Semi.Avalonia/src/Semi.Avalonia.TreeDataGrid/TreeDataGrid.axaml

<ResourceDictionary
    xmlns="https://github.com/avaloniaui"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:conv="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls.TreeDataGrid">
    <!--  Add Resources Here  -->
    <Design.PreviewWith>
        <StackPanel Margin="20">
            <TreeDataGridColumnHeader Header="123" />
        </StackPanel>
    </Design.PreviewWith>
    <ControlTheme x:Key="{x:Type TreeDataGrid}" TargetType="TreeDataGrid">
        <Setter Property="Template">
            <ControlTemplate TargetType="TreeDataGrid">
                <Border
                    Name="RootBorder"
                    Background="{TemplateBinding Background}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    CornerRadius="{TemplateBinding CornerRadius}">
                    <DockPanel>
                        <ScrollViewer
                            Name="PART_HeaderScrollViewer"
                            DockPanel.Dock="Top"
                            HorizontalScrollBarVisibility="Hidden"
                            IsVisible="{TemplateBinding ShowColumnHeaders}"
                            VerticalScrollBarVisibility="Disabled">
                            <Border Name="ColumnHeadersPresenterBorder">
                                <TreeDataGridColumnHeadersPresenter
                                    Name="PART_ColumnHeadersPresenter"
                                    ElementFactory="{TemplateBinding ElementFactory}"
                                    Items="{TemplateBinding Columns}" />
                            </Border>
                        </ScrollViewer>
                        <ScrollViewer Name="PART_ScrollViewer" HorizontalScrollBarVisibility="Auto">
                            <TreeDataGridRowsPresenter
                                Name="PART_RowsPresenter"
                                Columns="{TemplateBinding Columns}"
                                ElementFactory="{TemplateBinding ElementFactory}"
                                Items="{TemplateBinding Rows}" />
                        </ScrollViewer>
                    </DockPanel>
                </Border>
            </ControlTemplate>
        </Setter>
        <Style Selector="^/template/ Border#ColumnHeadersPresenterBorder">
            <Setter Property="BorderThickness" Value="0 0 0 1" />
            <Setter Property="BorderBrush" Value="{DynamicResource TreeDataGridGridLinesBrush}" />
        </Style>
    </ControlTheme>

    <ControlTheme x:Key="{x:Type TreeDataGridColumnHeader}" TargetType="TreeDataGridColumnHeader">
        <Setter Property="Background" Value="Transparent" />
        <Setter Property="MinHeight" Value="32" />
        <Setter Property="Padding" Value="8 2 0 2" />
        <Setter Property="Cursor" Value="Hand" />
        <Setter Property="CornerRadius" Value="4" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="Foreground" Value="{DynamicResource TreeDataGridColumnHeaderForeground}" />
        <Setter Property="Template">
            <ControlTemplate TargetType="TreeDataGridColumnHeader">
                <Panel>
                    <Border
                        Name="DataGridBorder"
                        Margin="4"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="{TemplateBinding CornerRadius}" />
                    <DockPanel VerticalAlignment="Stretch">
                        <Panel DockPanel.Dock="Right" TabIndex="2">
                            <Rectangle
                                Width="1"
                                HorizontalAlignment="Right"
                                Fill="{DynamicResource TreeDataGridGridLinesBrush}" />
                            <Thumb
                                Name="PART_Resizer"
                                Width="5"
                                Background="Transparent"
                                Cursor="SizeWestEast"
                                DockPanel.Dock="Right"
                                IsVisible="{TemplateBinding CanUserResize}">
                                <Thumb.Template>
                                    <ControlTemplate>
                                        <Border VerticalAlignment="Stretch" Background="{TemplateBinding Background}" />
                                    </ControlTemplate>
                                </Thumb.Template>
                            </Thumb>
                        </Panel>
                        <PathIcon
                            Name="SortIcon"
                            Width="8"
                            Height="8"
                            Margin="0,0,8,0"
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center"
                            DockPanel.Dock="Right"
                            Foreground="{TemplateBinding Foreground}"
                            TabIndex="1" />
                        <ContentPresenter
                            Name="PART_ContentPresenter"
                            Padding="{TemplateBinding Padding}"
                            HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                            VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                            Content="{TemplateBinding Header}"
                            ContentTemplate="{TemplateBinding ContentTemplate}"
                            TabIndex="0">
                            <ContentPresenter.DataTemplates>
                                <DataTemplate DataType="x:String">
                                    <TextBlock Text="{Binding}" TextTrimming="CharacterEllipsis" />
                                </DataTemplate>
                            </ContentPresenter.DataTemplates>
                        </ContentPresenter>
                    </DockPanel>
                </Panel>
            </ControlTemplate>
        </Setter>

        <Style Selector="^:pointerover /template/ Border#DataGridBorder">
            <Setter Property="Background" Value="{DynamicResource TreeDataGridHeaderPointerOverBackground}" />
            <Setter Property="BorderBrush" Value="{DynamicResource TreeDataGridHeaderPointerOverBorderBrush}" />
            <Setter Property="TextBlock.Foreground" Value="{DynamicResource TreeDataGridHeaderPointerOverForeground}" />
        </Style>

        <Style Selector="^:pressed /template/ Border#DataGridBorder">
            <Setter Property="Background" Value="{DynamicResource TreeDataGridHeaderPressedBackground}" />
            <Setter Property="BorderBrush" Value="{DynamicResource TreeDataGridHeaderPressedBorderBrush}" />
            <Setter Property="TextBlock.Foreground" Value="{DynamicResource TreeDataGridHeaderPressedForeground}" />
        </Style>

        <Style Selector="^[SortDirection=Ascending] /template/ PathIcon#SortIcon">
            <Setter Property="IsVisible" Value="True" />
            <Setter Property="Data" Value="{DynamicResource TreeDataGridSortIconAscendingPath}" />
        </Style>

        <Style Selector="^[SortDirection=Descending] /template/ PathIcon#SortIcon">
            <Setter Property="IsVisible" Value="True" />
            <Setter Property="Data" Value="{DynamicResource TreeDataGridSortIconDescendingPath}" />
        </Style>

    </ControlTheme>

    <ControlTheme x:Key="{x:Type TreeDataGridRow}" TargetType="TreeDataGridRow">
        <Setter Property="Background" Value="Transparent" />
        <Setter Property="CornerRadius" Value="3" />
        <Setter Property="MinHeight" Value="32" />
        <Setter Property="Cursor" Value="Hand" />
        <Setter Property="Template">
            <ControlTemplate>
                <Panel>
                    <Border
                        Name="RowBorder"
                        Margin="{DynamicResource TreeDataGridRowMargin}"
                        HorizontalAlignment="Stretch"
                        VerticalAlignment="Stretch"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="{TemplateBinding CornerRadius}" />
                    <TreeDataGridCellsPresenter
                        Name="PART_CellsPresenter"
                        ElementFactory="{TemplateBinding ElementFactory}"
                        Items="{TemplateBinding Columns}"
                        Rows="{TemplateBinding Rows}" />
                </Panel>
            </ControlTemplate>
        </Setter>
        <Style Selector="^:selected /template/ Border#RowBorder">
            <Setter Property="Background" Value="{DynamicResource TreeDataGridCellSelectedBackground}" />
        </Style>
    </ControlTheme>

    <ControlTheme x:Key="{x:Type TreeDataGridCheckBoxCell}" TargetType="TreeDataGridCheckBoxCell">
        <Setter Property="Padding" Value="4 2" />
        <Setter Property="Template">
            <ControlTemplate>
                <Border
                    Name="CellBorder"
                    Padding="{TemplateBinding Padding}"
                    Background="{TemplateBinding Background}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    CornerRadius="{TemplateBinding CornerRadius}">
                    <CheckBox
                        HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
                        VerticalAlignment="Center"
                        IsChecked="{TemplateBinding Value, Mode=TwoWay}"
                        IsEnabled="{Binding !IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}"
                        IsThreeState="{TemplateBinding IsThreeState}"
                        Theme="{DynamicResource SimpleCheckBox}" />
                </Border>
            </ControlTemplate>
        </Setter>
    </ControlTheme>

    <ControlTheme x:Key="TreeDataGridExpandCollapseChevron" TargetType="ToggleButton">
        <Setter Property="Margin" Value="0" />
        <Setter Property="Width" Value="8" />
        <Setter Property="Height" Value="8" />
        <Setter Property="Foreground" Value="{DynamicResource TreeDataGridColumnHeaderForeground}" />
        <Setter Property="Template">
            <ControlTemplate>
                <Border
                    Width="{TemplateBinding Width}"
                    Height="{TemplateBinding Height}"
                    HorizontalAlignment="Center"
                    VerticalAlignment="Center"
                    Background="Transparent">
                    <PathIcon
                        Name="ChevronPath"
                        HorizontalAlignment="Center"
                        VerticalAlignment="Center"
                        Data="{DynamicResource TreeDataGridItemCollapsedChevronPathData}"
                        Foreground="{TemplateBinding Foreground}" />
                </Border>
            </ControlTemplate>
        </Setter>
        <Style Selector="^:checked /template/ PathIcon#ChevronPath">
            <Setter Property="RenderTransform" Value="rotate(90deg)" />
        </Style>
    </ControlTheme>

    <ControlTheme x:Key="{x:Type TreeDataGridExpanderCell}" TargetType="TreeDataGridExpanderCell">
        <Setter Property="Template">
            <ControlTemplate>
                <Border
                    Name="CellBorder"
                    Padding="{TemplateBinding Indent,
                                              Converter={x:Static conv:IndentConverter.Instance}}"
                    Background="{TemplateBinding Background}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    CornerRadius="{TemplateBinding CornerRadius}">
                    <DockPanel>
                        <Border
                            Width="12"
                            Height="12"
                            Margin="4,0"
                            DockPanel.Dock="Left">
                            <ToggleButton
                                Focusable="False"
                                IsChecked="{TemplateBinding IsExpanded, Mode=TwoWay}"
                                IsVisible="{TemplateBinding ShowExpander}"
                                Theme="{StaticResource TreeDataGridExpandCollapseChevron}" />
                        </Border>
                        <Decorator Name="PART_Content" />
                    </DockPanel>
                </Border>
            </ControlTemplate>
        </Setter>
    </ControlTheme>

    <ControlTheme x:Key="{x:Type TreeDataGridTextCell}" TargetType="TreeDataGridTextCell">
        <Setter Property="Padding" Value="8 4" />
        <Setter Property="Template">
            <ControlTemplate>
                <Border
                    Name="CellBorder"
                    Padding="{TemplateBinding Padding}"
                    Background="{TemplateBinding Background}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    CornerRadius="{TemplateBinding CornerRadius}">
                    <TextBlock
                        HorizontalAlignment="Stretch"
                        VerticalAlignment="Center"
                        Background="Transparent"
                        Text="{TemplateBinding Value}"
                        TextTrimming="{TemplateBinding TextTrimming}"
                        TextWrapping="{TemplateBinding TextWrapping}" />
                </Border>
            </ControlTemplate>
        </Setter>

        <Style Selector="^:editing">
            <Setter Property="Padding" Value="4 2" />
            <Setter Property="Template">
                <ControlTemplate>
                    <Border
                        Name="CellBorder"
                        Padding="{TemplateBinding Padding}"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="{TemplateBinding CornerRadius}">
                        <TextBox
                            Name="PART_Edit"
                            Classes="Small"
                            Text="{TemplateBinding Value, Mode=TwoWay}" />
                    </Border>
                </ControlTemplate>
            </Setter>
        </Style>

        <Style Selector="^:editing /template/ TextBox#PART_Edit">
            <Setter Property="Background" Value="Transparent" />
            <Setter Property="MinHeight" Value="25" />
            <Setter Property="Padding" Value="10,3,6,3" />
            <Setter Property="VerticalAlignment" Value="Center" />
        </Style>

        <Style Selector="^:editing /template/ TextBox#PART_Edit DataValidationErrors">
            <Setter Property="Theme" Value="{DynamicResource TooltipDataValidationErrors}" />
        </Style>

    </ControlTheme>

    <ControlTheme x:Key="{x:Type TreeDataGridTemplateCell}" TargetType="TreeDataGridTemplateCell">
        <Setter Property="Template">
            <ControlTemplate>
                <ContentPresenter
                    Name="PART_ContentPresenter"
                    Padding="{TemplateBinding Padding}"
                    Background="{TemplateBinding Background}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    Content="{TemplateBinding Content}"
                    ContentTemplate="{TemplateBinding ContentTemplate}"
                    CornerRadius="{TemplateBinding CornerRadius}" />
            </ControlTemplate>
        </Setter>

        <Style Selector="^:editing">
            <Setter Property="Padding" Value="4 2" />
            <Setter Property="Template">
                <ControlTemplate>
                    <ContentPresenter
                        Name="PART_EditingContentPresenter"
                        Padding="{TemplateBinding Padding}"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        Content="{TemplateBinding Content}"
                        ContentTemplate="{TemplateBinding EditingTemplate}"
                        CornerRadius="{TemplateBinding CornerRadius}" />
                </ControlTemplate>
            </Setter>
        </Style>
    </ControlTheme>
</ResourceDictionary>