Modern look and feel

Would something like this be possible to do?

[WelterDevelopment]

Thank you for your request!
The actual differnces compared to the current implemantation I can identify from the editor in your picture are:

Visual stuff:

• Bindable background colors for the line number column and the text area (in this case it's both transparent to get the mica/acrylic effect shine through)
• Bindable font (to select MonoLisa/Fira/... instead of Consolas)
• Bindable selected line number color
• Different shades for selected and unselected line numbers
• Vertical indentation lines inside of the text area with the same color as unselected line numbers
• Current line has a semi-transparent shade of the unselected line number color (instead of the current rounded frame)

Logical stuff:

• Bindable current member hierarchy for external display e.g. as a breadcrumb bar

Lots of good ideas; I will work on that.

Yep, mainly things like the font and the colors used. I am willing to help on making these changes. It would be cool if it looked like a native windows widget*

[WelterDevelopment]

I implemented some of the ideas:

Font (string) and ShowIndentGuides (Enum: None, Line, Dashed) are new DependencyProperties that can be set in xaml with your ViewModel data:

<codewriter:CodeWriter x:Name="CW" Grid.Row="1" Margin="12,0,0,0" 
CornerRadius="{StaticResource OverlayCornerRadius}" 
Background="Transparent" 
Font="{Binding Font}" 
Language="{Binding EditorLanguage}" 
Text="{Binding Text, Mode=TwoWay}"  
TextChanged="CW_TextChanged" 
ErrorOccured="CW_ErrorOccured" 
FontSize="{Binding FontSize, Mode=TwoWay}" 
TabLength="{Binding TabLength}" 
RequestedTheme="{Binding RequestedTheme}" 
ShowIndentGuides="{Binding ShowIndentGuides}" 
ShowControlCharacters="{Binding ShowControlCharacters}" 
ShowLineNumbers="{Binding ShowLineNumbers}" 
ShowLineMarkers="{Binding ShowLineMarkers}" 
IsFoldingEnabled="{Binding IsFoldingEnabled}" 
IsWrappingEnabled="{Binding IsWrappingEnabled}" 
ShowScrollbarMarkers="{Binding ShowScrollbarMarkers}" 
ShowHorizontalTicks="{Binding ShowHorizontalTicks}" 
ShowScrollbars="True"/>

Regarding Fonts: I tried to add Fira Code and JetBrains Mono. The first seems to work but the text rendering gets reeeally slow. The second one does not work at all (I guess only specific types of ttf files are allowed). So as of now we are stuck to the preinstalled Windows monospaced fonts. I added the ones I know to the TestApp: "Consolas", "Courier New", "Lucida Sans Typewriter", "Cascadia Code", "Cascadia Mono".

Regarding 'colors used': All editor colors are exposed as public properties. They are not yet implemented as DependencyProperties but you can change all colors at runtime by e.g. by setting CodeWriter.Color_Background in C#. To change colors that are used to draw stuff in the Win2D Canvas (like CodeWriter.Color_LineNumber) at runtime you need to additionally call CodeWriter.Invalidate(). I will consolidate the Colors by removing redundancies and I will turn then into bindable DependencyProperties with automatic invalidation.

If you meant the syntax highlighting colors: They can be set globally by the static publicly exposed Dictionary<Token, Color> EditorOptions.TokenColors. Or (as shown in the TestApp) you can define a bindable List<TokenDefinition> to directly update the syntax colors at a color change:

For the line number and the indent guides to change color depending if the corresponding line is selected, I need to change the way how the stacked Canvases work. I will deal with that once I do the general code refactoring mentioned in the discussion #9 (comment).

Well done man!!!! I'm impressed. I'm starting out on C# UIs (XAML), where did you learn all this stuff? Docs aren't very good :/
Edit: You're doing this for free, the visual studio team should hire you

[WelterDevelopment]

Haha thanks, but .NET is just a hobby for me.
Well, the docs used to be sooo good back in the UWP days. Now that Win32, WPF, UWP, Windows App SDK and .NET MAUI all coexist, it is very messy. There is no good documentation for Windows App SDK, even though it is supposed to be the main tool for developing Windows apps. I started learning UWP development with Bob Tabor who made a very good and extensive video course on Channel 9 (now called Microsoft Learn): https://docs.microsoft.com/en-us/shows/windows-10-development-for-absolute-beginners/. Most of the XAML and C# syntax and namespaces haven't changed (exception: Windows.UI (=old UWP Controls) turned into Microsoft.UI (=new WinUI 3 controls)), so you can follow the course even using the Windows App SDK. Once you understand how MVVM and DataTemplates work you are good to go to develop for any .NET-based runtime; the basics haven't changed since WPF.

Closing in order to clean up my feed, thanks for implementing some of the changes ;)