# IVisualElementScheduler

> A scheduler provides the functionality to queue actions to run at a specific time or duration.

## Definition

* **Type:** Interface
* **Namespace:** [UnityEngine.UIElements](/engine/6000.7/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
public interface IVisualElementScheduler
```

## Remarks

You can use the scheduler to create animations, update the UI, or create tasks that require a delay or repeated action.

To schedule an action, use the [IVisualElementScheduler.Execute](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduler/execute.md) method. The scheduler runs the action at the next frame.

A [VisualElement](/engine/6000.7/script-reference/unityengine/uielements/visualelement.md) associates with the scheduler, which you can access through the [\_schedule](/engine/6000.7/script-reference/unityengine/uielements/visualelement/schedule.md) property. It returns an [IVisualElementScheduledItem](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduleditem.md) interface that provides methods to schedule the action.

For example, you can delay running of the action with the [IVisualElementScheduledItem.StartingIn](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduleditem/startingin.md) method. You can also specify a condition to unschedule the action with the [IVisualElementScheduledItem.Until](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduleditem/until.md) method.

To repeat the action at a specified interval, use the [IVisualElementScheduledItem.Every](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduleditem/every.md) method. To remove the scheduler, use the [IVisualElementScheduledItem.Pause](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduleditem/pause.md) method.

The scheduler is active only when the VisualElement is attached to a panel. Detaching the VisualElement from the panel pauses the scheduler, and reattaching it resumes the scheduler.

Additional Resources: [VisualElement.schedule](/engine/6000.7/script-reference/unityengine/uielements/visualelement/schedule.md), [VisualElement.panel](/engine/6000.7/script-reference/unityengine/uielements/visualelement/panel.md), [IVisualElementScheduledItem](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduleditem.md)

## Examples

```csharp
// This example uses the scheduler to animate the title logo by changing its background image
// to the next frame every 200 milliseconds.
int m_CurrentTitleLogoFrame = 0;
public List<Texture2D> m_TitleLogoFrames = new List<Texture2D>();
// Animate title logo.
var titleLogo = root.Q("menu-title-image");
titleLogo?.schedule.Execute(() =>
{
    if (m_TitleLogoFrames.Count == 0)
        return;

        m_CurrentTitleLogoFrame = (m_CurrentTitleLogoFrame + 1) % m_TitleLogoFrames.Count;
        var frame = m_TitleLogoFrames[m_CurrentTitleLogoFrame];
        titleLogo.style.backgroundImage = frame;
}).Every(200);
```

```csharp
// This example uses the scheduler to animate the scaling of a VisualElement.
IVisualElementScheduledItem m_AnimationScheduler = null;

public void DoScale()
{
// Scale the VisualElement.
}

m_AnimationScheduler = this.schedule.Execute(DoScale).Every(1).StartingIn(0);

// Stop the animation
m_AnimationScheduler.Pause();
```

## Methods

| Method                                                                                               | Description                                |
| ---------------------------------------------------------------------------------------------------- | ------------------------------------------ |
| [Execute](/engine/6000.7/script-reference/unityengine/uielements/ivisualelementscheduler/execute.md) | Schedule this action to be executed later. |