Create kpref single

4 files changed, 76 insertions, 14 deletions

diff --git a/core/src/main/kotlin/ca/allanwang/kau/kotlin/LazyResettable.kt b/core/src/main/kotlin/ca/allanwang/kau/kotlin/LazyResettable.kt
index f8947f3..2981dda 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/kotlin/LazyResettable.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/kotlin/LazyResettable.kt
@@ -13,11 +13,11 @@ internal object UNINITIALIZED
 
 fun <T : Any> lazyResettable(initializer: () -> T): LazyResettable<T> = LazyResettable<T>(initializer)
 
-class LazyResettable<T : Any>(private val initializer: () -> T, lock: Any? = null) : Lazy<T>, Serializable {
+class LazyResettable<T : Any>(private val initializer: () -> T, lock: Any? = null) : ILazyResettable<T>, Serializable {
     @Volatile private var _value: Any = UNINITIALIZED
     private val lock = lock ?: this
 
-    fun invalidate() {
+    override fun invalidate() {
         _value = UNINITIALIZED
     }
 
@@ -48,4 +48,8 @@ class LazyResettable<T : Any>(private val initializer: () -> T, lock: Any? = nul
     operator fun setValue(any: Any, property: KProperty<*>, t: T) {
         _value = t
     }
+}
+
+interface ILazyResettable<T> : Lazy<T> {
+    fun invalidate()
 }
\ No newline at end of file
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 7fd8955..fa6c5a9 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPref.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPref.kt
@@ -2,6 +2,7 @@ package ca.allanwang.kau.kpref
 
 import android.content.Context
 import android.content.SharedPreferences
+import ca.allanwang.kau.kotlin.ILazyResettable
 
 /**
  * Created by Allan Wang on 2017-06-07.
@@ -24,12 +25,12 @@ open class KPref {
         c.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE)
     }
 
-    internal val prefMap: MutableMap<String, KPrefDelegate<*>> = mutableMapOf()
+    internal val prefMap: MutableMap<String, ILazyResettable<*>> = mutableMapOf()
 
     fun reset() {
         prefMap.values.forEach { it.invalidate() }
     }
 
-    operator fun get(key: String): KPrefDelegate<*>? = prefMap[key]
+    operator fun get(key: String): ILazyResettable<*>? = prefMap[key]
 
 }
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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 4d57ff1..74792e1 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefDelegate.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefDelegate.kt
@@ -1,17 +1,19 @@
 package ca.allanwang.kau.kpref
 
+import ca.allanwang.kau.kotlin.ILazyResettable
+
 /**
  * Created by Allan Wang on 2017-06-07.
  */
-private object UNINITIALIZED
+object UNINITIALIZED
 
-fun KPref.kpref(key: String, fallback: Boolean, postSetter: (value: Boolean) -> Unit = {}): KPrefDelegate<Boolean> = KPrefDelegate(key, fallback, this, postSetter)
-fun KPref.kpref(key: String, fallback: Double, postSetter: (value: Float) -> Unit = {}): KPrefDelegate<Float> = KPrefDelegate(key, fallback.toFloat(), this, postSetter)
-fun KPref.kpref(key: String, fallback: Float, postSetter: (value: Float) -> Unit = {}): KPrefDelegate<Float> = KPrefDelegate(key, fallback, this, postSetter)
-fun KPref.kpref(key: String, fallback: Int, postSetter: (value: Int) -> Unit = {}): KPrefDelegate<Int> = KPrefDelegate(key, fallback, this, postSetter)
-fun KPref.kpref(key: String, fallback: Long, postSetter: (value: Long) -> Unit = {}): KPrefDelegate<Long> = KPrefDelegate(key, fallback, this, postSetter)
-fun KPref.kpref(key: String, fallback: Set<String>, postSetter: (value: Set<String>) -> Unit = {}): KPrefDelegate<StringSet> = KPrefDelegate(key, StringSet(fallback), this, postSetter)
-fun KPref.kpref(key: String, fallback: String, postSetter: (value: String) -> Unit = {}): KPrefDelegate<String> = KPrefDelegate(key, fallback, this, postSetter)
+fun KPref.kpref(key: String, fallback: Boolean, postSetter: (value: Boolean) -> Unit = {}) = KPrefDelegate(key, fallback, this, postSetter)
+fun KPref.kpref(key: String, fallback: Double, postSetter: (value: Float) -> Unit = {}) = KPrefDelegate(key, fallback.toFloat(), this, postSetter)
+fun KPref.kpref(key: String, fallback: Float, postSetter: (value: Float) -> Unit = {}) = KPrefDelegate(key, fallback, this, postSetter)
+fun KPref.kpref(key: String, fallback: Int, postSetter: (value: Int) -> Unit = {}) = KPrefDelegate(key, fallback, this, postSetter)
+fun KPref.kpref(key: String, fallback: Long, postSetter: (value: Long) -> Unit = {}) = KPrefDelegate(key, fallback, this, postSetter)
+fun KPref.kpref(key: String, fallback: Set<String>, postSetter: (value: Set<String>) -> Unit = {}) = KPrefDelegate(key, StringSet(fallback), this, postSetter)
+fun KPref.kpref(key: String, fallback: String, postSetter: (value: String) -> Unit = {}) = KPrefDelegate(key, fallback, this, postSetter)
 
 class StringSet(set: Collection<String>) : LinkedHashSet<String>(set)
 
@@ -20,7 +22,9 @@ class StringSet(set: Collection<String>) : LinkedHashSet<String>(set)
  * Contains a unique key for the shared preference as well as a nonnull fallback item
  * Also contains an optional mutable postSetter that will be called every time a new value is given
  */
-class KPrefDelegate<T : Any> internal constructor(private val key: String, private val fallback: T, private val pref: KPref, var postSetter: (value: T) -> Unit = {}, lock: Any? = null) : Lazy<T>, java.io.Serializable {
+class KPrefDelegate<T : Any> internal constructor(
+        private val key: String, private val fallback: T, private val pref: KPref, var postSetter: (value: T) -> Unit = {}, lock: Any? = null
+) : ILazyResettable<T>, java.io.Serializable {
 
     @Volatile private var _value: Any = UNINITIALIZED
     private val lock = lock ?: this
@@ -31,7 +35,7 @@ class KPrefDelegate<T : Any> internal constructor(private val key: String, priva
         pref.prefMap.put(key, this@KPrefDelegate)
     }
 
-    fun invalidate() {
+    override fun invalidate() {
         _value = UNINITIALIZED
     }
 
diff --git a/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefSingleDelegate.kt b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefSingleDelegate.kt
new file mode 100644
index 0000000..58e570f
--- /dev/null
+++ b/core/src/main/kotlin/ca/allanwang/kau/kpref/KPrefSingleDelegate.kt
@@ -0,0 +1,53 @@
+package ca.allanwang.kau.kpref
+
+import ca.allanwang.kau.kotlin.ILazyResettable
+
+/**
+ * Created by Allan Wang on 2017-06-07.
+ */
+fun KPref.kprefSingle(key: String) = KPrefSingleDelegate(key, this)
+
+/**
+ * Singular KPref Delegate for booleans
+ * When the shared pref is not initialized, it will return true then set the pref to false
+ * All subsequent retrievals will be false
+ * This is useful for one time toggles such as showcasing items
+ */
+class KPrefSingleDelegate internal constructor(private val key: String, private val pref: KPref, lock: Any? = null) : ILazyResettable<Boolean> {
+
+    @Volatile private var _value: Boolean? = null
+    private val lock = lock ?: this
+
+    init {
+        if (pref.prefMap.containsKey(key))
+            throw KPrefException("$key is already used elsewhere in preference ${pref.PREFERENCE_NAME}")
+        pref.prefMap.put(key, this@KPrefSingleDelegate)
+    }
+
+    override fun invalidate() {
+        _value = null
+    }
+
+    override val value: Boolean
+        get() {
+            val _v1 = _value
+            if (_v1 != null)
+                return _v1
+
+            return synchronized(lock) {
+                val _v2 = _value
+                if (_v2 != null) {
+                    _v2
+                } else {
+                    _value = pref.sp.getBoolean(key, true)
+                    if (_value!!) pref.sp.edit().putBoolean(key, false).apply()
+                    _value!!
+                }
+            }
+        }
+
+    override fun isInitialized(): Boolean = _value != null
+
+    override fun toString(): String = if (isInitialized()) value.toString() else "Lazy kPref $key not initialized yet."
+
+}
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