wkb-hook.c

/*
  Copyright (C) 2016-2020 Dimitar Toshkov Zhekov <dimitar.zhekov@gmail.com>

  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the Free
  Software Foundation; either version 2 of the License, or (at your option)
  any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  for more details.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#define STRICT
#include <windows.h>

#define WKB_MINI_DLL __declspec(dllexport)
#include "wkb-hook.h"

static UINT layoutMessage;

LRESULT CALLBACK windowProc(INT nCode, WPARAM wParam, LPARAM lParam)
{
	if (nCode == HC_ACTION)
	{
		const CWPSTRUCT *const cwp = (const CWPSTRUCT *) lParam;

		if (cwp->message == layoutMessage)
		{
			ActivateKeyboardLayout((HKL) cwp->lParam, 0);
			return TRUE;
		}
	}

	return CallNextHookEx(0, nCode, wParam, lParam);
}

LRESULT CALLBACK keyboardProc(INT nCode, WPARAM wParam, LPARAM lParam)
{
	if (nCode == HC_ACTION || nCode == HC_NOREMOVE)
		if (wParam == VK_SCROLL && ((lParam >> 16) & 0xFF) == 0xE0)
			return TRUE;

	return CallNextHookEx(0, nCode, wParam, lParam);
}

BOOL WINAPI DllMainCRTStartup(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
	(void) hinstDLL;
	(void) lpvReserved;

	if (fdwReason == DLL_PROCESS_ATTACH)
		layoutMessage = RegisterWindowMessage(WKB_LAYOUT_MESSAGE);

	return TRUE;
}