Create Tolk.lua

LuaJIT FFI wrapper for Tolk

src/lua/Tolk.lua

@@ -0,0 +1,128 @@
+--
+-- Product:       Tolk
+-- File:          Tolk.lua
+-- Description:   LuaJIT FFI (or compatible) wrapper module.
+-- Copyright:     (c) 2017, Avi Kelman <fiendish> <[email protected]>
+-- License:       LGPLv3
+--
+-- Usage:
+--    tolk = require "Tolk"
+--    tolk.Load()
+--    tolk.TrySAPI(true)
+--    tolk.Output("Tolk is now using "..tolk.DetectScreenReader()..".")
+
+local ffi = require "ffi"
+
+ffi.cdef [[
+   int MultiByteToWideChar(unsigned int CodePage, unsigned int dwFlags, const char* lpMultiByteStr, int cbMultiByte, wchar_t* lpWideCharStr, int cchWideChar);
+   int WideCharToMultiByte(unsigned int CodePage, unsigned int dwFlags, const wchar_t* lpWideCharStr, int cchWideChar, const char* lpMultiByteStr, int cbMultiByte, const char * lpDefaultChar, bool lpUsedDefaultChar);
+   void __cdecl Tolk_TrySAPI(bool);
+   void __cdecl Tolk_Load();
+   bool __cdecl Tolk_IsLoaded();
+   void __cdecl Tolk_Unload();
+   void __cdecl Tolk_PreferSAPI(bool);
+   const wchar_t * __cdecl Tolk_DetectScreenReader();
+   bool __cdecl Tolk_HasSpeech();
+   bool __cdecl Tolk_HasBraille();
+   bool __cdecl Tolk_Output(const wchar_t *str, bool interrupt);
+   bool __cdecl Tolk_Speak(const wchar_t *str, bool interrupt);
+   bool __cdecl Tolk_Braille(const wchar_t *str);
+   bool __cdecl Tolk_IsSpeaking();
+   bool __cdecl Tolk_Silence();
+]]
+
+local Tolk = ffi.load('Tolk.dll')
+
+local CP_UTF8 = 65001
+
+-- convert wchar_t[] to lua str
+function widestr_to_luastr(wstr)
+    local size_needed = ffi.C.WideCharToMultiByte(CP_UTF8, 0, wstr, -1, nil, 0, nil, false)
+    local str = ffi.new("char[?]", size_needed)
+    ffi.C.WideCharToMultiByte(CP_UTF8, 0, wstr, -1, str, size_needed, nil, false)
+    return ffi.string(str)
+end
+
+-- convert lua str to wchar_t[]
+function luastr_to_widestr(str)
+    local size_needed = ffi.C.MultiByteToWideChar(CP_UTF8, 0, str, -1, nil, 0)
+    local wstr = ffi.new("wchar_t[?]", size_needed)
+    ffi.C.MultiByteToWideChar(CP_UTF8, 0, str, #str, wstr, size_needed)
+    return wstr
+end
+
+local function IsLoaded()
+   return Tolk.Tolk_IsLoaded()
+end
+
+local function Load()
+   if not IsLoaded() then
+      Tolk.Tolk_Load()
+   end
+   return IsLoaded()
+end
+
+local function Unload()
+   Tolk.Tolk_Unload()
+   return not IsLoaded()
+end
+
+local function TrySAPI(yesno)
+   Tolk.Tolk_TrySAPI(yesno)
+end
+
+local function PreferSAPI(yesno)
+   Tolk.Tolk_PreferSAPI(yesno)
+end
+
+local function HasSpeech()
+   return Tolk.Tolk_HasSpeech()
+end
+
+local function HasBraille()
+   return Tolk.Tolk_HasBraille()
+end
+
+local function DetectScreenReader()
+   wstr = Tolk.Tolk_DetectScreenReader()
+   if nil == wstr then
+      return nil
+   end
+   return widestr_to_luastr(wstr)
+end
+
+local function Output(text, interrupt)
+   return Tolk.Tolk_Output(luastr_to_widestr(text), interrupt or false)
+end
+
+local function Speak(text, interrupt)
+   return Tolk.Tolk_Speak(luastr_to_widestr(text), interrupt or false)
+end
+
+local function Braille(text)
+   return Tolk.Tolk_Braille(luastr_to_widestr(text))
+end
+
+local function IsSpeaking()
+   return Tolk.Tolk_IsSpeaking()
+end
+
+local function Silence()
+   Tolk.Tolk_Silence()
+end
+
+return {
+   IsLoaded = IsLoaded,
+   Load = Load,
+   Unload = Unload,
+   TrySAPI = TrySAPI,
+   PreferSAPI = PreferSAPI,
+   HasSpeech = HasSpeech,
+   HasBraille = HasBraille,
+   DetectScreenReader = DetectScreenReader,
+   Output = Output,
+   Speak = Speak,
+   Braille = Braille,
+   IsSpeaking = IsSpeaking,
+   Silence = Silence
+}