Support undoing offline page deletion

components/offline_pages/offline_page_model.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 
 #include <map>
 #include <vector>
 
 #include "base/callback.h"
+#include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/scoped_observer.h"
 #include "components/bookmarks/browser/base_bookmark_model_observer.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/offline_pages/offline_page_archiver.h"
@@ skipping 69 matching lines @@
     CANCELLED,
     STORE_FAILURE,
   };
 
   // Observer of the OfflinePageModel.
   class Observer {
    public:
     // Invoked when the model has finished loading.
     virtual void OfflinePageModelLoaded(OfflinePageModel* model) = 0;
 
+    // Invoked when the model is being updated, due to adding, removing or
+    // updating an offline page.
+    virtual void OfflinePageModelChanged(OfflinePageModel* model) = 0;
+
    protected:
     virtual ~Observer() {}
   };
 
   typedef base::Callback<void(SavePageResult)> SavePageCallback;
   typedef base::Callback<void(DeletePageResult)> DeletePageCallback;
 
   // All blocking calls/disk access will happen on the provided |task_runner|.
   OfflinePageModel(
       scoped_ptr<OfflinePageMetadataStore> store,
@@ skipping 17 matching lines @@
   void SavePage(const GURL& url,
                 int64 bookmark_id,
                 scoped_ptr<OfflinePageArchiver> archiver,
                 const SavePageCallback& callback);
 
   // Marks that the offline page related to the passed |bookmark_id| has been
   // accessed. Its access info, including last access time and access count,
   // will be updated. Requires that the model is loaded.
   void MarkPageAccessed(int64 bookmark_id);
 
+  // Marks that the offline page related to the passed |bookmark_id| was going
+  // to be deleted. The deletion will occur in a short while. The undo can be
+  // done before this. Requires that the model is loaded.
+  void MarkPageForDeletion(int64 bookmark_id,
+                           const DeletePageCallback& callback);
+
   // Deletes an offline page related to the passed |bookmark_id|. Requires that
   // the model is loaded.
   void DeletePageByBookmarkId(int64 bookmark_id,
                               const DeletePageCallback& callback);
 
   // Deletes offline pages related to the passed |bookmark_ids|. Requires that
   // the model is loaded.
   void DeletePagesByBookmarkId(const std::vector<int64>& bookmark_ids,
                                const DeletePageCallback& callback);
 
+  void UndeletePage(int64 bookmark_id, const DeletePageCallback& callback);
+
   // Gets all available offline pages. Requires that the model is loaded.
   const std::vector<OfflinePageItem> GetAllPages() const;
 
   // Gets pages that should be removed to clean up storage. Requires that the
   // model is loaded.
   const std::vector<OfflinePageItem> GetPagesToCleanUp() const;
 
   // Returns an offline page associated with a specified |bookmark_id|. nullptr
   // is returned if not found.
   const OfflinePageItem* GetPageByBookmarkId(int64 bookmark_id) const;
 
   // Returns an offline page that is stored as |offline_url|. nullptr is
   // returned if not found.
   const OfflinePageItem* GetPageByOfflineURL(const GURL& offline_url) const;
 
   // Methods for testing only:
   OfflinePageMetadataStore* GetStoreForTesting();
 
   bool is_loaded() const { return is_loaded_; }
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(OfflinePageModelTest, MarkPageForDeletion);
+
   typedef ScopedVector<OfflinePageArchiver> PendingArchivers;
 
   // BaseBookmarkModelObserver:
   void BookmarkModelChanged() override;
+  void BookmarkNodeAdded(bookmarks::BookmarkModel* model,
+                         const bookmarks::BookmarkNode* parent,
+                         int index) override;
   void BookmarkNodeRemoved(bookmarks::BookmarkModel* model,
                            const bookmarks::BookmarkNode* parent,
                            int old_index,
                            const bookmarks::BookmarkNode* node,
                            const std::set<GURL>& removed_urls) override;
 
   // Callback for loading pages from the offline page metadata store.
   void OnLoadDone(bool success,
                   const std::vector<OfflinePageItem>& offline_pages);
 
@@ skipping 18 matching lines @@
   void OnDeleteArchiveFilesDone(
       const std::vector<int64>& bookmark_ids,
       const DeletePageCallback& callback,
       const bool* success);
   void OnRemoveOfflinePagesDone(const std::vector<int64>& bookmark_ids,
                                 const DeletePageCallback& callback,
                                 bool success);
   void InformDeletePageDone(const DeletePageCallback& callback,
                             DeletePageResult result);
 
-  void OnUpdateOfflinePageDone(const OfflinePageItem& offline_page_item,
-                               bool success);
+  void OnMarkPageAccesseDone(const OfflinePageItem& offline_page_item,
+                             bool success);
+
+  // Steps for marking an offline page for deletion that can be undo-ed.
+  void OnMarkPageForDeletionDone(const OfflinePageItem& offline_page_item,
+                                 const DeletePageCallback& callback,
+                                 bool success);
+  void FinalizePageDeletion();
+
+  // Steps for undoing a offline page deletion.
+  void UndoPageDeletion(int64 bookmark_id);
+  void OnUndoOfflinePageDone(const OfflinePageItem& offline_page, bool success);
 
   // Persistent store for offline page metadata.
   scoped_ptr<OfflinePageMetadataStore> store_;
 
   // The observers.
   base::ObserverList<Observer> observers_;
 
   bool is_loaded_;
 
   // In memory copy of the offline page metadata, keyed by bookmark IDs.
@@ skipping 11 matching lines @@
       scoped_observer_;
 
   base::WeakPtrFactory<OfflinePageModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageModel);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_