[CRD iOS] Add the host setup instruction page

remoting/ios/app/remoting_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/remoting_view_controller.h"
 
 #import "base/mac/bind_objc_block.h"
 #import "ios/third_party/material_components_ios/src/components/AnimationTiming/src/MaterialAnimationTiming.h"
 #import "ios/third_party/material_components_ios/src/components/AppBar/src/MaterialAppBar.h"
 #import "ios/third_party/material_components_ios/src/components/Dialogs/src/MaterialDialogs.h"
+#import "ios/third_party/material_components_ios/src/components/ShadowElevations/src/MaterialShadowElevations.h"
+#import "ios/third_party/material_components_ios/src/components/ShadowLayer/src/MaterialShadowLayer.h"
 #import "ios/third_party/material_components_ios/src/components/Snackbar/src/MaterialSnackbar.h"
 #import "remoting/ios/app/app_delegate.h"
 #import "remoting/ios/app/client_connection_view_controller.h"
 #import "remoting/ios/app/host_collection_view_controller.h"
+#import "remoting/ios/app/host_setup_view_controller.h"
 #import "remoting/ios/app/host_view_controller.h"
 #import "remoting/ios/app/remoting_menu_view_controller.h"
 #import "remoting/ios/app/remoting_theme.h"
 #import "remoting/ios/domain/client_session_details.h"
 #import "remoting/ios/facade/remoting_authentication.h"
 #import "remoting/ios/facade/remoting_service.h"
 
 #include "base/strings/sys_string_conversions.h"
 #include "remoting/base/oauth_token_getter.h"
 #include "remoting/client/connect_to_host_info.h"
 
 static CGFloat kHostInset = 5.f;
 
 @interface RemotingViewController ()<HostCollectionViewControllerDelegate,
                                      UIViewControllerAnimatedTransitioning,
                                      UIViewControllerTransitioningDelegate> {
   bool _isAuthenticated;
   MDCDialogTransitionController* _dialogTransitionController;
   MDCAppBar* _appBar;
   HostCollectionViewController* _collectionViewController;
+  HostSetupViewController* _setupViewController;
   RemotingService* _remotingService;
 }
 @end
 
 // TODO(nicholss): Localize this file.
 // TODO(nicholss): This file is not finished with integration, the app flow is
 // still pending development.
 
 @implementation RemotingViewController
 
 - (instancetype)init {
   _isAuthenticated = NO;
   UICollectionViewFlowLayout* layout =
       [[MDCCollectionViewFlowLayout alloc] init];
   layout.minimumInteritemSpacing = 0;
   CGFloat sectionInset = kHostInset * 2.f;
   [layout setSectionInset:UIEdgeInsetsMake(sectionInset, sectionInset,
                                            sectionInset, sectionInset)];
-  HostCollectionViewController* collectionVC = [
-      [HostCollectionViewController alloc] initWithCollectionViewLayout:layout];
-  self = [super initWithContentViewController:collectionVC];
+  self = [super init];
   if (self) {
     _remotingService = RemotingService.instance;
 
-    _collectionViewController = collectionVC;
-    _collectionViewController.flexHeaderContainerViewController = self;
+    _collectionViewController = [[HostCollectionViewController alloc]
+        initWithCollectionViewLayout:layout];
     _collectionViewController.delegate = self;
+    _collectionViewController.scrollViewDelegate = self.headerViewController;
+
+    _setupViewController = [[HostSetupViewController alloc] init];
+    _setupViewController.scrollViewDelegate = self.headerViewController;
 
     _appBar = [[MDCAppBar alloc] init];
     [self addChildViewController:_appBar.headerViewController];
 
-    self.navigationItem.title = @"Chrome Remote Desktop";
+    self.navigationItem.title = @"chrome remote desktop";
 
     UIBarButtonItem* menuButton =
         [[UIBarButtonItem alloc] initWithImage:RemotingTheme.menuIcon
                                          style:UIBarButtonItemStyleDone
                                         target:self
                                         action:@selector(didSelectMenu)];
     self.navigationItem.leftBarButtonItem = menuButton;
 
     UIBarButtonItem* refreshButton =
         [[UIBarButtonItem alloc] initWithImage:RemotingTheme.refreshIcon
                                          style:UIBarButtonItemStyleDone
                                         target:self
                                         action:@selector(didSelectRefresh)];
     self.navigationItem.rightBarButtonItem = refreshButton;
 
     _appBar.headerViewController.headerView.backgroundColor =
         RemotingTheme.hostListBackgroundColor;
     _appBar.navigationBar.backgroundColor =
         RemotingTheme.hostListBackgroundColor;
     MDCNavigationBarTextColorAccessibilityMutator* mutator =
         [[MDCNavigationBarTextColorAccessibilityMutator alloc] init];
     [mutator mutate:_appBar.navigationBar];
+
+    MDCFlexibleHeaderView* headerView = self.headerViewController.headerView;
+    headerView.backgroundColor = [UIColor clearColor];
+
+    // Use a custom shadow under the flexible header.
+    MDCShadowLayer* shadowLayer = [MDCShadowLayer layer];
+    [headerView setShadowLayer:shadowLayer
+        intensityDidChangeBlock:^(CALayer* layer, CGFloat intensity) {
+          CGFloat elevation = MDCShadowElevationAppBar * intensity;
+          [(MDCShadowLayer*)layer setElevation:elevation];
+        }];
   }
   return self;
 }
 
 #pragma mark - UIViewController
 
 - (void)viewDidLoad {
   [super viewDidLoad];
 
   UIImage* image = [UIImage imageNamed:@"Background"];
   UIImageView* imageView = [[UIImageView alloc] initWithImage:image];
   [self.view addSubview:imageView];
   [self.view sendSubviewToBack:imageView];
 
   imageView.translatesAutoresizingMaskIntoConstraints = NO;
   [NSLayoutConstraint activateConstraints:@[
     [[imageView widthAnchor]
         constraintGreaterThanOrEqualToAnchor:[self.view widthAnchor]],
     [[imageView heightAnchor]
         constraintGreaterThanOrEqualToAnchor:[self.view heightAnchor]],
   ]];
 
   [_appBar addSubviewsToParent];
 
   [[NSNotificationCenter defaultCenter]
       addObserver:self
-         selector:@selector(hostsDidUpdateNotification:)
-             name:kHostsDidUpdate
+         selector:@selector(hostListStateDidChangeNotification:)
+             name:kHostListStateDidChange
            object:nil];
   [[NSNotificationCenter defaultCenter]
       addObserver:self
          selector:@selector(userDidUpdateNotification:)
              name:kUserDidUpdate
            object:nil];
 }
 
 - (void)viewWillAppear:(BOOL)animated {
   [super viewWillAppear:animated];
@@ skipping 13 matching lines @@
     [_remotingService requestHostListFetch];
   }
 }
 
 - (UIStatusBarStyle)preferredStatusBarStyle {
   return UIStatusBarStyleLightContent;
 }
 
 #pragma mark - Remoting Service Notifications
 
-- (void)hostsDidUpdateNotification:(NSNotification*)notification {
-  [_collectionViewController.collectionView reloadData];
+- (void)hostListStateDidChangeNotification:(NSNotification*)notification {
+  [self refreshContent];
 }
 
 - (void)userDidUpdateNotification:(NSNotification*)notification {
   [self nowAuthenticated:_remotingService.authentication.user.isAuthenticated];
 }
 
 #pragma mark - RemotingAuthenticationDelegate
 
 - (void)nowAuthenticated:(BOOL)authenticated {
   if (authenticated) {
     MDCSnackbarMessage* message = [[MDCSnackbarMessage alloc] init];
     message.text = @"Logged In!";
     [MDCSnackbarManager showMessage:message];
   } else {
     MDCSnackbarMessage* message = [[MDCSnackbarMessage alloc] init];
     message.text = @"Not logged in.";
     [MDCSnackbarManager showMessage:message];
   }
   _isAuthenticated = authenticated;
-  [_collectionViewController.collectionView reloadData];
-}
-
-#pragma mark - RemotingHostListDelegate
-
-// TODO(nicholss): these need to be a stats change like "none, loading,
-// updated"...
-- (void)hostListUpdated {
-  [_collectionViewController.collectionView reloadData];
+  [self refreshContent];
 }
 
 #pragma mark - HostCollectionViewControllerDelegate
 
 - (void)didSelectCell:(HostCollectionViewCell*)cell
            completion:(void (^)())completionBlock {
   if (![cell.hostInfo isOnline]) {
     MDCSnackbarMessage* message = [[MDCSnackbarMessage alloc] init];
     message.text = @"Host is offline.";
     [MDCSnackbarManager showMessage:message];
@@ skipping 61 matching lines @@
 - (void)presentStatus {
   MDCSnackbarMessage* message = [[MDCSnackbarMessage alloc] init];
   if (_isAuthenticated) {
     message.text = [NSString
         stringWithFormat:@"Currently signed in as %@.",
                          _remotingService.authentication.user.userEmail];
     [MDCSnackbarManager showMessage:message];
   }
 }
 
+- (void)refreshContent {
+  if (_remotingService.hostListState == HostListStateNotFetched) {
+    self.contentViewController = nil;
+    return;
+  }
+
+  if (_remotingService.hostListState == HostListStateFetching) {
+    NSLog(@"Fetching host list... TODO: Show fetching UI here.");
+    return;
+  }
+
+  DCHECK(_remotingService.hostListState == HostListStateFetched);
+
+  if (_remotingService.hosts.count > 0) {
+    [_collectionViewController.collectionView reloadData];
+    self.headerViewController.headerView.trackingScrollView =
+        _collectionViewController.collectionView;
+    self.contentViewController = _collectionViewController;
+  } else {
+    self.contentViewController = _setupViewController;
+    self.headerViewController.headerView.trackingScrollView =
+        _setupViewController.collectionView;
+  }
+  self.contentViewController.view.frame = self.view.bounds;
+}
+
 @end