Update background color of selected ListView item to meet contrast ratio requirement (#2962)

* Add new SystemControlHighlightListAccentMediumLowBrush theme resource.

* Update ListViewItemBackgroundSelected theme resource to consume the previously added SystemControlHighlightListAccentMediumLowBrush theme resource.

* Updated ListViewItemBackgroundSelectedPointerOver for dark theme.

* Added new SystemControlHighlightListAccentVeryHighBrush theme resource.

* Updated ListViewItemBackgroundSelectedPressed to consume the new SystemControlHighlightListAccentVeryHighBrush theme resource.

Author: Felix-Dev

dev/Common/Common_themeresources.xaml

@@ -9,20 +9,26 @@
     <ResourceDictionary.ThemeDictionaries>
         <ResourceDictionary x:Key="Default">
             <SolidColorBrush x:Key="SystemControlTransparentBrush" Color="Transparent" />
+            <SolidColorBrush x:Key="SystemControlHighlightListAccentVeryHighBrush" Color="{ThemeResource SystemAccentColor}" Opacity="0.9" />
+            <SolidColorBrush x:Key="SystemControlHighlightListAccentMediumLowBrush" Color="{ThemeResource SystemAccentColor}" Opacity="0.75" />
             <x:Boolean x:Key="UseSystemFocusVisuals">True</x:Boolean>
             <Thickness x:Key="TextControlBorderThemeThickness">1</Thickness>
             <Thickness x:Key="TextControlBorderThemeThicknessFocused">2</Thickness>
             <Thickness x:Key="TextControlThemePadding">10,6,6,5</Thickness>
         </ResourceDictionary>
         <ResourceDictionary x:Key="Light">
             <SolidColorBrush x:Key="SystemControlTransparentBrush" Color="Transparent" />
+            <SolidColorBrush x:Key="SystemControlHighlightListAccentVeryHighBrush" Color="{ThemeResource SystemAccentColor}" Opacity="0.9" />
+            <SolidColorBrush x:Key="SystemControlHighlightListAccentMediumLowBrush" Color="{ThemeResource SystemAccentColor}" Opacity="0.75" />
             <x:Boolean x:Key="UseSystemFocusVisuals">True</x:Boolean>
             <Thickness x:Key="TextControlBorderThemeThickness">1</Thickness>
             <Thickness x:Key="TextControlBorderThemeThicknessFocused">2</Thickness>
             <Thickness x:Key="TextControlThemePadding">10,6,6,5</Thickness>
         </ResourceDictionary>
         <ResourceDictionary x:Key="HighContrast">
             <SolidColorBrush x:Key="SystemControlTransparentBrush" Color="Transparent" />
+            <SolidColorBrush x:Key="SystemControlHighlightListAccentVeryHighBrush" Color="{ThemeResource SystemColorHighlightColor}" />
+            <SolidColorBrush x:Key="SystemControlHighlightListAccentMediumLowBrush" Color="{ThemeResource SystemColorHighlightColor}" />
             <x:Boolean x:Key="UseSystemFocusVisuals">True</x:Boolean>
             <Thickness x:Key="TextControlBorderThemeThickness">1</Thickness>
             <Thickness x:Key="TextControlBorderThemeThicknessFocused">2</Thickness>

dev/CommonStyles/ListViewItem_themeresources.xaml

@@ -20,9 +20,9 @@
             <StaticResource x:Key="ListViewItemBackground" ResourceKey="SystemControlTransparentBrush" />
             <StaticResource x:Key="ListViewItemBackgroundPointerOver" ResourceKey="SystemControlHighlightListLowBrush" />
             <StaticResource x:Key="ListViewItemBackgroundPressed" ResourceKey="SystemControlHighlightListMediumBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelected" ResourceKey="SystemControlHighlightListAccentLowBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelectedPointerOver" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelectedPressed" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelected" ResourceKey="SystemControlHighlightListAccentMediumLowBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelectedPointerOver" ResourceKey="SystemControlHighlightListAccentLowBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelectedPressed" ResourceKey="SystemControlHighlightListAccentVeryHighBrush" />
             <StaticResource x:Key="ListViewItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
             <StaticResource x:Key="ListViewItemForegroundPointerOver" ResourceKey="SystemControlHighlightAltBaseHighBrush" />
             <StaticResource x:Key="ListViewItemForegroundSelected" ResourceKey="SystemControlHighlightAltBaseHighBrush" />
@@ -57,9 +57,9 @@
             <StaticResource x:Key="ListViewItemBackground" ResourceKey="SystemControlTransparentBrush" />
             <StaticResource x:Key="ListViewItemBackgroundPointerOver" ResourceKey="SystemControlHighlightListLowBrush" />
             <StaticResource x:Key="ListViewItemBackgroundPressed" ResourceKey="SystemControlHighlightListMediumBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelected" ResourceKey="SystemControlHighlightListAccentLowBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelected" ResourceKey="SystemControlHighlightListAccentMediumLowBrush" />
             <StaticResource x:Key="ListViewItemBackgroundSelectedPointerOver" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelectedPressed" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelectedPressed" ResourceKey="SystemControlHighlightListAccentVeryHighBrush" />
             <StaticResource x:Key="ListViewItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
             <StaticResource x:Key="ListViewItemForegroundPointerOver" ResourceKey="SystemControlHighlightAltBaseHighBrush" />
             <StaticResource x:Key="ListViewItemForegroundSelected" ResourceKey="SystemControlHighlightAltBaseHighBrush" />
@@ -116,9 +116,9 @@
             <StaticResource x:Key="ListViewItemBackground" ResourceKey="SystemControlTransparentBrush" />
             <StaticResource x:Key="ListViewItemBackgroundPointerOver" ResourceKey="SystemControlHighlightListLowBrush" />
             <StaticResource x:Key="ListViewItemBackgroundPressed" ResourceKey="SystemControlHighlightListMediumBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelected" ResourceKey="SystemControlHighlightListAccentLowBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelected" ResourceKey="SystemControlHighlightListAccentMediumLowBrush" />
             <StaticResource x:Key="ListViewItemBackgroundSelectedPointerOver" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
-            <StaticResource x:Key="ListViewItemBackgroundSelectedPressed" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+            <StaticResource x:Key="ListViewItemBackgroundSelectedPressed" ResourceKey="SystemControlHighlightListAccentVeryHighBrush" />
             <StaticResource x:Key="ListViewItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
             <StaticResource x:Key="ListViewItemForegroundPointerOver" ResourceKey="SystemControlHighlightAltBaseHighBrush" />
             <StaticResource x:Key="ListViewItemForegroundSelected" ResourceKey="SystemControlHighlightAltBaseHighBrush" />