/// <summary>
/// Construct a character string object by extracting text info from text run
/// </summary>
internal CharacterBufferRange(TextRun textRun)
{
_charBufferRef = textRun.CharacterBufferReference;
_length = textRun.Length;
}
/// <summary>
/// Break a run of text into individually shape items.
/// Shape items are delimited by
/// Change of writing system
/// Change of glyph typeface
/// </summary>
IList <TextShapeableSymbols> ITextSymbols.GetTextShapeableSymbols(
GlyphingCache glyphingCache,
CharacterBufferReference characterBufferReference,
int length,
bool rightToLeft,
bool isRightToLeftParagraph,
CultureInfo digitCulture,
TextModifierScope textModifierScope,
TextFormattingMode textFormattingMode,
bool isSideways
)
{
if (characterBufferReference.CharacterBuffer == null)
{
throw new ArgumentNullException("characterBufferReference.CharacterBuffer");
}
int offsetToFirstChar = characterBufferReference.OffsetToFirstChar - _characterBufferReference.OffsetToFirstChar;
Debug.Assert(characterBufferReference.CharacterBuffer == _characterBufferReference.CharacterBuffer);
Debug.Assert(offsetToFirstChar >= 0 && offsetToFirstChar < _length);
if (length < 0 ||
offsetToFirstChar + length > _length)
{
length = _length - offsetToFirstChar;
}
// Get the actual text run properties in effect, after invoking any
// text modifiers that may be in scope.
TextRunProperties textRunProperties = _textRunProperties;
if (textModifierScope != null)
{
textRunProperties = textModifierScope.ModifyProperties(textRunProperties);
}
if (!rightToLeft)
{
// Fast loop early out for run with all non-complex characters
// which can be optimized by not going thru shaping engine.
int nominalLength;
if (textRunProperties.Typeface.CheckFastPathNominalGlyphs(
new CharacterBufferRange(characterBufferReference, length),
textRunProperties.FontRenderingEmSize,
(float)textRunProperties.PixelsPerDip,
1.0,
double.MaxValue, // widthMax
true, // keepAWord
digitCulture != null,
CultureMapper.GetSpecificCulture(textRunProperties.CultureInfo),
textFormattingMode,
isSideways,
false, //breakOnTabs
out nominalLength
) && length == nominalLength)
{
return(new TextShapeableCharacters[]
{
new TextShapeableCharacters(
new CharacterBufferRange(characterBufferReference, nominalLength),
textRunProperties,
textRunProperties.FontRenderingEmSize,
new MS.Internal.Text.TextInterface.ItemProps(),
null, // shapeTypeface (no shaping required)
false, // nullShape,
textFormattingMode,
isSideways
)
});
}
}
IList <TextShapeableSymbols> shapeables = new List <TextShapeableSymbols>(2);
glyphingCache.GetShapeableText(
textRunProperties.Typeface,
characterBufferReference,
length,
textRunProperties,
digitCulture,
isRightToLeftParagraph,
shapeables,
this as IShapeableTextCollector,
textFormattingMode
);
return(shapeables);
}
