2 files changed, 16 insertions, 11 deletions
diff --git a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPref.kt b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPref.kt
index 2f8a6aa..a45d66d 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPref.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPref.kt
@@ -42,6 +42,12 @@ open class KPref private constructor(
 
     internal val prefMap: MutableMap<String, ILazyResettable<*>> = mutableMapOf()
 
+     fun add(entry : KPrefDelegate<*>) {
+        if (prefMap.containsKey(entry.key))
+            throw KPrefException("${entry.key} is already used elsewhere in preference $preferenceName")
+        prefMap[entry.key] = entry
+    }
+
     fun reset() {
         prefMap.values.forEach { it.invalidate() }
     }
diff --git a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefDelegate.kt b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefDelegate.kt
index d54c54d..c17d3df 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefDelegate.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefDelegate.kt
@@ -27,13 +27,14 @@ import ca.allanwang.kau.kotlin.ILazyResettable
  */
 
 interface KPrefDelegate<T> : ILazyResettable<T> {
+    val key: String
     operator fun setValue(any: Any, property: kotlin.reflect.KProperty<*>, t: T)
 }
 
 class KPrefException(message: String) : IllegalAccessException(message)
 
 class KPrefDelegateAndroid<T> internal constructor(
-    private val key: String,
+    override val key: String,
     private val fallback: T,
     private val pref: KPref,
     private val prefBuilder: KPrefBuilderAndroid,
@@ -50,9 +51,7 @@ class KPrefDelegateAndroid<T> internal constructor(
     private val lock = this
 
     init {
-        if (pref.prefMap.containsKey(key))
-            throw KPrefException("$key is already used elsewhere in preference ${pref.preferenceName}")
-        pref.prefMap[key] = this@KPrefDelegateAndroid
+        pref.add(this)
     }
 
     override fun invalidate() {
@@ -79,7 +78,8 @@ class KPrefDelegateAndroid<T> internal constructor(
 
     override fun isInitialized(): Boolean = _value !== UNINITIALIZED
 
-    override fun toString(): String = if (isInitialized()) value.toString() else "Lazy kPref $key not initialized yet."
+    override fun toString(): String =
+        if (isInitialized()) value.toString() else "Lazy kPref $key not initialized yet."
 
     override operator fun setValue(any: Any, property: kotlin.reflect.KProperty<*>, t: T) {
         _value = t
@@ -91,7 +91,7 @@ class KPrefDelegateAndroid<T> internal constructor(
 }
 
 class KPrefDelegateInMemory<T> internal constructor(
-    private val key: String,
+    override val key: String,
     private val fallback: T,
     private val pref: KPref,
     private var postSetter: (value: T) -> Unit = {}
@@ -104,13 +104,11 @@ class KPrefDelegateInMemory<T> internal constructor(
     private val lock = this
 
     init {
-        if (pref.prefMap.containsKey(key))
-            throw KPrefException("$key is already used elsewhere in preference ${pref.preferenceName}")
-        pref.prefMap[key] = this
+       pref.add(this)
     }
 
     override fun invalidate() {
-        // No op
+        _value = UNINITIALIZED
     }
 
     @Suppress("UNCHECKED_CAST")
@@ -133,7 +131,8 @@ class KPrefDelegateInMemory<T> internal constructor(
 
     override fun isInitialized(): Boolean = _value !== UNINITIALIZED
 
-    override fun toString(): String = if (isInitialized()) value.toString() else "Lazy kPref $key not initialized yet."
+    override fun toString(): String =
+        if (isInitialized()) value.toString() else "Lazy kPref $key not initialized yet."
 
     override operator fun setValue(any: Any, property: kotlin.reflect.KProperty<*>, t: T) {
         _value = t