Left out FXRouter from previous commit

src/main/scala/nova/monadic_sfx/ui/components/router/FXRouter.scala

@@ -1,5 +1,7 @@
 package nova.monadic_sfx.ui.components.router
 
+import scala.concurrent.duration._
+
 import io.circe.Codec
 import io.circe.Decoder
 import io.circe.Encoder
@@ -7,15 +9,15 @@ import io.circe.generic.JsonCodec
 import io.circe.generic.semiauto._
 import io.odin.Logger
 import monix.bio.Task
+import monix.eval.Coeval
+import monix.reactive.Observable
 import nova.monadic_sfx.util.IOUtils
+import nova.monadic_sfx.util.MutHistory
+import nova.monadic_sfx.util.controls.JFXSpinner
 import nova.monadic_sfx.util.reactive.store.Middlewares
 import nova.monadic_sfx.util.reactive.store.Reducer
 import nova.monadic_sfx.util.reactive.store.Store
 import scalafx.scene.Parent
-import monix.reactive.Observable
-import nova.monadic_sfx.util.controls.JFXSpinner
-import scala.concurrent.duration._
-import monix.eval.Coeval
 
 object FXRouter {
 
@@ -23,6 +25,9 @@ object FXRouter {
 
   sealed abstract class Action[+T]
   final case class Replace[T](page: T) extends Action[T]
+  final case class HistoryEvent[T](page: T) extends Action[T]
+  final case object Forward extends Action[Nothing]
+  final case object Backward extends Action[Nothing]
 
   object Action {
     implicit def codec[T: Encoder: Decoder]: Codec[Action[T]] = deriveCodec
@@ -32,7 +37,10 @@ object FXRouter {
 
 }
 
-class FXRouter[P]()(implicit E: Encoder[P], D: Decoder[P]) {
+class FXRouter[P](history: MutHistory[P])(implicit
+    E: Encoder[P],
+    D: Decoder[P]
+) {
   import FXRouter._
 
   def store(initialPage: P, logger: Logger[Task]): Task[FXStore[P]] =
@@ -58,7 +66,12 @@ class FXRouter[P]()(implicit E: Encoder[P], D: Decoder[P]) {
     action match {
       // case Init => (state, None)
       case Replace(p) =>
+        history.push(p)
+        (state.copy(page = p), None)
+      case HistoryEvent(p) =>
         (state.copy(page = p), None)
+      case Forward  => (state, None)
+      case Backward => (state, None)
     }
 
   def render(