OpenEuphoria

Re: How to get info about foreground window in Windows?

• Posted by DerekParnell (admin) Jun 01, 2013
• 1235 views

Here is a sample program...

include std/dll.e 
include std/machine.e 
include std/os.e 
 
atom WINuser32 = 0 
atom WINkernel32 = 0 
 
atom WINGetForegroundWindow = 0 
atom WINGetWindowInfo = 0 
atom WINSendMessage = 0 
atom WINGetLastError = 0 
 
----------------- 
procedure InitWinAPI() 
----------------- 
	WINuser32 = open_dll("user32.dll") 
	WINkernel32 = open_dll("kernel32.dll") 
 
	if WINuser32 != 0 then 
		WINGetForegroundWindow = define_c_func(WINuser32, "GetForegroundWindow", {}, C_POINTER) 
		WINGetWindowInfo       = define_c_func(WINuser32, "GetWindowInfo", {C_POINTER, C_POINTER}, C_INT) 
		WINSendMessage         = define_c_func(WINuser32, "SendMessageA", {C_POINTER, C_INT, C_POINTER, C_POINTER}, C_INT)  
	end if 
	 
	if WINkernel32 != 0 then 
		WINGetLastError        = define_c_func(WINkernel32, "GetLastError", {}, C_POINTER) 
	end if 
end procedure 
 
 
------------------- 
public function GetForegroundWindow() 
------------------- 
	return c_func( WINGetForegroundWindow, {}) 
end function 
 
------------------- 
public function SendMessage(atom pHwd, atom pMsg, atom pwParm, atom plParm) 
------------------- 
	return c_func( WINSendMessage, {pHwd, pMsg, pwParm, plParm}) 
end function 
 
constant WM_GETTEXT = #000D 
 
 
------------------- 
public function GetLastError() 
------------------- 
	return c_func( WINGetLastError, {}) 
end function 
 
 
-- This needs the handle of the window whose information you want. 
-- 
-- It returns a sequence containing ... 
--	 An atom. 0 if the function succeeded otherwise the error code returned by Windows. 
--       (If not zero, it is the only item in the return sequence.) 
--   A sequence containing the Window's pixel co-ords for left, top, right, bottom 
--   A sequence containing the Window client area pixel co-ords for left, top, right, bottom 
--   An atom containing the Style bits 
--   An atom containing the ExStyle bits 
--   An integer. 1 if the window is active, zero otherwise. 
--   An integer. The height of the horizontal borders (in pixels) 
--   An integer. The height of the vertical borders (in pixels) 
--   The Window's class identifier.  
--   The version of Windows of the application that created this window. 
--   The text of the Window's title bar 
 
------------------- 
public function GetWindowInfo(atom pHandle) 
------------------- 
	atom lWinData 
	sequence lWinInfo 
	atom lError 
	 
	lWinData = allocate(62) 
-- typedef struct tagWINDOWINFO { 
--   DWORD cbSize   #  0 
--   RECT  rcWindow #  4 
--   RECT  rcClient # 20 
--   DWORD dwStyle  # 36 
--   DWORD dwExStyle # 40 
--   DWORD dwWindowStatus # 44 
--   UINT  cxWindowBorders # 48 
--   UINT  cyWindowBorders # 52 
--   ATOM  atomWindowType  # 56 
--   WORD  wCreatorVersion # 60 
-- } WINDOWINFO   # 62 
	 
	poke4(lWinData, 0) 
	if c_func( WINGetWindowInfo, {pHandle, lWinData}) then 
		lError = 0 
		lWinInfo = { 
			{peek4s(lWinData + 04), 
			 peek4s(lWinData + 08), 
			 peek4s(lWinData + 12), 
			 peek4s(lWinData + 16)}, 
			 
			{peek4s(lWinData + 20), 
			 peek4s(lWinData + 24), 
			 peek4s(lWinData + 28), 
			 peek4s(lWinData + 32)}, 
 
			peek4u(lWinData + 36), 
			peek4u(lWinData + 40), 
			peek4u(lWinData + 44), 
			peek4s(lWinData + 48), 
			peek4s(lWinData + 52), 
			peek4s(lWinData + 56), 
			peek2s(lWinData + 60) 
			 
		} 
		 
		-- Note: Assumes ANSI Window Text 
		atom lText 
		atom lTextLen 
		 
		lText = allocate(1000) 
		lTextLen = SendMessage(pHandle, WM_GETTEXT, 999, lText) 
	 
		lWinInfo = append(lWinInfo, peek({lText, lTextLen})) 
		free(lText) 
	else 
		lError = GetLastError() 
		lWinInfo = {} 
	end if 
	 
	free(lWinData) 
	 
	return lError & lWinInfo 
end function 
 
 
 
InitWinAPI() 
include std/console.e 
 
sleep(5)  -- gives you a chance to select a window to look at. 
display (GetWindowInfo( GetForegroundWindow() ))