ExprContext

Prepares graph expansion by copying control properties over for subsequent look-up through getProperty.

Creates a temporary nested context into which all visit calls are redirected, thus a compound Disposable can be returned.

Installs a reaction to an event. Depending on the type of context, this will simply call event.changed.react with the given fun (when the context is for an Act or Control or Widget), or in will register the event as used (when the context is for an ex-obj).