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 "base/compiler_specific.h"
+#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), for compliance with EXTENSION_FUNCTION_VALIDATE.
+  virtual bool RunWithStorageImpl(ExtensionSettingsStorage* storage) = 0;
+
+  virtual bool RunImpl() OVERRIDE;
+
+  // 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();
+    virtual void OnSuccess(DictionaryValue* settings) OVERRIDE;
+    virtual void OnFailure(const std::string& message) OVERRIDE;
+
+   private:
+    scoped_refptr<SettingsFunction> settings_function_;
+  };
+
+ private:
+  // Callback method from GetStorage(); delegates to RunWithStorageImpl.
+  void RunWithStorage(ExtensionSettingsStorage* storage);
+};
+
+class GetSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.get");
+
+ protected:
+  virtual bool RunWithStorageImpl(ExtensionSettingsStorage* storage) OVERRIDE;
+};
+
+class SetSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.set");
+
+ protected:
+  virtual bool RunWithStorageImpl(ExtensionSettingsStorage* storage) OVERRIDE;
+};
+
+class RemoveSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.remove");
+
+ protected:
+  virtual bool RunWithStorageImpl(ExtensionSettingsStorage* storage) OVERRIDE;
+};
+
+class ClearSettingsFunction : public SettingsFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.settings.clear");
+
+ protected:
+  virtual bool RunWithStorageImpl(ExtensionSettingsStorage* storage) OVERRIDE;
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_API_H_