WPF

public class SourceDiagramBase : FrameworkElement, INotifyPropertyChanged
{
    private VisualCollection _children;

    public SourceDiagramBase()
    {
        _children = new VisualCollection(this);
        _children.Add(CreateDrawingVisual());
    }

    protected override int VisualChildrenCount { get { return _children.Count; } }


    protected override Visual GetVisualChild(int index)
    {
        return _children[index];
    }



    public double Scale
    {
        get { return (double)GetValue(ScaleProperty); }
        set { SetValue(ScaleProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Scale.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty ScaleProperty =
        DependencyProperty.Register("Scale", typeof(double), typeof(SourceDiagramBase), new PropertyMetadata(20d));

    protected override Size MeasureOverride(Size availableSize)
    {
        return new Size(this.Scale * 12d, this.Scale * 12d);
    }


    private DrawingVisual CreateDrawingVisual()
    {
        DrawingVisual drawingVisual = new DrawingVisual();
        DrawingContext drawingContext = drawingVisual.RenderOpen();

        drawingContext.PushTransform(new ScaleTransform(this.Scale, this.Scale));

        double thick = 0.04;
        drawingContext.DrawEllipse(Brushes.Transparent, new Pen(Brushes.Black, thick), new Point(6, 6), 3,3);

        drawingContext.DrawLine(new Pen(Brushes.Black, thick), new Point(6, 3), new Point(6, 2));
        drawingContext.DrawLine(new Pen(Brushes.Black, thick), new Point(6, 9), new Point(6, 10));

        drawingContext.DrawLine(new Pen(Brushes.Black, thick), new Point(6, 2), new Point(12, 2));
        drawingContext.DrawLine(new Pen(Brushes.Black, thick), new Point(6, 10), new Point(12, 10));

        drawingContext.Close();
        return drawingVisual;
    }

    public event PropertyChangedEventHandler PropertyChanged;

    // This method is called by the Set accessor of each property.
    // The CallerMemberName attribute that is applied to the optional propertyName
    // parameter causes the property name of the caller to be substituted as an argument.
    private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

from c in db.Companies
join p in db.Projects on c.Id equals p.CompanyId
join j in db.Jobs on p.Id equals j.ProjectId
where c.DeletedDT == null && p.DeletedDT == null && j.DeletedDT == null
...

query = query.Where(i => i.ProjectStatusId == awardedId);

// Add optional query parameters
if (companyId > 0)
{
    query = query.Where(i => i.CompanyId == companyId);
}

if (projectId > 0)
{
    query = query.Where(i => i.ProjectId == projectId);
}

if (startDate != null)
{
    query = query.Where(i => i.StartDate >= startDate);
}

if (endDate != null)
{
    query = query.Where(i => i.StartDate <= endDate);
}

results = query.ToList();

<ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">

<Style TargetType="TabItem">

    <Setter Property="ContextMenu">
        <Setter.Value>
            <ContextMenu DataContext="{Binding DataContext, ElementName=Window}">

                <MenuItem Header="Close" 
                            Command="{Binding CloseTabCommand}"
                            CommandParameter="{Binding}"/>

                <MenuItem Header="Close All Tabs" 
                            Command="{Binding CloseAllTabsCommand}"
                            CommandParameter="{Binding}"/>

                <MenuItem Header="Close All But This" 
                            Command="{Binding CloseAllButThisTabCommand}"
                            CommandParameter="{Binding}"/>

            </ContextMenu>
        </Setter.Value>
    </Setter>

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TabItem">
                <Grid Name="Panel">
                    <ContentPresenter x:Name="ContentSite"
                                        VerticalAlignment="Center"
                                        HorizontalAlignment="Center"
                                        ContentSource="Header"
                                        Margin="10,2"/>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter TargetName="Panel" Property="Background" Value="LightSkyBlue" />
                    </Trigger>
                    <Trigger Property="IsSelected" Value="False">
                        <Setter TargetName="Panel" Property="Background" Value="White" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>

</Style>

<Style TargetType="TabItem">

    <Setter Property="ContextMenu">
        <Setter.Value>
            <ContextMenu DataContext="{Binding DataContext, RelativeSource={RelativeSource AncestorType=Window}}"
                    x:Name="tabMenu">

                <MenuItem Header="Close" 
                    Command="{Binding CloseTabCommand}"
                    CommandParameter="{Binding}"/>

                <MenuItem Header="Close All Tabs" 
                    Command="{Binding CloseAllTabsCommand}"
                    CommandParameter="{Binding}"/>

                <MenuItem Header="Close All But This" 
                    Command="{Binding CloseAllButThisTabCommand}"
                    CommandParameter="{Binding}"/>

            </ContextMenu>
        </Setter.Value>
    </Setter>

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TabItem">
                <Grid Name="Panel">
                    <ContentPresenter x:Name="ContentSite"
                                VerticalAlignment="Center"
                                HorizontalAlignment="Center"
                                ContentSource="Header"
                                Margin="10,2"/>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter TargetName="Panel" Property="Background" Value="LightSkyBlue" />
                    </Trigger>
                    <Trigger Property="IsSelected" Value="False">
                        <Setter TargetName="Panel" Property="Background" Value="White" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>

</Style>

System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Window', AncestorLevel='1''. BindingExpression:Path=DataContext; DataItem=null; target element is 'ContextMenu' (Name='tabMenu'); target property is 'DataContext' (type 'Object')

<Style TargetType="TabItem">

    <Setter Property="ContextMenu">
        <Setter.Value>
            <ContextMenu DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}" >

                <MenuItem Header="Class Tab" 
                            Command="{Binding Source={StaticResource Proxy}, Path=Data.CloseTabCommand}"
                            CommandParameter="{Binding}"/>

                <MenuItem Header="Class All Tabs" 
                            Command="{Binding Source={StaticResource Proxy}, Path=Data.CloseAllTabsCommand}"
                            CommandParameter="{Binding}"/>

                <MenuItem Header="Close All But This" 
                            Command="{Binding Source={StaticResource Proxy}, Path=Data.CloseAllButThisTabCommand}"
                            CommandParameter="{Binding}"/>

            </ContextMenu>
        </Setter.Value>
    </Setter>

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TabItem">
                <Grid Name="Panel">
                    <ContentPresenter x:Name="ContentSite"
                                VerticalAlignment="Center"
                                HorizontalAlignment="Center"
                                ContentSource="Header"
                                Margin="10,2"/>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsSelected" Value="True">
                        <Setter TargetName="Panel" Property="Background" Value="LightSkyBlue" />
                    </Trigger>
                    <Trigger Property="IsSelected" Value="False">
                        <Setter TargetName="Panel" Property="Background" Value="White" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>

</Style>