Add mainWindow property to app context.

Signal/src/AppDelegate.m

@@ -168,12 +168,12 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
         return YES;
     }
 
-    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
-
+    UIWindow *mainWindow = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
+    self.window = mainWindow;
+    CurrentAppContext().mainWindow = mainWindow;
     // Show the launch screen until the async database view registrations are complete.
-    self.window.rootViewController = [self loadingRootViewController];
-
-    [self.window makeKeyAndVisible];
+    mainWindow.rootViewController = [self loadingRootViewController];
+    [mainWindow makeKeyAndVisible];
 
     // performUpdateCheck must be invoked after Environment has been initialized because
     // upgrade process may depend on Environment.

Signal/src/UIApplication+OWS.swift

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 import Foundation
@@ -7,16 +7,19 @@ import Foundation
 extension UIApplication {
 
     var frontmostViewControllerIgnoringAlerts: UIViewController? {
-        return findFrontmostViewController(ignoringAlerts:true)
+        return findFrontmostViewController(ignoringAlerts: true)
     }
 
     var frontmostViewController: UIViewController? {
-        return findFrontmostViewController(ignoringAlerts:false)
+        return findFrontmostViewController(ignoringAlerts: false)
     }
 
     internal func findFrontmostViewController(ignoringAlerts: Bool) -> UIViewController? {
-        let window = UIApplication.shared.keyWindow
-        guard let viewController = window!.rootViewController else {
+        guard let window = CurrentAppContext().mainWindow else {
+            return nil
+        }
+        Logger.error("findFrontmostViewController: \(window)")
+        guard let viewController = window.rootViewController else {
             owsFail("\(self.logTag) in \(#function) Missing root view controller.")
             return nil
         }

Signal/src/util/MainAppContext.m

@@ -13,6 +13,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @implementation MainAppContext
 
+@synthesize mainWindow = _mainWindow;
+
 - (instancetype)init
 {
     self = [super init];
@@ -174,11 +176,6 @@ NS_ASSUME_NONNULL_BEGIN
     return UIApplication.sharedApplication.frontmostViewControllerIgnoringAlerts;
 }
 
-- (nullable UIView *)rootReferenceView
-{
-    return UIApplication.sharedApplication.keyWindow;
-}
-
 - (nullable UIAlertAction *)openSystemSettingsAction
 {
     return [UIAlertAction actionWithTitle:CommonStrings.openSettingsButton

SignalServiceKit/src/Util/AppContext.h

@@ -29,8 +29,7 @@ typedef void (^BackgroundTaskExpirationHandler)(void);
 
 @property (nonatomic, readonly) BOOL isRunningTests;
 
-// Useful for translating coordinates to the "entire screen"
-@property (nonatomic, readonly, nullable) UIView *rootReferenceView;
+@property (atomic, nullable) UIWindow *mainWindow;
 
 // Should only be called if isMainApp is YES.
 //

SignalShareExtension/utils/ShareAppExtensionContext.m

@@ -19,6 +19,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @implementation ShareAppExtensionContext
 
+@synthesize mainWindow = _mainWindow;
+
 - (instancetype)initWithRootViewController:(UIViewController *)rootViewController
 {
     self = [super init];
@@ -172,11 +174,6 @@ NS_ASSUME_NONNULL_BEGIN
     return [self.rootViewController findFrontmostViewController:YES];
 }
 
-- (nullable UIView *)rootReferenceView
-{
-    return self.rootViewController.view;
-}
-
 - (nullable UIAlertAction *)openSystemSettingsAction
 {
     return nil;