Typed multi machine

README.md

@@ -133,6 +133,7 @@ val commonMain by getting {
 - [Welcome](examples/welcome/welcome) - multi-module example of user on-boarding flow
 - [Parallel](examples/multi/parallel) - two machines running in parallel in one proxy state
 - [Navbar](examples/multi/navbar) - several machines running in proxy state, one of them active at a time
+- [Mixed](examples/multi/mixed) - two machines of different gesture/UI system mixed in one state
 - [Lifecycle](examples/lifecycle) - track your Android app lifecycle to pause pending operations when the app is suspended
 
 ## The basic task - Load-Content-Error
@@ -1258,12 +1259,12 @@ private sealed class MultiGesture {
   data class StringGesture(val data: String) : MultiGesture()
 }
 
-private open class TestState : MultiMachineState<MultiGesture, String>() {
+private open class TestState : MultiMachineState<MultiGesture, String, Any, Any>() {
 
   private data object IntKey : MachineKey<Int, Int>(null) // Int for gesture and state
   private data object StringKey : MachineKey<String, String>(null) // String for gesture and state
 
-  override val container: ProxyMachineContainer = AllTogetherMachineContainer(
+  override val container: ProxyMachineContainer<Any, Any> = AllTogetherMachineContainer(
     listOf(
       object : MachineInit<Int, Int> {
         override val key: MachineKey<Int, Int> = IntKey
@@ -1310,8 +1311,8 @@ private open class TestState : MultiMachineState<MultiGesture, String>() {
   private data object StringKey : MachineKey<String, String>(null) // String for gesture and state
 
   // ... machine init omitted
-  
-  override fun mapUiState(provider: UiStateProvider, changedKey: MachineKey<*, *>?): String {
+
+  override fun mapUiState(provider: UiStateProvider<Any>, changedKey: MachineKey<*, out Any>?): String {
     val i: Int = provider.getValue(IntKey)       // Cast to Int
     val s: String = provider.getValue(StringKey) // Cast to String
     return "$i - $s" // Combined state of any kind you like
@@ -1347,7 +1348,7 @@ private open class TestState : MultiMachineState<MultiGesture, String>() {
   // ... machine init omitted
 
   // Our parent gesture is 
-  override fun mapGesture(parent: MultiGesture, processor: GestureProcessor) = when(parent) {
+  override fun mapGesture(parent: MultiGesture, processor: GestureProcessor<Any, Any>) = when(parent) {
     is MultiGesture.IntGesture -> {
       processor.process(IntKey, parent.data) // Int expected
     }

commonstatemachine/src/commonMain/kotlin/com/motorro/commonstatemachine/CommonStateMachine.kt

@@ -17,7 +17,7 @@ package com.motorro.commonstatemachine
  * Common state machine input - from the outside world to the current state
  * @param G UI gesture
  */
-interface MachineInput<G: Any> {
+interface MachineInput<in G: Any> {
     /**
      * Updates state with UI gesture
      * @param gesture UI gesture to proceed
@@ -51,7 +51,7 @@ interface MachineOutput<G: Any, U: Any> {
 /**
  * Current public machine status
  */
-interface MachineStatus<U : Any> {
+interface MachineStatus<out U : Any> {
     /**
      * Checks if machine is started
      */
@@ -71,6 +71,11 @@ interface MachineStatus<U : Any> {
  */
 interface CommonStateMachine<G: Any, U: Any> : MachineInput<G>, MachineOutput<G, U>, MachineStatus<U> {
 
+    /**
+     * Starts the machine
+     */
+    fun start()
+
     /**
      * Base state-machine implementation
      * @param G UI gesture
@@ -104,9 +109,9 @@ interface CommonStateMachine<G: Any, U: Any> : MachineInput<G>, MachineOutput<G,
         }
 
         /**
-         * Starts machine
+         * Starts the machine
          */
-        fun start() {
+        override fun start() {
             if (started.not()) {
                 activeState = init()
                 startMachineState()
@@ -136,5 +141,4 @@ interface CommonStateMachine<G: Any, U: Any> : MachineInput<G>, MachineOutput<G,
             activeState.start(this)
         }
     }
-}
-
+}

commonstatemachine/src/commonMain/kotlin/com/motorro/commonstatemachine/multi/ActiveStateMachine.kt

@@ -28,7 +28,7 @@ import com.motorro.commonstatemachine.lifecycle.MachineLifecycle
  */
 internal class ActiveStateMachine<G: Any, U: Any>(
     init: MachineInit<G, U>,
-    onUiChanged: (MachineKey<*, *>, Any) -> Unit
+    onUiChanged: (MachineKey<G, U>, U) -> Unit
 ) : CommonStateMachine<G, U>, Activated {
     /**
      * Machine lifecycle
@@ -41,7 +41,10 @@ internal class ActiveStateMachine<G: Any, U: Any>(
         { onUiChanged(init.key, it.child) }
     )
 
-    init {
+    /**
+     * Starts the machine
+     */
+    override fun start() {
         machine.start()
     }
 

commonstatemachine/src/commonMain/kotlin/com/motorro/commonstatemachine/multi/MachineAccess.kt

@@ -13,55 +13,71 @@
 
 package com.motorro.commonstatemachine.multi
 
-import com.motorro.commonstatemachine.CommonStateMachine
+/**
+ * Provides access to the state-machine
+ * @param CG Child gesture system
+ * @param CU Child UI-state system
+ */
+interface MachineAccess<CG: Any, CU: Any> {
+    /**
+     * Keys collection
+     */
+    val keys: Set<MachineKey<*, out CU>>
+
+    /**
+     * Retrieves UI state.
+     * [MachineInit] and [key] bind types securely.
+     * @param U Concrete UI state bound with the [key], subtype of CU
+     * @param key Machine key
+     */
+    fun <U: CU> getState(key: MachineKey<*, U>): U?
+
+    /**
+     * Processes machine gesture.
+     * [MachineInit] and [key] bind types securely.
+     * @param G Concrete gesture, subtype of th [CG]
+     * @param key Machine key
+     * @param gesture Gesture to process
+     */
+    fun <G: CG> process(key: MachineKey<G, out CU>, gesture: G)
+}
 
 /**
  * Retrieves a ui-state given the [MachineKey]
  */
-interface UiStateProvider {
+interface UiStateProvider<CU: Any> {
 
     /**
      * Retrieves all running machine keys
      */
-    fun getMachineKeys(): Set<MachineKey<*, *>>
+    fun getMachineKeys(): Set<MachineKey<*, out CU>>
 
     /**
      * Gets a concrete UI-state
      * @param key Machine key your state is bound to
      * @throws IllegalStateException if state is not found in common state
      */
-    fun <U: Any> getValue(key: MachineKey<*, U>): U = checkNotNull(get(key)) {
+    fun <U: CU> getValue(key: MachineKey<*, out U>): U = checkNotNull(get(key)) {
         "Key $key not found in machine map"
     }
 
     /**
      * Gets a concrete UI-state
      * @param key Machine key your state is bound to
      */
-    operator fun <U: Any> get(key: MachineKey<*, U>): U?
+    operator fun <U: CU> get(key: MachineKey<*, U>): U?
 }
 
 /**
  * Redirects your gesture to be processed with a child machine
  * identified by [MachineKey]
  */
-interface GestureProcessor {
+interface GestureProcessor<CG: Any, CU: Any> {
     /**
      * Redirects your gesture to be processed by child machine
      * if machine identified by [key] is found
      * @param key Machine key
      * @param gesture Gesture to process
      */
-    fun <G: Any> process(key: MachineKey<G, *>, gesture: G)
-}
-
-/**
- * Runs [block] with machine stored in [machineMap] under this key
- */
-@Suppress("UNCHECKED_CAST")
-internal inline fun <G: Any, U: Any, R> withMachine(
-    key: MachineKey<G, U>,
-    machineMap: MachineMap,
-    block: CommonStateMachine<G, U>.() -> R
-): R? = (machineMap[key] as? CommonStateMachine<G, U>)?.block()
-
+    fun <G: CG> process(key: MachineKey<G, out CU>, gesture: G)
+}

commonstatemachine/src/commonMain/kotlin/com/motorro/commonstatemachine/multi/MultiMachineState.kt

@@ -21,11 +21,11 @@ import com.motorro.commonstatemachine.CommonMachineState
  * - Override [mapUiState] to build a combined UI state af all the machines
  * - Override [container] with a [ProxyMachineContainer] of your choice
  */
-abstract class MultiMachineState<PG: Any, PU: Any> : CommonMachineState<PG, PU>() {
+abstract class MultiMachineState<PG: Any, PU: Any, CG: Any, CU: Any> : CommonMachineState<PG, PU>() {
     /**
      * Proxy machines container
      */
-    protected abstract val container: ProxyMachineContainer
+    protected abstract val container: ProxyMachineContainer<CG, CU>
 
     /**
      * A part of [start] template to initialize state
@@ -45,20 +45,18 @@ abstract class MultiMachineState<PG: Any, PU: Any> : CommonMachineState<PG, PU>(
      * Updates machine view-state
      */
     @Suppress("UNUSED_PARAMETER")
-    private fun onUiStateChange(key: MachineKey<*, *>, uiState: Any) {
+    private fun onUiStateChange(key: MachineKey<*, out CU>, uiState: CU) {
         setUiState(buildUiState(key))
     }
 
     /**
      * Builds common UI state
      */
-    private fun buildUiState(changedKey: MachineKey<*, *>?): PU {
-        val machineMap = container.getMachines()
-        val uiStateProvider = object : UiStateProvider {
-            override fun getMachineKeys(): Set<MachineKey<*, *>> = machineMap.keys
-            override fun <U : Any> get(key: MachineKey<*, U>): U? {
-                return withMachine(key, machineMap) { getUiState() }
-            }
+    private fun buildUiState(changedKey: MachineKey<*, out CU>?): PU {
+        val access = container.machineAccess
+        val uiStateProvider = object : UiStateProvider<CU> {
+            override fun getMachineKeys(): Set<MachineKey<*, out CU>> = access.keys
+            override fun <U : CU> get(key: MachineKey<*, U>): U? = access.getState(key)
         }
         return mapUiState(uiStateProvider, changedKey)
     }
@@ -74,10 +72,10 @@ abstract class MultiMachineState<PG: Any, PU: Any> : CommonMachineState<PG, PU>(
      * A part of [process] template to process UI gesture
      */
     override fun doProcess(gesture: PG) {
-        val machineMap = container.getMachines()
-        val processor = object : GestureProcessor {
-            override fun <G : Any> process(key: MachineKey<G, *>, gesture: G) {
-                withMachine(key, machineMap) { process(gesture) }
+        val access = container.machineAccess
+        val processor = object : GestureProcessor<CG, CU> {
+            override fun <G : CG> process(key: MachineKey<G, out CU>, gesture: G) {
+                access.process(key, gesture)
             }
         }
         mapGesture(gesture, processor)
@@ -88,13 +86,13 @@ abstract class MultiMachineState<PG: Any, PU: Any> : CommonMachineState<PG, PU>(
      * @param parent Parent gesture
      * @param processor Use it to send child gesture to the relevant child machine
      */
-    protected abstract fun mapGesture(parent: PG, processor: GestureProcessor)
+    protected abstract fun mapGesture(parent: PG, processor: GestureProcessor<CG, CU>)
 
     /**
      * Maps combined child UI state to parent
      * @param provider Provides child UI states
      * @param changedKey Key of machine that changed the UI state. Null if called explicitly via [updateUi]
      * @see updateUi
      */
-    protected abstract fun mapUiState(provider: UiStateProvider, changedKey: MachineKey<*, *>?): PU
+    protected abstract fun mapUiState(provider: UiStateProvider<CU>, changedKey: MachineKey<*, out CU>?): PU
 }