internal CachedTypeface(
FontStyle canonicalStyle,
FontWeight canonicalWeight,
FontStretch canonicalStretch,
IFontFamily firstFontFamily,
ITypefaceMetrics typefaceMetrics,
bool nullFont
)
{
_canonicalStyle = canonicalStyle;
_canonicalWeight = canonicalWeight;
_canonicalStretch = canonicalStretch;
Invariant.Assert(firstFontFamily != null && typefaceMetrics != null);
_firstFontFamily = firstFontFamily;
_typefaceMetrics = typefaceMetrics;
_nullFont = nullFont;
}
internal CachedTypeface(
FontStyle canonicalStyle,
FontWeight canonicalWeight,
FontStretch canonicalStretch,
IFontFamily firstFontFamily,
ITypefaceMetrics typefaceMetrics,
bool nullFont
)
{
_canonicalStyle = canonicalStyle;
_canonicalWeight = canonicalWeight;
_canonicalStretch = canonicalStretch;
Invariant.Assert(firstFontFamily != null && typefaceMetrics != null);
_firstFontFamily = firstFontFamily;
_typefaceMetrics = typefaceMetrics;
_nullFont = nullFont;
}
private CachedTypeface ConstructCachedTypeface()
{
FontStyle canonicalStyle = _style;
FontWeight canonicalWeight = _weight;
FontStretch canonicalStretch = _stretch;
//
// We always call FontFamily.FindFirstFontFamilyAndFace() method to resolve the
// canonical styles since the implied styles in FontFamily name will override
// the given styles in the Typeface. But we don't always use the IFontFamily
// instance returned from this method because an equal instance might already be
// cached.
//
FontFamily sourceFontFamily = FontFamily;
IFontFamily firstFontFamily = sourceFontFamily.FindFirstFontFamilyAndFace(
ref canonicalStyle,
ref canonicalWeight,
ref canonicalStretch
);
if (firstFontFamily == null)
{
if (FallbackFontFamily != null)
{
sourceFontFamily = FallbackFontFamily;
firstFontFamily = sourceFontFamily.FindFirstFontFamilyAndFace(
ref canonicalStyle,
ref canonicalWeight,
ref canonicalStretch
);
}
if (firstFontFamily == null)
{
sourceFontFamily = null;
firstFontFamily = FontFamily.LookupFontFamily(FontFamily.NullFontFamilyCanonicalName);
}
}
// If it's a named font, map all occurrences of the same name to one cached IFontFamily.
if (sourceFontFamily != null && sourceFontFamily.Source != null)
{
// We lookup in the cache to see if there is cached IFontFamily instance of the source FontFamily. Otherwise,
// this IFontFamily value is added to the TypefaceMetrics cache.
IFontFamily cachedValue = TypefaceMetricsCache.ReadonlyLookup(sourceFontFamily.FamilyIdentifier) as IFontFamily;
if (cachedValue != null)
{
firstFontFamily = cachedValue;
}
else
{
TypefaceMetricsCache.Add(sourceFontFamily.FamilyIdentifier, firstFontFamily);
}
}
ITypefaceMetrics typefaceMetrics = firstFontFamily.GetTypefaceMetrics(canonicalStyle, canonicalWeight, canonicalStretch);
return(new CachedTypeface(
canonicalStyle,
canonicalWeight,
canonicalStretch,
firstFontFamily,
typefaceMetrics,
sourceFontFamily == null
));
}