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Unity Engine

ExecuteDefaultActionAtTarget(EventBase)

Executes logic after the callbacks registered on each element in the BubbleUp phase have been executed, unless the event propagation is stopped by one of the callbacks. EventBase.PreventDefault().
Read time 3 minutesLast updated 10 days ago

Definition

Warning
Deprecated. Use HandleEventBubbleUp. Before proceeding, make sure you understand the latest changes to UIToolkit event propagation rules by visiting Unity's manual page https://docs.unity3d.com/Manual/UIE-Events-Dispatching.html
[EventInterest(EventInterestOptions.Inherit)]protected virtual void ExecuteDefaultActionAtTarget(EventBase evt)

Parameters

evt

EventBase
The event instance.

Remarks

This method is designed to be overriden by subclasses. Use it to implement event handling without registering callbacks, which guarantees precedences of callbacks registered by users of the subclass.
Use EventInterestAttribute on this method to specify a range of event types that this method needs to receive. Events that don't fall into the specified types might not be sent to this method.
This method is obsolete. Use CallbackEventHandler.HandleEventBubbleUp and CallbackEventHandler.HandleEventTrickleDown to handle events on an element without registering callbacks. Note that you might need to add a check if only the event's target processes it.
Also, the execution order or ExecuteDefaultAction-type and HandleEvent-type methods might differ when compared to other registered callbacks:
  • ExecuteDefaultAction
    and 
    ExecuteDefaultActionAtTarget
    are executed during the obsolete 
    DefaultAction
    and 
    DefaultActionAtTarget
    propagation phases.
  • HandleEventTrickleDown
    and 
    HandleEventBubbleUp
    are executed during the 
    TrickleDown
    and 
    BubbleUp
    propagation phases.
  • Registered callbacks are executed during the 
    TrickleDown
    and 
    BubbleUp
    propagation phases.
Additional Resources: CallbackEventHandler.HandleEventBubbleUp, CallbackEventHandler.HandleEventTrickleDown, PropagationPhase

Examples

using UnityEngine;using UnityEngine.UIElements;public class HandleEventExample : VisualElement{    // This method is obsolete! Use HandleEventTrickleDown instead and add the "at target" check.    // Note that this may impact the execution order between the content of this method and other callbacks    // on parent or child elements. It's recommended not to mix ExecuteDefaultAction and HandleEvent methods.    protected override void ExecuteDefaultActionAtTarget(EventBase evt)    {        Debug.Log("Received event " + evt + ", at target, before bubble up on parents.");        DoSomethingEarlyOnTarget();    }    // This method is obsolete! Use HandleEventBubbleUp instead and add the "at target" check.    // Note that this may impact the execution order between the content of this method and other callbacks    // on parent or child elements. It's recommended not to mix ExecuteDefaultAction and HandleEvent methods.    protected override void ExecuteDefaultAction(EventBase evt)    {        Debug.Log("Received event " + evt + ", at target, after bubble up on parents.");        DoSomethingLateOnTarget();    }    // This is the recommended method to use. Note that you can also handle events on the element if it's not the target.    protected override void HandleEventTrickleDown(EventBase evt)    {        Debug.Log("Received event " + evt + " before trickle down on children.");        if (evt.target == this)        {            Debug.Log("Received event " + evt + ", at target, before trickle down on children.");            DoSomethingEarlyOnTarget();        }    }    // The recommended way to go. Note that you can also handle events on the element if it's not the target.    protected override void HandleEventBubbleUp(EventBase evt)    {        Debug.Log("Received event " + evt + " before bubble up on parents.");        if (evt.target == this)        {            Debug.Log("Received event " + evt + ", at target, before bubble up on parents.");            DoSomethingLateOnTarget();        }    }    private void DoSomethingEarlyOnTarget() { }    private void DoSomethingLateOnTarget() { }}