widget/windows/nsBidiKeyboard.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include <stdio.h>
   8 #include "nsBidiKeyboard.h"
   9 #include "prmem.h"
  10 #include <tchar.h>
  11
  12 NS_IMPL_ISUPPORTS(nsBidiKeyboard, nsIBidiKeyboard)
  13
  14 nsBidiKeyboard::nsBidiKeyboard() : nsIBidiKeyboard()
  15 {
  16   Reset();
  17 }
  18
  19 nsBidiKeyboard::~nsBidiKeyboard()
  20 {
  21 }
  22
  23 NS_IMETHODIMP nsBidiKeyboard::Reset()
  24 {
  25   mInitialized = false;
  26   mHaveBidiKeyboards = false;
  27   mLTRKeyboard[0] = '\0';
  28   mRTLKeyboard[0] = '\0';
  29   mCurrentLocaleName[0] = '\0';
  30   return NS_OK;
  31 }
  32
  33 NS_IMETHODIMP nsBidiKeyboard::IsLangRTL(bool *aIsRTL)
  34 {
  35   *aIsRTL = false;
  36
  37   nsresult result = SetupBidiKeyboards();
  38   if (NS_FAILED(result))
  39     return result;
  40
  41   HKL  currentLocale;
  42
  43   currentLocale = ::GetKeyboardLayout(0);
  44   *aIsRTL = IsRTLLanguage(currentLocale);
  45
  46   if (!::GetKeyboardLayoutNameW(mCurrentLocaleName))
  47     return NS_ERROR_FAILURE;
  48
  49   NS_ASSERTION(*mCurrentLocaleName,
  50     "GetKeyboardLayoutName return string length == 0");
  51   NS_ASSERTION((wcslen(mCurrentLocaleName) < KL_NAMELENGTH),
  52     "GetKeyboardLayoutName return string length >= KL_NAMELENGTH");
  53
  54   // The language set by the user overrides the default language for that direction
  55   if (*aIsRTL) {
  56     wcsncpy(mRTLKeyboard, mCurrentLocaleName, KL_NAMELENGTH);
  57     mRTLKeyboard[KL_NAMELENGTH-1] = '\0'; // null terminate
  58   } else {
  59     wcsncpy(mLTRKeyboard, mCurrentLocaleName, KL_NAMELENGTH);
  60     mLTRKeyboard[KL_NAMELENGTH-1] = '\0'; // null terminate
  61   }
  62
  63   NS_ASSERTION((wcslen(mRTLKeyboard) < KL_NAMELENGTH),
  64     "mLTRKeyboard has string length >= KL_NAMELENGTH");
  65   NS_ASSERTION((wcslen(mLTRKeyboard) < KL_NAMELENGTH),
  66     "mRTLKeyboard has string length >= KL_NAMELENGTH");
  67   return NS_OK;
  68 }
  69
  70 NS_IMETHODIMP nsBidiKeyboard::GetHaveBidiKeyboards(bool* aResult)
  71 {
  72   NS_ENSURE_ARG_POINTER(aResult);
  73
  74   nsresult result = SetupBidiKeyboards();
  75   if (NS_FAILED(result))
  76     return result;
  77
  78   *aResult = mHaveBidiKeyboards;
  79   return NS_OK;
  80 }
  81
  82
  83 // Get the list of keyboard layouts available in the system
  84 // Set mLTRKeyboard to the first LTR keyboard in the list and mRTLKeyboard to the first RTL keyboard in the list
  85 // These defaults will be used unless the user explicitly sets something else.
  86 nsresult nsBidiKeyboard::SetupBidiKeyboards()
  87 {
  88   if (mInitialized)
  89     return mHaveBidiKeyboards ? NS_OK : NS_ERROR_FAILURE;
  90
  91   int keyboards;
  92   HKL far* buf;
  93   HKL locale;
  94   wchar_t localeName[KL_NAMELENGTH];
  95   bool isLTRKeyboardSet = false;
  96   bool isRTLKeyboardSet = false;
  97
  98   // GetKeyboardLayoutList with 0 as first parameter returns the number of keyboard layouts available
  99   keyboards = ::GetKeyboardLayoutList(0, nullptr);
 100   if (!keyboards)
 101     return NS_ERROR_FAILURE;
 102
 103   // allocate a buffer to hold the list
 104   buf = (HKL far*) PR_Malloc(keyboards * sizeof(HKL));
 105   if (!buf)
 106     return NS_ERROR_OUT_OF_MEMORY;
 107
 108   // Call again to fill the buffer
 109   if (::GetKeyboardLayoutList(keyboards, buf) != keyboards) {
 110     PR_Free(buf);
 111     return NS_ERROR_UNEXPECTED;
 112   }
 113
 114   // Go through the list and pick a default LTR and RTL keyboard layout
 115   while (keyboards--) {
 116     locale = buf[keyboards];
 117     if (IsRTLLanguage(locale)) {
 118       _snwprintf(mRTLKeyboard, KL_NAMELENGTH, L"%.*x", KL_NAMELENGTH - 1,
 119                  LANGIDFROMLCID((DWORD_PTR)locale));
 120       isRTLKeyboardSet = true;
 121     }
 122     else {
 123       _snwprintf(mLTRKeyboard, KL_NAMELENGTH, L"%.*x", KL_NAMELENGTH - 1,
 124                  LANGIDFROMLCID((DWORD_PTR)locale));
 125       isLTRKeyboardSet = true;
 126     }
 127   }
 128   PR_Free(buf);
 129   mInitialized = true;
 130
 131   // If there is not at least one keyboard of each directionality, Bidi
 132   // keyboard functionality will be disabled.
 133   mHaveBidiKeyboards = (isRTLKeyboardSet && isLTRKeyboardSet);
 134   if (!mHaveBidiKeyboards)
 135     return NS_ERROR_FAILURE;
 136
 137   // Get the current keyboard layout and use it for either mRTLKeyboard or
 138   // mLTRKeyboard as appropriate. If the user has many keyboard layouts
 139   // installed this prevents us from arbitrarily resetting the current
 140   // layout (bug 80274)
 141   locale = ::GetKeyboardLayout(0);
 142   if (!::GetKeyboardLayoutNameW(localeName))
 143     return NS_ERROR_FAILURE;
 144
 145   NS_ASSERTION(*localeName,
 146     "GetKeyboardLayoutName return string length == 0");
 147   NS_ASSERTION((wcslen(localeName) < KL_NAMELENGTH),
 148     "GetKeyboardLayout return string length >= KL_NAMELENGTH");
 149
 150   if (IsRTLLanguage(locale)) {
 151     wcsncpy(mRTLKeyboard, localeName, KL_NAMELENGTH);
 152     mRTLKeyboard[KL_NAMELENGTH-1] = '\0'; // null terminate
 153   }
 154   else {
 155     wcsncpy(mLTRKeyboard, localeName, KL_NAMELENGTH);
 156     mLTRKeyboard[KL_NAMELENGTH-1] = '\0'; // null terminate
 157   }
 158
 159   NS_ASSERTION(*mRTLKeyboard,
 160     "mLTRKeyboard has string length == 0");
 161   NS_ASSERTION(*mLTRKeyboard,
 162     "mLTRKeyboard has string length == 0");
 163
 164   return NS_OK;
 165 }
 166
 167 // Test whether the language represented by this locale identifier is a
 168 //  right-to-left language, using bit 123 of the Unicode subset bitfield in
 169 //  the LOCALESIGNATURE
 170 // See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/intl/unicode_63ub.asp
 171 bool nsBidiKeyboard::IsRTLLanguage(HKL aLocale)
 172 {
 173   LOCALESIGNATURE localesig;
 174   return (::GetLocaleInfoW(PRIMARYLANGID((DWORD_PTR)aLocale),
 175                            LOCALE_FONTSIGNATURE,
 176                            (LPWSTR)&localesig,
 177                            (sizeof(localesig)/sizeof(WCHAR))) &&
 178           (localesig.lsUsb[3] & 0x08000000));
 179 }