netripper

// KeypadLedControl.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <windows.h>
#include <pmpolicy.h>

// From MSDN: http://msdn.microsoft.com/en-us/library/ms838354.aspx
#pragma region Power management defines

// GDI Escapes for ExtEscape()
#define QUERYESCSUPPORT    8

// The following are unique to CE
#define GETVFRAMEPHYSICAL   6144
#define GETVFRAMELEN    6145
#define DBGDRIVERSTAT    6146
#define SETPOWERMANAGEMENT   6147
#define GETPOWERMANAGEMENT   6148

typedef struct _VIDEO_POWER_MANAGEMENT {
    ULONG Length;
    ULONG DPMSVersion;
    ULONG PowerState;
} VIDEO_POWER_MANAGEMENT, *PVIDEO_POWER_MANAGEMENT;

typedef enum _VIDEO_POWER_STATE {
    VideoPowerOn = 1,
    VideoPowerStandBy,
    VideoPowerSuspend,
    VideoPowerOff
} VIDEO_POWER_STATE, *PVIDEO_POWER_STATE;

#pragma endregion // Power management defines

int _tmain(int argc, _TCHAR* argv[])
{
    // Create an event for ourselves, so that we can be turned off as well
    HANDLE appEvent = CreateEvent(NULL, TRUE, FALSE, L"KeypadLedControlApp");
    if (appEvent == NULL)
    {
        MessageBox(NULL, L"Couldn't create an event for ourselves", L"Error", MB_OK);
        return 1;
    }

    // If the app is already running, we set the event so that it will close itself.
    if (GetLastError() == ERROR_ALREADY_EXISTS)
    {
        SetEvent(appEvent);
        CloseHandle(appEvent);
        return 1;
    }

    // Get the keyped led event (this one is used for Leo at least)
    HANDLE iconOnEvent = CreateEvent(NULL, TRUE, FALSE, L"IconLedOnEvent");
    if (iconOnEvent == NULL)
    {
        // Oops, error creating the event?
        MessageBox(NULL, L"Couldn't create the 'IconLedOnEvent' keypad light event", L"Error", MB_OK);
        return 1;
    }
    if (GetLastError() != ERROR_ALREADY_EXISTS)
    {
        // This even didn't exist yet. Let's see if we can try another event (it's IconLedEvent for Rhodium)
        CloseHandle(iconOnEvent);
        iconOnEvent = CreateEvent(NULL, TRUE, FALSE, L"IconLedEvent");
        if (iconOnEvent == NULL)
        {
            MessageBox(NULL, L"Couldn't create the 'IconLedEvent' keypad light event", L"Error", MB_OK);
            return 1;
        }
        if (GetLastError() != ERROR_ALREADY_EXISTS)
        {
            // This event didn't exist either.
            MessageBox(NULL, L"Sorry, this device is not supported it seems", L"Error", MB_OK);
            CloseHandle(iconOnEvent);
            return 1;
        }
    }

    // Get the keypad led event to turn it off
    HANDLE iconOffEvent = CreateEvent(NULL, TRUE, FALSE, L"IconLedOffEvent");
    if (iconOffEvent == NULL)
    {
        // Oops, error creating the event?
        MessageBox(NULL, L"Couldn't create the 'IconLedOffEvent' keypad light event", L"Error", MB_OK);
        return 1;
    }
    if (GetLastError() != ERROR_ALREADY_EXISTS)
    {
        // This event didn't exist yet. This means this device does not use this event. Which means we will just ignore it and hope
        // the keypad lights goes off automatically when it goes into standby.
        CloseHandle(iconOffEvent);
        iconOffEvent = NULL;
    }

    // Check if the driver supports power management information
    HDC gdc = GetDC(NULL);
    int iESC = GETPOWERMANAGEMENT;
    if (ExtEscape(gdc, QUERYESCSUPPORT, sizeof(int), (LPCSTR)&iESC, 0, NULL) == 0)
    {
        MessageBox(NULL, L"This device does not support checking for LCD state", L"Error", MB_OK);
        CloseHandle(iconOnEvent);
        ReleaseDC(NULL, gdc);
        return 1;
    }

    // Request that we stay in UNATTENDED power mode, so that we keep getting CPU cycles while LCD is turned off
    // We must keep track of unattended mode. It uses a refcount. If we would forget to release, the device would never enter real standby anymore = battery drain.
    bool bUsingUnattendedMode = true;
    bool res = PowerPolicyNotify(PPN_UNATTENDEDMODE, TRUE);

    // Variables for the loop. To prevent overhead we create these variables outside the loop.
    VIDEO_POWER_MANAGEMENT pm;
    pm.Length = sizeof(pm);
    int ret;
    while (true)
    {
        // Get current power management information
        ret = ExtEscape(gdc, GETPOWERMANAGEMENT, 0, NULL, pm.Length, (LPSTR)&pm);

        // Check the power state
        if (pm.PowerState == VideoPowerOn)
        {
            // LCD is on, set the event so that the keypad lights go on
            SetEvent(iconOnEvent);

            // Also enable unattended mode if it wasn't already enabled
            if (!bUsingUnattendedMode)
            {
                PowerPolicyNotify(PPN_UNATTENDEDMODE, TRUE);
                bUsingUnattendedMode = true;
            }
        }
        else
        {
            // LCD is either in standby, suspend or off. Set the event to turn keypad lights off (if we can).
            if (iconOffEvent != NULL)
            {
                SetEvent(iconOffEvent);
            }

            // And release unattended mode
            if (bUsingUnattendedMode)
            {
                PowerPolicyNotify(PPN_UNATTENDEDMODE, FALSE);
                bUsingUnattendedMode = false;
            }
        }

        // We'll keep on running this app as long as the event hasn't been set (by starting this app again)
        // Use a 1-second delay. This means that:
        // - If the device goes into standby, it may take up to 1 second before the keypad light goes off (i.e. for Rhodium where
        //   keypad is not turned off by the driver).
        // - The device won't stay in unattended mode longer than 1 second, as the LCD power is re-evaluated within this time and
        //   unattended mode is released when LCD is off after setting the event. This prevents power drain.
        if (WaitForSingleObject(appEvent, 1000) != WAIT_TIMEOUT)
        {
            break;
        }
    }

    // Cleanup
    ReleaseDC(NULL, gdc);
    CloseHandle(iconOnEvent);
    CloseHandle(appEvent);
    if (iconOffEvent != NULL)
    {
        CloseHandle(iconOffEvent);
    }
    if (bUsingUnattendedMode)
    {
        PowerPolicyNotify(PPN_UNATTENDEDMODE, FALSE);
        bUsingUnattendedMode = false;
    }

    return 0;
}