (#5317)

lib/ios/RNNNavigationController.m

 
 const NSInteger TOP_BAR_TRANSPARENT_TAG = 78264803;
 
-@interface RNNNavigationController()
-
-@property (nonatomic, strong) NSMutableDictionary* originalTopBarImages;
-
-@end
-
 @implementation RNNNavigationController
 
 - (void)viewDidLayoutSubviews {
 }
 
 - (CGFloat)getTopBarHeight {
-    return self.navigationBar.frame.size.height;
+	return self.navigationBar.frame.size.height;
 }
 
 - (UIInterfaceOrientationMask)supportedInterfaceOrientations {
 		
 		if (bgColorAlpha == 0.0) {
 			if (![self.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG]){
-				[self storeOriginalTopBarImages:self];
 				UIView *transparentView = [[UIView alloc] initWithFrame:CGRectZero];
 				transparentView.backgroundColor = [UIColor clearColor];
 				transparentView.tag = TOP_BAR_TRANSPARENT_TAG;
 			UIView *transparentView = [self.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG];
 			if (transparentView){
 				[transparentView removeFromSuperview];
-				[self.navigationBar setBackgroundImage:self.originalTopBarImages[@"backgroundImage"] forBarMetrics:UIBarMetricsDefault];
-				self.navigationBar.shadowImage = self.originalTopBarImages[@"shadowImage"];
-				self.originalTopBarImages = nil;
 			}
 		}
 	} else {
 		UIView *transparentView = [self.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG];
 		if (transparentView){
 			[transparentView removeFromSuperview];
-			[self.navigationBar setBackgroundImage:self.originalTopBarImages[@"backgroundImage"] ? self.originalTopBarImages[@"backgroundImage"] : [self.navigationBar backgroundImageForBarMetrics:UIBarMetricsDefault] forBarMetrics:UIBarMetricsDefault];
-			self.navigationBar.shadowImage = self.originalTopBarImages[@"shadowImage"] ? self.originalTopBarImages[@"shadowImage"] : self.navigationBar.shadowImage;
-			self.originalTopBarImages = nil;
 		}
 		
 		self.navigationBar.barTintColor = nil;
 	}
 }
 
-- (void)storeOriginalTopBarImages:(UINavigationController *)navigationController {
-	NSMutableDictionary *originalTopBarImages = [@{} mutableCopy];
-	UIImage *bgImage = [navigationController.navigationBar backgroundImageForBarMetrics:UIBarMetricsDefault];
-	if (bgImage != nil) {
-		originalTopBarImages[@"backgroundImage"] = bgImage;
-	}
-	UIImage *shadowImage = navigationController.navigationBar.shadowImage;
-	if (shadowImage != nil) {
-		originalTopBarImages[@"shadowImage"] = shadowImage;
-	}
-	self.originalTopBarImages = originalTopBarImages;
-}
-
-
 @end

lib/ios/ReactNativeNavigationTests/RNNNavigationControllerTest.m

 	[(id)self.uut.options verify];
 }
 
+- (void)testSetTopBarBackgroundColor_ShouldSetBackgroundColor {
+	UIColor* color = UIColor.redColor;
+	[self.uut setTopBarBackgroundColor:color];
+	XCTAssertEqual(self.uut.navigationBar.barTintColor, color);
+}
+
+- (void)testSetTopBarBackgroundColor_ShouldSetTransparentBackgroundColor {
+	UIColor* transparentColor = UIColor.clearColor;
+	[self.uut setTopBarBackgroundColor:transparentColor];
+
+	XCTAssertEqual(self.uut.navigationBar.backgroundColor, transparentColor);
+	XCTAssertTrue(self.uut.navigationBar.translucent);
+	XCTAssertNotNil(self.uut.navigationBar.shadowImage);
+	XCTAssertNotNil([self.uut.navigationBar backgroundImageForBarMetrics:UIBarMetricsDefault]);
+}
+
+- (void)testSetTopBarBackgroundColor_ShouldRemoveTransparentView {
+	UIColor* transparentColor = UIColor.clearColor;
+	UIColor* redColor = UIColor.redColor;
+	
+	[self.uut setTopBarBackgroundColor:transparentColor];
+	XCTAssertNotNil([self.uut.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG]);
+	[self.uut setTopBarBackgroundColor:redColor];
+	XCTAssertNil([self.uut.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG]);
+}
+
+- (void)testSetTopBarBackgroundColor_NilColorShouldResetNavigationBar {
+	UIColor* transparentColor = UIColor.clearColor;
+	UIColor* redColor = UIColor.redColor;
+	
+	[self.uut setTopBarBackgroundColor:transparentColor];
+	[self.uut setTopBarBackgroundColor:redColor];
+	[self.uut setTopBarBackgroundColor:nil];
+	
+	XCTAssertNil([self.uut.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG]);
+	XCTAssertNil(self.uut.navigationBar.barTintColor);
+}
+
 - (RNNNavigationController *)createNavigationControllerWithOptions:(RNNNavigationOptions *)options {
 	RNNNavigationController* nav = [[RNNNavigationController alloc] initWithLayoutInfo:nil creator:_creator options:options defaultOptions:nil presenter:[[RNNNavigationControllerPresenter alloc] init] eventEmitter:nil childViewControllers:@[_vc1]];
 	return nav;