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      1 // Copyright 2013 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.
      4 
      5 #ifndef COMPONENTS_POLICY_CORE_COMMON_FORWARDING_POLICY_PROVIDER_H_
      6 #define COMPONENTS_POLICY_CORE_COMMON_FORWARDING_POLICY_PROVIDER_H_
      7 
      8 #include "base/basictypes.h"
      9 #include "base/compiler_specific.h"
     10 #include "components/policy/core/common/configuration_policy_provider.h"
     11 #include "components/policy/core/common/policy_namespace.h"
     12 #include "components/policy/policy_export.h"
     13 
     14 namespace policy {
     15 
     16 // A policy provider that forwards calls to another provider.
     17 // This provider also tracks the SchemaRegistry, and becomes ready after making
     18 // sure the delegate provider has refreshed its policies with an updated view
     19 // of the complete schema. It is expected that the delegate's SchemaRegistry
     20 // is a CombinedSchemaRegistry tracking the forwarding provider's registry.
     21 class POLICY_EXPORT ForwardingPolicyProvider
     22     : public ConfigurationPolicyProvider,
     23       public ConfigurationPolicyProvider::Observer {
     24  public:
     25   // The |delegate| must outlive this provider.
     26   explicit ForwardingPolicyProvider(ConfigurationPolicyProvider* delegate);
     27   virtual ~ForwardingPolicyProvider();
     28 
     29   // ConfigurationPolicyProvider:
     30   //
     31   // Note that Init() and Shutdown() are not forwarded to the |delegate_|, since
     32   // this provider does not own it and its up to the |delegate_|'s owner to
     33   // initialize it and shut it down.
     34   //
     35   // Note also that this provider may have a SchemaRegistry passed in Init()
     36   // that doesn't match the |delegate_|'s; therefore OnSchemaRegistryUpdated()
     37   // and OnSchemaRegistryReady() are not forwarded either. It is assumed that
     38   // the |delegate_|'s SchemaRegistry contains a superset of this provider's
     39   // SchemaRegistry though (i.e. it's a CombinedSchemaRegistry that contains
     40   // this provider's SchemaRegistry).
     41   //
     42   // This provider manages its own initialization state for all policy domains
     43   // except POLICY_DOMAIN_CHROME, whose status is always queried from the
     44   // |delegate_|. RefreshPolicies() calls are also forwarded, since this
     45   // provider doesn't have a "real" policy source of its own.
     46   virtual void Init(SchemaRegistry* registry) OVERRIDE;
     47   virtual bool IsInitializationComplete(PolicyDomain domain) const OVERRIDE;
     48   virtual void RefreshPolicies() OVERRIDE;
     49   virtual void OnSchemaRegistryReady() OVERRIDE;
     50   virtual void OnSchemaRegistryUpdated(bool has_new_schemas) OVERRIDE;
     51 
     52   // ConfigurationPolicyProvider::Observer:
     53   virtual void OnUpdatePolicy(ConfigurationPolicyProvider* provider) OVERRIDE;
     54 
     55  private:
     56   enum InitializationState {
     57     WAITING_FOR_REGISTRY_READY,
     58     WAITING_FOR_REFRESH,
     59     READY,
     60   };
     61 
     62   ConfigurationPolicyProvider* delegate_;
     63   InitializationState state_;
     64 
     65   DISALLOW_COPY_AND_ASSIGN(ForwardingPolicyProvider);
     66 };
     67 
     68 }  // namespace policy
     69 
     70 #endif  // COMPONENTS_POLICY_CORE_COMMON_FORWARDING_POLICY_PROVIDER_H_
     71