Fixed display of alerts on top of modal window

Reviewed By: javache

Differential Revision: D2616170

fb-gh-sync-id: f72f728008099fff6fc966d7a2ce4c0d27a4fefd

React/Base/RCTUtils.h

@@ -58,6 +58,10 @@ RCT_EXTERN BOOL RCTRunningInAppExtension(void);
 // Returns the shared UIApplication instance, or nil if running in an App Extension
 RCT_EXTERN UIApplication *RCTSharedApplication(void);
 
+// Returns the current main window, useful if you need to access the root view
+// or view controller, e.g. to present a modal view controller or alert.
+RCT_EXTERN UIWindow *RCTKeyWindow(void);
+
 // Return a UIAlertView initialized with the given values
 // or nil if running in an app extension
 RCT_EXTERN UIAlertView *RCTAlertView(NSString *title,

React/Base/RCTUtils.m

@@ -342,26 +342,35 @@ BOOL RCTRunningInAppExtension(void)
   return [[[[NSBundle mainBundle] bundlePath] pathExtension] isEqualToString:@"appex"];
 }
 
-id RCTSharedApplication(void)
+UIApplication *RCTSharedApplication(void)
 {
   if (RCTRunningInAppExtension()) {
     return nil;
   }
-  
   return [[UIApplication class] performSelector:@selector(sharedApplication)];
 }
 
-id RCTAlertView(NSString *title,
-                NSString *message,
-                id delegate,
-                NSString *cancelButtonTitle,
-                NSArray<NSString *> *otherButtonTitles)
+UIWindow *RCTKeyWindow(void)
+{
+  if (RCTRunningInAppExtension()) {
+    return nil;
+  }
+
+  // TODO: replace with a more robust solution
+  return RCTSharedApplication().keyWindow;
+}
+
+UIAlertView *RCTAlertView(NSString *title,
+                          NSString *message,
+                          id delegate,
+                          NSString *cancelButtonTitle,
+                          NSArray<NSString *> *otherButtonTitles)
 {
   if (RCTRunningInAppExtension()) {
     RCTLogError(@"RCTAlertView is unavailable when running in an app extension");
     return nil;
   }
-  
+
   UIAlertView *alertView = [UIAlertView new];
   alertView.title = title;
   alertView.message = message;

React/Modules/RCTAlertManager.m

@@ -89,7 +89,7 @@ RCT_EXPORT_METHOD(alertWithArgs:(NSDictionary *)args
     return;
   }
 
-  UIViewController *presentingController = RCTSharedApplication().delegate.window.rootViewController;
+  UIViewController *presentingController = RCTKeyWindow().rootViewController;
   if (presentingController == nil) {
     RCTLogError(@"Tried to display alert view but there is no application window. args: %@", args);
     return;

React/Modules/RCTDevMenu.m

@@ -454,7 +454,7 @@ RCT_EXPORT_METHOD(show)
   actionSheet.cancelButtonIndex = actionSheet.numberOfButtons - 1;
 
   actionSheet.actionSheetStyle = UIBarStyleBlack;
-  [actionSheet showInView:RCTSharedApplication().keyWindow.rootViewController.view];
+  [actionSheet showInView:RCTKeyWindow().rootViewController.view];
   _actionSheet = actionSheet;
   _presentedItems = items;
 }