Display MainGame.mnu and map in ordoor simultaneously

It's a complete mess for now - many things are out of place or shown
when they shouldn't be - and we can't move around the game map. But,
it's a good start.

internal/flow/flow.go

@@ -40,38 +40,9 @@ type Flow struct {
 	exit error
 }
 
-type driverName string
-
-const (
-	// Names of all the drivers
-	main      driverName = "Main"
-	levelPly  driverName = "LevelPly"
-	singles   driverName = "Singles"
-	randomMap driverName = "RandomMap"
-	newGame   driverName = "NewGame"
-	loadGame  driverName = "LoadGame"
-	options   driverName = "Options"
-	kbd       driverName = "Keyboard"
-	bridge    driverName = "Bridge"
-	briefing  driverName = "Briefing"
-	choices   driverName = "Choices"
-	saveGame  driverName = "SaveGame"
-	credits   driverName = "Credits"
-	arrange   driverName = "Arrange"
-
-	configureUltEquip      driverName = "Configure_UltEquip"
-	configureVehiclesUltra driverName = "Configure_Vehicles_Ultra"
-)
-
 var (
 	ErrExit = errors.New("exiting gracefully")
 
-	driverNames = []driverName{
-		main, levelPly, singles, randomMap, newGame, loadGame, options, kbd,
-		bridge, briefing, choices, saveGame, credits, arrange,
-		configureUltEquip, configureVehiclesUltra,
-	}
-
 	// Constants used for sliders
 
 	h3Slider = map[int]int{1: 8, 2: 56, 3: 110, 4: 120}
@@ -245,25 +216,7 @@ func (f *Flow) setValueBool(driver driverName, id string, value bool) {
 	f.exit = f.drivers[driver].SetValueBool(id, value)
 }
 
-func (f *Flow) setDriver(name driverName) func() {
-	return func() {
-		f.setDriverNow(name)
-	}
-}
-
-func (f *Flow) setDriverNow(name driverName) {
-	f.current = f.drivers[name]
-}
-
-// from is the parent menu, to is the child
-func (f *Flow) setReturningDriver(from, to driverName) func() {
-	return func() {
-		f.returns[to] = from
-		f.setDriverNow(to)
-	}
-}
-
-func (f *Flow) playNextScenario() func() {
+func (f *Flow) playNextScenario(from driverName) func() {
 	return func() {
 		log.Printf("Loading scenario: %v", f.ship.NextScenario)
 
@@ -275,24 +228,11 @@ func (f *Flow) playNextScenario() func() {
 			return
 		}
 
-		f.current = nil // TODO: show the UI for a scenario
+		f.setReturningDriverNow(from, mainGame)
 		f.scenario = scenario
 	}
 }
 
-// from is the child menu, to is the parent
-func (f *Flow) returnToLastDriverNow(from driverName) error {
-	to, ok := f.returns[from]
-	if !ok {
-		return fmt.Errorf("Couldn't work out where to return to from %v", from)
-	}
-
-	delete(f.returns, from)
-
-	f.setDriverNow(to)
-	return nil
-}
-
 func (f *Flow) setExit() {
 	f.exit = ErrExit
 }