Events

Event Dispatching

The Event class and its derivatives manage the flow of events throughout the system. Events are categorized and dispatched using the EventDispatcher.

Key Components

1. Event Categories:
   • Defined using bit flags, allowing a single event to belong to multiple categories.
2. Event Types:
   • Predefined types like WindowResize, KeyPressed, MouseMoved, etc.
3. EventDispatcher:
   • Maps event types to their respective handlers.

Example

from Event import Event, EventDispatcher, EventType

dispatcher = EventDispatcher()

def on_window_resize(event):
    print(f"Window resized: {event}")
    return True

dispatcher.AddHandler(EventType.WindowResize, on_window_resize)

# Simulating an event
event = WindowResizeEvent()
dispatcher.Dispatch(event)

Event Flow in Layers

1. Events are first propagated to overlays in the LayerStack.
2. If an overlay handles the event, propagation stops.
3. If not, the event is passed to the layers in the stack.

Example of Layer Handling Events

class CustomLayer(Layer):
    def OnEvent(self, event):
        if event.EventType == EventType.KeyPressed:
            print(f"Key pressed event handled by {self.Name}")
            return True
        return False

layer_stack = LayerStack()
layer_stack.AddLayer(CustomLayer("GameLayer"))
layer_stack.OnEvent(event)

By using the LayerStack and Event system, the engine provides a robust foundation for organizing application logic and handling events efficiently.