State lives in a view-model

A widget’s fields — an entry’s text, a list’s items, a table’s rows — are its view of the state, not the state. An application that assigns them from wherever it happens to be scatters its state across call sites, and two of those call sites eventually disagree about what is on screen.

So state lives in a view-model: plain Go values wrapped in observables, with no widget in sight, testable without a window. The view binds each widget to the view-model once, and from then on the binding — not the application — keeps them in step, in both directions.