Avalonia/src/Avalonia.Themes.Fluent/Controls/CheckBox.xaml

<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <Design.PreviewWith>
    <Border Padding="20">
      <CheckBox IsThreeState="True" IsChecked="True" Content="Content" Foreground="Gold" />
    </Border>
  </Design.PreviewWith>
  <Style Selector="CheckBox">
    <Setter Property="Padding" Value="8,0,0,0" />
    <Setter Property="HorizontalAlignment" Value="Left" />
    <Setter Property="VerticalAlignment" Value="Center" />
    <Setter Property="HorizontalContentAlignment" Value="Left" />
    <Setter Property="VerticalContentAlignment" Value="Center" />    
    <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}" />
    <Setter Property="MinWidth" Value="120" />
    <Setter Property="MinHeight" Value="32" />
    <!--<Setter Property="UseSystemFocusVisuals" Value="{StaticResource UseSystemFocusVisuals}" />
    <Setter Property="FocusVisualMargin" Value="-7,-3,-7,-3" />-->
    <Setter Property="Template">
      <ControlTemplate>
        <Grid x:Name="RootGrid" ColumnDefinitions="20,*">
          <Border x:Name="PART_Border"
                  Grid.ColumnSpan="2"
                  Background="{TemplateBinding Background}"
                  BorderBrush="{TemplateBinding BorderBrush}"
                  BorderThickness="{TemplateBinding BorderThickness}" />

          <Grid VerticalAlignment="Top" Height="32">
            <Border x:Name="NormalRectangle"
                BorderThickness="{DynamicResource CheckBoxBorderThemeThickness}"
                UseLayoutRounding="False"
                Height="20"
                Width="20" />

            <Viewbox UseLayoutRounding="False">
              <Panel>
                <Panel Height="16" Width="16" />
                <Path x:Name="CheckGlyph" Stretch="Uniform" VerticalAlignment="Center" />
              </Panel>
            </Viewbox>
          </Grid>
          <ContentPresenter x:Name="ContentPresenter"
                         ContentTemplate="{TemplateBinding ContentTemplate}"
                         Content="{TemplateBinding Content}"
                         Margin="{TemplateBinding Padding}"
                         HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                         VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                         Grid.Column="1" />
          <!-- TODO: TextWrapping="Wrap" on contentpresenter -->
        </Grid>
      </ControlTemplate>
    </Setter>
  </Style>
  
  <Style Selector="CheckBox /template/ Border#PART_Border">
    <Setter Property="CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
  </Style>

  <Style Selector="CheckBox /template/ Border#NormalRectangle">
    <Setter Property="CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
  </Style>

  <!-- Unchecked Normal State -->
  <Style Selector="CheckBox">
    <Setter Property="Foreground" Value="{DynamicResource CheckBoxForegroundUnchecked}" />
  </Style>

  <Style Selector="CheckBox">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundUnchecked}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushUnchecked}" />
  </Style>

  <Style Selector="CheckBox /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeUnchecked}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillUnchecked}" />
  </Style>

  <Style Selector="CheckBox /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundUnchecked}" />
    <Setter Property="Opacity" Value="0" />
  </Style>

  <!-- Unchecked PointerOver State -->
  <Style Selector="CheckBox:pointerover /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundUncheckedPointerOver}" />
  </Style>

  <Style Selector="CheckBox:pointerover /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundUncheckedPointerOver}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushUncheckedPointerOver}" />
  </Style>

  <Style Selector="CheckBox:pointerover /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeUncheckedPointerOver}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillUncheckedPointerOver}" />
  </Style>

  <Style Selector="CheckBox:pointerover /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundUncheckedPointerOver}" />
  </Style>

  <!-- Unchecked Pressed State -->
  <Style Selector="CheckBox:pressed /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundUncheckedPressed}" />
  </Style>

  <Style Selector="CheckBox:pressed /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundUncheckedPressed}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushUncheckedPressed}" />
  </Style>

  <Style Selector="CheckBox:pressed /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeUncheckedPressed}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillUncheckedPressed}" />
  </Style>

  <Style Selector="CheckBox:pressed /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundUncheckedPressed}" />
  </Style>

  <!-- Unchecked Disabled state -->
  <Style Selector="CheckBox:disabled /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundUncheckedDisabled}" />
  </Style>

  <Style Selector="CheckBox:disabled /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundUncheckedDisabled}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushUncheckedDisabled}" />
  </Style>

  <Style Selector="CheckBox:disabled /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeUncheckedDisabled}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillUncheckedDisabled}" />
  </Style>

  <Style Selector="CheckBox:disabled /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundUncheckedDisabled}" />
  </Style>


  <!-- Checked Normal State -->
  <Style Selector="CheckBox:checked">
    <Setter Property="Foreground" Value="{DynamicResource CheckBoxForegroundChecked}" />
  </Style>

  <Style Selector="CheckBox:checked">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundChecked}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushChecked}" />
  </Style>

  <Style Selector="CheckBox:checked /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundFillChecked}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillChecked}" />
  </Style>

  <Style Selector="CheckBox:checked /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundChecked}" />
    <Setter Property="Data" Value="M1507 31L438 1101L-119 543L-29 453L438 919L1417 -59L1507 31Z" />
    <Setter Property="Width" Value="9" />
    <Setter Property="Opacity" Value="1" />
  </Style>

  <!-- Checked PointerOver State -->
  <Style Selector="CheckBox:checked:pointerover /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundCheckedPointerOver}" />
  </Style>

  <Style Selector="CheckBox:checked:pointerover /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundCheckedPointerOver}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushCheckedPointerOver}" />
  </Style>

  <Style Selector="CheckBox:checked:pointerover /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeCheckedPointerOver}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillCheckedPointerOver}" />
  </Style>

  <Style Selector="CheckBox:checked:pointerover /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundCheckedPointerOver}" />
  </Style>

  <!-- Checked Pressed State -->
  <Style Selector="CheckBox:checked:pressed /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundCheckedPressed}" />
  </Style>

  <Style Selector="CheckBox:checked:pressed /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundCheckedPressed}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushCheckedPressed}" />
  </Style>

  <Style Selector="CheckBox:checked:pressed /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeCheckedPressed}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillCheckedPressed}" />
  </Style>

  <Style Selector="CheckBox:checked:pressed /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundCheckedPressed}" />
  </Style>

  <!-- Checked Disabled State -->
  <Style Selector="CheckBox:checked:disabled /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundCheckedDisabled}" />
  </Style>

  <Style Selector="CheckBox:checked:disabled /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundCheckedDisabled}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushCheckedDisabled}" />
  </Style>

  <Style Selector="CheckBox:checked:disabled /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeCheckedDisabled}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillCheckedDisabled}" />
  </Style>

  <Style Selector="CheckBox:checked:disabled /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundCheckedDisabled}" />
  </Style>


  <!-- Indeterminate Normal State -->
  <Style Selector="CheckBox:indeterminate">
    <Setter Property="Foreground" Value="{DynamicResource CheckBoxForegroundIndeterminate}" />
  </Style>

  <Style Selector="CheckBox:indeterminate">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundIndeterminate}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushIndeterminate}" />
  </Style>

  <Style Selector="CheckBox:indeterminate /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeIndeterminate}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillIndeterminate}" />
  </Style>

  <Style Selector="CheckBox:indeterminate /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundIndeterminate}" />
    <Setter Property="Data" Value="M1536 1536v-1024h-1024v1024h1024z" />
    <Setter Property="Width" Value="7" />
    <Setter Property="Opacity" Value="1" />
  </Style>

  <!-- Indeterminate PointerOver State -->
  <Style Selector="CheckBox:indeterminate:pointerover /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundIndeterminatePointerOver}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:pointerover /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundIndeterminatePointerOver}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushIndeterminatePointerOver}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:pointerover /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeIndeterminatePointerOver}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillIndeterminatePointerOver}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:pointerover /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundIndeterminatePointerOver}" />
  </Style>

  <!-- Indeterminate Pressed State -->
  <Style Selector="CheckBox:indeterminate:pressed /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundIndeterminatePressed}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:pressed /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundIndeterminatePressed}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushIndeterminatePressed}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:pressed /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeIndeterminatePressed}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillIndeterminatePressed}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:pressed /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundIndeterminatePressed}" />
  </Style>

  <!-- Indeterminate Disabled State -->
  <Style Selector="CheckBox:indeterminate:disabled /template/ ContentPresenter#ContentPresenter">
    <Setter Property="TextBlock.Foreground" Value="{DynamicResource CheckBoxForegroundIndeterminateDisabled}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:disabled /template/ Border#PART_Border">
    <Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundIndeterminateDisabled}" />
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushIndeterminateDisabled}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:disabled /template/ Border#NormalRectangle">
    <Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeIndeterminateDisabled}" />
    <Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillIndeterminateDisabled}" />
  </Style>

  <Style Selector="CheckBox:indeterminate:disabled /template/ Path#CheckGlyph">
    <Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundIndeterminateDisabled}" />
  </Style>
</Styles>