[CRD iOS] Add the host setup instruction page

remoting/ios/app/host_setup_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/host_setup_view_controller.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 "remoting/ios/app/host_setup_footer_view.h"
+#import "remoting/ios/app/host_setup_header_view.h"
+#import "remoting/ios/app/host_setup_view_cell.h"
+#import "remoting/ios/app/remoting_theme.h"
+
+static NSString* const kReusableIdentifierItem = @"remotingSetupStepVCItem";
+
+// TODO(yuweih): i18n
+// Clang doesn't allow string literal concatenation in string array but
+// `git cl format` will break down long lines into multiple string literals.
+// This is to disable the warning until we move these to a better place.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wobjc-string-concatenation"
+static NSArray<NSString*>* const kSetupSteps = @[
+  @"Go to the computer that you want to remotely access",
+  @"Visit google.com/remotedesktop from your Chrome browser",
+  @"Install the Chrome Remote Desktop software and follow the instructions to "
+   "complete the setup",
+  @"After your remote device is setup, you can access it directly from this "
+   "page",
+];
+#pragma clang diagnostic pop
+
+static const CGFloat kHeaderHeight = 80.f;
+static const CGFloat kFooterHeight = 80.f;
+
+@implementation HostSetupViewController
+
+@synthesize scrollViewDelegate = _scrollViewDelegate;
+
+- (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout*)layout {
+  self = [super initWithCollectionViewLayout:layout];
+  if (self) {
+    self.collectionView.backgroundColor = UIColor.clearColor;
+    [self.collectionView registerClass:[HostSetupViewCell class]
+            forCellWithReuseIdentifier:kReusableIdentifierItem];
+
+    [self.collectionView registerClass:[HostSetupHeaderView class]
+            forSupplementaryViewOfKind:UICollectionElementKindSectionHeader
+                   withReuseIdentifier:UICollectionElementKindSectionHeader];
+
+    [self.collectionView registerClass:[HostSetupFooterView class]
+            forSupplementaryViewOfKind:UICollectionElementKindSectionFooter
+                   withReuseIdentifier:UICollectionElementKindSectionFooter];
+  }
+  return self;
+}
+
+#pragma mark - UIViewController
+
+- (void)viewDidLoad {
+  [super viewDidLoad];
+  self.styler.cellStyle = MDCCollectionViewCellStyleGrouped;
+  self.styler.cellLayoutType = MDCCollectionViewCellLayoutTypeList;
+  self.styler.shouldHideSeparators = YES;
+}
+
+#pragma mark - UICollectionViewDataSource
+
+- (NSInteger)collectionView:(UICollectionView*)collectionView
+     numberOfItemsInSection:(NSInteger)section {
+  return kSetupSteps.count;
+}
+
+- (UICollectionViewCell*)collectionView:(UICollectionView*)collectionView
+                 cellForItemAtIndexPath:(NSIndexPath*)indexPath {
+  HostSetupViewCell* cell = [collectionView
+      dequeueReusableCellWithReuseIdentifier:kReusableIdentifierItem
+                                forIndexPath:indexPath];
+  [cell setContentText:kSetupSteps[indexPath.item] number:indexPath.item + 1];
+  return cell;
+}
+
+- (UICollectionReusableView*)collectionView:(UICollectionView*)collectionView
+          viewForSupplementaryElementOfKind:(NSString*)kind
+                                atIndexPath:(NSIndexPath*)indexPath {
+  return [collectionView dequeueReusableSupplementaryViewOfKind:kind
+                                            withReuseIdentifier:kind
+                                                   forIndexPath:indexPath];
+}
+
+#pragma mark - MDCCollectionViewStylingDelegate
+
+- (CGFloat)collectionView:(UICollectionView*)collectionView
+    cellHeightAtIndexPath:(NSIndexPath*)indexPath {
+  return MDCCellDefaultThreeLineHeight;
+}
+
+#pragma mark - UICollectionViewDelegateFlowLayout
+
+- (CGSize)collectionView:(UICollectionView*)collectionView
+                             layout:
+                                 (UICollectionViewLayout*)collectionViewLayout
+    referenceSizeForHeaderInSection:(NSInteger)section {
+  return CGSizeMake(collectionView.bounds.size.width, kHeaderHeight);
+}
+
+- (CGSize)collectionView:(UICollectionView*)collectionView
+                             layout:
+                                 (UICollectionViewLayout*)collectionViewLayout
+    referenceSizeForFooterInSection:(NSInteger)section {
+  return CGSizeMake(collectionView.bounds.size.width, kFooterHeight);
+}
+
+#pragma mark - UIScrollViewDelegate
+
+- (void)scrollViewDidScroll:(UIScrollView*)scrollView {
+  [_scrollViewDelegate scrollViewDidScroll:scrollView];
+}
+
+@end