public TextCharacters(ReadOnlySlice <char> text, int offsetToFirstCharacter, int length,
TextRunProperties properties)
{
Text = text.Skip(offsetToFirstCharacter).Take(length);
TextSourceLength = length;
Properties = properties;
}
public TextRun GetTextRun(int textSourceIndex)
{
if (textSourceIndex > _text.Length)
{
return(null);
}
var runText = _text.Skip(textSourceIndex);
return(runText.IsEmpty ? null : new TextCharacters(runText, _defaultGenericPropertiesRunProperties));
}
public TextRun GetTextRun(int textSourceIndex)
{
var runText = _text.Skip(textSourceIndex);
if (runText.IsEmpty)
{
return(new TextEndOfParagraph());
}
return(new TextCharacters(runText, _defaultGenericPropertiesRunProperties));
}
public void Should_Skip()
{
var buffer = new[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
var slice = new ReadOnlySlice <int>(buffer);
var skipped = slice.Skip(2);
var expected = buffer.Skip(2);
Assert.Equal(expected, skipped);
}
public TextRun GetTextRun(int textSourceIndex)
{
var runText = _text.Skip(textSourceIndex);
if (runText.IsEmpty)
{
return(new TextEndOfLine());
}
var textStyleRun = CreateTextStyleRunWithOverride(runText, _defaultStyle, _textStyleOverrides);
return(new TextCharacters(runText.Take(textStyleRun.TextPointer.Length), textStyleRun.Style));
}
public TextRun GetTextRun(int textSourceIndex)
{
if (_textStyleRuns.IsEmpty)
{
return(new TextEndOfParagraph());
}
var styleRun = _textStyleRuns[0];
_textStyleRuns = _textStyleRuns.Skip(1);
return(new TextCharacters(_text.AsSlice(styleRun.TextPointer.Start, styleRun.TextPointer.Length),
_defaultStyle));
}
public TextRun GetTextRun(int textSourceIndex)
{
if (_styleSpans.IsEmpty)
{
return(new TextEndOfParagraph());
}
var currentSpan = _styleSpans[0];
_styleSpans = _styleSpans.Skip(1);
return(new TextCharacters(_text.AsSlice(currentSpan.Start, currentSpan.Length),
_defaultStyle));
}
/// <summary>
/// Moves to the next <see cref="Codepoint"/>.
/// </summary>
/// <returns></returns>
public bool MoveNext()
{
if (_text.IsEmpty)
{
Current = Codepoint.ReplacementCodepoint;
return(false);
}
Current = Codepoint.ReadAt(_text, 0, out var count);
_text = _text.Skip(count);
return(true);
}
public TextRun GetTextRun(int textSourceIndex)
{
if (textSourceIndex > _text.End)
{
return(new TextEndOfLine());
}
var runText = _text.Skip(textSourceIndex);
if (runText.IsEmpty)
{
return(new TextEndOfLine());
}
var textStyleRun = CreateTextStyleRun(runText, _defaultProperties, _textModifier);
return(new TextCharacters(runText.Take(textStyleRun.Length), textStyleRun.Value));
}
/// <summary>
/// Gets a list of <see cref="ShapeableTextCharacters"/>.
/// </summary>
/// <returns>The shapeable text characters.</returns>
internal IReadOnlyList <ShapeableTextCharacters> GetShapeableCharacters(ReadOnlySlice <char> runText, sbyte biDiLevel,
ref TextRunProperties?previousProperties)
{
var shapeableCharacters = new List <ShapeableTextCharacters>(2);
while (!runText.IsEmpty)
{
var shapeableRun = CreateShapeableRun(runText, Properties, biDiLevel, ref previousProperties);
shapeableCharacters.Add(shapeableRun);
runText = runText.Skip(shapeableRun.Text.Length);
previousProperties = shapeableRun.Properties;
}
return(shapeableCharacters);
}
/// <summary>
/// Creates a shapeable text run with unique properties.
/// </summary>
/// <param name="text">The text to create text runs from.</param>
/// <param name="defaultProperties">The default text run properties.</param>
/// <param name="biDiLevel">The bidi level of the run.</param>
/// <param name="previousProperties"></param>
/// <returns>A list of shapeable text runs.</returns>
private static ShapeableTextCharacters CreateShapeableRun(ReadOnlySlice <char> text,
TextRunProperties defaultProperties, sbyte biDiLevel, ref TextRunProperties?previousProperties)
{
var defaultTypeface = defaultProperties.Typeface;
var currentTypeface = defaultTypeface;
var previousTypeface = previousProperties?.Typeface;
if (TryGetShapeableLength(text, currentTypeface, null, out var count, out var script))
{
if (script == Script.Common && previousTypeface is not null)
{
if (TryGetShapeableLength(text, previousTypeface.Value, defaultTypeface, out var fallbackCount, out _))
{
return(new ShapeableTextCharacters(text.Take(fallbackCount),
defaultProperties.WithTypeface(previousTypeface.Value), biDiLevel));
}
}
return(new ShapeableTextCharacters(text.Take(count), defaultProperties.WithTypeface(currentTypeface),
biDiLevel));
}
if (previousTypeface is not null)
{
if (TryGetShapeableLength(text, previousTypeface.Value, defaultTypeface, out count, out _))
{
return(new ShapeableTextCharacters(text.Take(count),
defaultProperties.WithTypeface(previousTypeface.Value), biDiLevel));
}
}
var codepoint = Codepoint.ReplacementCodepoint;
var codepointEnumerator = new CodepointEnumerator(text.Skip(count));
while (codepointEnumerator.MoveNext())
{
if (codepointEnumerator.Current.IsWhiteSpace)
{
continue;
}
codepoint = codepointEnumerator.Current;
break;
}
//ToDo: Fix FontFamily fallback
var matchFound =
FontManager.Current.TryMatchCharacter(codepoint, defaultTypeface.Style, defaultTypeface.Weight,
defaultTypeface.Stretch, defaultTypeface.FontFamily, defaultProperties.CultureInfo,
out currentTypeface);
if (matchFound && TryGetShapeableLength(text, currentTypeface, defaultTypeface, out count, out _))
{
//Fallback found
return(new ShapeableTextCharacters(text.Take(count), defaultProperties.WithTypeface(currentTypeface),
biDiLevel));
}
// no fallback found
currentTypeface = defaultTypeface;
var glyphTypeface = currentTypeface.GlyphTypeface;
var enumerator = new GraphemeEnumerator(text);
while (enumerator.MoveNext())
{
var grapheme = enumerator.Current;
if (!grapheme.FirstCodepoint.IsWhiteSpace && glyphTypeface.TryGetGlyph(grapheme.FirstCodepoint, out _))
{
break;
}
count += grapheme.Text.Length;
}
return(new ShapeableTextCharacters(text.Take(count), defaultProperties, biDiLevel));
}
