Class ScyllaScheduler

Editor-facing UI Toolkit scheduler helpers that pair every recurring or debounced scheduled item with an automatic UnityEngine.UIElements.DetachFromPanelEvent cancellation. Use these in place of raw host.schedule.Execute(...).Every(...) / .StartingIn(...) to avoid stale-reference callbacks after the hosting inspector or window tears down.

Inheritance
object
ScyllaScheduler
Inherited Members
Namespace: Scylla.Core.Editor
Assembly: ScyllaCore.Editor.dll
Syntax
public static class ScyllaScheduler
Remarks

The behavior lives in ScyllaSafeScheduler, which serves runtime panels as well. This wrapper exists so editor code reports a failing callback under Editor rather than UI, and so the editor-specific hazard below stays documented where editor authors will read it.

Scheduled items registered via UI Toolkit's UnityEngine.UIElements.VisualElement.schedule keep firing until they are explicitly paused, or until the panel they live on is destroyed. Between an inspector teardown and the next UnityEngine.UIElements.DetachFromPanelEvent, captured UnityEditor.SerializedProperty instances may already be disposed. Reading from a disposed property throws InvalidOperationException inside the scheduled callback. Pausing on detach prevents that window.

The framework convention (per code-style.md UI Toolkit Mandate) is to use these helpers for any new recurring or debounced scheduled item. Direct host.schedule.Execute(...).Every(...) without a matching DetachFromPanelEvent Pause is rejected at code review.

Methods

DebouncedSafe(VisualElement, Action, long)

Creates a one-shot debounced scheduled item that fires callback after delayMs milliseconds, and pauses automatically on UnityEngine.UIElements.DetachFromPanelEvent. Pause the returned item and call ExecuteLater(long) on it to reset the debounce window without allocating a fresh scheduler entry.

Declaration
public static IVisualElementScheduledItem DebouncedSafe(VisualElement host, Action callback, long delayMs)
Parameters
Type Name Description
VisualElement host

The visual element whose panel attachment controls the lifetime of the scheduled item. Must not be null.
Action callback

The action to invoke after the delay. Must not be null.
long delayMs

The initial delay in milliseconds before the first fire.
Returns
Type Description
IVisualElementScheduledItem

The created UnityEngine.UIElements.IVisualElementScheduledItem, already scheduled. Call Pause() then ExecuteLater(delayMs) on it to restart the debounce window on subsequent triggers.
Remarks

Typical debounce pattern when responding to a text field's value-changed event: 

var debounce = ScyllaScheduler.DebouncedSafe(root, OnSearchChanged, 300);
searchField.RegisterValueChangedCallback(evt =>
{
    debounce.Pause();
    debounce.ExecuteLater(300);
});

This reuses the single allocated scheduler entry across every keystroke, avoiding per-keystroke allocations.

Exceptions
Type Condition
ArgumentNullException

Thrown when host or callback is null.

OnceSafe(VisualElement, Action)

Creates a scheduled item that fires callback once on the next scheduler pass, and pauses automatically on UnityEngine.UIElements.DetachFromPanelEvent.

Declaration
public static IVisualElementScheduledItem OnceSafe(VisualElement host, Action callback)
Parameters
Type Name Description
VisualElement host

The visual element whose panel attachment controls the lifetime of the scheduled item. Must not be null.
Action callback

The action to invoke once. Must not be null.
Returns
Type Description
IVisualElementScheduledItem

The created UnityEngine.UIElements.IVisualElementScheduledItem.
Remarks

Use this to coalesce a burst of changes into a single piece of work, such as rebuilding an inspector section once after several properties are written rather than once per property.

Exceptions
Type Condition
ArgumentNullException

Thrown when host or callback is null.

RecurringSafe(VisualElement, Action, long)

Creates a recurring scheduled item that fires callback every intervalMs milliseconds while host is attached to a panel, and pauses automatically on UnityEngine.UIElements.DetachFromPanelEvent.

Declaration
public static IVisualElementScheduledItem RecurringSafe(VisualElement host, Action callback, long intervalMs)
Parameters
Type Name Description
VisualElement host

The visual element whose panel attachment controls the lifetime of the scheduled item. Must not be null.
Action callback

The action to invoke on every tick. Must not be null.
long intervalMs

The tick interval in milliseconds.
Returns
Type Description
IVisualElementScheduledItem

The created UnityEngine.UIElements.IVisualElementScheduledItem. Keep the reference if you need to pause the item manually before the host detaches.
Exceptions
Type Condition
ArgumentNullException

Thrown when host or callback is null.

See Also