UeEventDispatcher

Base class that provides a lightweight event system for all engine objects. It is used as the parent class for UeTransform, which means every object that inherits from UeTransform (including UeObject3D, UeMesh, cameras, etc.) automatically gains event capabilities.

Constructor

new UeEventDispatcher()

Creates an empty dispatcher. Internally it stores listeners in a private _listeners struct.

Methods (inherited via UeEventDispatcher)

• on(type, listener) – Registers listener for the given event type.
• off(type, listener) – Unregisters a previously added listener.
• once(type, listener) – Registers a listener that will be invoked only the first time the event fires, then automatically removed.
• dispatch(event) – Fires an event struct. The struct must contain a type field (string). The dispatcher sets event.target to the object during propagation.

Event struct

var event = {
    type: "added",   // name of the event
    data: any,        // optional payload
    target: undefined // will be set by dispatcher
};

Usage example

var obj = new UeObject3D();
obj.on("added", function(e) {
    show_debug_message("Object added to parent!");
});

var parent = new UeObject3D();
parent.add(obj); // triggers "added" on obj and "childAdded" on parent