public override int GetLineNumberFromPosition(int position)
{
if ((position < 0) || (position > this.Length))
{
throw new ArgumentOutOfRangeException(nameof(position));
}
//Convert position to a position relative to the start of _text.
if (position == this.Length)
{
//Handle positions at the end of the span as a special case since otherwise we
//return the incorrect value if the last line break extends past the end of _textSpan.
return(this.LineBreakCount);
}
position += _textSpanStart;
int start = _lineBreakSpanStart;
int end = this.LineBreakSpanEnd;
while (start < end)
{
int middle = (start + end) / 2;
if (position < _lineBreaks.EndOfLineBreak(middle))
{
end = middle;
}
else
{
start = middle + 1;
}
}
return(start - _lineBreakSpanStart);
}
public override LineSpan GetLineFromLineNumber(int lineNumber)
{
if ((lineNumber < 0) || (lineNumber > this.LineBreakCount))
{
throw new ArgumentOutOfRangeException("lineNumber");
}
ILineBreaks lineBreaks = _storage.LineBreaks;
int absoluteLineNumber = _lineBreakSpanStart + lineNumber;
int start = (lineNumber == 0)
? 0
: (Math.Min(this.TextSpanEnd, lineBreaks.EndOfLineBreak(absoluteLineNumber - 1)) - _textSpanStart);
int end;
int breakLength;
if (lineNumber < this.LineBreakCount)
{
end = Math.Max(_textSpanStart, lineBreaks.StartOfLineBreak(absoluteLineNumber));
breakLength = Math.Min(this.TextSpanEnd, lineBreaks.EndOfLineBreak(absoluteLineNumber)) - end;
end -= _textSpanStart;
}
else
{
end = this.Length;
breakLength = 0;
}
return(new LineSpan(lineNumber, Span.FromBounds(start, end), breakLength));
}
/// <summary>
/// Gets <see cref="Span"/> of whole <paramref name="line"/>.
/// </summary>
/// <param name="lineBreaks">Information about line breaks in the document. Cannot be <c>null</c>.</param>
/// <param name="line">Line number.</param>
/// <returns><see cref="Span"/> of line specified by parameter <paramref name="line"/> within the document <paramref name="lineBreaks"/>.</returns>
public static Span GetLineSpan(this ILineBreaks /*!*/ lineBreaks, int line)
{
if (lineBreaks == null)
{
throw new ArgumentNullException("lineBreaks");
}
if (line < 0 || line > lineBreaks.Count)
{
throw new ArgumentException("line");
}
int start = (line != 0) ? lineBreaks.EndOfLineBreak(line - 1) : 0;
int end = (line < lineBreaks.Count) ? lineBreaks.EndOfLineBreak(line) : lineBreaks.TextLength;
return(Span.FromBounds(start, end));
}
