public static List <DrawableTextRun>?Collapse(TextLine textLine, TextCollapsingProperties properties, bool isWordEllipsis) { if (textLine.TextRuns is not List <DrawableTextRun> textRuns || textRuns.Count == 0) { return(null); } var runIndex = 0; var currentWidth = 0.0; var collapsedLength = 0; var shapedSymbol = TextFormatterImpl.CreateSymbol(properties.Symbol, FlowDirection.LeftToRight); if (properties.Width < shapedSymbol.GlyphRun.Size.Width) { //Not enough space to fit in the symbol return(new List <DrawableTextRun>(0)); } var availableWidth = properties.Width - shapedSymbol.Size.Width; while (runIndex < textRuns.Count) { var currentRun = textRuns[runIndex]; switch (currentRun) { case ShapedTextCharacters shapedRun: { currentWidth += shapedRun.Size.Width; if (currentWidth > availableWidth) { if (shapedRun.TryMeasureCharacters(availableWidth, out var measuredLength)) { if (isWordEllipsis && measuredLength < textLine.Length) { var currentBreakPosition = 0; var lineBreaker = new LineBreakEnumerator(currentRun.Text); while (currentBreakPosition < measuredLength && lineBreaker.MoveNext()) { var nextBreakPosition = lineBreaker.Current.PositionMeasure; if (nextBreakPosition == 0) { break; } if (nextBreakPosition >= measuredLength) { break; } currentBreakPosition = nextBreakPosition; } measuredLength = currentBreakPosition; } } collapsedLength += measuredLength; var collapsedRuns = new List <DrawableTextRun>(textRuns.Count); if (collapsedLength > 0) { var splitResult = TextFormatterImpl.SplitDrawableRuns(textRuns, collapsedLength); collapsedRuns.AddRange(splitResult.First); } collapsedRuns.Add(shapedSymbol); return(collapsedRuns); } availableWidth -= currentRun.Size.Width; break; } case { } drawableRun: { //The whole run needs to fit into available space if (currentWidth + drawableRun.Size.Width > availableWidth) { var collapsedRuns = new List <DrawableTextRun>(textRuns.Count); if (collapsedLength > 0) { var splitResult = TextFormatterImpl.SplitDrawableRuns(textRuns, collapsedLength); collapsedRuns.AddRange(splitResult.First); } collapsedRuns.Add(shapedSymbol); return(collapsedRuns); } break; } } collapsedLength += currentRun.TextSourceLength; runIndex++; } return(null); }
public override List <DrawableTextRun>?Collapse(TextLine textLine) { if (textLine.TextRuns is not List <DrawableTextRun> textRuns || textRuns.Count == 0) { return(null); } var runIndex = 0; var currentWidth = 0.0; var shapedSymbol = TextFormatterImpl.CreateSymbol(Symbol, FlowDirection.LeftToRight); if (Width < shapedSymbol.GlyphRun.Size.Width) { return(new List <DrawableTextRun>(0)); } // Overview of ellipsis structure // Prefix length run | Ellipsis symbol | Post split run growing from the end | var availableWidth = Width - shapedSymbol.Size.Width; while (runIndex < textRuns.Count) { var currentRun = textRuns[runIndex]; switch (currentRun) { case ShapedTextCharacters shapedRun: { currentWidth += currentRun.Size.Width; if (currentWidth > availableWidth) { shapedRun.TryMeasureCharacters(availableWidth, out var measuredLength); var collapsedRuns = new List <DrawableTextRun>(textRuns.Count); if (measuredLength > 0) { List <DrawableTextRun>?preSplitRuns = null; List <DrawableTextRun>?postSplitRuns; if (_prefixLength > 0) { var splitResult = TextFormatterImpl.SplitDrawableRuns(textRuns, Math.Min(_prefixLength, measuredLength)); collapsedRuns.AddRange(splitResult.First); preSplitRuns = splitResult.First; postSplitRuns = splitResult.Second; } else { postSplitRuns = textRuns; } collapsedRuns.Add(shapedSymbol); if (measuredLength <= _prefixLength || postSplitRuns is null) { return(collapsedRuns); } var availableSuffixWidth = availableWidth; if (preSplitRuns is not null) { foreach (var run in preSplitRuns) { availableSuffixWidth -= run.Size.Width; } } for (var i = postSplitRuns.Count - 1; i >= 0; i--) { var run = postSplitRuns[i]; switch (run) { case ShapedTextCharacters endShapedRun: { if (endShapedRun.TryMeasureCharactersBackwards(availableSuffixWidth, out var suffixCount, out var suffixWidth)) { availableSuffixWidth -= suffixWidth; if (suffixCount > 0) { var splitSuffix = endShapedRun.Split(run.TextSourceLength - suffixCount); collapsedRuns.Add(splitSuffix.Second !); } } break; } } } } else { collapsedRuns.Add(shapedSymbol); } return(collapsedRuns); } break; } } availableWidth -= currentRun.Size.Width; runIndex++; } return(null); }