Added initial support for Service Power events.

Renamed variable to match previous naming conventions

Added the mappings to Topshelf types

Updated variable name.

Added comments

Updated log messages

src/Topshelf/Configuration/Builders/ControlServiceBuilder.cs

@@ -111,6 +111,17 @@ public void SessionChanged(HostControl hostControl, SessionChangedArguments argu
                 }
             }
 
+            public bool PowerEvent(HostControl hostControl, PowerEventArguments arguments)
+            {
+                var powerEvent = _service as ServicePowerEvent;
+                if (powerEvent != null)
+                {
+                    return powerEvent.PowerEvent(hostControl, arguments);
+                }
+
+                return false;
+            }
+
             public void CustomCommand(HostControl hostControl, int command)
             {
                 var customCommand = _service as ServiceCustomCommand;

src/Topshelf/Configuration/Builders/DelegateServiceBuilder.cs

@@ -27,11 +27,13 @@ public class DelegateServiceBuilder<T> :
         readonly Func<T, HostControl, bool> _start;
         readonly Func<T, HostControl, bool> _stop;
         readonly Action<T, HostControl, SessionChangedArguments> _sessionChanged;
+        readonly Func<T, HostControl, PowerEventArguments, bool> _powerEvent;
         readonly Action<T, HostControl, int> _customCommand;
 
         public DelegateServiceBuilder(ServiceFactory<T> serviceFactory, Func<T, HostControl, bool> start,
             Func<T, HostControl, bool> stop, Func<T, HostControl, bool> pause, Func<T, HostControl, bool> @continue,
             Action<T, HostControl> shutdown, Action<T, HostControl, SessionChangedArguments> sessionChanged,
+            Func<T, HostControl, PowerEventArguments, bool> powerEvent,
             Action<T, HostControl, int> customCommand, ServiceEvents serviceEvents)
         {
             _serviceFactory = serviceFactory;
@@ -41,6 +43,7 @@ public DelegateServiceBuilder(ServiceFactory<T> serviceFactory, Func<T, HostCont
             _continue = @continue;
             _shutdown = shutdown;
             _sessionChanged = sessionChanged;
+            _powerEvent = powerEvent;
             _customCommand = customCommand;
             _serviceEvents = serviceEvents;
         }
@@ -51,7 +54,7 @@ public ServiceHandle Build(HostSettings settings)
             {
                 T service = _serviceFactory(settings);
 
-                return new DelegateServiceHandle(service, _start, _stop, _pause, _continue, _shutdown, _sessionChanged, _customCommand, _serviceEvents);
+                return new DelegateServiceHandle(service, _start, _stop, _pause, _continue, _shutdown, _sessionChanged, _powerEvent, _customCommand, _serviceEvents);
             }
             catch (Exception ex)
             {
@@ -70,11 +73,12 @@ class DelegateServiceHandle :
             readonly Func<T, HostControl, bool> _start;
             readonly Func<T, HostControl, bool> _stop;
             readonly Action<T, HostControl, SessionChangedArguments> _sessionChanged;
+            readonly Func<T, HostControl, PowerEventArguments, bool> _powerEvent;
             readonly Action<T, HostControl, int> _customCommand;
 
             public DelegateServiceHandle(T service, Func<T, HostControl, bool> start, Func<T, HostControl, bool> stop,
                 Func<T, HostControl, bool> pause, Func<T, HostControl, bool> @continue, Action<T, HostControl> shutdown,
-                Action<T, HostControl, SessionChangedArguments> sessionChanged,
+                Action<T, HostControl, SessionChangedArguments> sessionChanged, Func<T, HostControl, PowerEventArguments, bool> powerEvent,
                 Action<T, HostControl, int> customCommand, ServiceEvents serviceEvents)
             {
                 _service = service;
@@ -84,6 +88,7 @@ public DelegateServiceHandle(T service, Func<T, HostControl, bool> start, Func<T
                 _continue = @continue;
                 _shutdown = shutdown;
                 _sessionChanged = sessionChanged;
+                _powerEvent = powerEvent;
                 _customCommand = customCommand;
                 _serviceEvents = serviceEvents;
             }
@@ -141,6 +146,14 @@ public void SessionChanged(HostControl hostControl, SessionChangedArguments argu
                     _sessionChanged(_service, hostControl, arguments);
             }
 
+            public bool PowerEvent(HostControl hostControl, PowerEventArguments arguments)
+            {
+                if (_powerEvent != null)
+                    return _powerEvent(_service, hostControl, arguments);
+
+                return false;
+            }
+
             public void CustomCommand(HostControl hostControl, int command)
             {
                 if (_customCommand != null)

src/Topshelf/Configuration/ServiceConfiguratorExtensions.cs

@@ -134,5 +134,17 @@ public static ServiceConfigurator<T> WhenSessionChanged<T>(this ServiceConfigura
 
            return configurator;
        }
-  }
+
+        public static ServiceConfigurator<T> WhenPowerEvent<T>(this ServiceConfigurator<T> configurator, 
+            Func<T, PowerEventArguments, bool> callback)
+            where T : class
+        {
+            if (configurator == null)
+                throw new ArgumentNullException("configurator");
+
+            configurator.WhenPowerEvent((service, control, arguments) => callback(service, arguments));
+
+            return configurator;
+        }
+    }
 }

src/Topshelf/Configuration/ServiceConfigurators/DelegateServiceConfigurator.cs

@@ -32,7 +32,9 @@ public class DelegateServiceConfigurator<T> :
 
         bool _pauseConfigured;
         bool _sessionChangeConfigured;
+        bool _powerEventConfigured;
         Action<T, HostControl, SessionChangedArguments> _sessionChanged;
+        Func<T, HostControl, PowerEventArguments, bool> _powerEvent;
         Action<T, HostControl> _shutdown;
         bool _shutdownConfigured;
         Func<T, HostControl, bool> _start;
@@ -57,6 +59,8 @@ public IEnumerable<ValidateResult> Validate()
                 yield return this.Failure("Shutdown", "must not be null if shutdown is allowed");
             if (_sessionChangeConfigured && _sessionChanged == null)
                 yield return this.Failure("SessionChange", "must not be null if session change is allowed");
+            if (_powerEventConfigured && _powerEvent == null)
+                yield return this.Failure("PowerEvent", "must not be null if power event reaction is allowed");
             if (_customCommandReceivedConfigured && _customCommandReceived == null)
                 yield return this.Failure("CustomCommand", "must not be null if custom command is allowed");
         }
@@ -100,6 +104,12 @@ public void WhenSessionChanged(Action<T, HostControl, SessionChangedArguments> s
             _sessionChanged = sessionChanged;
         }
 
+        public void WhenPowerEvent(Func<T, HostControl, PowerEventArguments, bool> powerEvent)
+        {
+            _powerEventConfigured = true;
+            _powerEvent = powerEvent;
+        }
+
         public void WhenCustomCommandReceived(Action<T, HostControl, int> customCommandReceived)
         {
             _customCommandReceivedConfigured = true;
@@ -109,7 +119,7 @@ public void WhenCustomCommandReceived(Action<T, HostControl, int> customCommandR
         public ServiceBuilder Build()
         {
             var serviceBuilder = new DelegateServiceBuilder<T>(_factory, _start, _stop, _pause, _continue, _shutdown,
-                _sessionChanged, _customCommandReceived, ServiceEvents);
+                _sessionChanged, _powerEvent, _customCommandReceived, ServiceEvents);
             return serviceBuilder;
         }
     }

src/Topshelf/Configuration/ServiceConfigurators/ServiceConfigurator.cs

@@ -49,6 +49,7 @@ public interface ServiceConfigurator<T> :
         void WhenContinued(Func<T, HostControl, bool> @continue);
         void WhenShutdown(Action<T, HostControl> shutdown);
         void WhenSessionChanged(Action<T, HostControl, SessionChangedArguments> sessionChanged);
+        void WhenPowerEvent(Func<T, HostControl, PowerEventArguments, bool> powerEvent);
         void WhenCustomCommandReceived(Action<T, HostControl, int> customCommandReceived);
     }
 }

src/Topshelf/Hosts/ConsoleRunHost.cs

@@ -53,6 +53,11 @@ public ConsoleRunHost(HostSettings settings, HostEnvironment environment, Servic
             {
                 SystemEvents.SessionSwitch += OnSessionChanged;
             }
+
+            if (settings.CanHandlePowerEvent)
+            {
+                SystemEvents.PowerModeChanged += OnPowerModeChanged;
+            }
         }
 
         void OnSessionChanged(object sender, SessionSwitchEventArgs e)
@@ -62,6 +67,13 @@ void OnSessionChanged(object sender, SessionSwitchEventArgs e)
             _serviceHandle.SessionChanged(this, arguments);
         }
 
+        void OnPowerModeChanged(object sender, PowerModeChangedEventArgs e)
+        {
+            var arguments = new ConsolePowerEventArguments(e.Mode);
+
+            _serviceHandle.PowerEvent(this, arguments);
+        }
+
 
         public TopshelfExitCode Run()
         {
@@ -251,5 +263,33 @@ public int SessionId
                 get { return _sessionId; }
             }
         }
+
+        class ConsolePowerEventArguments :
+            PowerEventArguments
+        {
+            readonly PowerEventCode _eventCode;
+            public ConsolePowerEventArguments(PowerModes powerMode)
+            {
+                switch (powerMode)
+                {
+                    case PowerModes.Resume:
+                        _eventCode = PowerEventCode.ResumeAutomatic; 
+                        break;
+                    case PowerModes.StatusChange:
+                        _eventCode = PowerEventCode.PowerStatusChange;
+                        break;
+                    case PowerModes.Suspend:
+                        _eventCode = PowerEventCode.Suspend;
+                        break;
+                    default:
+                        throw new ArgumentOutOfRangeException(nameof(powerMode), powerMode, null);
+                }
+            }
+
+            public PowerEventCode EventCode
+            {
+                get { return _eventCode; }
+            }
+        }
     }
 }

src/Topshelf/Hosts/InstallHost.cs

@@ -179,6 +179,14 @@ public bool CanSessionChanged
                 get { return _settings.CanSessionChanged; }
             }
 
+            /// <summary>
+            /// True if the service handles power change events
+            /// </summary>
+            public bool CanHandlePowerEvent
+            {
+                get { return _settings.CanHandlePowerEvent; }
+            }
+
             public Credentials Credentials
             {
                 get { return _credentials; }

src/Topshelf/PowerEventArguments.cs

@@ -0,0 +1,19 @@
+// Copyright 2007-2013 Chris Patterson, Dru Sellers, Travis Smith, et. al.
+//  
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use 
+// this file except in compliance with the License. You may obtain a copy of the 
+// License at 
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0 
+// 
+// Unless required by applicable law or agreed to in writing, software distributed 
+// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the 
+// specific language governing permissions and limitations under the License.
+namespace Topshelf
+{
+    public interface PowerEventArguments
+    {
+        PowerEventCode EventCode { get; }
+    }
+}

src/Topshelf/PowerEventCode.cs

@@ -0,0 +1,62 @@
+// Copyright 2007-2013 Chris Patterson, Dru Sellers, Travis Smith, et. al.
+//  
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use 
+// this file except in compliance with the License. You may obtain a copy of the 
+// License at 
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0 
+// 
+// Unless required by applicable law or agreed to in writing, software distributed 
+// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the 
+// specific language governing permissions and limitations under the License.
+namespace Topshelf
+{
+    using Hosts;
+
+    public enum PowerEventCode
+    {
+        /// <summary>
+        /// The system has requested permission to suspend the computer. An application that grants permission should carry out preparations for the suspension before returning.
+        /// <remarks>Not supported by <see cref="ConsoleRunHost"/></remarks>
+        /// </summary>
+        QuerySuspend = 0,
+        /// <summary>
+        /// The system was denied permission to suspend the computer. This status is broadcast if any application or driver denied a previous <see cref="QuerySuspend"/> status.
+        /// <remarks>Not supported by <see cref="ConsoleRunHost"/></remarks>
+        /// </summary>
+        QuerySuspendFailed = 2,
+        /// <summary>
+        /// The computer is about to enter a suspended state. This event is typically broadcast when all applications and installable drivers have returned true to a previous QuerySuspend state.
+        /// </summary>
+        Suspend = 4,
+        /// <summary>
+        /// The system has resumed operation after a critical suspension caused by a failing battery.
+        /// <remarks>Not supported by <see cref="ConsoleRunHost"/></remarks>
+        /// </summary>
+        ResumeCritical = 6,
+        /// <summary>
+        /// The system has resumed operation after being suspended.
+        /// <remarks>Not supported by <see cref="ConsoleRunHost"/></remarks>
+        /// </summary>
+        ResumeSuspend = 7,
+        /// <summary>
+        /// Battery power is low.
+        /// <remarks>Not supported by <see cref="ConsoleRunHost"/></remarks>
+        /// </summary>
+        BatteryLow = 9,
+        /// <summary>
+        /// A change in the power status of the computer is detected, such as a switch from battery power to A/C. The system also broadcasts this event when remaining battery power slips below the threshold specified by the user or if the battery power changes by a specified percentage.
+        /// </summary>
+        PowerStatusChange = 10,
+        /// <summary>
+        /// An Advanced Power Management (APM) BIOS signaled an APM OEM event.
+        /// <remarks>Not supported by <see cref="ConsoleRunHost"/></remarks>
+        /// </summary>
+        OemEvent = 11,
+        /// <summary>
+        /// The computer has woken up automatically to handle an event.
+        /// </summary>
+        ResumeAutomatic = 18
+    }
+}

src/Topshelf/Runtime/HostSettings.cs

@@ -60,6 +60,11 @@ public interface HostSettings
         /// </summary>
         bool CanSessionChanged { get; }
 
+        /// <summary>
+        /// True if the service handles power change events
+        /// </summary>
+        bool CanHandlePowerEvent { get; }
+
         /// <summary>
         /// The amount of time to wait for the service to start before timing out. Default is 10 seconds.
         /// </summary>

src/Topshelf/Runtime/ServiceHandle.cs

@@ -62,6 +62,13 @@ public interface ServiceHandle :
         /// <param name="arguments"></param>
         void SessionChanged(HostControl hostControl, SessionChangedArguments arguments);
 
+        /// <summary>
+        /// Handle the power change event
+        /// </summary>
+        /// <param name="hostControl"></param>
+        /// <param name="arguments"></param>
+        bool PowerEvent(HostControl hostControl, PowerEventArguments arguments);
+
         /// <summary>
         /// Handle the custom command
         /// </summary>

src/Topshelf/Runtime/Windows/WindowsHostSettings.cs

@@ -102,6 +102,8 @@ public string ServiceName
 
         public bool CanSessionChanged { get; set; }
 
+        public bool CanHandlePowerEvent { get; set; }
+
         public TimeSpan StartTimeOut { get; set; }
 
         public TimeSpan StopTimeOut { get; set; }