| // Copyright (c) 2012 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_POLICY_POLICY_SERVICE_H_ |
| #define CHROME_BROWSER_POLICY_POLICY_SERVICE_H_ |
| |
| #include <map> |
| #include <string> |
| |
| #include "base/basictypes.h" |
| #include "base/callback.h" |
| #include "base/memory/ref_counted.h" |
| #include "chrome/browser/policy/policy_map.h" |
| #include "components/policy/core/common/policy_namespace.h" |
| |
| namespace policy { |
| |
| class PolicyDomainDescriptor; |
| |
| // The PolicyService merges policies from all available sources, taking into |
| // account their priorities. Policy clients can retrieve policy for their domain |
| // and register for notifications on policy updates. |
| // |
| // The PolicyService is available from BrowserProcess as a global singleton. |
| // There is also a PolicyService for browser-wide policies available from |
| // BrowserProcess as a global singleton. |
| class PolicyService { |
| public: |
| class Observer { |
| public: |
| // Invoked whenever policies for the given |ns| namespace are modified. |
| // This is only invoked for changes that happen after AddObserver is called. |
| // |previous| contains the values of the policies before the update, |
| // and |current| contains the current values. |
| virtual void OnPolicyUpdated(const PolicyNamespace& ns, |
| const PolicyMap& previous, |
| const PolicyMap& current) = 0; |
| |
| // Invoked at most once for each |domain|, when the PolicyService becomes |
| // ready. If IsInitializationComplete() is false, then this will be invoked |
| // once all the policy providers have finished loading their policies for |
| // |domain|. |
| virtual void OnPolicyServiceInitialized(PolicyDomain domain) {} |
| |
| protected: |
| virtual ~Observer() {} |
| }; |
| |
| virtual ~PolicyService() {} |
| |
| // Observes changes to all components of the given |domain|. |
| virtual void AddObserver(PolicyDomain domain, Observer* observer) = 0; |
| |
| virtual void RemoveObserver(PolicyDomain domain, Observer* observer) = 0; |
| |
| // Registers the |descriptor| of a policy domain, indicated by |
| // |descriptor->domain()|. This overrides the descriptor previously set, if |
| // there was one. |
| // This registration signals that there is interest in receiving policy for |
| // the components listed in the descriptor. The policy providers will try to |
| // load policy for these components, and validate it against the descriptor. |
| // Cached data for components that aren't registered anymore may be dropped. |
| virtual void RegisterPolicyDomain( |
| scoped_refptr<const PolicyDomainDescriptor> descriptor) = 0; |
| |
| virtual const PolicyMap& GetPolicies(const PolicyNamespace& ns) const = 0; |
| |
| virtual scoped_refptr<const PolicyDomainDescriptor> GetPolicyDomainDescriptor( |
| PolicyDomain domain) const = 0; |
| |
| // The PolicyService loads policy from several sources, and some require |
| // asynchronous loads. IsInitializationComplete() returns true once all |
| // sources have loaded their policies for the given |domain|. |
| // It is safe to read policy from the PolicyService even if |
| // IsInitializationComplete() is false; there will be an OnPolicyUpdated() |
| // notification once new policies become available. |
| // |
| // OnPolicyServiceInitialized() is called when IsInitializationComplete() |
| // becomes true, which happens at most once for each domain. |
| // If IsInitializationComplete() is already true for |domain| when an Observer |
| // is registered, then that Observer will not receive an |
| // OnPolicyServiceInitialized() notification. |
| virtual bool IsInitializationComplete(PolicyDomain domain) const = 0; |
| |
| // Asks the PolicyService to reload policy from all available policy sources. |
| // |callback| is invoked once every source has reloaded its policies, and |
| // GetPolicies() is guaranteed to return the updated values at that point. |
| virtual void RefreshPolicies(const base::Closure& callback) = 0; |
| }; |
| |
| // A registrar that only observes changes to particular policies within the |
| // PolicyMap for the given policy namespace. |
| class PolicyChangeRegistrar : public PolicyService::Observer { |
| public: |
| typedef base::Callback<void(const Value*, const Value*)> UpdateCallback; |
| |
| // Observes updates to the given (domain, component_id) namespace in the given |
| // |policy_service|, and notifies |observer| whenever any of the registered |
| // policy keys changes. Both the |policy_service| and the |observer| must |
| // outlive |this|. |
| PolicyChangeRegistrar(PolicyService* policy_service, |
| const PolicyNamespace& ns); |
| |
| virtual ~PolicyChangeRegistrar(); |
| |
| // Will invoke |callback| whenever |policy_name| changes its value, as long |
| // as this registrar exists. |
| // Only one callback can be registed per policy name; a second call with the |
| // same |policy_name| will overwrite the previous callback. |
| void Observe(const std::string& policy_name, const UpdateCallback& callback); |
| |
| // Implementation of PolicyService::Observer: |
| virtual void OnPolicyUpdated(const PolicyNamespace& ns, |
| const PolicyMap& previous, |
| const PolicyMap& current) OVERRIDE; |
| |
| private: |
| typedef std::map<std::string, UpdateCallback> CallbackMap; |
| |
| PolicyService* policy_service_; |
| PolicyNamespace ns_; |
| CallbackMap callback_map_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PolicyChangeRegistrar); |
| }; |
| |
| } // namespace policy |
| |
| #endif // CHROME_BROWSER_POLICY_POLICY_SERVICE_H_ |