extensions: Create AppSorting interface.

Create an AppSorting interface in extensions/browser/ and
make ChromeAppSorting (formerly ExtensionSorting) implement
it.

BUG=313284

Review URL: https://codereview.chromium.org/74613003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236500 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 119 insertions, 0 deletions

diff --git a/extensions/browser/DEPS b/extensions/browser/DEPS
index b561344..cf696c7 100644
--- a/extensions/browser/DEPS
+++ b/extensions/browser/DEPS
@@ -1,5 +1,6 @@
 include_rules = [
   "+content/public/browser",
+  "+sync",
 
   # Temporarily allowed includes as part of the app shell/extensions refactor.
   #
@@ -14,6 +15,7 @@ include_rules = [
   "+chrome/browser/extensions/extension_function_histogram_value.h",
   "+chrome/browser/extensions/extension_host.h",
   "+chrome/browser/extensions/extension_host_mac.h",
+  "+chrome/browser/extensions/extension_prefs.h",
   "+chrome/browser/extensions/extension_service.h",
   "+chrome/browser/extensions/extension_system.h",
   "+chrome/browser/extensions/extension_util.h",
diff --git a/extensions/browser/app_sorting.h b/extensions/browser/app_sorting.h
new file mode 100644
index 0000000..46b90e1
--- /dev/null
+++ b/extensions/browser/app_sorting.h
@@ -0,0 +1,116 @@
+// Copyright 2013 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 EXTENSIONS_BROWSER_APP_SORTING_H_
+#define EXTENSIONS_BROWSER_APP_SORTING_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "chrome/browser/extensions/extension_prefs.h"
+#include "extensions/common/extension.h"
+#include "sync/api/string_ordinal.h"
+
+class ExtensionSyncService;
+
+namespace extensions {
+
+// An interface that provides a fixed ordering for a set of apps.
+class AppSorting {
+ public:
+  AppSorting() {}
+  virtual ~AppSorting() {}
+
+  // Set up the ExtensionSyncService to inform of changes that require syncing.
+  virtual void SetExtensionSyncService(
+      ExtensionSyncService* extension_sync_service) = 0;
+
+  // Properly initialize internal values that require |extension_ids|.
+  virtual void Initialize(const extensions::ExtensionIdList& extension_ids) = 0;
+
+  // Resolves any conflicts the might be created as a result of syncing that
+  // results in two icons having the same page and app launch ordinal. After
+  // this is called it is guaranteed that there are no collisions of NTP icons.
+  virtual void FixNTPOrdinalCollisions() = 0;
+
+  // This ensures that the extension has valid ordinals, and if it doesn't then
+  // properly initialize them. |suggested_page| will be used if it is valid and
+  // the extension has no valid user-set page ordinal.
+  virtual void EnsureValidOrdinals(
+      const std::string& extension_id,
+      const syncer::StringOrdinal& suggested_page) = 0;
+
+  // Updates the app launcher value for the moved extension so that it is now
+  // located after the given predecessor and before the successor.
+  // Empty strings are used to indicate no successor or predecessor.
+  virtual void OnExtensionMoved(const std::string& moved_extension_id,
+                                const std::string& predecessor_extension_id,
+                                const std::string& successor_extension_id) = 0;
+
+  // Get the application launch ordinal for an app with |extension_id|. This
+  // determines the order in which the app appears on the page it's on in the
+  // New Tab Page (Note that you can compare app launch ordinals only if the
+  // apps are on the same page). A string value close to |a*| generally
+  // indicates top left. If the extension has no launch ordinal, an invalid
+  // StringOrdinal is returned.
+  virtual syncer::StringOrdinal GetAppLaunchOrdinal(
+      const std::string& extension_id) const = 0;
+
+  // Sets a specific launch ordinal for an app with |extension_id|.
+  virtual void SetAppLaunchOrdinal(
+      const std::string& extension_id,
+      const syncer::StringOrdinal& new_app_launch_ordinal) = 0;
+
+  // Returns a StringOrdinal that is lower than any app launch ordinal for the
+  // given page.
+  virtual syncer::StringOrdinal CreateFirstAppLaunchOrdinal(
+      const syncer::StringOrdinal& page_ordinal) const = 0;
+
+  // Returns a StringOrdinal that is higher than any app launch ordinal for the
+  // given page.
+  virtual syncer::StringOrdinal CreateNextAppLaunchOrdinal(
+      const syncer::StringOrdinal& page_ordinal) const = 0;
+
+  // Returns a StringOrdinal that is lower than any existing page ordinal.
+  virtual syncer::StringOrdinal CreateFirstAppPageOrdinal() const = 0;
+
+  // Gets the page a new app should install to, which is the earliest non-full
+  // page.  The returned ordinal may correspond to a page that doesn't yet exist
+  // if all pages are full.
+  virtual syncer::StringOrdinal GetNaturalAppPageOrdinal() const = 0;
+
+  // Get the page ordinal for an app with |extension_id|. This determines
+  // which page an app will appear on in page-based NTPs.  If the app has no
+  // page specified, an invalid StringOrdinal is returned.
+  virtual syncer::StringOrdinal GetPageOrdinal(
+      const std::string& extension_id) const = 0;
+
+  // Sets a specific page ordinal for an app with |extension_id|.
+  virtual void SetPageOrdinal(
+      const std::string& extension_id,
+      const syncer::StringOrdinal& new_page_ordinal) = 0;
+
+  // Removes the ordinal values for an app.
+  virtual void ClearOrdinals(const std::string& extension_id) = 0;
+
+  // Convert the page StringOrdinal value to its integer equivalent. This takes
+  // O(# of apps) worst-case.
+  virtual int PageStringOrdinalAsInteger(
+      const syncer::StringOrdinal& page_ordinal) const = 0;
+
+  // Converts the page index integer to its StringOrdinal equivalent. This takes
+  // O(# of apps) worst-case.
+  virtual syncer::StringOrdinal PageIntegerAsStringOrdinal(
+      size_t page_index) = 0;
+
+  // Hidden extensions don't appear in the new tab page.
+  virtual void MarkExtensionAsHidden(const std::string& extension_id) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(AppSorting);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_APP_SORTING_H_
diff --git a/extensions/extensions.gyp b/extensions/extensions.gyp
index b9ae281..af642d4 100644
--- a/extensions/extensions.gyp
+++ b/extensions/extensions.gyp
@@ -156,6 +156,7 @@
       'sources': [
         'browser/admin_policy.cc',
         'browser/admin_policy.h',
+        'browser/app_sorting.h',
         'browser/event_listener_map.cc',
         'browser/event_listener_map.h',
         'browser/extension_prefs_scope.h',