libui/windows/dwrite.cpp

91 lines
2.8 KiB
C++

// 14 april 2016
#include "uipriv_windows.hpp"
#include "attrstr.hpp"
IDWriteFactory *dwfactory = NULL;
// TOOD rename to something else, maybe
HRESULT uiprivInitDrawText(void)
{
// TOOD use DWRITE_FACTORY_TYPE_ISOLATED instead?
return DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED,
__uuidof (IDWriteFactory),
(IUnknown **) (&dwfactory));
}
void uiprivUninitDrawText(void)
{
dwfactory->Release();
}
fontCollection *uiprivLoadFontCollection(void)
{
fontCollection *fc;
HRESULT hr;
fc = uiprivNew(fontCollection);
// always get the latest available font information
hr = dwfactory->GetSystemFontCollection(&(fc->fonts), TRUE);
if (hr != S_OK)
logHRESULT(L"error getting system font collection", hr);
fc->userLocaleSuccess = GetUserDefaultLocaleName(fc->userLocale, LOCALE_NAME_MAX_LENGTH);
return fc;
}
void uiprivFontCollectionFree(fontCollection *fc)
{
fc->fonts->Release();
uiprivFree(fc);
}
WCHAR *uiprivFontCollectionFamilyName(fontCollection *fc, IDWriteFontFamily *family)
{
IDWriteLocalizedStrings *names;
WCHAR *str;
HRESULT hr;
hr = family->GetFamilyNames(&names);
if (hr != S_OK)
logHRESULT(L"error getting names of font out", hr);
str = fontCollectionCorrectString(fc, names);
names->Release();
return str;
}
WCHAR *uiprivFontCollectionCorrectString(fontCollection *fc, IDWriteLocalizedStrings *names)
{
UINT32 index;
BOOL exists;
UINT32 length;
WCHAR *wname;
HRESULT hr;
// this is complex, but we ignore failure conditions to allow fallbacks
// 1) If the user locale name was successfully retrieved, try it
// 2) If the user locale name was not successfully retrieved, or that locale's string does not exist, or an error occurred, try L"en-us", the US English locale
// 3) And if that fails, assume the first one
// This algorithm is straight from MSDN: https://msdn.microsoft.com/en-us/library/windows/desktop/dd368214%28v=vs.85%29.aspx
// For step 2 to work, start by setting hr to S_OK and exists to FALSE.
// TODO does it skip step 2 entirely if step 1 fails? rewrite it to be a more pure conversion of the MSDN code?
hr = S_OK;
exists = FALSE;
if (fc->userLocaleSuccess != 0)
hr = names->FindLocaleName(fc->userLocale, &index, &exists);
if (hr != S_OK || (hr == S_OK && !exists))
hr = names->FindLocaleName(L"en-us", &index, &exists);
// TODO check hr again here? or did I decide that would be redundant because COM requires output arguments to be filled regardless of return value?
if (!exists)
index = 0;
hr = names->GetStringLength(index, &length);
if (hr != S_OK)
logHRESULT(L"error getting length of font name", hr);
// GetStringLength() does not include the null terminator, but GetString() does
wname = (WCHAR *) uiAlloc((length + 1) * sizeof (WCHAR), "WCHAR[]");
hr = names->GetString(index, wname, length + 1);
if (hr != S_OK)
logHRESULT(L"error getting font name", hr);
return wname;
}