Function draw_play_confirmation 

fn draw_play_confirmation(
    ui: &mut Ui,
    dirty_paths: &[PathBuf],
) -> Option<PlayConfirmAction>

Shown instead of the normal editor UI while EditorScene::play_confirmation is set — Play was requested while one or more tabs have unsaved edits. Lists which scenes are dirty so the choice is informed, then lets the user save everything first, play anyway (accepting that a scene.change(...) to one of these would load its last-saved, not current, contents), or cancel.