Function note_input 

pub fn note_input(event: &WindowEvent)

Note that event is being handled: what it opens or closes follows it (input_source). The window’s event entry points call this before dispatching, so every surface the toolkit shows knows what asked for it without each owner threading the source through.

The pointer merely moving asks for nothing, so it does not count: a menu a key opened lands at once even if the mouse is nudged before the frame.