Originally posted by **batwomankt** March 15, 2024
Before the fix for issue 367 was merged, if the character at the end of a split for word wrap was whitespace, it would be trimmed. However, with the 367 fix introduced, that particular bit of trimming is missed in `SplitAt` and images have lingering whitespaces at the end of the line that are not trimmed properly.
After some fiddling, I have a suggestion on how to have both the desired line split behavior and whitespace trimming. This still passes the 3 line count desired by the opener of issue 367, while also removing any trailing whitespaces from text lines!
In the `TextLine` class, add a method something like:
```
private void TrimTrailingWhitespaceAndRecalculateMetrics()
{
int index = this.data.Count;
while (index > 0)
{
if (!CodePoint.IsWhiteSpace(this.data[index - 1].CodePoint))
{
break;
}
index--;
}
if (index < this.data.Count)
{
this.data.RemoveRange(index, this.data.Count - index);
}
// Lastly recalculate this line metrics.
float advance = 0;
float ascender = 0;
float descender = 0;
float lineHeight = 0;
foreach (GlyphLayoutData glyph in this.data)
{
advance += glyph.ScaledAdvance;
ascender = MathF.Max(ascender, glyph.ScaledAscender);
descender = MathF.Max(descender, glyph.ScaledDescender);
lineHeight = MathF.Max(lineHeight, glyph.ScaledLineHeight);
}
this.ScaledLineAdvance = advance;
this.ScaledMaxAscender = ascender;
this.ScaledMaxDescender = descender;
this.ScaledMaxLineHeight = lineHeight;
}
```
and have the `SplitAt` function adjusted to something like:
```
public TextLine SplitAt(LineBreak lineBreak, bool keepAll)
{
int index = this.data.Count;
GlyphLayoutData glyphWrap = default;
while (index > 0)
{
glyphWrap = this.data[--index];
if (glyphWrap.Offset == lineBreak.PositionWrap)
{
break;
}
}
if (index == 0)
{
// Now trim trailing whitespace from this line.
this.TrimTrailingWhitespaceAndRecalculateMetrics();
return this;
}
// Word breaks should not be used for Chinese/Japanese/Korean (CJK) text
// when word-breaking mode is keep-all.
if (keepAll && UnicodeUtility.IsCJKCodePoint((uint)glyphWrap.CodePoint.Value))
{
// Loop through previous glyphs to see if there is
// a non CJK codepoint we can break at.
while (index > 0)
{
glyphWrap = this.data[--index];
if (!UnicodeUtility.IsCJKCodePoint((uint)glyphWrap.CodePoint.Value))
{
index++;
break;
}
}
if (index == 0)
{
return this;
}
}
// Create a new line ensuring we capture the initial metrics.
TextLine result = new();
result.data.AddRange(this.data.GetRange(index, this.data.Count - index));
float advance = 0;
float ascender = 0;
float descender = 0;
float lineHeight = 0;
for (int i = 0; i < result.data.Count; i++)
{
GlyphLayoutData glyph = result.data[i];
advance += glyph.ScaledAdvance;
ascender = MathF.Max(ascender, glyph.ScaledAscender);
descender = MathF.Max(descender, glyph.ScaledDescender);
lineHeight = MathF.Max(lineHeight, glyph.ScaledLineHeight);
}
result.ScaledLineAdvance = advance;
result.ScaledMaxAscender = ascender;
result.ScaledMaxDescender = descender;
result.ScaledMaxLineHeight = lineHeight;
// Remove those items from this line.
this.data.RemoveRange(index, this.data.Count - index);
// Now trim trailing whitespace from this line.
this.TrimTrailingWhitespaceAndRecalculateMetrics();
return result;
}
```
Desired behavior:
Current behavior:
batwomankt
commented
8 months ago
Discussed in https://github.com/SixLabors/Fonts/discussions/392