inabox/InABox.Avalonia/Theme/Layouts.axaml

<ResourceDictionary xmlns="https://github.com/avaloniaui"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:system="clr-namespace:System;assembly=System.Runtime"
                    xmlns:inabox="clr-namespace:InABox.Avalonia">

    <Thickness x:Key="PrsControlSpacing">2</Thickness>

    <system:Double x:Key="PrsLineThickness">0.75</system:Double>

    <!-- <inabox:ThicknessProvider x:Key="PrsBorderThickness" -->
    <!--                           Left="{StaticResource PrsLineThickness}" -->
    <!--                           Top="{StaticResource PrsLineThickness}" -->
    <!--                           Right="{StaticResource PrsLineThickness}" -->
    <!--                           Bottom="{StaticResource PrsLineThickness}" /> -->
    <Thickness x:Key="PrsBorderThickness">0.5</Thickness>
    
    <CornerRadius x:Key="PrsCornerRadius">4</CornerRadius>

    <system:Double x:Key="PrsSmallImageWidth">20</system:Double>
    <system:Double x:Key="PrsSmallImageHeight">20</system:Double>

    <system:Double x:Key="PrsMediumImageWidth">30</system:Double>
    <system:Double x:Key="PrsMediumImageHeight">30</system:Double>

    <system:Double x:Key="PrsLargeImageWidth">50</system:Double>
    <system:Double x:Key="PrsLargeImageHeight">50</system:Double>

    <system:Double x:Key="PrsExtraLargeImageWidth">70</system:Double>
    <system:Double x:Key="PrsExtraLargeImageHeight">70</system:Double>

    <ItemsPanelTemplate x:Key="HorizontalItemsPanelTemplate">
        <StackPanel Orientation="Horizontal" />
    </ItemsPanelTemplate>

</ResourceDictionary>