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);
}
