// 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 NET_PROXY_PROXY_CONFIG_SERVICE_H_
#define NET_PROXY_PROXY_CONFIG_SERVICE_H_
#include "net/base/net_export.h"
namespace net {
class ProxyConfig;
// Service for watching when the proxy settings have changed.
class NET_EXPORT ProxyConfigService {
public:
// Indicates whether proxy configuration is valid, and if not, why.
enum ConfigAvailability {
// Configuration is pending, observers will be notified later.
CONFIG_PENDING,
// Configuration is present and valid.
CONFIG_VALID,
// No configuration is set.
CONFIG_UNSET
};
// Observer for being notified when the proxy settings have changed.
class NET_EXPORT Observer {
public:
virtual ~Observer() {}
// Notification callback that should be invoked by ProxyConfigService
// implementors whenever the configuration changes. |availability| indicates
// the new availability status and can be CONFIG_UNSET or CONFIG_VALID (in
// which case |config| contains the configuration). Implementors must not
// pass CONFIG_PENDING.
virtual void OnProxyConfigChanged(const ProxyConfig& config,
ConfigAvailability availability) = 0;
};
virtual ~ProxyConfigService() {}
// Adds/Removes an observer that will be called whenever the proxy
// configuration has changed.
virtual void AddObserver(Observer* observer) = 0;
virtual void RemoveObserver(Observer* observer) = 0;
// Gets the most recent availability status. If a configuration is present,
// the proxy configuration is written to |config| and CONFIG_VALID is
// returned. Returns CONFIG_PENDING if it is not available yet. In this case,
// it is guaranteed that subscribed observers will be notified of a change at
// some point in the future once the configuration is available.
// Note that to avoid re-entrancy problems, implementations should not
// dispatch any change notifications from within this function.
virtual ConfigAvailability GetLatestProxyConfig(ProxyConfig* config) = 0;
// ProxyService will call this periodically during periods of activity.
// It can be used as a signal for polling-based implementations.
//
// Note that this is purely used as an optimization -- polling
// implementations could simply set a global timer that goes off every
// X seconds at which point they check for changes. However that has
// the disadvantage of doing continuous work even during idle periods.
virtual void OnLazyPoll() {}
};
} // namespace net
#endif // NET_PROXY_PROXY_CONFIG_SERVICE_H_