Add flutter-driven navigation on iOS (#3865)

shell/platform/darwin/ios/BUILD.gn

@@ -24,6 +24,7 @@ shared_library("flutter_framework_dylib") {
     "framework/Headers/FlutterMacros.h",
     "framework/Headers/FlutterPlugin.h",
     "framework/Headers/FlutterViewController.h",
+    "framework/Headers/FlutterNavigationController.h",
     "framework/Source/FlutterAppDelegate.mm",
     "framework/Source/FlutterChannels.mm",
     "framework/Source/FlutterCodecs.mm",
@@ -41,6 +42,7 @@ shared_library("flutter_framework_dylib") {
     "framework/Source/FlutterView.h",
     "framework/Source/FlutterView.mm",
     "framework/Source/FlutterViewController.mm",
+    "framework/Source/FlutterNavigationController.mm",
     "framework/Source/accessibility_bridge.h",
     "framework/Source/accessibility_bridge.mm",
     "framework/Source/flutter_main_ios.h",
@@ -165,6 +167,7 @@ copy("framework_headers") {
     "framework/Headers/FlutterMacros.h",
     "framework/Headers/FlutterPlugin.h",
     "framework/Headers/FlutterViewController.h",
+    "framework/Headers/FlutterNavigationController.h",
   ]
   outputs = [
     "$_flutter_framework_dir/Headers/{{source_file_part}}",

shell/platform/darwin/ios/framework/Headers/Flutter.h

@@ -13,5 +13,6 @@
 #include "FlutterMacros.h"
 #include "FlutterPlugin.h"
 #include "FlutterViewController.h"
+#include "FlutterNavigationController.h"
 
 #endif  // FLUTTER_FLUTTER_H_

shell/platform/darwin/ios/framework/Headers/FlutterNavigationController.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <UIKit/UIKit.h>
+
+@interface FlutterNavigationController: UINavigationController
+
+@end

shell/platform/darwin/ios/framework/Source/FlutterNavigationController.mm

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterNavigationController.h"
+
+@implementation FlutterNavigationController
+
+- (void) viewWillAppear:(BOOL)animated {
+  [self setNavigationBarHidden:YES];
+  [super viewWillAppear:animated];
+}
+
+@end

shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.mm

@@ -151,7 +151,13 @@ using namespace shell;
 }
 
 - (void)popSystemNavigator {
-  // Apple's human user guidelines say not to terminate iOS applications.
+  // Apple's human user guidelines say not to terminate iOS applications. However, if the
+  // root view of the app is a navigation controller, it is instructed to back up a level
+  // in the navigation hierarchy.
+  UIViewController* viewController = [UIApplication sharedApplication].keyWindow.rootViewController;
+  if ([viewController isKindOfClass:[UINavigationController class]]) {
+   [((UINavigationController*)viewController) popViewControllerAnimated:NO];
+  }
 }
 
 - (NSDictionary*)getClipboardData:(NSString*)format {

travis/licenses_golden/licenses_flutter

@@ -1458,9 +1458,11 @@ FILE: ../../../flutter/shell/platform/android/platform_view_android_jni.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterBinaryMessenger.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterChannels.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterCodecs.h
+FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterNavigationController.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterChannels.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterCodecs.mm
+FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterNavigationController.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterStandardCodec.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterStandardCodec_Internal.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/flutter_codecs_unittest.mm