Generic base class for events, implementing event pooling and automatic registration to the event type system.
| eventTypeId | Retrieves the type ID for this event instance. |
| Dispose | Implementation of IDispose. |
| Init | Resets all event members to their initial values. |
| GetPooled | Gets an event from the event pool. Use this function instead of creating new events. Events obtained using this method need to be released back to the pool. You can use `Dispose()` to release them. |
| TypeId | Gets the type ID for the event class. |
| bubbles | Whether this event type bubbles up in the event propagation path. |
| currentTarget | The current target of the event. This is the VisualElement, in the propagation path, for which event handlers are currently being executed. |
| dispatch | Whether the event is being dispatched to a visual element. An event cannot be redispatched while it being dispatched. If you need to recursively dispatch an event, it is recommended that you use a copy of the event. |
| eventTypeId | Retrieves the type ID for this event instance. |
| imguiEvent | The IMGUIEvent at the source of this event. The source can be null since not all events are generated by IMGUI. |
| isDefaultPrevented | Return true if the default actions should not be executed for this event. |
| isImmediatePropagationStopped | Whether StopImmediatePropagation() was called for this event. |
| isPropagationStopped | Whether StopPropagation() was called for this event. |
| originalMousePosition | The original mouse position of the IMGUI event, before it is transformed to the current target local coordinates. |
| pooled | Whether the event is allocated from a pool of events. |
| propagationPhase | The current propagation phase. |
| target | The target visual element that received this event. Unlike currentTarget, this target does not change when the event is sent to other elements along the propagation path. |
| timestamp | The time when the event was created. |
| tricklesDown | Whether this event is sent down the event propagation path during the TrickleDown phase. |
| PreventDefault | Whether the default actions are prevented from being executed for this event. |
| StopImmediatePropagation | Immediately stops the propagation of the event. The event is not sent to other elements along the propagation path. This method prevents other event handlers from executing on the current target. |
| StopPropagation | Stops propagating this event. The event is not sent to other elements along the propagation path. This method does not prevent other event handlers from executing on the current target. |
| RegisterEventType | Registers an event class to the event type system. |