Updating trunk VERSION from 2139.0 to 2140.0
[chromium-blink-merge.git] / extensions / browser / browser_context_keyed_api_factory.h
blob15728dc55d294ab1a52b774f609bbd267b214ecf
1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef EXTENSIONS_BROWSER_BROWSER_CONTEXT_KEYED_API_FACTORY_H_
6 #define EXTENSIONS_BROWSER_BROWSER_CONTEXT_KEYED_API_FACTORY_H_
8 #include "components/keyed_service/content/browser_context_dependency_manager.h"
9 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
10 #include "components/keyed_service/core/keyed_service.h"
11 #include "extensions/browser/extension_system_provider.h"
12 #include "extensions/browser/extensions_browser_client.h"
14 namespace extensions {
16 template <typename T>
17 class BrowserContextKeyedAPIFactory;
19 // Instantiations of BrowserContextKeyedAPIFactory should use this base class
20 // and also define a static const char* service_name() function (used in the
21 // BrowserContextKeyedBaseFactory constructor). These fields should
22 // be accessible to the BrowserContextKeyedAPIFactory for the service.
23 class BrowserContextKeyedAPI : public KeyedService {
24 protected:
25 // Defaults for flags that control BrowserContextKeyedAPIFactory behavior.
26 // These can be overridden by subclasses to change that behavior.
27 // See BrowserContextKeyedBaseFactory for usage.
29 // These flags affect what instance is returned when Get() is called
30 // on an incognito profile. By default, it returns NULL. If
31 // kServiceRedirectedInIncognito is true, it returns the instance for the
32 // corresponding regular profile. If kServiceHasOwnInstanceInIncognito
33 // is true, it returns a separate instance.
34 static const bool kServiceRedirectedInIncognito = false;
35 static const bool kServiceHasOwnInstanceInIncognito = false;
37 // If set to false, don't start the service at BrowserContext creation time.
38 // (The default differs from the BrowserContextKeyedBaseFactory default,
39 // because historically, BrowserContextKeyedAPIs often do tasks at startup.)
40 static const bool kServiceIsCreatedWithBrowserContext = true;
42 // If set to true, GetForProfile returns NULL for TestingBrowserContexts.
43 static const bool kServiceIsNULLWhileTesting = false;
45 // Users of this factory template must define a GetFactoryInstance()
46 // and manage their own instances (typically using LazyInstance or
47 // Singleton), because those cannot be included in more than one
48 // translation unit (and thus cannot be initialized in a header file).
50 // In the header file, declare GetFactoryInstance(), e.g.:
51 // class HistoryAPI {
52 // ...
53 // public:
54 // static BrowserContextKeyedAPIFactory<HistoryAPI>* GetFactoryInstance();
55 // };
57 // In the cc file, provide the implementation, e.g.:
58 // static base::LazyInstance<BrowserContextKeyedAPIFactory<HistoryAPI> >
59 // g_factory = LAZY_INSTANCE_INITIALIZER;
61 // // static
62 // BrowserContextKeyedAPIFactory<HistoryAPI>*
63 // HistoryAPI::GetFactoryInstance() {
64 // return g_factory.Pointer();
65 // }
68 // A template for factories for KeyedServices that manage extension APIs. T is
69 // a KeyedService that uses this factory template instead of its own separate
70 // factory definition to manage its per-profile instances.
71 template <typename T>
72 class BrowserContextKeyedAPIFactory : public BrowserContextKeyedServiceFactory {
73 public:
74 static T* Get(content::BrowserContext* context) {
75 return static_cast<T*>(
76 T::GetFactoryInstance()->GetServiceForBrowserContext(context, true));
79 // Declare dependencies on other factories.
80 // By default, ExtensionSystemFactory is the only dependency; however,
81 // specializations can override this. Declare your specialization in
82 // your header file after the BrowserContextKeyedAPI class definition.
83 // Then in the cc file (or inline in the header), define it, e.g.:
84 // template <>
85 // void BrowserContextKeyedAPIFactory<
86 // PushMessagingAPI>::DeclareFactoryDependencies() {
87 // DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
88 // DependsOn(ProfileSyncServiceFactory::GetInstance());
89 // }
90 void DeclareFactoryDependencies() {
91 DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
94 BrowserContextKeyedAPIFactory()
95 : BrowserContextKeyedServiceFactory(
96 T::service_name(),
97 BrowserContextDependencyManager::GetInstance()) {
98 DeclareFactoryDependencies();
101 virtual ~BrowserContextKeyedAPIFactory() {}
103 private:
104 // BrowserContextKeyedServiceFactory implementation.
105 virtual KeyedService* BuildServiceInstanceFor(
106 content::BrowserContext* context) const OVERRIDE {
107 return new T(context);
110 // BrowserContextKeyedBaseFactory implementation.
111 // These can be effectively overridden with template specializations.
112 virtual content::BrowserContext* GetBrowserContextToUse(
113 content::BrowserContext* context) const OVERRIDE {
114 if (T::kServiceRedirectedInIncognito)
115 return ExtensionsBrowserClient::Get()->GetOriginalContext(context);
117 if (T::kServiceHasOwnInstanceInIncognito)
118 return context;
120 return BrowserContextKeyedServiceFactory::GetBrowserContextToUse(context);
123 virtual bool ServiceIsCreatedWithBrowserContext() const OVERRIDE {
124 return T::kServiceIsCreatedWithBrowserContext;
127 virtual bool ServiceIsNULLWhileTesting() const OVERRIDE {
128 return T::kServiceIsNULLWhileTesting;
131 DISALLOW_COPY_AND_ASSIGN(BrowserContextKeyedAPIFactory);
134 } // namespace extensions
136 #endif // EXTENSIONS_BROWSER_BROWSER_CONTEXT_KEYED_API_FACTORY_H_