Drop idea of FinishedDataEvent

There is not clear way to use its generic parameter, so data filed
is added to simple FinishedEvent. User will use cast to get its value,
 but it is more clear than using multiple event types spiced with some "library magic".

Author: nsk90

docs/index.md

@@ -411,8 +411,9 @@ Notifications about finishing are available in two forms:
    Transition for `FinishedEvent` is detected by the library and matched by special kind of `EventMatcher`,
    so such transition is triggered only for `FinishedEvent` that corresponds to this state.
    `FinishingEvent` generated by finishing of another state will not trigger such transition.
+
+   If `FinalState` that triggered `FinishedEvent` is also a `DataState` then its data field will be copied into `FinishedEvent`.
    See [transition on FinishedEvent sample](https://github.com/nsk90/kstatemachine/tree/master/samples/src/main/kotlin/ru/nsk/samples/FinishedEventSample.kt)
-   .
 
 ## Nested states
 

kstatemachine/src/main/kotlin/ru/nsk/kstatemachine/BaseStateImpl.kt

@@ -1,5 +1,6 @@
 package ru.nsk.kstatemachine
 
+import ru.nsk.kstatemachine.ChildMode.*
 import ru.nsk.kstatemachine.TransitionType.EXTERNAL
 import ru.nsk.kstatemachine.TreeAlgorithms.findPathFromTargetToLca
 import ru.nsk.kstatemachine.visitors.GetActiveStatesVisitor
@@ -68,7 +69,7 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
 
     override fun <S : IState> addState(state: S, init: StateBlock<S>?): S {
         check(!machine.isRunning) { "Can not add state after state machine started" }
-        if (childMode == ChildMode.PARALLEL) {
+        if (childMode == PARALLEL) {
             require(state !is IFinalState) { "Can not add IFinalState in parallel child mode" }
             require(state !is PseudoState) { "Can not add PseudoState in parallel child mode" }
         }
@@ -87,7 +88,7 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
 
     override fun setInitialState(state: IState) {
         require(states.contains(state)) { "$state is not part of $this machine, use addState() first" }
-        check(childMode == ChildMode.EXCLUSIVE) { "Can not set initial state in parallel child mode" }
+        check(childMode == EXCLUSIVE) { "Can not set initial state in parallel child mode" }
         check(!machine.isRunning) { "Can not change initial state after state machine started" }
 
         data.initialState = state as InternalState
@@ -135,7 +136,7 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
     }
 
     override fun afterChildFinished(finishedChild: InternalState, transitionParams: TransitionParams<*>) {
-        if (childMode == ChildMode.PARALLEL && states.all { it.isFinished }) {
+        if (childMode == PARALLEL && states.all { it.isFinished }) {
             data.isFinished = true
             notifyStateFinish(finishedChild, transitionParams)
         }
@@ -162,7 +163,7 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
         if (states.isEmpty()) return
 
         when (childMode) {
-            ChildMode.EXCLUSIVE -> {
+            EXCLUSIVE -> {
                 val initialState = checkNotNull(initialState) {
                     "Initial state is not set, call setInitialState() first"
                 }
@@ -171,7 +172,7 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
                     initialState.recursiveEnterInitialStates(transitionParams)
             }
 
-            ChildMode.PARALLEL -> data.states.forEach {
+            PARALLEL -> data.states.forEach {
                 handleStateEntry(it, transitionParams)
                 if (it !is StateMachine) // inner state machine manages its internal state by its own
                     it.recursiveEnterInitialStates(transitionParams)
@@ -211,12 +212,12 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
     private fun requireCurrentState() = requireNotNull(data.currentState) { "Current state is not set" }
 
     override fun getCurrentStates() = when (childMode) {
-        ChildMode.EXCLUSIVE -> listOfNotNull(data.currentState)
-        ChildMode.PARALLEL -> data.states.toList()
+        EXCLUSIVE -> listOfNotNull(data.currentState)
+        PARALLEL -> data.states.toList()
     }
 
     private fun setCurrentState(state: InternalState, transitionParams: TransitionParams<*>) {
-        require(childMode == ChildMode.EXCLUSIVE) { "Cannot set current state in child mode $childMode" }
+        require(childMode == EXCLUSIVE) { "Cannot set current state in child mode $childMode" }
         require(states.contains(state)) { "$state is not a child of $this" }
 
         if (data.currentState == state && transitionParams.transition.type != EXTERNAL) return
@@ -234,8 +235,8 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
 
     private fun handleStateEntry(state: InternalState, transitionParams: TransitionParams<*>) {
         val finished = when (childMode) {
-            ChildMode.EXCLUSIVE -> state is IFinalState
-            ChildMode.PARALLEL -> states.all { it.isFinished }
+            EXCLUSIVE -> state is IFinalState
+            PARALLEL -> states.all { it.isFinished }
         }
         data.isFinished = finished
 
@@ -257,10 +258,10 @@ open class BaseStateImpl(override val name: String?, override val childMode: Chi
 
     private fun makeFinishedEvent(state: InternalState): FinishedEvent {
         // check for both interfaces as client is not forced to use FinalDataState
-        return if (state is DataState<*> && state is IFinalState) // possible in exclusive child mode only
-            FinishedDataEventImpl(this, state.data)
+        return if (childMode == EXCLUSIVE && state is DataState<*> && state is IFinalState)
+            FinishedEvent(this, state.data)
         else
-            FinishedEventImpl(this)
+            FinishedEvent(this)
     }
 
     internal fun switchToTargetState(

kstatemachine/src/main/kotlin/ru/nsk/kstatemachine/TransitionParams.kt

@@ -26,19 +26,12 @@ interface GeneratedEvent : Event
  * Special event generated by the library when a state is finished.
  * Transitions use special event matcher by default to match only related events.
  */
-interface FinishedEvent : GeneratedEvent {
-    val state: IState
-}
-
-interface FinishedDataEvent<D : Any> : FinishedEvent, DataEvent<D>
-
-internal class FinishedEventImpl(override val state: IState) : FinishedEvent
-internal class FinishedDataEventImpl<D : Any>(override val state: IState, override val data: D) : FinishedDataEvent<D>
+class FinishedEvent internal constructor(val state: IState, val data: Any? = null): GeneratedEvent
 
 /**
  * Initial event which is processed on state machine start
  */
-class StartEvent internal constructor() : Event
+class StartEvent internal constructor() : GeneratedEvent
 
 /**
  * System event which is used by the library to wrap original event and argument,

kstatemachine/src/main/kotlin/ru/nsk/kstatemachine/TransitionStateApi.kt

@@ -148,10 +148,8 @@ inline fun <reified E : DataEvent<D>, D : Any> TransitionStateApi.dataTransition
     return addTransition(builder.build())
 }
 
-inline fun <reified E : Event> matcherForEvent(state: IState): EventMatcher<E> {
-    @Suppress("UNCHECKED_CAST")
-    return if (E::class == FinishedEvent::class)
-        finishedEventMatcher(state) as EventMatcher<E>
-    else
-        isInstanceOf()
+@Suppress("UNCHECKED_CAST")
+inline fun <reified E : Event> matcherForEvent(state: IState) = when {
+    E::class == FinishedEvent::class -> finishedEventMatcher(state) as EventMatcher<E>
+    else -> isInstanceOf()
 }

kstatemachine/src/test/kotlin/ru/nsk/kstatemachine/FinishedEventTest.kt

@@ -57,7 +57,7 @@ class FinishedEventTest : StringSpec({
         machine.isFinished shouldBe false
     }
 
-    "FinishedDataEvent" {
+    "FinishedEvent with data" {
         val callbacks = mockkCallbacks()
         data class IntEvent(override val data: Int) : DataEvent<Int>
         val intData = 42
@@ -74,7 +74,7 @@ class FinishedEventTest : StringSpec({
                     }
                 }
 
-                transitionOn<FinishedDataEvent<Int>> {
+                transitionOn<FinishedEvent> {
                     targetState = {
                         event.data shouldBe intData
                         state2
@@ -85,7 +85,7 @@ class FinishedEventTest : StringSpec({
         }
         machine.processEvent(IntEvent(intData))
         verifySequence {
-            callbacks.onTriggeredTransition(ofType<FinishedDataEvent<Int>>())
+            callbacks.onTriggeredTransition(ofType<FinishedEvent>())
         }
     }
 
@@ -109,4 +109,24 @@ class FinishedEventTest : StringSpec({
             callbacks.onTriggeredTransition(ofType<FinishedEvent>())
         }
     }
+
+    "FinishedEvent from start" {
+        val callbacks = mockkCallbacks()
+
+        createStateMachine {
+            initialState {
+                setInitialState(finalState())
+                transition<FinishedEvent> {
+                    onTriggered {
+                        it.event.data shouldBe null
+                        callbacks.onTriggeredTransition(it.event)
+                    }
+                }
+            }
+        }
+
+        verifySequence {
+            callbacks.onTriggeredTransition(ofType<FinishedEvent>())
+        }
+    }
 })