Create debounce and update searchview (#27)

* Prepare version

* Create debounce base

* Add debouncer and fix transition crash

* Add debounce docs

* Update links

* Update searchview docs

* Test without a ref

* Add links to core components

* Update links

* Update to bullet points

* Test core md

* Test slash

* Test slash

* Specify implemented dependencies

4 files changed, 181 insertions, 1 deletions

diff --git a/core/src/main/kotlin/ca/allanwang/kau/kotlin/Debouncer.kt b/core/src/main/kotlin/ca/allanwang/kau/kotlin/Debouncer.kt
new file mode 100644
index 0000000..4fba2c8
--- /dev/null
+++ b/core/src/main/kotlin/ca/allanwang/kau/kotlin/Debouncer.kt
@@ -0,0 +1,124 @@
+package ca.allanwang.kau.kotlin
+
+import ca.allanwang.kau.logging.KL
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
+
+/**
+ * Created by Allan Wang on 2017-08-05.
+ *
+ * Thread safe function wrapper to allow for debouncing
+ * With reference to <a href="https://stackoverflow.com/a/20978973/4407321">Stack Overflow</a>
+ */
+
+/**
+ * The debouncer base
+ * Implements everything except for the callback,
+ * as the number of variables is different between implementations
+ * You may still use this without extending it, but you'll have to pass a callback each time
+ */
+open class Debouncer(var interval: Long) {
+    private val sched = Executors.newScheduledThreadPool(1)
+    private var task: DebounceTask? = null
+
+    /**
+     * Generic invocation to pass a callback to the new task
+     * Pass a new callback for the task
+     * If another task is pending, it will be invalidated
+     */
+    operator fun invoke(callback: () -> Unit) {
+        synchronized(this) {
+            task?.invalidate()
+            val newTask = DebounceTask(callback)
+            KL.v("Debouncer task created: $newTask in $this")
+            sched.schedule(newTask, interval, TimeUnit.MILLISECONDS)
+            task = newTask
+        }
+    }
+
+    /**
+     * Call to cancel all pending requests and shutdown the thread pool
+     * The debouncer cannot be used after this
+     */
+    fun terminate() = sched.shutdownNow()
+
+    /**
+     * Invalidate any pending tasks
+     */
+    fun cancel() {
+        synchronized(this) {
+            if (task != null) KL.v("Debouncer cancelled for $task in $this")
+            task?.invalidate()
+            task = null
+        }
+    }
+
+}
+
+/*
+ * Helper extensions for functions with 0 to 3 arguments
+ */
+
+/**
+ * The debounced task
+ * Holds a callback to execute if the time has come and it is still valid
+ * All methods can be viewed as synchronous as the invocation is synchronous
+ */
+private class DebounceTask(inline val callback: () -> Unit) : Runnable {
+    private var valid = true
+
+    fun invalidate() {
+        valid = false
+    }
+
+    override fun run() {
+        if (!valid) return
+        valid = false
+        KL.v("Debouncer task executed $this")
+        try {
+            callback()
+        } catch (e: Exception) {
+            KL.e(e, "DebouncerTask exception")
+        }
+    }
+}
+
+/**
+ * A zero input debouncer
+ */
+class Debouncer0 internal constructor(interval: Long, val callback: () -> Unit) : Debouncer(interval) {
+    operator fun invoke() = invoke(callback)
+}
+
+fun debounce(interval: Long, callback: () -> Unit) = Debouncer0(interval, callback)
+fun (() -> Unit).debounce(interval: Long) = debounce(interval, this)
+
+/**
+ * A one argument input debouncer
+ */
+class Debouncer1<T> internal constructor(interval: Long, val callback: (T) -> Unit) : Debouncer(interval) {
+    operator fun invoke(key: T) = invoke { callback(key) }
+}
+
+fun <T> debounce(interval: Long, callback: (T) -> Unit) = Debouncer1(interval, callback)
+fun <T> ((T) -> Unit).debounce(interval: Long) = debounce(interval, this)
+
+/**
+ * A two argument input debouncer
+ */
+class Debouncer2<T, V> internal constructor(interval: Long, val callback: (T, V) -> Unit) : Debouncer(interval) {
+    operator fun invoke(arg0: T, arg1: V) = invoke { callback(arg0, arg1) }
+}
+
+fun <T, V> debounce(interval: Long, callback: (T, V) -> Unit) = Debouncer2(interval, callback)
+fun <T, V> ((T, V) -> Unit).debounce(interval: Long) = debounce(interval, this)
+
+/**
+ * A three argument input debouncer
+ */
+class Debouncer3<T, U, V> internal constructor(interval: Long, val callback: (T, U, V) -> Unit) : Debouncer(interval) {
+    operator fun invoke(arg0: T, arg1: U, arg2: V) = invoke { callback(arg0, arg1, arg2) }
+}
+
+fun <T, U, V> debounce(interval: Long, callback: ((T, U, V) -> Unit)) = Debouncer3(interval, callback)
+fun <T, U, V> ((T, U, V) -> Unit).debounce(interval: Long) = debounce(interval, this)
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 2ac5d2f..ceeaa30 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/kotlin/LazyResettable.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/kotlin/LazyResettable.kt
@@ -13,7 +13,7 @@ internal object UNINITIALIZED
 
 fun <T : Any> lazyResettable(initializer: () -> T): LazyResettable<T> = LazyResettable<T>(initializer)
 
-open class LazyResettable<T : Any>(private val initializer: () -> T, lock: Any? = null) : ILazyResettable<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
 
diff --git a/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt b/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt
index 4c6d655..4cf566a 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt
@@ -18,4 +18,7 @@ open class TimberLogger(tag: String) {
     inline fun i(s: String) = Timber.i(TAG, s)
     inline fun v(s: String) = Timber.v(TAG, s)
     inline fun eThrow(s: String) = e(Throwable(s))
+//    fun plant() {
+//     Timber.plant(Timber.Tree())
+//    }
 }
\ No newline at end of file
diff --git a/core/src/test/kotlin/ca/allanwang/kau/kotlin/DebounceTest.kt b/core/src/test/kotlin/ca/allanwang/kau/kotlin/DebounceTest.kt
new file mode 100644
index 0000000..12bc5a4
--- /dev/null
+++ b/core/src/test/kotlin/ca/allanwang/kau/kotlin/DebounceTest.kt
@@ -0,0 +1,53 @@
+package ca.allanwang.kau.kotlin
+
+import org.jetbrains.anko.doAsync
+import org.junit.Test
+import kotlin.test.assertEquals
+
+/**
+ * Created by Allan Wang on 2017-08-05.
+ */
+class DebounceTest {
+
+    @Test
+    fun basic() {
+        var i = 0
+        val debounce = debounce(20) { i++ }
+        assertEquals(0, i, "i should start as 0")
+        (1..5).forEach { debounce() }
+        Thread.sleep(50)
+        assertEquals(1, i, "Debouncing did not cancel previous requests")
+    }
+
+    @Test
+    fun basicExtension() {
+        var i = 0
+        val increment: () -> Unit = { i++ }
+        (1..5).forEach { increment() }
+        assertEquals(5, i, "i should be 5")
+        val debounce = increment.debounce(50)
+        (6..10).forEach { debounce() }
+        assertEquals(5, i, "i should not have changed")
+        Thread.sleep(100)
+        assertEquals(6, i, "i should increment to 6")
+    }
+
+    @Test
+    fun multipleDebounces() {
+        var i = 0
+        val debounce = debounce<Int>(10) { i += it }
+        debounce(1) //ignore -> i = 0
+        Thread.sleep(5)
+        assertEquals(0, i)
+        debounce(2) //accept -> i = 2
+        Thread.sleep(15)
+        assertEquals(2, i)
+        debounce(4) //ignore -> i = 2
+        Thread.sleep(5)
+        assertEquals(2, i)
+        debounce(8) //accept -> i = 10
+        Thread.sleep(15)
+        assertEquals(10, i)
+    }
+
+}
\ No newline at end of file