Implement an initial extension settings API.

chrome/browser/extensions/extension_settings_api.h

+// Copyright (c) 2011 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_EXTENSIONS_EXTENSION_SETTINGS_API_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_API_H_
+#pragma once
+
+#include "chrome/browser/extensions/extension_function.h"
+#include "chrome/browser/extensions/extension_settings.h"
+#include "chrome/browser/extensions/extension_settings_storage.h"
+
+// Superclass of all settings functions.
+class SettingsFunction : public AsyncExtensionFunction {
+ public:
+  virtual ~SettingsFunction() {}
+
+  // Extension settings function implementations should do their work here, and
+  // either run a StorageResultCallback or fill the function result / call
+  // SendResponse themselves.
+  // The exception is that implementations can return false to immediately
+  // call SendResponse(false) -- this is so that the extensions macros work.
+  virtual bool RunWithStorage(ExtensionSettingsStorage* storage) = 0;
+
+  bool RunImpl();
+
+ protected:
+  // GetStorage() callback to run the given ExtensionFunction's RunWithStorage.
+  // Declared here to access to the protected members of ExtensionFunction.
+  class GetStorageCallback : public ExtensionSettings::Callback {
+   public:
+    explicit GetStorageCallback(SettingsFunction* settings_function);
+    ~GetStorageCallback();
+    void Run(ExtensionSettingsStorage* storage);
+
+   private:
+    scoped_refptr<SettingsFunction> settings_function_;
+  };
+
+  // Callback from all storage methods (Get/Set/Remove/Clear) which sets the
+  // appropriate fields of the extension function (result/error) and sends a
+  // response.
+  // Declared here to access to the protected members of ExtensionFunction.
+  class StorageResultCallback : public ExtensionSettingsStorage::Callback {
+   public:
+    explicit StorageResultCallback(SettingsFunction* settings_function);
+    ~StorageResultCallback();
+    void OnSuccess(DictionaryValue* settings);
+    void OnFailure(const std::string& message);
+
+   private:
+    scoped_refptr<SettingsFunction> settings_function_;
+  };
+};
+
+class GetSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.get");
+
+ protected:
+  bool RunWithStorage(ExtensionSettingsStorage* storage);
+  std::string Thing();
+};
+
+class SetSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.set");
+
+ protected:
+  bool RunWithStorage(ExtensionSettingsStorage* storage);
+  std::string Thing();
+};
+
+class RemoveSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.remove");
+
+ protected:
+  bool RunWithStorage(ExtensionSettingsStorage* storage);
+  std::string Thing();
+};
+
+class ClearSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.clear");
+
+ protected:
+  bool RunWithStorage(ExtensionSettingsStorage* storage);
+  std::string Thing();
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_API_H_