Respect UI language flow direction in message boxes

- Add a function to check flow direction of currently selected
UI language
- Add MB_RIGHT|MB_RTLREADING to message boxes when language is RTL

Note: though we use MessageBoxEx() for popups, and pass langId to it,
buttons like OK/Cancel are not automatically localized. It seems these
get localized based on the current locale, not the langID passed in.

Signed-off-by: Selva Nair <selva.nair@gmail.com>

localization.c

@@ -69,6 +69,22 @@ FindResourceLang(PTSTR resType, PTSTR resId, LANGID langId)
     return FindResource(o.hInstance, resId, resType);
 }
 
+/*
+ * Return value: 0 for LTR, 1 for RTL, 2 or 3 for vertical
+ */
+int
+LangFlowDirection(void)
+{
+    int res = 0; /* LTR by default */
+    wchar_t lcname[LOCALE_NAME_MAX_LENGTH];
+    wchar_t data[2];
+    if (LCIDToLocaleName(MAKELCID(GetGUILanguage(), SORT_DEFAULT), lcname, _countof(lcname), 0) != 0
+        && GetLocaleInfoEx(lcname, LOCALE_IREADINGLAYOUT, data, 2) != 0)
+    {
+        res = _wtoi(data);
+    }
+    return res;
+}
 
 LANGID
 GetGUILanguage(void)
@@ -257,10 +273,9 @@ static int
 __ShowLocalizedMsgEx(const UINT type, HANDLE parent, LPCTSTR caption, const UINT stringId, va_list args)
 {
     return MessageBoxEx(parent, __LoadLocalizedString(stringId, args), caption,
-        type | MB_SETFOREGROUND, GetGUILanguage());
+        type | MB_SETFOREGROUND | MBOX_RTL_FLAGS, GetGUILanguage());
 }
 
-
 int
 ShowLocalizedMsgEx(const UINT type, HANDLE parent, LPCTSTR caption, const UINT stringId, ...)
 {

localization.h

@@ -37,5 +37,11 @@ HWND CreateLocalizedDialogParam(const UINT, DLGPROC, const LPARAM);
 HWND CreateLocalizedDialog(const UINT, DLGPROC);
 INT_PTR CALLBACK GeneralSettingsDlgProc(HWND, UINT, WPARAM, LPARAM);
 LANGID GetGUILanguage(void);
+/*
+ * Detect whether the selected UI language is LTR or RTL.
+ * Returns 0 for LTR, 1 for RTL, 2 or 3 for vertical
+ */
+int LangFlowDirection(void);
+#define MBOX_RTL_FLAGS ((LangFlowDirection() == 1) ? MB_RIGHT|MB_RTLREADING : 0)
 
 #endif

main.c

@@ -938,7 +938,7 @@ ErrorExit(int exit_code, const wchar_t *msg)
 {
     if (msg)
         MessageBoxExW(NULL, msg, TEXT(PACKAGE_NAME),
-                      MB_OK | MB_SETFOREGROUND|MB_ICONERROR, GetGUILanguage());
+                      MB_OK | MB_SETFOREGROUND | MB_ICONERROR | MBOX_RTL_FLAGS, GetGUILanguage());
     if (o.hWnd)
     {
         StopAllOpenVPN();

openvpn.c

@@ -1283,8 +1283,8 @@ OnTimeout(connection_t *c, UNUSED char *msg)
     c->state = connecting;
     if (!OpenManagement(c))
     {
-        MessageBoxEx(NULL, L"Failed to open management", _T(PACKAGE_NAME),
-                     MB_OK|MB_SETFOREGROUND|MB_ICONERROR, GetGUILanguage());
+        MessageBoxExW(NULL, L"Failed to open management", _T(PACKAGE_NAME),
+                     MB_OK | MB_SETFOREGROUND | MB_ICONERROR | MBOX_RTL_FLAGS, GetGUILanguage());
         StopOpenVPN(c);
     }
     return;
@@ -1316,8 +1316,8 @@ OnStop(connection_t *c, UNUSED char *msg)
             SetForegroundWindow(c->hwndStatus);
             ShowWindow(c->hwndStatus, SW_SHOW);
         }
-        MessageBox(c->hwndStatus, LoadLocalizedString(IDS_NFO_CONN_TERMINATED, c->config_file),
-                   _T(PACKAGE_NAME), MB_OK);
+        MessageBoxExW(c->hwndStatus, LoadLocalizedString(IDS_NFO_CONN_TERMINATED, c->config_file),
+                   _T(PACKAGE_NAME), MB_OK | MBOX_RTL_FLAGS, GetGUILanguage());
         SendMessage(c->hwndStatus, WM_CLOSE, 0, 0);
         break;
 
@@ -1340,7 +1340,8 @@ OnStop(connection_t *c, UNUSED char *msg)
             SetForegroundWindow(c->hwndStatus);
             ShowWindow(c->hwndStatus, SW_SHOW);
         }
-        MessageBox(c->hwndStatus, LoadLocalizedString(msg_id, c->config_name), _T(PACKAGE_NAME), MB_OK);
+        MessageBoxExW(c->hwndStatus, LoadLocalizedString(msg_id, c->config_name),
+                   _T(PACKAGE_NAME), MB_OK | MBOX_RTL_FLAGS, GetGUILanguage());
         SendMessage(c->hwndStatus, WM_CLOSE, 0, 0);
         break;
 
@@ -1764,7 +1765,7 @@ OnNeedOk (connection_t *c, char *msg)
     }
 
     const char *fmt;
-    if (MessageBoxW (NULL, wstr, L""PACKAGE_NAME, MB_OKCANCEL) == IDOK)
+    if (MessageBoxExW(NULL, wstr, L""PACKAGE_NAME, MB_OKCANCEL | MBOX_RTL_FLAGS, GetGUILanguage()) == IDOK)
     {
         fmt = "needok \'%s\' ok";
     }
@@ -2124,8 +2125,8 @@ ThreadOpenVPNStatus(void *p)
 
     if (!OpenManagement(c))
     {
-        MessageBoxEx(NULL, L"Failed to open management", _T(PACKAGE_NAME),
-                     MB_OK|MB_SETFOREGROUND|MB_ICONERROR, GetGUILanguage());
+        MessageBoxExW(NULL, L"Failed to open management", _T(PACKAGE_NAME),
+                     MB_OK | MB_SETFOREGROUND | MB_ICONERROR | MBOX_RTL_FLAGS, GetGUILanguage());
         StopOpenVPN(c);
     }
 

options.c

@@ -96,7 +96,7 @@ add_option(options_t *options, int i, TCHAR **p)
 
         LoadLocalizedStringBuf(caption, _countof(caption), IDS_NFO_USAGECAPTION);
         LoadLocalizedStringBuf(msg, _countof(msg), IDS_NFO_USAGE);
-        MessageBoxEx(NULL, msg, caption, MB_OK | MB_SETFOREGROUND, GetGUILanguage());
+        MessageBoxExW(NULL, msg, caption, MB_OK | MB_SETFOREGROUND | MBOX_RTL_FLAGS, GetGUILanguage());
         exit(0);
     }
     else if (streq(p[0], _T("connect")) && p[1])