Allow to unsubscribe from the ObservableState.

3 files changed, 13 insertions, 3 deletions

diff --git a/src/main/kotlin/pl/treksoft/kvision/state/ObservableList.kt b/src/main/kotlin/pl/treksoft/kvision/state/ObservableList.kt
index 92109814..7d41e05c 100644
--- a/src/main/kotlin/pl/treksoft/kvision/state/ObservableList.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/state/ObservableList.kt
@@ -35,9 +35,12 @@ interface ObservableList<T> : MutableList<T>, ObservableState<List<T>> {
 class ObservableListWrapper<T>(val mutableList: MutableList<T> = mutableListOf()) : MutableList<T>, ObservableList<T>,
     ObservableState<List<T>> {
 
-    override fun subscribe(observer: (List<T>) -> Unit) {
+    override fun subscribe(observer: (List<T>) -> Unit): () -> Unit {
         onUpdate += observer
         observer(this)
+        return {
+            onUpdate -= observer
+        }
     }
 
     override val onUpdate: MutableCollection<(MutableList<T>) -> Unit> = mutableListOf()
diff --git a/src/main/kotlin/pl/treksoft/kvision/state/ObservableState.kt b/src/main/kotlin/pl/treksoft/kvision/state/ObservableState.kt
index 9dc9af0d..f1cba7f0 100644
--- a/src/main/kotlin/pl/treksoft/kvision/state/ObservableState.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/state/ObservableState.kt
@@ -28,5 +28,5 @@ interface ObservableState<S> {
     /**
      * Subscribe for the state change notifications.
      */
-    fun subscribe(observer: (S) -> Unit)
+    fun subscribe(observer: (S) -> Unit): () -> Unit
 }
diff --git a/src/main/kotlin/pl/treksoft/kvision/state/StateBinding.kt b/src/main/kotlin/pl/treksoft/kvision/state/StateBinding.kt
index 7df82adc..adb7d3be 100644
--- a/src/main/kotlin/pl/treksoft/kvision/state/StateBinding.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/state/StateBinding.kt
@@ -22,8 +22,10 @@ class StateBinding<S : Any, CONT : Container, CONTENT>(
     private val factory: (CONT.(S) -> CONTENT)
 ) : Widget(setOf()) {
 
+    private val unsubscribe: () -> Unit
+
     init {
-        observableState.subscribe { update(it) }
+        unsubscribe = observableState.subscribe { update(it) }
     }
 
     private var updateState: ((S, CONTENT) -> Unit)? = null
@@ -51,6 +53,11 @@ class StateBinding<S : Any, CONT : Container, CONTENT>(
         this.updateState = updateState
     }
 
+    override fun dispose() {
+        unsubscribe()
+        super.dispose()
+    }
+
     companion object {
         /**
          * DSL builder extension function.