Feature/avalonia Ubuntu color issue and slider tweaks (#188)

* Override a default color so slider looks same on all platforms

* Tweak slider layout to vertically align with other controls

* Tweak slider disabled color

Author: highbyte

src/apps/Avalonia/Highbyte.DotNet6502.App.Avalonia.Core/App.axaml

@@ -24,10 +24,15 @@
         <SolidColorBrush x:Key="WarningColor">#B89D5F</SolidColorBrush>
         <SolidColorBrush x:Key="DangerColor">#A85E5E</SolidColorBrush>
         <SolidColorBrush x:Key="BorderColor">#4A5566</SolidColorBrush>
+
     </Application.Resources>
 
     <Application.Styles>
-        <FluentTheme />
+        <FluentTheme>
+            <FluentTheme.Palettes>
+                <ColorPaletteResources x:Key="Dark" Accent="#6B8CAE" />
+            </FluentTheme.Palettes>
+        </FluentTheme>
 
         <!-- Include style files organized by control type -->
         <StyleInclude Source="avares://Highbyte.DotNet6502.App.Avalonia.Core/Styles/TextStyles.axaml"/>

src/apps/Avalonia/Highbyte.DotNet6502.App.Avalonia.Core/Styles/InputStyles.axaml

@@ -188,8 +188,19 @@
     <!-- ========================================== -->
 
     <Style Selector="Slider">
+        <Style.Resources>
+            <GridLength x:Key="SliderPreContentMargin">6</GridLength>
+            <GridLength x:Key="SliderPostContentMargin">0</GridLength>
+            <x:Double x:Key="SliderHorizontalHeight">20</x:Double>
+        </Style.Resources>
         <Setter Property="Foreground" Value="{DynamicResource AccentBlue}"/>
         <Setter Property="VerticalAlignment" Value="Center"/>
+        <Setter Property="Margin" Value="0"/>
+    </Style>
+
+    <Style Selector="Slider.small">
+        <Setter Property="MinHeight" Value="20"/>
+        <Setter Property="Height" Value="20"/>
     </Style>
 
     <Style Selector="Slider /template/ Thumb">
@@ -205,6 +216,17 @@
         <Setter Property="Height" Value="10"/>
     </Style>
 
+    <!-- Override disabled colors to be more visible on dark background -->
+    <Style Selector="Slider:disabled /template/ Thumb">
+        <Setter Property="Background" Value="{DynamicResource BorderColor}"/>
+    </Style>
+    <Style Selector="Slider:disabled /template/ RepeatButton#PART_DecreaseButton">
+        <Setter Property="Background" Value="{DynamicResource BorderColor}"/>
+    </Style>
+    <Style Selector="Slider:disabled /template/ RepeatButton#PART_IncreaseButton">
+        <Setter Property="Background" Value="{DynamicResource BorderColor}"/>
+    </Style>
+
     <Style Selector="Slider.small">
         <Setter Property="MinHeight" Value="20"/>
         <Setter Property="Height" Value="20"/>