1 files changed, 30 insertions, 0 deletions
diff --git a/src/WindowsEnv/Utils.hs b/src/WindowsEnv/Utils.hs
new file mode 100644
index 0000000..c852229
--- /dev/null
+++ b/src/WindowsEnv/Utils.hs
@@ -0,0 +1,30 @@
+-- |
+-- Copyright   : (c) 2016 Egor Tensin <Egor.Tensin@gmail.com>
+-- License     : MIT
+-- Maintainer  : Egor.Tensin@gmail.com
+-- Stability   : experimental
+-- Portability : Windows-only
+
+module WindowsEnv.Utils
+    ( notifyEnvironmentUpdate
+    ) where
+
+import           Foreign.C.Types          (CIntPtr(..))
+import qualified Graphics.Win32.GDI.Types as WinAPI
+import qualified Graphics.Win32.Message   as WinAPI
+import qualified System.Win32.Types       as WinAPI
+
+foreign import ccall "Windows.h SendNotifyMessageW"
+    c_SendNotifyMessage :: WinAPI.HWND -> WinAPI.WindowMessage -> WinAPI.WPARAM -> WinAPI.LPARAM -> IO WinAPI.LRESULT
+
+notifyEnvironmentUpdate :: IO ()
+notifyEnvironmentUpdate =
+    WinAPI.withTString "Environment" $ \lparamPtr -> do
+        let wparam = 0
+        let lparam = fromIntegral $ WinAPI.castPtrToUINTPtr lparamPtr
+        _ <- c_SendNotifyMessage allWindows messageCode wparam lparam
+        return ()
+  where
+    messageCode = WinAPI.wM_WININICHANGE
+    hWND_BROADCAST = WinAPI.castUINTPtrToPtr 0xffff
+    allWindows = hWND_BROADCAST