Description
When FlowDirection="RightToLeft" is applied to a TextBlock, Noesis renders paired brackets incorrectly. One of the brackets in a pair is visually reordered and appears on the wrong side of the text.
The issue is related to RTL (BiDi) reordering. RichText was used only to highlight parts of the text for demonstration purposes and is not the root cause of the problem.
Steps to Reproduce
- Create a
TextBlock with FlowDirection="RightToLeft".
- Use
noesis:RichText.Text with color tags and escaped bracketed text, for example:
[color=Red]\[text1\][/color]
- Compare rendering with standard HTML behavior using
dir="rtl".
Expected Result
Bracket pairs ([], (), {}, # #) should remain correctly positioned around the text in RTL layout, matching standard RTL behavior (e.g., HTML with dir="rtl").
Actual Result
One of the brackets in the pair is visually reordered and displayed on the wrong side of the text.
Additional Notes
- The issue reproduces only when using
FlowDirection="RightToLeft".
- The same text renders correctly in web browsers with
dir="rtl".
RichText was used only for color highlighting in the repro case and is not required to observe the issue.- The problem appears to be related to incorrect BiDi handling of neutral characters (paired delimiters) in RTL context.
Minimial code to reproduce:
<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:noesis="clr-namespace:NoesisGUIExtensions;assembly=Noesis.GUI.Extensions"
>
<StackPanel Orientation="Vertical" FlowDirection="RightToLeft">
<TextBlock Foreground="White" FontSize="20"
noesis:RichText.Text="[color=Red]\[text1\][/color] [color=Green]\[text2\][/color] [color=Blue]\[text3\][/color] \[text4\] text5 text6"
/>
<TextBlock Foreground="White" FontSize="20"
noesis:RichText.Text="[color=Red]\[1:2:3\][/color] [color=Green]\[4:5:6\][/color] [color=Blue]\[text3\][/color] \[text4\] text5 text6"
/>
<TextBlock Foreground="White" FontSize="20"
noesis:RichText.Text="[color=Red](1:2:3)[/color] [color=Green](4:5:6)[/color] [color=Blue](text3)[/color] (text4) text5 text6"
/>
<TextBlock Foreground="White" FontSize="20"
noesis:RichText.Text="[color=Red]{1:2:3}[/color] [color=Green]{4:5:6}[/color] [color=Blue]{text3}[/color] {text4} text5 text6"
/>
<TextBlock Foreground="White" FontSize="20"
noesis:RichText.Text="[color=Red]#1:2:3#[/color] [color=Green]#4:5:6#[/color] [color=Blue]#text3#[/color] #text4# text5 text6"
/>
<TextBlock Foreground="White" FontSize="20"
noesis:RichText.Text="[color=Red]1:2:3[/color] [color=Green]4:5:6[/color] [color=Blue]text3[/color] text4 text5 text6"
/>
</StackPanel>
</Grid>
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