TextEditor: Single line based formatting of text

[FabianGolembiewski-sp]

Hello,

when I change the formatting of the TextEditor, e.g. FontFamily, FontSize, FontWeight etc.
this styling is applied to the whole text of the editor.
Is it possible to format only a single line, or a selection?

[mgarstenauer]

What is the use-case? (Note that AvaloniaEdit is a source code editor, not a rich text editor.)

The AvaloniaEdit.Demo contains an example UnderlineAndStrikeThroughTransformer, which applies underline and strikethrough format. See

AvaloniaEdit/src/AvaloniaEdit.Demo/MainWindow.xaml.cs

Line 348 in 7fa5d88

class UnderlineAndStrikeThroughTransformer : DocumentColorizingTransformer

Example: Let's say you want to make all source code comments in the text italic.

To achieve this, you can:

• Implement your own MyCommentTransformer derived from DocumentColorizingTransformer.
• Override the method ColorizeLine. Check if the text line contains a comment (like "// ...") and then call ChangeLinePart for that text part with: visualLine.TextRunProperties.SetTypeface(new Typeface("Consolas", FontStyle.Italic));

[FabianGolembiewski-sp]

Okay, I didn't know it's only a source code editor.
Your example is helpful and could do what I want.
Thank you.