Add the android partner bookmark shim.

chrome/browser/ui/webui/ntp/android/partner_bookmarks_shim.h

+// Copyright (c) 2012 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 CHROME_BROWSER_UI_WEBUI_NTP_ANDROID_PARTNER_BOOKMARKS_SHIM_H_
+#define CHROME_BROWSER_UI_WEBUI_NTP_ANDROID_PARTNER_BOOKMARKS_SHIM_H_
+
+#include "base/android/jni_helper.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/bookmarks/bookmark_model.h"
+
+// A shim that lives on top of a BookmarkModel that allows the injection of
+// Partner bookmarks without submitting changes to the user configured bookmark
+// model.
+// Partner bookmarks folder is pseudo-injected as a subfolder to "attach node".
+// Because we cannot modify the BookmarkModel, the following needs to
+// be done on a client side:
+// 1. bookmark_node->is_root() -> shim->IsRootNode(bookmark_node)
+// 2. bookmark_node->parent() -> shim->GetParentOf(bookmark_node)
+// 3. bookmark_model->GetNodeByID(id) -> shim->GetNodeByID(id)
+class PartnerBookmarksShim {
+ public:
+  // Constructor is public for LazyInstance; DON'T CALL; use ::GetInstance().
+  PartnerBookmarksShim();
+  // Destructor is public for LazyInstance;
+  ~PartnerBookmarksShim();
+
+  // Returns the active instance of the shim.
+  static PartnerBookmarksShim* GetInstance();
+
+  // Resets back to the initial state.  Clears any attached observers, deletes
+  // the partner bookmarks if any, and returns back to the unloaded state.
+  void Reset();
+
+  // Pseudo-injects partner bookmarks (if any) under the "attach_node".
+  void AttachTo(BookmarkModel* bookmark_model,
+                const BookmarkNode* attach_node);
+  // Returns true if everything got loaded and attached
+  bool IsLoaded() const;
+  // Returns true if there are partner bookmarks
+  bool HasPartnerBookmarks() const;
+
+  // For "Loaded" and "ShimBeingDeleted" notifications
+  class Observer {
+   public:
+    // Called when everything is loaded and attached
+    virtual void PartnerShimLoaded(PartnerBookmarksShim*) {}
+    // Called just before everything got destroyed
+    virtual void ShimBeingDeleted(PartnerBookmarksShim*) {}
+   protected:
+    virtual ~Observer() {}
+  };
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // Replacements for BookmarkModel/BookmarkNode methods
+  bool IsBookmarkEditable(const BookmarkNode* node);
+  bool IsRootNode(const BookmarkNode* node) const;
+  const BookmarkNode* GetNodeByID(int64 id, bool is_partner) const;
+  const BookmarkNode* GetParentOf(const BookmarkNode* node) const;
+  const BookmarkNode* get_attach_point() const { return attach_point_; }
+  bool IsPartnerBookmark(const BookmarkNode* node);
+  const BookmarkNode* GetPartnerBookmarksRoot() const;
+  // Sets the root node of the partner bookmarks and notifies any observers that
+  // the shim has now been loaded.  Takes ownership of |root_node|.
+  void SetPartnerBookmarksRoot(BookmarkNode* root_node);
+
+ private:
+  const BookmarkNode* GetNodeByID(const BookmarkNode* parent, int64 id) const;
+
+  scoped_ptr<BookmarkNode> partner_bookmarks_root_;
+  BookmarkModel* bookmark_model_;
+  const BookmarkNode* attach_point_;
+  bool loaded_;  // Set only on UI thread
+
+  // The observers.
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(PartnerBookmarksShim);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_NTP_ANDROID_PARTNER_BOOKMARKS_SHIM_H_