Switch

Overview

Switch derives directly from the native ToggleButton (IsThreeState forced false), with a mandatory PART_Thumb template part styled off the same IsChecked/IsEnabled triggers as the track, and an OnToggle() override that no-ops while ReadOnly rather than exposing a separate lock property.

Usage

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

<navius:NaviusSwitch x:Name="Notifications"
                      IsChecked="{Binding NotificationsEnabled, Mode=TwoWay}"
                      Content="Email notifications" />

Properties

Property	Type	Default	From	Description
IsChecked	bool?	false	System.Windows.Controls.Primitives.ToggleButton	On/off state. IsThreeState is forced false in the constructor. Two-way bindable by default.
ReadOnly	bool	false	NaviusSwitch	Focusable but the value cannot change; enforced by an OnToggle() override that no-ops (skips base.OnToggle()) without touching IsEnabled/Focusable. Programmatic IsChecked changes still work.
Required	bool	false	NaviusSwitch	Exposed for API parity; no enforcement behavior in this port.

Events

Event	Signature	Fires when
Checked / Unchecked (inherited)	RoutedEventHandler	IsChecked flips via user click (blocked while ReadOnly or Disabled) or programmatic set.

Keyboard interactions

Key	Behavior
Space	Native ButtonBase press-on-key-down/click-on-key-up activation toggles IsChecked; verified via real routed KeyDown/KeyUp events (SwitchTests.SpaceKey_TogglesCheckedState).
Enter	Native ButtonBase click-on-key-down activation (via KeyboardNavigation.AcceptsReturn, metadata-overridden to true by ButtonBase) toggles IsChecked; verified the same way (SwitchTests.EnterKey_TogglesCheckedState).

Both keys are blocked while ReadOnly (EnterKey_BlockedWhenReadOnly); a disabled element never receives the key events at all.

UIA mechanism

NaviusSwitch ships no custom AutomationPeer; it inherits ToggleButtonAutomationPeer, exposing UIA TogglePattern, the closest native mapping to role="switch"/aria-checked available in WPF. PART_Thumb is a template part only, with no dedicated CLR type, styled directly off the same IsChecked/IsEnabled triggers as the track. The unit suite exercises the inherited peer (AutomationPeer_IsToggleButtonAutomationPeer_WithTogglePattern), the mandatory PART_Thumb part, ReadOnly’s focusable-but-immutable guard, and both Space and Enter via real routed key events on an HwndSource-hosted control.

Web deltas

• Form-submission mirroring (Name, Value, Form) is dropped entirely; no WPF form model.
• ReadOnly has no native WPF ToggleButton equivalent; implemented via an OnToggle() override, the same pattern used by NaviusCheckbox/NaviusRadioGroupItem.
• NaviusSwitchThumb (a cascaded-context component on the web) becomes PART_Thumb, a mandatory template part with no CLR type, styled directly by Style triggers instead of mirroring state through a shared context object.
• Thumb slide is a 120ms DoubleAnimation on a TranslateTransform, driven by Trigger.EnterActions/ExitActions in Themes/Switch.xaml (plain WPF Storyboard, no motion-library dependency).
• Attributes splat is dropped.
• An earlier audit draft briefly added a custom OnKeyDown override after misreading Enter as dead (a test-harness artifact: invoking OnKeyDown directly bypasses ButtonBase’s e.OriginalSource == this gate); the override was removed once real routed-key tests proved native ButtonBase already activates on both Space and Enter, so NaviusSwitch.cs ships with no custom key handling at all.

Captures

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