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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
//
//
// Contents: Composite font family
//
//
using System.Globalization;
using System.Windows;
using System.Windows.Markup; // for XmlLanguage
using System.Windows.Media;
using System.Windows.Media.TextFormatting;
using MS.Internal.FontFace;
using MS.Internal.TextFormatting;
using FontFamily = System.Windows.Media.FontFamily;
namespace MS.Internal.Shaping
{
/// <summary>
/// Composite font family
/// </summary>
internal sealed class CompositeFontFamily : IFontFamily
{
private readonly CompositeFontInfo _fontInfo;
private IFontFamily _firstFontFamily;
#region Constructors
/// <summary>
/// Construct a default composite font family
/// </summary>
internal CompositeFontFamily()
: this(new CompositeFontInfo())
{}
/// <summary>
/// Construct a composite font family from composite font info
/// </summary>
internal CompositeFontFamily(CompositeFontInfo fontInfo)
{
_fontInfo = fontInfo;
}
/// <summary>
/// Construct a composite font family with a single target family name
/// </summary>
internal CompositeFontFamily(
string friendlyName
) :
this(
friendlyName,
null // firstFontFamily
)
{}
/// <summary>
/// Construct a composite font family with a single target family name
/// after the first font family in the target family is known
/// </summary>
internal CompositeFontFamily(
string friendlyName,
IFontFamily firstFontFamily
) :
this()
{
FamilyMaps.Add(
new FontFamilyMap(
0, FontFamilyMap.LastUnicodeScalar,
null, // any language
friendlyName,
1 // scaleInEm
)
);
_firstFontFamily = firstFontFamily;
}
#endregion
#region IFontFamily properties
/// <summary>
/// Font family name table indexed by culture
/// </summary>
IDictionary<XmlLanguage, string> IFontFamily.Names
{
get
{
return _fontInfo.FamilyNames;
}
}
/// <summary>
/// Distance from character cell top to English baseline relative to em size.
/// </summary>
public double Baseline(double emSize, double toReal, double pixelsPerDip, TextFormattingMode textFormattingMode)
{
if (textFormattingMode == TextFormattingMode.Ideal)
{
return ((IFontFamily)this).BaselineDesign * emSize;
}
else
{
// If the composite font has a pre specified Baseline then we respect it in calculating the
// baseline but we round it since Compatible metrics are pixel aligned.
if (_fontInfo.Baseline != 0)
{
return Math.Round(_fontInfo.Baseline * emSize);
}
// If the composite font has no specifed Baseline then we get the compatible font metrics of the
// first fontfamily in the composite font.
else
{
return GetFirstFontFamily().Baseline(emSize, toReal, pixelsPerDip, textFormattingMode);
}
}
}
public void SetBaseline(double value)
{
_fontInfo.Baseline = value;
}
/// <summary>
/// Recommended baseline-to-baseline distance for text in this font.
/// </summary>
public double LineSpacing(double emSize, double toReal, double pixelsPerDip, TextFormattingMode textFormattingMode)
{
if (textFormattingMode == TextFormattingMode.Ideal)
{
return ((IFontFamily)this).LineSpacingDesign * emSize;
}
else
{
// If the composite font has a pre specified LineSpacing then we respect it in calculating the
// linespacing but we round it since Compatible metrics are pixel aligned.
if (_fontInfo.LineSpacing != 0)
{
return Math.Round(_fontInfo.LineSpacing * emSize);
}
// If the composite font has no specifed LineSpacing then we get the compatible font metrics of the
// first fontfamily in the composite font.
else
{
return GetFirstFontFamily().LineSpacing(emSize, toReal, pixelsPerDip, textFormattingMode);
}
}
}
double IFontFamily.BaselineDesign
{
get
{
if (_fontInfo.Baseline == 0)
{
_fontInfo.Baseline = GetFirstFontFamily().BaselineDesign;
}
return _fontInfo.Baseline;
}
}
double IFontFamily.LineSpacingDesign
{
get
{
if (_fontInfo.LineSpacing == 0)
{
_fontInfo.LineSpacing = GetFirstFontFamily().LineSpacingDesign;
}
return _fontInfo.LineSpacing;
}
}
public void SetLineSpacing(double value)
{
_fontInfo.LineSpacing = value;
}
/// <summary>
/// Get typeface metrics of the specified typeface
/// </summary>
ITypefaceMetrics IFontFamily.GetTypefaceMetrics(
FontStyle style,
FontWeight weight,
FontStretch stretch
)
{
if (_fontInfo.FamilyTypefaces == null &&
_fontInfo.FamilyMaps.Count == 1 &&
_fontInfo.FamilyMaps[0].IsSimpleFamilyMap)
{
// Typical e.g. "MyFont, sans-serif"
return GetFirstFontFamily().GetTypefaceMetrics(style, weight, stretch);
}
return FindTypefaceMetrics(style, weight, stretch);
}
/// <summary>
/// Look up device font for the typeface.
/// </summary>
IDeviceFont IFontFamily.GetDeviceFont(FontStyle style, FontWeight weight, FontStretch stretch)
{
FamilyTypeface bestFace = FindExactFamilyTypeface(style, weight, stretch);
if (bestFace != null && bestFace.DeviceFontName != null)
return bestFace;
else
return null;
}
/// <summary>
/// Get family name correspondent to the first n-characters of the specified character string
/// </summary>
bool IFontFamily.GetMapTargetFamilyNameAndScale(
CharacterBufferRange unicodeString,
CultureInfo culture,
CultureInfo digitCulture,
double defaultSizeInEm,
out int cchAdvance,
out string targetFamilyName,
out double scaleInEm
)
{
Invariant.Assert(unicodeString.CharacterBuffer != null && unicodeString.Length > 0);
Invariant.Assert(culture != null);
// Get the family map. This will find the first family map that matches
// the specified culture, an ancestor neutral culture, or "any" culture.
FontFamilyMap familyMap = GetTargetFamilyMap(
unicodeString,
culture,
digitCulture,
out cchAdvance
);
// Return the values for the matching FontFamilyMap. If there is none this is
// FontFamilyMap.Default which has Target == null and Scale == 1.0.
targetFamilyName = familyMap.Target;
scaleInEm = familyMap.Scale;
return true;
}
ICollection<Typeface> IFontFamily.GetTypefaces(FontFamilyIdentifier familyIdentifier)
{
return new TypefaceCollection(new FontFamily(familyIdentifier), FamilyTypefaces);
}
#endregion
#region collections exposed by FontFamily
internal LanguageSpecificStringDictionary FamilyNames
{
get { return _fontInfo.FamilyNames; }
}
internal FamilyTypefaceCollection FamilyTypefaces
{
get { return _fontInfo.GetFamilyTypefaceList(); }
}
internal FontFamilyMapCollection FamilyMaps
{
get { return _fontInfo.FamilyMaps; }
}
#endregion
private FontFamilyMap GetTargetFamilyMap(
CharacterBufferRange unicodeString,
CultureInfo culture,
CultureInfo digitCulture,
out int cchAdvance
)
{
DigitMap digitMap = new DigitMap(digitCulture);
ushort[] familyMaps = _fontInfo.GetFamilyMapsOfLanguage(XmlLanguage.GetLanguage(culture.IetfLanguageTag));
int sizeofChar = 0;
int ch = 0;
// skip all the leading joinder characters. They need to be shaped with the
// surrounding strong characters.
cchAdvance = Classification.AdvanceWhile(unicodeString, ItemClass.JoinerClass);
if (cchAdvance >= unicodeString.Length)
{
// It is rare that the run only contains joiner characters.
// If it really happens, just map them to the initial family map.
return _fontInfo.GetFamilyMapOfChar(
familyMaps,
Classification.UnicodeScalar(unicodeString, out sizeofChar)
);
}
//
// If the run starts with combining marks, we will not be able to find base characters for them
// within the run. These combining marks will be mapped to their best fonts as normal characters.
//
ch = Classification.UnicodeScalar(
new CharacterBufferRange(unicodeString, cchAdvance, unicodeString.Length - cchAdvance),
out sizeofChar
);
bool hasBaseChar = !Classification.IsCombining(ch);
ch = digitMap[ch];
FontFamilyMap familyMap = _fontInfo.GetFamilyMapOfChar(familyMaps, ch);
Invariant.Assert(familyMap != null);
for (cchAdvance += sizeofChar; cchAdvance < unicodeString.Length; cchAdvance += sizeofChar)
{
ch = Classification.UnicodeScalar(
new CharacterBufferRange(unicodeString, cchAdvance, unicodeString.Length - cchAdvance),
out sizeofChar
);
if (Classification.IsJoiner(ch))
continue; // continue to advance if current char is a joiner
if (!Classification.IsCombining(ch))
{
hasBaseChar = true;
}
else if (hasBaseChar)
{
continue; // continue to advance for combining mark with base char
}
ch = digitMap[ch];
if (_fontInfo.GetFamilyMapOfChar(familyMaps, ch) != familyMap)
break;
}
return familyMap;
}
/// <summary>
/// Get the first font family of the first target family name
/// </summary>
private IFontFamily GetFirstFontFamily()
{
if(_firstFontFamily == null)
{
if (_fontInfo.FamilyMaps.Count != 0)
{
_firstFontFamily = FontFamily.FindFontFamilyFromFriendlyNameList(_fontInfo.FamilyMaps[0].Target);
}
else
{
_firstFontFamily = FontFamily.LookupFontFamily(FontFamily.NullFontFamilyCanonicalName);
}
Invariant.Assert(_firstFontFamily != null);
}
return _firstFontFamily;
}
private ITypefaceMetrics FindTypefaceMetrics(
FontStyle style,
FontWeight weight,
FontStretch stretch
)
{
FamilyTypeface bestFace = FindNearestFamilyTypeface(style, weight, stretch);
if (bestFace == null)
return new CompositeTypefaceMetrics();
else
return bestFace;
}
/// <summary>
/// Find the face closest to the specified style, weight and stretch.
/// Returns null if there is no matching face.
/// </summary>
private FamilyTypeface FindNearestFamilyTypeface(
FontStyle style,
FontWeight weight,
FontStretch stretch
)
{
if (_fontInfo.FamilyTypefaces == null || _fontInfo.FamilyTypefaces.Count == 0)
{
return null;
}
FamilyTypeface bestFace = (FamilyTypeface)_fontInfo.FamilyTypefaces[0];
MatchingStyle bestMatch = new MatchingStyle(bestFace.Style, bestFace.Weight, bestFace.Stretch);
MatchingStyle target = new MatchingStyle(style, weight, stretch);
for (int i = 1; i < _fontInfo.FamilyTypefaces.Count; i++)
{
FamilyTypeface currentFace = (FamilyTypeface)_fontInfo.FamilyTypefaces[i];
MatchingStyle currentMatch = new MatchingStyle(currentFace.Style, currentFace.Weight, currentFace.Stretch);
if (MatchingStyle.IsBetterMatch(target, bestMatch, ref currentMatch))
{
bestFace = currentFace;
bestMatch = currentMatch;
}
}
return bestFace;
}
/// <summary>
/// Find the face exactly matching the specified style, weight and stretch.
/// Returns null if there is no matching face.
/// </summary>
private FamilyTypeface FindExactFamilyTypeface(
FontStyle style,
FontWeight weight,
FontStretch stretch
)
{
if (_fontInfo.FamilyTypefaces == null || _fontInfo.FamilyTypefaces.Count == 0)
{
return null;
}
MatchingStyle target = new MatchingStyle(style, weight, stretch);
foreach (FamilyTypeface currentFace in _fontInfo.FamilyTypefaces)
{
MatchingStyle currentMatch = new MatchingStyle(currentFace.Style, currentFace.Weight, currentFace.Stretch);
if (currentMatch == target)
{
return currentFace;
}
}
return null;
}
}
}
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