Separator

Overview

Separator (NaviusSeparator) is a single self-contained lookless Control rendering a horizontal or vertical divider line. WPF’s stock Separator was rejected as a base because it has no standalone Orientation of its own (it visually adapts to a hosting ItemsControl instead), so this is a small custom control with its own Orientation dependency property.

Usage

xmlns:navius="clr-namespace:Navius.Wpf.Primitives.Controls;assembly=Navius.Wpf.Primitives"

<StackPanel>
    <TextBlock Text="Section one" />
    <navius:NaviusSeparator />
    <TextBlock Text="Section two" />
    <navius:NaviusSeparator Orientation="Vertical" Decorative="True" />
</StackPanel>

Properties

Property	Type	Default	From	Description
Orientation	Orientation	Horizontal	NaviusSeparator	Native WPF enum (Horizontal/Vertical); structurally rules out an invalid token, unlike the web contract’s runtime isValidOrientation guard.
Decorative	bool	false	NaviusSeparator	When true, removed from the accessibility tree (IsControlElementCore/IsContentElementCore both return false).

UIA mechanism

NaviusSeparatorAutomationPeer (a FrameworkElementAutomationPeer) reports AutomationControlType.Separator with an orientation-aware GetOrientationCore(). When Decorative is true, IsControlElementCore()/IsContentElementCore() both return false (combined with the base implementation, which additionally depends on UIElement.IsVisible), removing the element from the accessibility tree. The pure decorative-vs-not decision is split into a public static IsAccessibilityTreeMember(bool decorative) so it is unit-testable without a real, shown window; the unit suite (9 tests) covers both that pure logic and the “decorative always forces false” case on a real peer instance.

Web deltas

• Decorative is modeled as one boolean-driven automation-peer override rather than two separate templates or peer classes, even though the web literally renders two different divs (with/ without role).
• Orientation is the native System.Windows.Controls.Orientation enum rather than a string, which structurally obsoletes the web’s isValidOrientation invalid-token guard (an enum has no “diagonal” value to reject).
• WPF’s stock Separator control was rejected as a base (no standalone Orientation, adapts to a hosting ItemsControl instead); this is a small custom lookless Control instead.

Captures

The Separator Gallery page rendered at the pinned commit, in each theme.