makepad-event-action

Makepad event handling uses the handle_event function to process lifecycle, mouse, touch, and keyboard events, then emits actions via cx.action(). Widgets capture child actions using cx.capture_actions to trigger higher-level behavior.

Action propagation in Makepad flows from child to parent. Child widgets emit actions using cx.action(...), and parent widgets capture them via cx.capture_actions to update state and coordinate behavior across the widget tree.

The DefaultNone pattern provides a default empty action state for Makepad widgets. It satisfies ActionTrait definitions by ensuring actions initialize safely before any user interaction triggers an actual event payload.

Yes, Makepad widget event handling standardizes processing for MouseDown, KeyDown, TouchUpdate, and lifecycle events. The system applies ActionTrait definitions to emit and forward these events consistently.

Standardizing Makepad event-to-action communication involves defining actions that satisfy ActionTrait, emitting them from child widgets with cx.action, and capturing them in parents. This creates a clear, consistent flow for nested widget trees.

Makepad actions fail to capture when parents do not call cx.capture_actions or when child widgets omit cx.action emissions. Ensure both the ActionTrait definition and the capture logic are correctly implemented in the widget tree.