Mike-Ward.Net

Tweetz Release 1.2.4 - Screen Off Detection

This release fixes a long standing problem where tweetz wakes up the screen after it automatically shuts off as directed by the user’s power settings. Just determining what caused it to wake up was a mystery. Eventually, I determined that the web requests to twitter that tweetz initiates were the culprit.

Figuring out when the screen powers down was something of a trial. There are dozens of posts about how to this. I tried them all only to discover none of them worked reliably. I was convinced it wasn’t possible until I stumbled upon some code in an old Microsoft Application that contained the secret sauce.

I’ve been testing this on several computers for a couple of weeks now and it hasn’t once triggered a monitor wakeup, so I think maybe I have solved it.

Download Link

Thanks to everyone who donates. I know I don’t kick out updates often to this program, but I do try to keep it current with changes introduced by twitter (like the recent 280 character enhancement).

And Merry Christmas, if that’s your thing.


For developers out there, here’s the relevant code. You can also get it from tweetz’s source code under the PowerManagement folder. Much of this comes from the MS Application I mentioned earlier.

using System;
using System.Runtime.InteropServices;

namespace tweetz5.Utilities.PowerManagment
{
    internal static class PowerManagementNativeMethods
    {
        #region Power Management

        internal const uint PowerBroadcastMessage = 536;
        internal const uint PowerSettingChangeMessage = 32787;
        internal const uint ScreenSaverSetActive = 0x0011;
        internal const uint UpdateInFile = 0x0001;
        internal const uint SendChange = 0x0002;

        // This structure is sent when the PBT_POWERSETTINGSCHANGE message is sent.
        // It describes the power setting that has changed and 
        // contains data about the change.
        [StructLayout(LayoutKind.Sequential, Pack = 4)]
        public struct PowerBroadcastSetting
        {
            public Guid PowerSetting;
            public Int32 DataLength;
        }

        // This structure is used when calling CallNtPowerInformation 
        // to retrieve SystemPowerCapabilities
        [StructLayout(LayoutKind.Sequential)]
        public struct SystemPowerCapabilities
        {
            [MarshalAs(UnmanagedType.I1)]
            public bool PowerButtonPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool SleepButtonPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool LidPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool SystemS1;
            [MarshalAs(UnmanagedType.I1)]
            public bool SystemS2;
            [MarshalAs(UnmanagedType.I1)]
            public bool SystemS3;
            [MarshalAs(UnmanagedType.I1)]
            public bool SystemS4;
            [MarshalAs(UnmanagedType.I1)]
            public bool SystemS5;
            [MarshalAs(UnmanagedType.I1)]
            public bool HiberFilePresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool FullWake;
            [MarshalAs(UnmanagedType.I1)]
            public bool VideoDimPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool ApmPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool UpsPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool ThermalControl;
            [MarshalAs(UnmanagedType.I1)]
            public bool ProcessorThrottle;
            public byte ProcessorMinimumThrottle;
            public byte ProcessorMaximumThrottle;
            [MarshalAs(UnmanagedType.I1)]
            public bool FastSystemS4;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
            public byte[] spare2;
            [MarshalAs(UnmanagedType.I1)]
            public bool DiskSpinDown;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public byte[] spare3;
            [MarshalAs(UnmanagedType.I1)]
            public bool SystemBatteriesPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool BatteriesAreShortTerm;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
            public BatteryReportingScale[] BatteryScale;
            public SystemPowerState AcOnlineWake;
            public SystemPowerState SoftLidWake;
            public SystemPowerState RtcWake;
            public SystemPowerState MinimumDeviceWakeState;
            public SystemPowerState DefaultLowLatencyWake;
        }

        public enum PowerInformationLevel
        {
            SystemPowerPolicyAc,
            SystemPowerPolicyDc,
            VerifySystemPolicyAc,
            VerifySystemPolicyDc,
            SystemPowerCapabilities,
            SystemBatteryState,
            SystemPowerStateHandler,
            ProcessorStateHandler,
            SystemPowerPolicyCurrent,
            AdministratorPowerPolicy,
            SystemReserveHiberFile,
            ProcessorInformation,
            SystemPowerInformation,
            ProcessorStateHandler2,
            LastWakeTime,
            LastSleepTime,
            SystemExecutionState,
            SystemPowerStateNotifyHandler,
            ProcessorPowerPolicyAc,
            ProcessorPowerPolicyDc,
            VerifyProcessorPowerPolicyAc,
            VerifyProcessorPowerPolicyDc,
            ProcessorPowerPolicyCurrent,
            SystemPowerStateLogging,
            SystemPowerLoggingEntry,
            SetPowerSettingValue,
            NotifyUserPowerSetting,
            PowerInformationLevelUnused0,
            PowerInformationLevelUnused1,
            SystemVideoState,
            TraceApplicationPowerMessage,
            TraceApplicationPowerMessageEnd,
            ProcessorPerfStates,
            ProcessorIdleStates,
            ProcessorCap,
            SystemWakeSource,
            SystemHiberFileInformation,
            TraceServicePowerMessage,
            ProcessorLoad,
            PowerShutdownNotification,
            MonitorCapabilities,
            SessionPowerInit,
            SessionDisplayState,
            PowerRequestCreate,
            PowerRequestAction,
            GetPowerRequestList,
            ProcessorInformationEx,
            NotifyUserModeLegacyPowerEvent,
            GroupPark,
            ProcessorIdleDomains,
            WakeTimerList,
            SystemHiberFileSize,
            PowerInformationLevelMaximum
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct BatteryReportingScale
        {
            public UInt32 Granularity;
            public UInt32 Capacity;
        }

        public enum SystemPowerState
        {
            Unspecified = 0,
            Working = 1,
            Sleeping1 = 2,
            Sleeping2 = 3,
            Sleeping3 = 4,
            Hibernate = 5,
            Shutdown = 6,
            Maximum = 7
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct SystemBatteryState
        {
            [MarshalAs(UnmanagedType.I1)]
            public bool AcOnLine;
            [MarshalAs(UnmanagedType.I1)]
            public bool BatteryPresent;
            [MarshalAs(UnmanagedType.I1)]
            public bool Charging;
            [MarshalAs(UnmanagedType.I1)]
            public bool Discharging;
            public byte Spare1;
            public byte Spare2;
            public byte Spare3;
            public byte Spare4;
            public uint MaxCapacity;
            public uint RemainingCapacity;
            public uint Rate;
            public uint EstimatedTime;
            public uint DefaultAlert1;
            public uint DefaultAlert2;
        }

        [DllImport("powrprof.dll")]
        internal static extern UInt32 CallNtPowerInformation(
             PowerInformationLevel informationLevel,
             IntPtr inputBuffer,
             UInt32 inputBufferSize,
             out SystemPowerCapabilities outputBuffer,
             UInt32 outputBufferSize
        );

        [DllImport("powrprof.dll")]
        internal static extern UInt32 CallNtPowerInformation(
             PowerInformationLevel informationLevel,
             IntPtr inputBuffer,
             UInt32 inputBufferSize,
             out SystemBatteryState outputBuffer,
             UInt32 outputBufferSize
        );

        /// <summary>
        /// Gets the Guid relating to the currently active power scheme.
        /// </summary>
        /// <param name="rootPowerKey">Reserved for future use, this must be set to IntPtr.Zero</param>
        /// <param name="activePolicy">Returns a Guid referring to the currently active power scheme.</param>
        [DllImport("powrprof.dll")]
        internal static extern void PowerGetActiveScheme(
            IntPtr rootPowerKey,
            [MarshalAs(UnmanagedType.LPStruct)]
            out Guid activePolicy);

        [DllImport("User32", SetLastError = true,
            EntryPoint = "RegisterPowerSettingNotification",
            CallingConvention = CallingConvention.StdCall)]
        internal static extern int RegisterPowerSettingNotification(
                IntPtr hRecipient,
                ref Guid PowerSettingGuid,
                Int32 Flags);

        [DllImport("kernel32.dll", SetLastError = true)]
        internal static extern ExecutionStates SetThreadExecutionState(ExecutionStates esFlags);

        #endregion
    }
}

using System;

namespace tweetz5.Utilities.PowerManagment
{
    [Flags]
    public enum ExecutionStates
    {
        /// <summary>
        /// No state configured.
        /// </summary>
        None = 0,

        /// <summary>
        /// Forces the system to be in the working state by resetting the system idle timer.
        /// </summary>
        SystemRequired = 0x1,

        /// <summary>
        /// Forces the display to be on by resetting the display idle timer.
        /// </summary>
        DisplayRequired = 0x2,

        /// <summary>
        /// Enables away mode. This value must be specified with ES_CONTINUOUS.
        /// Away mode should be used only by media-recording and media-distribution applications that must perform critical background processing on desktop computers while the computer appears to be sleeping. See Remarks.
        /// 
        /// Windows Server 2003 and Windows XP/2000:  ES_AWAYMODE_REQUIRED is not supported.
        /// </summary>
        AwayModeRequired = 0x40,

        /// <summary>
        /// Informs the system that the state being set should remain in effect until the next call that uses ES_CONTINUOUS and one of the other state flags is cleared.
        /// </summary>
        Continuous = unchecked((int)0x80000000)
    }
}

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;

namespace tweetz5.Utilities.PowerManagment
{
    internal static class PowerManager
    {
        internal static Guid MonitorPowerStatus = 
            new Guid(0x02731015, 0x4510, 0x4526, 0x99, 0xe6, 0xe5, 0xa1, 0x7e, 0xbd, 0x1a, 0xea);

        public static void RegisterMonitorStatusChange(Window window)
        {
            PowerManagementNativeMethods.RegisterPowerSettingNotification(
                new WindowInteropHelper(window).Handle, ref MonitorPowerStatus, 0);
        }

        public static int MonitorStatus(IntPtr wParam, IntPtr lParam)
        {
            var ps = (PowerManagementNativeMethods.PowerBroadcastSetting)Marshal
                .PtrToStructure(lParam, typeof(PowerManagementNativeMethods.PowerBroadcastSetting));

            var pData = new IntPtr(lParam.ToInt64() + Marshal.SizeOf(ps));
            var monitorStatus = -1;

            if (ps.PowerSetting == MonitorPowerStatus && 
                ps.DataLength == Marshal.SizeOf(typeof(int)))
            {
                monitorStatus = (int)Marshal.PtrToStructure(pData, typeof(int));
            }
            return monitorStatus;
        }
    }
}

Register a window by calling RegisterMonitorStatusChange. Then override the registerd windows WndProc to handle the notificiatons. Here’s what tweetz does.

private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
      {
          switch (msg)
          {
              case (int)PowerManagementNativeMethods.PowerBroadcastMessage:
                  if ((int)wParam == PowerManagementNativeMethods.PowerSettingChangeMessage)
                  {
                      var monitorStatus = PowerManager.MonitorStatus(wParam, lParam);
                      if (monitorStatus == 0) Timeline.Controller.StopTimelines();
                      if (monitorStatus == 1) Timeline.Controller.StartTimelines();
                  }
                  break;
          }
          return IntPtr.Zero;
      }
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