public FontFile CreateFontFile(Uri filePathUri)
{
IDWriteFontFile dwriteFontFile = null;
try {
dwriteFontFile = CreateFontFile(_pFactory, WpfFontFileLoader, filePathUri);
}
catch {
// If DWrite's CreateFontFileReference fails then try opening the file using WPF's logic.
// The failures that WPF returns are more granular than the HRESULTs that DWrite returns
// thus we use WPF's logic to open the file to throw the same exceptions that
// WPF would have thrown before.
IFontSource fontSource = _fontSourceFactory.Create(filePathUri.AbsoluteUri);
fontSource.TestFileOpenable();
throw;
}
return(new FontFile(dwriteFontFile));
}
unsafe public FontFace CreateFontFace(Uri filePathUri, uint faceIndex, FontSimulations fontSimulationFlags)
{
FontFile fontFile = CreateFontFile(filePathUri);
FontFileType dwriteFontFileType;
FontFaceType dwriteFontFaceType;
uint numberOfFaces = 0;
int hr;
if (fontFile.Analyze(
out dwriteFontFileType,
out dwriteFontFaceType,
out numberOfFaces,
out hr
))
{
if (faceIndex >= numberOfFaces)
{
throw new ArgumentOutOfRangeException("faceIndex");
}
IntPtr dwriteFontFace = IntPtr.Zero; // IDWriteFontFace
IntPtr dwriteFontFile = fontFile.DWriteFontFileIface;
try {
dwriteFontFace = _pFactory.CreateFontFace(
dwriteFontFaceType,
1,
&dwriteFontFile,
faceIndex,
fontSimulationFlags
);
}
finally {
Marshal.Release(dwriteFontFile);
}
return(new FontFace(dwriteFontFace));
}
// This path is here because there is a behavior mismatch between DWrite and WPF.
// If a directory was given instead of a font uri WPF previously throws
// System.UnauthorizedAccessException. We handle most of the exception behavior mismatch
// in FontFile^ Factory::CreateFontFile by opening the file using WPF's previous (prior to DWrite integration) logic if
// CreateFontFileReference fails (please see comments in FontFile^ Factory::CreateFontFile).
// However in this special case DWrite's CreateFontFileReference will succeed if given
// a directory instead of a font file and it is the Analyze() call will fail returning DWRITE_E_FILEFORMAT.
// Thus, incase the hr returned from Analyze() was DWRITE_E_FILEFORMAT we do as we did in FontFile^ Factory::CreateFontFile
// to try and open the file using WPF old logic and throw System.UnauthorizedAccessException as WPF used to do.
// If a file format exception is expected then opening the file should succeed and ConvertHresultToException()
// Should throw the correct exception.
// A final note would be that this overhead is only incurred in error conditions and so the normal execution path should
// not be affected.
else
{
if (hr == unchecked ((int)0x88985000)) // DWRITE_E_FILEFORMAT
{
IFontSource fontSource = _fontSourceFactory.Create(filePathUri.AbsoluteUri);
fontSource.TestFileOpenable();
}
Marshal.ThrowExceptionForHR(hr);
}
return(null);
}
