/// <summary>
/// Fetches text runs.
/// </summary>
/// <param name="textSource">The text source.</param>
/// <param name="firstTextSourceIndex">The first text source index.</param>
/// <param name="endOfLine"></param>
/// <param name="textRange"></param>
/// <returns>
/// The formatted text runs.
/// </returns>
private static List <TextCharacters> FetchTextRuns(ITextSource textSource, int firstTextSourceIndex,
out TextEndOfLine?endOfLine, out TextRange textRange)
{
var length = 0;
endOfLine = null;
var textRuns = new List <TextCharacters>();
var textRunEnumerator = new TextRunEnumerator(textSource, firstTextSourceIndex);
while (textRunEnumerator.MoveNext())
{
var textRun = textRunEnumerator.Current;
if (textRun == null)
{
break;
}
switch (textRun)
{
case TextCharacters textCharacters:
{
if (TryGetLineBreak(textCharacters, out var runLineBreak))
{
var splitResult = new TextCharacters(textCharacters.Text.Take(runLineBreak.PositionWrap),
textCharacters.Properties);
textRuns.Add(splitResult);
length += runLineBreak.PositionWrap;
textRange = new TextRange(firstTextSourceIndex, length);
return(textRuns);
}
textRuns.Add(textCharacters);
break;
}
case TextEndOfLine textEndOfLine:
endOfLine = textEndOfLine;
break;
}
length += textRun.Text.Length;
}
textRange = new TextRange(firstTextSourceIndex, length);
return(textRuns);
}
/// <summary>
/// Fetches text runs.
/// </summary>
/// <param name="textSource">The text source.</param>
/// <param name="firstTextSourceIndex">The first text source index.</param>
/// <param name="previousLineBreak">Previous line break. Can be null.</param>
/// <param name="nextLineBreak">Next line break. Can be null.</param>
/// <returns>
/// The formatted text runs.
/// </returns>
private static IReadOnlyList <ShapedTextCharacters> FetchTextRuns(ITextSource textSource,
int firstTextSourceIndex, TextLineBreak previousLineBreak, out TextLineBreak nextLineBreak)
{
nextLineBreak = default;
var currentLength = 0;
var textRuns = new List <ShapedTextCharacters>();
if (previousLineBreak != null)
{
foreach (var shapedCharacters in previousLineBreak.RemainingCharacters)
{
if (shapedCharacters == null)
{
continue;
}
textRuns.Add(shapedCharacters);
if (TryGetLineBreak(shapedCharacters, out var runLineBreak))
{
var splitResult = SplitTextRuns(textRuns, currentLength + runLineBreak.PositionWrap);
nextLineBreak = new TextLineBreak(splitResult.Second);
return(splitResult.First);
}
currentLength += shapedCharacters.Text.Length;
}
}
firstTextSourceIndex += currentLength;
var textRunEnumerator = new TextRunEnumerator(textSource, firstTextSourceIndex);
while (textRunEnumerator.MoveNext())
{
var textRun = textRunEnumerator.Current;
switch (textRun)
{
case TextCharacters textCharacters:
{
var shapeableRuns = textCharacters.GetShapeableCharacters();
foreach (var run in shapeableRuns)
{
var glyphRun = TextShaper.Current.ShapeText(run.Text, run.Properties.Typeface,
run.Properties.FontRenderingEmSize, run.Properties.CultureInfo);
var shapedCharacters = new ShapedTextCharacters(glyphRun, run.Properties);
textRuns.Add(shapedCharacters);
}
break;
}
}
if (TryGetLineBreak(textRun, out var runLineBreak))
{
var splitResult = SplitTextRuns(textRuns, currentLength + runLineBreak.PositionWrap);
nextLineBreak = new TextLineBreak(splitResult.Second);
return(splitResult.First);
}
currentLength += textRun.Text.Length;
}
return(textRuns);
}