libui/windows/drawtext.cpp

110 lines
3.6 KiB
C++

// 22 december 2015
// Before we begin, you may be wondering why this file is C++.
// Simple: <dwrite.h> is C++ only! Thanks Microsoft!
// And unlike UI Automation which accidentally just forgets the 'struct' and 'enum' tags in places, <dwrite.h> is a full C++ header file, with class definitions and the use of __uuidof. Oh well :/
#include "uipriv_windows.h"
// notes:
// only available in windows 8 and newer:
// - character spacing
// - kerning control
// - justficiation (how could I possibly be making this up?!)
// - vertical text (SERIOUSLY?! WHAT THE ACTUAL FUCK, MICROSOFT?!?!?!? bonus: some parts of MSDN even say 8.1 only!)
static IDWriteFactory *dwfactory = NULL;
HRESULT initDrawText(void)
{
// TOOD use DWRITE_FACTORY_TYPE_ISOLATED instead?
return DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED,
__uuidof (IDWriteFactory),
(IUnknown **) (&dwfactory));
}
void uninitDrawText(void)
{
dwfactory->Release();
}
struct uiDrawFontFamilies {
IDWriteFontCollection *fonts;
WCHAR userLocale[LOCALE_NAME_MAX_LENGTH];
int userLocaleSuccess;
};
uiDrawFontFamilies *uiDrawListFontFamilies(void)
{
uiDrawFontFamilies *ff;
HRESULT hr;
ff = uiNew(uiDrawFontFamilies);
// always get the latest available font information
hr = dwfactory->GetSystemFontCollection(&(ff->fonts), TRUE);
if (hr != S_OK)
logHRESULT("error getting list of system fonts in uiDrawListFontFamilies()", hr);
ff->userLocaleSuccess = GetUserDefaultLocaleName(ff->userLocale, LOCALE_NAME_MAX_LENGTH);
return ff;
}
uintmax_t uiDrawFontFamiliesNumFamilies(uiDrawFontFamilies *ff)
{
return ff->fonts->GetFontFamilyCount();
}
char *uiDrawFontFamiliesFamily(uiDrawFontFamilies *ff, uintmax_t n)
{
IDWriteFontFamily *family;
IDWriteLocalizedStrings *names;
UINT32 index;
BOOL exists;
UINT32 length;
WCHAR *wname;
char *name;
HRESULT hr;
hr = ff->fonts->GetFontFamily(n, &family);
if (hr != S_OK)
logHRESULT("error getting font out of collection in uiDrawFontFamiliesFamily()", hr);
hr = family->GetFamilyNames(&names);
if (hr != S_OK)
logHRESULT("error getting names of font out in uiDrawFontFamiliesFamily()", 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 (ff->userLocaleSuccess != 0)
hr = names->FindLocaleName(ff->userLocale, &index, &exists);
if (hr != S_OK || (hr == S_OK && !exists))
hr = names->FindLocaleName(L"en-us", &index, &exists);
if (!exists)
index = 0;
hr = names->GetStringLength(index, &length);
if (hr != S_OK)
logHRESULT("error getting length of font name in uiDrawFontFamiliesFamily()", 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("error getting font name in uiDrawFontFamiliesFamily()", hr);
name = toUTF8(wname);
uiFree(wname);
names->Release();
family->Release();
return name;
}
void uiDrawFreeFontFamilies(uiDrawFontFamilies *ff)
{
ff->fonts->Release();
uiFree(ff);
}