Adding Sign-in promo for bookmark view.

ios/chrome/browser/ui/bookmarks/bookmark_folder_collection_view.mm

 // Copyright 2014 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 "ios/chrome/browser/ui/bookmarks/bookmark_folder_collection_view.h"
 
 #include "base/logging.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "ios/chrome/browser/bookmarks/bookmarks_utils.h"
 #include "ios/chrome/browser/experimental_flags.h"
+#import "ios/chrome/browser/ui/authentication/signin_promo_view.h"
+#import "ios/chrome/browser/ui/authentication/signin_promo_view_configurator.h"
+#import "ios/chrome/browser/ui/authentication/signin_promo_view_consumer.h"
+#import "ios/chrome/browser/ui/authentication/signin_promo_view_mediator.h"
 #import "ios/chrome/browser/ui/bookmarks/bookmark_collection_cells.h"
 #import "ios/chrome/browser/ui/bookmarks/bookmark_promo_cell.h"
+#import "ios/chrome/browser/ui/bookmarks/bookmark_signin_promo_cell.h"
 #import "ios/chrome/browser/ui/bookmarks/bookmark_utils_ios.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 using bookmarks::BookmarkNode;
 
-@interface BookmarkFolderCollectionView ()<BookmarkPromoCellDelegate> {
+@interface BookmarkFolderCollectionView ()<BookmarkPromoCellDelegate,
+                                           SigninPromoViewConsumer> {
   // A vector of folders to display in the collection view.
   std::vector<const BookmarkNode*> _subFolders;
   // A vector of bookmark urls to display in the collection view.
   std::vector<const BookmarkNode*> _subItems;
 
   // True if the promo is visible.
   BOOL _promoVisible;
+
+  // Mediator, helper for the sign-in promo view.
+  SigninPromoViewMediator* _signinPromoViewMediator;
 }
 @property(nonatomic, assign) const bookmarks::BookmarkNode* folder;
 
 // Section indices.
 @property(nonatomic, readonly, assign) NSInteger promoSection;
 @property(nonatomic, readonly, assign) NSInteger folderSection;
 @property(nonatomic, readonly, assign) NSInteger itemsSection;
 @property(nonatomic, readonly, assign) NSInteger sectionCount;
 
-// Keep a reference to the promo cell to deregister as delegate.
-@property(nonatomic, strong) BookmarkPromoCell* promoCell;
-
 @end
 
 @implementation BookmarkFolderCollectionView
 @synthesize delegate = _delegate;
 @synthesize folder = _folder;
-@synthesize promoCell = _promoCell;
 
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState
                                frame:(CGRect)frame {
   self = [super initWithBrowserState:browserState frame:frame];
   if (self) {
     [self updateCollectionView];
   }
   return self;
 }
 
-- (void)dealloc {
-  _promoCell.delegate = nil;
-}
-
 - (void)setDelegate:(id<BookmarkFolderCollectionViewDelegate>)delegate {
   _delegate = delegate;
   [self promoStateChangedAnimated:NO];
 }
 
 - (NSInteger)promoSection {
   return [self shouldShowPromoCell] ? 0 : -1;
 }
 
 - (NSInteger)folderSection {
@@ skipping 277 matching lines @@
   else if (section == self.itemsSection)
     insets.top = [self interitemSpacingForSectionAtIndex:section] / 2.;
   else if (section == self.promoSection)
     (void)0;  // No insets to update.
   else
     NOTREACHED();
   return insets;
 }
 
 // Parent class override.
+- (CGSize)cellSizeForIndexPath:(NSIndexPath*)indexPath {
+  if ([self isPromoSection:indexPath.section]) {
+    UICollectionViewCell* cell =
+        [self.collectionView cellForItemAtIndexPath:indexPath];
+    CGRect estimatedFrame =

[msarda, 2017/04/27 11:58:24]

I think this is not the estimated frame, but rather a frame that has fixed size
0, fixed width and very large height.
How about we rename it to cellFrameToComputeHeightThat or
fixedWidthMaxHeightFrame.

[jlebel, 2017/04/27 14:01:28]

Done.

+        CGRectMake(0, 0, CGRectGetWidth(self.bounds), CGFLOAT_MAX);
+    CGPoint originalPosition = CGPointZero;

[msarda, 2017/04/27 11:58:24]

Optional nit:
s/originalPosition/initialCellOrigin

[jlebel, 2017/04/27 14:01:28]

Done.

+    if (cell) {
+      originalPosition = cell.frame.origin;
+    } else {
+      // -[UICollectionView
+      // dequeueReusableCellWithReuseIdentifier:forIndexPath:] cannot be used
+      // here since this method is called by -[id<UICollectionViewDelegate>
+      // collectionView:layout:sizeForItemAtIndexPath:]. This would generate
+      // crash: SIGFPE, EXC_I386_DIV.
+      if (experimental_flags::IsSigninPromoEnabled()) {

[msarda, 2017/04/27 11:58:24]

I think this code would be easier to read if we have a function in anonymous
namespace that is called, that has a similar implementation to the one in
https://cs.chromium.org/chromium/src/ios/chrome/browser/ui/collection_view/ce...):
(CGFloat)PreferredHeightForWidth(UICollectionViewCell cell, width)

[jlebel, 2017/04/27 14:01:28]

Done.

+        DCHECK(_signinPromoViewMediator);
+        BookmarkSigninPromoCell* signinPromoCell =
+            [[BookmarkSigninPromoCell alloc] initWithFrame:estimatedFrame];
+        [[_signinPromoViewMediator createConfigurator]
+            configureSigninPromoView:signinPromoCell.signinPromoView];
+        cell = signinPromoCell;
+      } else {
+        cell = [[BookmarkPromoCell alloc] initWithFrame:estimatedFrame];
+      }
+    }
+    cell.frame = estimatedFrame;

[msarda, 2017/04/27 11:58:24]

Nit: Move this inside the if(cell) as on the else case the cell has the size set
to estimatedFrame

[jlebel, 2017/04/27 14:01:28]

Done.

+    [cell setNeedsLayout];
+    [cell layoutIfNeeded];
+    CGSize result =
+        [cell systemLayoutSizeFittingSize:UILayoutFittingCompressedSize
+            withHorizontalFittingPriority:UILayoutPriorityRequired
+                  verticalFittingPriority:UILayoutPriorityDefaultLow];
+    cell.frame = CGRectMake(originalPosition.x, originalPosition.y,
+                            result.width, result.height);
+    return result;
+  }
+  return [super cellSizeForIndexPath:indexPath];
+}
+
+// Parent class override.
 - (UICollectionViewCell*)cellAtIndexPath:(NSIndexPath*)indexPath {
   if (indexPath.section == self.promoSection) {
-    self.promoCell = [self.collectionView
-        dequeueReusableCellWithReuseIdentifier:[BookmarkPromoCell
-                                                   reuseIdentifier]
-                                  forIndexPath:indexPath];
-    self.promoCell.delegate = self;
-    return self.promoCell;
+    if (experimental_flags::IsSigninPromoEnabled()) {
+      BookmarkSigninPromoCell* signinPromoCell = [self.collectionView
+          dequeueReusableCellWithReuseIdentifier:[BookmarkSigninPromoCell
+                                                     reuseIdentifier]
+                                    forIndexPath:indexPath];
+      signinPromoCell.signinPromoView.sendChromeCommand = YES;
+      [[_signinPromoViewMediator createConfigurator]
+          configureSigninPromoView:signinPromoCell.signinPromoView];
+      return signinPromoCell;
+    } else {
+      BookmarkPromoCell* promoCell = [self.collectionView
+          dequeueReusableCellWithReuseIdentifier:[BookmarkPromoCell
+                                                     reuseIdentifier]
+                                    forIndexPath:indexPath];
+      promoCell.delegate = self;
+      return promoCell;
+    }
   }
   const BookmarkNode* node = [self nodeAtIndexPath:indexPath];
 
   if (indexPath.section == self.folderSection)
     return [self cellForFolder:node indexPath:indexPath];
 
   BookmarkItemCell* cell = [self cellForBookmark:node indexPath:indexPath];
   return cell;
 }
 
@@ skipping 61 matching lines @@
 - (void)promoStateChangedAnimated:(BOOL)animate {
   BOOL newPromoState =
       !self.editing && self.folder &&
       self.folder->type() == BookmarkNode::MOBILE &&
       [self.delegate bookmarkCollectionViewShouldShowPromoCell:self];
   if (newPromoState != _promoVisible) {
     // This is awful, but until the old code to do the refresh when switching
     // in and out of edit mode is fixed, this is probably the cleanest thing to
     // do.
     _promoVisible = newPromoState;
+    if (experimental_flags::IsSigninPromoEnabled()) {
+      if (!_promoVisible) {
+        _signinPromoViewMediator.consumer = nil;
+        _signinPromoViewMediator = nil;
+      } else {
+        _signinPromoViewMediator = [[SigninPromoViewMediator alloc] init];
+        _signinPromoViewMediator.consumer = self;
+      }
+    }
     [self.collectionView reloadData];
   }
 }
 
 #pragma mark - BookmarkPromoCellDelegate
 
 - (void)bookmarkPromoCellDidTapSignIn:(BookmarkPromoCell*)bookmarkPromoCell {
   [self.delegate bookmarkCollectionViewShowSignIn:self];
 }
 
 - (void)bookmarkPromoCellDidTapDismiss:(BookmarkPromoCell*)bookmarkPromoCell {
   [self.delegate bookmarkCollectionViewDismissPromo:self];
 }
 
 #pragma mark - Promo Cell
 
 - (BOOL)shouldShowPromoCell {
   return _promoVisible;
 }
 
+#pragma mark - SigninPromoViewConsumer
+
+- (void)configureSigninPromoViewWithNewIdentity:(BOOL)newIdentity
+                                   configurator:(SigninPromoViewConfigurator*)
+                                                    configurator {
+  DCHECK(_signinPromoViewMediator);
+  if (newIdentity) {
+    NSIndexSet* indexSet = [NSIndexSet indexSetWithIndex:self.promoSection];
+    [self.collectionView reloadSections:indexSet];
+    return;
+  }
+  NSIndexPath* indexPath =
+      [NSIndexPath indexPathForRow:0 inSection:self.promoSection];
+  UICollectionViewCell* cell =
+      [self.collectionView cellForItemAtIndexPath:indexPath];
+  BookmarkSigninPromoCell* signinPromoCell =
+      static_cast<BookmarkSigninPromoCell*>(cell);
+  if (!signinPromoCell)
+    return;
+  [configurator configureSigninPromoView:signinPromoCell.signinPromoView];
+}
+
 @end