Get Symbolic Name Of Key Combination Code

[miksayer]

I've got such source code from MFC:

CString CHotKeyCtrl::GetKeyName(UINT vk, BOOL fExtended)
{
    LONG lScan = MapVirtualKey(vk, 0) << 16;

    // if it's an extended key, add the extended flag
    if (fExtended)
        lScan |= 0x01000000L;

    CString str;
    int nBufferLen = 64;
    int nLen;
    do
    {
        nBufferLen *= 2;
        LPTSTR psz = str.GetBufferSetLength(nBufferLen);
        nLen = ::GetKeyNameText(lScan, psz, nBufferLen + 1);
        str.ReleaseBuffer(nLen);
    }
    while (nLen == nBufferLen);
    return str;
}

CString CHotKeyCtrl::GetHotKeyName() const
{
    ASSERT(::IsWindow(m_hWnd));

    CString strKeyName;
    WORD wCode;
    WORD wModifiers;

    GetHotKey(wCode, wModifiers);
    if (wCode != 0 || wModifiers != 0)
    {
        if (wModifiers & HOTKEYF_CONTROL)
        {
            strKeyName += GetKeyName(VK_CONTROL, FALSE);
            strKeyName += szPlus;
        }

        if (wModifiers & HOTKEYF_SHIFT)
        {
            strKeyName += GetKeyName(VK_SHIFT, FALSE);
            strKeyName += szPlus;
        }

        if (wModifiers & HOTKEYF_ALT)
        {
            strKeyName += GetKeyName(VK_MENU, FALSE);
            strKeyName += szPlus;
        }

        strKeyName += GetKeyName(wCode, wModifiers & HOTKEYF_EXT);
    }

    return strKeyName;
}

i want to rewrite it using std::string(or char []), but i don't know std::string prototypes for CString::GetBufferSetLength and CString::ReleaseBuffer. Can you help me?

[_Superman_]

You could dynamically allocate a TCHAR array and then deallocate it after use.

TCHAR* psz = new TCHAR[nBufferLen + 1];
.
.
.
delete [] psz;

char and string don't work with unicode data.

[miksayer]

I hve code like this(i rewrite this code for your recommendations):

std::wstring getKeyName(UINT vk, BOOL fExtended)
	{
		LONG lScan = MapVirtualKey(vk, 0) << 16;

		// if it's an extended key, add the extended flag
		if (fExtended)
			lScan |= 0x01000000L;
		int nBufferLen = 64;
		wchar_t* str;
		int nLen;
		do
		{
			nBufferLen *= 2;
			str = new wchar_t[nBufferLen + 1];
			nLen = ::GetKeyNameText(lScan, (LPWSTR)str, nBufferLen + 1);
			delete [] str; 
		}
		while (nLen == nBufferLen);
		return str;
	}

	std::wstring getHotkeyName(Hotkey hk)
	{

		std::wstring strKeyName;
		WORD wCode = LOBYTE(hk);
		WORD wModifiers = HIBYTE(hk);

		if (wCode != 0 || wModifiers != 0)
		{
			if (wModifiers & HOTKEYF_CONTROL)
			{
				strKeyName += getKeyName(VK_CONTROL, FALSE);
				strKeyName += L"+";
			}

			if (wModifiers & HOTKEYF_SHIFT)
			{
				strKeyName += getKeyName(VK_SHIFT, FALSE);
				strKeyName += L"+";
			}

			if (wModifiers & HOTKEYF_ALT)
			{
				strKeyName += getKeyName(VK_MENU, FALSE);
				strKeyName += L"+";
			}

			strKeyName += getKeyName(wCode, FALSE);
		}

		return strKeyName;
	}

but i've got error in wcslen.c. What i do unduly?

[ovidiucucu]

You are trying to return some garbage ('str' is deleted before).
To replace CString with std::wstring, use the next code

   // ... same as above
   std::wstring str;
   int nLen;
   do
   {
      nBufferLen *= 2;
      str.resize(nBufferLen);
      nLen = ::GetKeyNameTextW(lScan, &str[0], nBufferLen);
   }
   while (nLen == nBufferLen);
   return str;
}

[miksayer]

2 ovidiucucu
but i all the same have garbage(see attache)
my code:

	std::wstring getKeyName(UINT vk, BOOL fExtended)
	{
		LONG lScan = MapVirtualKey(vk, 0) << 16;

		// if it's an extended key, add the extended flag
		if (fExtended)
			lScan |= 0x01000000L;
		int nBufferLen = 64;
		std::wstring str;
		int nLen;
		do
		{
			nBufferLen *= 2;
			str.resize(nBufferLen);
			nLen = ::GetKeyNameTextW(lScan, &str[0], nBufferLen);
		}
		while (nLen == nBufferLen);
		return str;
	}

[miksayer]

problem located in this function

std::wstring getHotkeyName(Hotkey hk)
	{

		std::wstring strKeyName;
		WORD wCode = LOBYTE(hk);
		WORD wModifiers = HIBYTE(hk);

		if (wCode != 0 || wModifiers != 0)
		{
			if (wModifiers & HOTKEYF_CONTROL)
			{
				strKeyName += getKeyName(VK_CONTROL, FALSE);
				strKeyName += L"+";
			}

			if (wModifiers & HOTKEYF_SHIFT)
			{
				strKeyName += getKeyName(VK_SHIFT, FALSE);
				strKeyName += L"+";
			}

			if (wModifiers & HOTKEYF_ALT)
			{
				strKeyName += getKeyName(VK_MENU, FALSE);
				strKeyName += L"+";
			}

			strKeyName += getKeyName(wCode, FALSE);
		}

		return strKeyName;
	}

because getKeyName is working normally(i understood it by debugging). What i do unduly?

[ovidiucucu]

Ah, forgot a little detail

std::wstring getKeyName(UINT vk, BOOL fExtended)
{
   // same as in my previous post
   return str.c_str();
}

I hope now is "unduly".

[miksayer]

ovidiucucu, big thx