Fetch images for ContentSuggestions

ios/chrome/browser/ui/content_suggestions/content_suggestions_article_item.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 "ios/chrome/browser/ui/content_suggestions/content_suggestions_article_item.h"
 
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 const CGFloat kImageSize = 100;
 const CGFloat kStandardSpacing = 8;
 }
 
 @interface ContentSuggestionsArticleItem ()
 
 @property(nonatomic, copy) NSString* subtitle;
+@property(nonatomic, weak) id<ContentSuggestionsArticleItemDelegate> delegate;
 
 @end
 
 #pragma mark - ContentSuggestionsArticleItem
 
 @implementation ContentSuggestionsArticleItem
 
 @synthesize title = _title;
 @synthesize subtitle = _subtitle;
 @synthesize image = _image;
 @synthesize articleURL = _articleURL;
 @synthesize suggestionID = _suggestionID;
+@synthesize delegate = _delegate;
+@synthesize imageBeingFetched = _imageBeingFetched;
 
 - (instancetype)initWithType:(NSInteger)type
                        title:(NSString*)title
                     subtitle:(NSString*)subtitle
-                       image:(UIImage*)image
+                    delegate:(id<ContentSuggestionsArticleItemDelegate>)delegate
                          url:(const GURL&)url {
   self = [super initWithType:type];
   if (self) {
     self.cellClass = [ContentSuggestionsArticleCell class];
     _title = [title copy];
     _subtitle = [subtitle copy];
-    _image = image;
     _articleURL = url;
+    _delegate = delegate;
   }
   return self;
 }
 
 - (void)configureCell:(ContentSuggestionsArticleCell*)cell {
   [super configureCell:cell];
+  if (!self.image && !self.imageBeingFetched) {
+    self.imageBeingFetched = YES;

[marq (ping after 24h), 2017/02/21 11:27:08]

I think it would be better to set this to YES in the delegate method for a
couple of reasons.

- It will be close to where it is set to NO, so it's easy to verify.

- If the delegate is nil, then it is never set to YES (because it isn't being
fetched).

That does mean that it's up to the delegate to maintain the state of this
variable; that should probably be documented in the header.

[gambard, 2017/02/21 15:07:53]

Done.

+    [self.delegate loadImageForArticleItem:self];
+  }
   cell.titleLabel.text = _title;
   cell.subtitleLabel.text = _subtitle;
   cell.imageView.image = _image;
 }
 
 @end
 
 #pragma mark - ContentSuggestionsArticleCell
 
 @implementation ContentSuggestionsArticleCell
@@ skipping 58 matching lines @@
   // changes, for instance on screen rotation.
   CGFloat parentWidth = CGRectGetWidth(self.contentView.bounds);
   self.subtitleLabel.preferredMaxLayoutWidth = parentWidth - kImageSize - 3 * 8;
 
   // Re-layout with the new preferred width to allow the label to adjust its
   // height.
   [super layoutSubviews];
 }
 
 @end