Widget

Widget is the concrete tree type the runtime mounts. Variants cover every builder (Frame, Flow, Button, Checkbox, …). See the widgets overview for the full list.

Conversions

Each builder implements Into<Widget> / From, so Frame::child / Flow::child accept builders directly:

.child(Text::new("hi"))
.child(Button::new("Go"))
.child(Flow::new().direction(GuiDirection::Horizontal).child(Text::new("nested")))

Return impl Into<Widget> from your app function (usually a root Frame).

Mount

widget.mount(parent); // creates Factorio elements under `parent`

runtime::mount wraps this for screen roots and applies the mount root_name when the root frame has no explicit .name(...).