Easy way to tell if unicode character is supported in current font?

Question

I\'m using Borland C++ Builder 2009 and I display the right and left pointing arrows like so:

Button2->Hint = L\"Ctrl+\\u2190\" ;
Button3->Hint = L\"Ct         


        

Answer 1

Just for reference and the Google Gods:

bool UnicodeCharSupported(HWND Handle, wchar_t Char)
{
if (Handle)
    {
    DWORD dwSize = GetFontUnicodeRanges(Handle, NULL);
    if (dwSize)
        {
        bool Supported = false ;
        BYTE* bBuffer = new BYTE[dwSize];
        GLYPHSET* pGlyphSet = reinterpret_cast(bBuffer);
        if (GetFontUnicodeRanges(Handle, pGlyphSet))
            {
            for (DWORD x = 0 ; x < pGlyphSet->cRanges && !Supported ; x++)
                {
                Supported = (Char >= pGlyphSet->ranges[x].wcLow &&
                             Char < (pGlyphSet->ranges[x].wcLow + pGlyphSet->ranges[x].cGlyphs)) ;
                }
            }
        delete[] bBuffer;
        return Supported ;
        }
    }
return false ;
}

Example, relating to my Question:

if (!UnicodeCharSupported(Canvas->Handle, 0x2190))
    { /* Character not supported in current Font, use different character */ }