Upstream Chrome on iOS source code [7/11].

ios/chrome/browser/ui/reading_list/reading_list_menu_notifier.mm

Index: ios/chrome/browser/ui/reading_list/reading_list_menu_notifier.mm
diff --git a/ios/chrome/browser/ui/reading_list/reading_list_menu_notifier.mm b/ios/chrome/browser/ui/reading_list/reading_list_menu_notifier.mm
new file mode 100644
index 0000000000000000000000000000000000000000..47fb7a6eaf5fe1db25075d5bd81728d858ef273f
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+++ b/ios/chrome/browser/ui/reading_list/reading_list_menu_notifier.mm
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+// Copyright 2016 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/reading_list/reading_list_menu_notifier.h"
+
+#include <memory>
+
+#include "components/reading_list/ios/reading_list_model.h"
+#import "ios/chrome/browser/ui/reading_list/reading_list_menu_notification_delegate.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+class ReadingListObserverBridge;
+
+@interface ReadingListMenuNotifier () {
+  // Observer for reading list changes.
+  std::unique_ptr<ReadingListObserverBridge> _readingListObserverBridge;
+
+  // Backing object for property of the same name.
+  __weak id<ReadingListMenuNotificationDelegate> _delegate;
+
+  // Keep a reference to detach before deallocing.
+  ReadingListModel* _readingListModel;  // weak
+}
+
+// Detach the observer on the reading list.
+- (void)detachReadingListModel;
+
+// Handle callbacks from the reading list model observer.
+- (void)readingListModelCompletedBatchUpdates:(const ReadingListModel*)model;
+
+@end
+
+// TODO(crbug.com/590725): use the one-and-only protocol-based implementation of
+// ReadingListModelObserver
+class ReadingListObserverBridge : public ReadingListModelObserver {
+ public:
+  explicit ReadingListObserverBridge(ReadingListMenuNotifier* owner)
+      : owner_(owner) {}
+
+  ~ReadingListObserverBridge() override {}
+
+  void ReadingListModelLoaded(const ReadingListModel* model) override {}
+
+  void ReadingListModelBeganBatchUpdates(
+      const ReadingListModel* model) override {}
+
+  void ReadingListModelCompletedBatchUpdates(
+      const ReadingListModel* model) override {
+    [owner_ readingListModelCompletedBatchUpdates:model];
+  }
+
+  void ReadingListModelBeingDeleted(const ReadingListModel* model) override{};
+
+  void ReadingListDidApplyChanges(ReadingListModel* model) override {
+    [owner_ readingListModelCompletedBatchUpdates:model];
+  }
+
+ private:
+  ReadingListMenuNotifier* owner_;  // weak, owns us
+};
+
+@implementation ReadingListMenuNotifier
+@synthesize delegate = _delegate;
+
+- (instancetype)initWithReadingList:(ReadingListModel*)readingListModel {
+  if (self = [super init]) {
+    _readingListObserverBridge.reset(new ReadingListObserverBridge(self));
+    _readingListModel = readingListModel;
+    _readingListModel->AddObserver(_readingListObserverBridge.get());
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [self detachReadingListModel];
+}
+
+- (void)detachReadingListModel {
+  _readingListModel->RemoveObserver(_readingListObserverBridge.get());
+  _readingListObserverBridge.reset();
+}
+
+- (void)readingListModelCompletedBatchUpdates:(const ReadingListModel*)model {
+  [_delegate unreadCountChanged:model->unread_size()];
+  [_delegate unseenStateChanged:model->HasUnseenEntries()];
+}
+
+- (NSInteger)readingListUnreadCount {
+  return _readingListModel->unread_size();
+}
+
+- (BOOL)readingListUnseenItemsExist {
+  return _readingListModel->HasUnseenEntries();
+}
+
+@end