feat: Pass NS app to the native app instead of presenting it over the root VC (#5967)

* feat: Pass NS app native controller to the native app instead of presenting it over the rootViewController

When NativeScript embedded app is created from the native one we check for whether the topmost UIViewController has NativeScriptEmbedder protocol (implemented in the iOS Runtime) method 'presentNativeScriptApp:'. If yes, we call it with the NS app viewcontroller as a parameter so the embedder has control over the NS app (where and how to present it etc.) For backwards compatibility we present the NS app on top of the topmost UIViewController as a fallback.

* style: Fix lint errors

* feat: Check for protocol instead of selector in embedding

I

* Check for rootController instead of topViewController to prevent crash if !rootController

* feat: Introduce NativeScriptEmbedder singleton

NativeScriptEmbedder is responsive for communication between the NS and the native iOS app. His delegate will implement methods which we can call from javascript such as "presentNativeScriptApp:".

.gitignore

@@ -5,6 +5,7 @@ libs
 node_modules
 package
 platforms
+!tns-core-modules/platforms
 reports
 tags
 

tns-core-modules/application/application.ios.ts

@@ -131,16 +131,26 @@ class IOSApplication implements IOSApplicationDefinition {
         // TODO: Expose Window module so that it can we styled from XML & CSS
         this._window.backgroundColor = utils.ios.getter(UIColor, UIColor.whiteColor);
 
+        this.notifyAppStarted(notification);
+
+    }
+
+    public notifyAppStarted(notification?: NSNotification) {
         const args: LaunchEventData = {
             eventName: launchEvent,
             object: this,
-            ios: notification.userInfo && notification.userInfo.objectForKey("UIApplicationLaunchOptionsLocalNotificationKey") || null
+            ios: notification && notification.userInfo && notification.userInfo.objectForKey("UIApplicationLaunchOptionsLocalNotificationKey") || null
         };
 
         notify(args);
         notify(<LoadAppCSSEventData>{ eventName: "loadAppCss", object: <any>this, cssFile: getCssFileName() });
 
-        this.setWindowContent(args.root);
+        // this._window will be undefined when NS app is embedded in a native one
+        if (this._window) {
+            this.setWindowContent(args.root);
+        } else {
+            this._window = UIApplication.sharedApplication.delegate.window;
+        }   
     }
 
     @profile
@@ -235,6 +245,7 @@ class IOSApplication implements IOSApplicationDefinition {
             this._window.makeKeyAndVisible();
         }
     }
+
 }
 
 const iosApp = new IOSApplication();
@@ -296,7 +307,14 @@ export function start(entry?: string | NavigationEntry) {
                 if (rootController) {
                     const controller = getViewController(rootView);
                     rootView._setupAsRootView({});
-                    rootController.presentViewControllerAnimatedCompletion(controller, true, null);
+                    let embedderDelegate = NativeScriptEmbedder.sharedInstance().delegate;
+                    if (embedderDelegate) {
+                        embedderDelegate.performSelectorWithObject("presentNativeScriptApp:", controller);
+                    } else {
+                        let visibleVC = utils.ios.getVisibleViewController(rootController);
+                        visibleVC.presentViewControllerAnimatedCompletion(controller, true, null);
+                    }
+                    iosApp.notifyAppStarted();
                 }
             }
         }

tns-core-modules/platforms/README.md

@@ -0,0 +1 @@
+## Platform specific native code

tns-core-modules/platforms/ios/src/NativeScriptEmbedder.h

@@ -0,0 +1,26 @@
+//
+//  NativeScriptEmbedder.h
+//  NativeScript
+//
+//  Created by Teodor Dermendzhiev on 6/19/18.
+//
+#include <UIKit/UIKit.h>
+
+// When embedding NativeScript application embedder needs to conform to this protocol
+// in order to have control over the NativeScript UIViewController
+// otherwise NativeScript application is presented over the topmost UIViewController.
+@protocol NativeScriptEmbedderDelegate
+- (id)presentNativeScriptApp:(UIViewController*)vc;
+@end
+
+@interface NativeScriptEmbedder : NSObject
+
+@property(nonatomic, retain, readonly) id<NativeScriptEmbedderDelegate> delegate;
+
++ (NativeScriptEmbedder *)sharedInstance;
+
+- (void)setDelegate:(id <NativeScriptEmbedderDelegate>)aDelegate;
+
+
+@end
+

tns-core-modules/platforms/ios/src/NativeScriptEmbedder.m

@@ -0,0 +1,19 @@
+#import "NativeScriptEmbedder.h"
+
+@implementation NativeScriptEmbedder
+
++ (NativeScriptEmbedder *)sharedInstance {
+    static NativeScriptEmbedder *sharedInstance = nil;
+    static dispatch_once_t onceToken; 
+    dispatch_once(&onceToken, ^{
+        sharedInstance = [[NativeScriptEmbedder alloc] init];
+    });
+
+     return sharedInstance;
+}
+
+- (void)setDelegate:(id <NativeScriptEmbedderDelegate>)aDelegate {
+    _delegate = aDelegate;
+}
+
+@end

tns-core-modules/platforms/ios/src/module.modulemap

@@ -0,0 +1,4 @@
+module NativeScriptEmbedder {
+    header "NativeScriptEmbedder.h"
+    export *
+}

tns-core-modules/tns-core-modules.d.ts

@@ -160,3 +160,14 @@ interface Array<T> {
 //Dialogs
 declare function alert(message?: any): void;
 declare function confirm(message?: string): boolean;
+
+// Embedding
+declare interface NativeScriptEmbedderDelegate /* NSObject */ {
+    presentNativeScriptApp(any/* UIViewController*/): any;
+    performSelectorWithObject(string, any): any;
+}
+
+declare class NativeScriptEmbedder {
+    public static sharedInstance(): NativeScriptEmbedder;
+    public delegate: NativeScriptEmbedderDelegate;
+}

tns-core-modules/utils/utils.d.ts

@@ -247,6 +247,13 @@ export module ios {
      * iOS - this folder is read-only and contains the app and all its resources.
      */
     export function getCurrentAppPath(): string;
+
+    /**
+     * Gets the currently visible(topmost) UIViewController.
+     * @param rootViewController The root UIViewController instance to start searching from (normally window.rootViewController).
+     * Returns the visible UIViewController.
+     */
+    export function getVisibleViewController(rootViewController: any/* UIViewController*/ ): any/* UIViewController*/;
 }
 
 /**

tns-core-modules/utils/utils.ios.ts

@@ -116,6 +116,25 @@ export module ios {
 
         return NSString.stringWithString(NSString.pathWithComponents(<any>paths)).stringByStandardizingPath;
     }
+
+    export function getVisibleViewController(rootViewController: UIViewController): UIViewController {
+        if (rootViewController.presentedViewController) {
+            return getVisibleViewController(rootViewController.presentedViewController);
+        }
+
+        if (rootViewController.isKindOfClass(UINavigationController.class())) {
+            return getVisibleViewController((<UINavigationController>rootViewController).visibleViewController);
+        }
+
+        if (rootViewController.isKindOfClass(UITabBarController.class())) {
+            let selectedTab = (<UITabBarController>rootViewController).selectedViewController;
+            return getVisibleViewController(<UITabBarController>rootViewController);
+        }
+
+        return rootViewController;
+
+    }
+
 }
 
 export function GC() {