[CRD iOS] Make the side menu help button work

This CL:

* Implements a WebViewController that automatically adds a close button
  to the nav bar when it's the first VC in the nav stack, and allow
  overriding the right nav button.
* Adds the Credits button to the help center VC.
* Makes the side menu's help button work.

Bug: 740240
Change-Id: I28436ada3ea1a9e588be0cedfc2e5b874c82d4d9
Reviewed-on: https://chromium-review.googlesource.com/572602Reviewed-by: Scott Nichols <nicholss@chromium.org>
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487248}

remoting/ios/app/BUILD.gn

@@ -56,6 +56,8 @@ source_set("common_source_set") {
     "side_menu_items.mm",
     "user_status_presenter.h",
     "user_status_presenter.mm",
+    "web_view_controller.h",
+    "web_view_controller.mm",
   ]
 
   deps = [

remoting/ios/app/app_delegate.h

@@ -23,6 +23,9 @@
 // controller.
 - (void)navigateToHelpCenter:(UINavigationController*)navigationController;
 
+// Presents the help center modally onto the topmost view controller.
+- (void)presentHelpCenter;
+
 // This will present the Send Feedback view controller onto the topmost view
 // controller.
 // context: a unique identifier for the user's place within the app which can be

remoting/ios/app/app_delegate.mm

@@ -8,8 +8,6 @@
 
 #import "remoting/ios/app/app_delegate.h"
 
-#import <WebKit/WebKit.h>
-
 #include "base/logging.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -19,6 +17,7 @@
 #import "remoting/ios/app/help_and_feedback.h"
 #import "remoting/ios/app/remoting_view_controller.h"
 #import "remoting/ios/app/user_status_presenter.h"
+#import "remoting/ios/app/web_view_controller.h"
 #import "remoting/ios/facade/remoting_oauth_authentication.h"
 
 @interface AppDelegate ()<FirstLaunchViewControllerDelegate> {
@@ -118,21 +117,32 @@ static NSString* const kFAQsUrl =
 #pragma mark - AppDelegate
 
 - (void)navigateToFAQs:(UINavigationController*)navigationController {
-  [self navigateToUrl:kFAQsUrl
-                     title:@"FAQs"
-      navigationController:navigationController];
+  WebViewController* viewController =
+      [[WebViewController alloc] initWithUrl:kFAQsUrl title:@"FAQs"];
+  [navigationController pushViewController:viewController animated:YES];
 }
 
 - (void)navigateToHelpCenter:(UINavigationController*)navigationController {
-  [self navigateToUrl:kHelpCenterUrl
-                     title:@"Help Center"
-      navigationController:navigationController];
+  [navigationController pushViewController:[self createHelpViewController]
+                                  animated:YES];
+}
+
+- (void)presentHelpCenter {
+  UINavigationController* navController = [[UINavigationController alloc]
+      initWithRootViewController:[self createHelpViewController]];
+  [AppDelegate.topPresentingVC presentViewController:navController
+                                            animated:YES
+                                          completion:nil];
 }
 
 - (void)presentFeedbackFlowWithContext:(NSString*)context {
   [HelpAndFeedback.instance presentFeedbackFlowWithContext:context];
 }
 
+- (void)emailSetupInstructions {
+  NSLog(@"TODO: emailSetupInstructions");
+}
+
 #pragma mark - FirstLaunchViewPresenterDelegate
 
 - (void)presentSignInFlow {
@@ -142,24 +152,31 @@ static NSString* const kFAQsUrl =
 
 #pragma mark - Private
 
-- (void)navigateToUrl:(NSString*)url
-                   title:(NSString*)title
-    navigationController:(UINavigationController*)navigationController {
-  UIViewController* viewController = [[UIViewController alloc] init];
-  viewController.title = title;
-
-  NSURLRequest* request =
-      [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
-  WKWebView* webView =
-      [[WKWebView alloc] initWithFrame:viewController.view.frame
-                         configuration:[[WKWebViewConfiguration alloc] init]];
-  [viewController.view addSubview:webView];
-  [navigationController pushViewController:viewController animated:YES];
-  [webView loadRequest:request];
+- (WebViewController*)createHelpViewController {
+  WebViewController* viewController =
+      [[WebViewController alloc] initWithUrl:kHelpCenterUrl
+                                       title:@"Help Center"];
+  viewController.navigationItem.rightBarButtonItem =
+      [[UIBarButtonItem alloc] initWithTitle:@"Credits"
+                                       style:UIBarButtonItemStylePlain
+                                      target:self
+                                      action:@selector(onTapCredits:)];
+  return viewController;
 }
 
-- (void)emailSetupInstructions {
-  NSLog(@"TODO: emailSetupInstructions");
+- (void)onTapCredits:(id)button {
+  NSLog(@"tap credits");
+}
+
++ (UIViewController*)topPresentingVC {
+  UIViewController* topController =
+      UIApplication.sharedApplication.keyWindow.rootViewController;
+
+  while (topController.presentedViewController) {
+    topController = topController.presentedViewController;
+  }
+
+  return topController;
 }
 
 @end

remoting/ios/app/side_menu_items.mm

@@ -59,7 +59,7 @@ static NSString* const kFeedbackContext = @"SideMenuFeedbackContext";
       [[SideMenuItem alloc] initWithTitle:@"Help"
                                      icon:RemotingTheme.helpIcon
                                    action:^{
-                                     NSLog(@"Tapped help");
+                                     [AppDelegate.instance presentHelpCenter];
                                    }],
     ] ];
   });

remoting/ios/app/web_view_controller.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.
+
+#ifndef REMOTING_IOS_APP_WEB_VIEW_CONTROLLER_H_
+#define REMOTING_IOS_APP_WEB_VIEW_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+// A simple VC for showing a web view for the given url. It will show a close
+// navigation button when it is the first VC in the navigation stack.
+@interface WebViewController : UIViewController
+
+- (instancetype)initWithUrl:(NSString*)url title:(NSString*)title;
+
+@end
+
+#endif  // REMOTING_IOS_APP_WEB_VIEW_CONTROLLER_H_

remoting/ios/app/web_view_controller.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.
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+#import "remoting/ios/app/web_view_controller.h"
+
+#import <WebKit/WebKit.h>
+
+#import "remoting/ios/app/remoting_theme.h"
+
+@interface WebViewController () {
+  NSString* _urlString;
+}
+@end
+
+@implementation WebViewController
+
+- (instancetype)initWithUrl:(NSString*)url title:(NSString*)title {
+  if (self = [super init]) {
+    _urlString = url;
+    self.title = title;
+  }
+  return self;
+}
+
+#pragma mark - UIViewController
+
+- (void)loadView {
+  WKWebView* webView =
+      [[WKWebView alloc] initWithFrame:CGRectZero
+                         configuration:[[WKWebViewConfiguration alloc] init]];
+  NSURLRequest* request =
+      [NSURLRequest requestWithURL:[NSURL URLWithString:_urlString]];
+  [webView loadRequest:request];
+  self.view = webView;
+}
+
+- (void)viewWillAppear:(BOOL)animated {
+  [super viewWillAppear:animated];
+
+  // Show a close button if it is the first view in the navigation stack.
+  UIViewController* firstViewController =
+      [self.navigationController.viewControllers firstObject];
+  if ((firstViewController == self ||
+       firstViewController == self.parentViewController) &&
+      !self.navigationItem.leftBarButtonItem &&
+      !self.navigationItem.leftBarButtonItems.count) {
+    self.navigationItem.leftBarButtonItem =
+        [[UIBarButtonItem alloc] initWithImage:RemotingTheme.closeIcon
+                                         style:UIBarButtonItemStylePlain
+                                        target:self
+                                        action:@selector(didTapClose:)];
+  }
+}
+
+#pragma mark - Private
+
+- (void)didTapClose:(id)button {
+  [self dismissViewControllerAnimated:YES completion:nil];
+}
+
+@end