Enhancement/coroutines (#180)

* Add coroutine dependency

* Add coroutines to kprefactivity

* Change base job to supervisor

* Update coroutines for faq

* Update changelog

* Use preloading in media picker core

* Make test logging internal

* Remove anko

9 files changed, 170 insertions, 162 deletions

diff --git a/core/src/main/kotlin/ca/allanwang/kau/internal/KauBaseActivity.kt b/core/src/main/kotlin/ca/allanwang/kau/internal/KauBaseActivity.kt
index 85e711b..bf977f2 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/internal/KauBaseActivity.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/internal/KauBaseActivity.kt
@@ -15,8 +15,14 @@
  */
 package ca.allanwang.kau.internal
 
+import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import ca.allanwang.kau.permissions.kauOnRequestPermissionsResult
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlin.coroutines.CoroutineContext
 
 /**
  * Created by Allan Wang on 2017-08-01.
@@ -26,11 +32,31 @@ import ca.allanwang.kau.permissions.kauOnRequestPermissionsResult
  * Ensures that some singleton methods are called.
  * This is simply a convenience class;
  * you can always copy and paste this to your own class.
+ *
+ * This also implements [CoroutineScope] that adheres to the activity lifecycle.
+ * Note that by default, [SupervisorJob] is used, to avoid exceptions in one child from affecting that of another.
+ * The default job can be overridden within [defaultJob]
  */
-abstract class KauBaseActivity : AppCompatActivity() {
+abstract class KauBaseActivity : AppCompatActivity(), CoroutineScope {
+
+    open lateinit var job: Job
+    override val coroutineContext: CoroutineContext
+        get() = Dispatchers.Main + job
+
+    open fun defaultJob(): Job = SupervisorJob()
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        job = defaultJob()
+    }
+
+    override fun onDestroy() {
+        job.cancel()
+        super.onDestroy()
+    }
 
     override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults)
         kauOnRequestPermissionsResult(permissions, grantResults)
     }
-}
+}
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/kotlin/Zip.kt b/core/src/main/kotlin/ca/allanwang/kau/kotlin/Zip.kt
deleted file mode 100644
index b767b30..0000000
--- a/core/src/main/kotlin/ca/allanwang/kau/kotlin/Zip.kt
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright 2018 Allan Wang
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package ca.allanwang.kau.kotlin
-
-import org.jetbrains.anko.doAsync
-import java.util.concurrent.atomic.AtomicInteger
-
-/**
- * Created by Allan Wang on 2017-08-06.
- *
- * Collection of zip methods that aim to replicate
- * <a href="http://reactivex.io/documentation/operators/zip.html">Reactive Zips</a>
- * For unit returning functions
- *
- * Typically, the functions will execute asynchronously and call their given callbacks when finished.
- * Once all callbacks are called, the final onFinish callback will be executed.
- *
- * There is also a helper zipper to wrap synchronous functions with Anko's doAsync to achieve the same results
- *
- * Note that not wrapping synchronous functions will render these methods useless,
- * as you can simply define an inline callback after all functions are finished
- */
-
-/**
- * Callback which will only execute the first time
- */
-open class ZipCallbackBase {
-    var completed: Boolean = false
-
-    inline operator fun invoke(callback: () -> Unit) {
-        if (completed) return
-        completed = true
-        callback()
-    }
-}
-
-class ZipCallback<T>(val onReceived: (T) -> Unit) : ZipCallbackBase() {
-    operator fun invoke(result: T) = invoke { onReceived(result) }
-}
-
-class ZipEmptyCallback(val onReceived: () -> Unit) : ZipCallbackBase() {
-    operator fun invoke() = invoke(onReceived)
-}
-
-/**
- * Given a default result, a series of tasks, and a finished callback,
- * this method will run all tasks and wait until all tasks emit a response
- * The response will then be sent back to the callback
- *
- * ALl tasks must invoke the task callback for [onFinished] to execute
- */
-inline fun <reified T> Collection<(ZipCallback<T>) -> Unit>.zip(
-    defaultResult: T,
-    crossinline onFinished: (results: Array<T>) -> Unit
-) {
-    val result = Array(size) { defaultResult }
-    val countDown = AtomicInteger(size)
-    forEachIndexed { index, asyncFun ->
-        asyncFun(ZipCallback {
-            result[index] = it
-            if (countDown.decrementAndGet() <= 0)
-                onFinished(result)
-        })
-    }
-}
-
-/**
- * Simplified zip method with no finished callback arguments
- */
-inline fun Collection<(ZipEmptyCallback) -> Unit>.zip(crossinline onFinished: () -> Unit) {
-    val countDown = AtomicInteger(size)
-    forEach { asyncFun ->
-        asyncFun(ZipEmptyCallback {
-            if (countDown.decrementAndGet() <= 0)
-                onFinished()
-        })
-    }
-}
-
-/**
- * Converts a collection of synchronous tasks to asynchronous tasks with a common callback
- */
-inline fun Collection<() -> Unit>.zipAsync(crossinline onFinished: () -> Unit) {
-    map { synchronousFun ->
-        { callback: ZipEmptyCallback ->
-            doAsync {
-                synchronousFun()
-                callback()
-            }; Unit
-        }
-    }.zip(onFinished)
-}
diff --git a/core/src/main/kotlin/ca/allanwang/kau/logging/KL.kt b/core/src/main/kotlin/ca/allanwang/kau/logging/KL.kt
index f92edb3..52e5415 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/logging/KL.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/logging/KL.kt
@@ -22,4 +22,9 @@ import ca.allanwang.kau.BuildConfig
  *
  * Internal KAU logger
  */
-object KL : KauLogger("KAU", { BuildConfig.DEBUG })
+object KL : KauLogger("KAU", { BuildConfig.DEBUG }) {
+    internal inline fun test(message: () -> Any?) {
+        if (BuildConfig.DEBUG)
+            d { "Test1234 ${message()}" }
+    }
+}
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt
index a655e5b..3dd4bb9 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/ActivityUtils.kt
@@ -28,13 +28,13 @@ import android.os.Build
 import android.os.Bundle
 import android.view.Menu
 import android.view.View
+import android.view.ViewGroup
 import androidx.annotation.ColorInt
 import androidx.annotation.RequiresApi
 import androidx.annotation.StringRes
 import ca.allanwang.kau.R
 import com.google.android.material.snackbar.Snackbar
 import com.mikepenz.iconics.typeface.IIcon
-import org.jetbrains.anko.contentView
 
 /**
  * Created by Allan Wang on 2017-06-21.
@@ -160,6 +160,17 @@ inline fun Activity.showKeyboard() {
     currentFocus?.showKeyboard()
 }
 
+/**
+ * Gets the view set by [Activity.setContentView] if it exists.
+ *
+ * Taken courtesy of <a href="https://github.com/Kotlin/anko">Anko</a>
+ *
+ * Previously, Anko was a dependency in KAU, but has been removed on 12/24/2018
+ * as most of the methods weren't used
+ */
+inline val Activity.contentView: View?
+    get() = (findViewById(android.R.id.content) as? ViewGroup)?.getChildAt(0)
+
 inline fun Activity.snackbar(
     text: String,
     duration: Int = Snackbar.LENGTH_LONG,
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/BundleUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/BundleUtils.kt
index 314ca60..5b4b188 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/BundleUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/BundleUtils.kt
@@ -20,10 +20,12 @@ import android.app.Activity
 import android.app.ActivityOptions
 import android.content.Context
 import android.os.Bundle
+import android.os.Parcelable
 import android.util.Pair
 import android.view.View
 import androidx.annotation.AnimRes
 import ca.allanwang.kau.R
+import java.io.Serializable
 
 /**
  * Created by Allan Wang on 10/12/17.
@@ -37,6 +39,56 @@ infix fun Bundle.with(bundle: Bundle?): Bundle {
 }
 
 /**
+ * Saves all bundle args based on their respective types.
+ *
+ * Taken courtesy of <a href="https://github.com/Kotlin/anko">Anko</a>
+ *
+ * Previously, Anko was a dependency in KAU, but has been removed on 12/24/2018
+ * as most of the methods weren't used
+ */
+fun bundleOf(vararg params: kotlin.Pair<String, Any?>): Bundle {
+    val b = Bundle()
+    for (p in params) {
+        val (k, v) = p
+        when (v) {
+            null -> b.putSerializable(k, null)
+            is Boolean -> b.putBoolean(k, v)
+            is Byte -> b.putByte(k, v)
+            is Char -> b.putChar(k, v)
+            is Short -> b.putShort(k, v)
+            is Int -> b.putInt(k, v)
+            is Long -> b.putLong(k, v)
+            is Float -> b.putFloat(k, v)
+            is Double -> b.putDouble(k, v)
+            is String -> b.putString(k, v)
+            is CharSequence -> b.putCharSequence(k, v)
+            is Parcelable -> b.putParcelable(k, v)
+            is Serializable -> b.putSerializable(k, v)
+            is BooleanArray -> b.putBooleanArray(k, v)
+            is ByteArray -> b.putByteArray(k, v)
+            is CharArray -> b.putCharArray(k, v)
+            is DoubleArray -> b.putDoubleArray(k, v)
+            is FloatArray -> b.putFloatArray(k, v)
+            is IntArray -> b.putIntArray(k, v)
+            is LongArray -> b.putLongArray(k, v)
+            is Array<*> -> {
+                @Suppress("UNCHECKED_CAST")
+                when {
+                    v.isArrayOf<Parcelable>() -> b.putParcelableArray(k, v as Array<out Parcelable>)
+                    v.isArrayOf<CharSequence>() -> b.putCharSequenceArray(k, v as Array<out CharSequence>)
+                    v.isArrayOf<String>() -> b.putStringArray(k, v as Array<out String>)
+                    else -> throw KauException("Unsupported bundle component (${v.javaClass})")
+                }
+            }
+            is ShortArray -> b.putShortArray(k, v)
+            is Bundle -> b.putBundle(k, v)
+            else -> throw KauException("Unsupported bundle component (${v.javaClass})")
+        }
+    }
+    return b
+}
+
+/**
  * Adds transition bundle if context is activity and build is lollipop+
  */
 @SuppressLint("NewApi")
@@ -62,7 +114,8 @@ fun Bundle.withSceneTransitionAnimation(parent: View, data: Map<Int, String>) =
 @SuppressLint("NewApi")
 fun Bundle.withSceneTransitionAnimation(context: Context, data: Map<View, String>) {
     if (context !is Activity || !buildIsLollipopAndUp) return
-    val options = ActivityOptions.makeSceneTransitionAnimation(context,
+    val options = ActivityOptions.makeSceneTransitionAnimation(
+        context,
         *data.map { (view, tag) -> Pair(view, tag) }.toTypedArray()
     )
     putAll(options.toBundle())
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt
index 134126d..60ef236 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/ContextUtils.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 Allan Wang
+ * Copyright 2017 Allan Wang
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,6 +26,8 @@ import android.content.pm.PackageManager
 import android.graphics.drawable.Drawable
 import android.net.Uri
 import android.os.Bundle
+import android.os.Handler
+import android.os.Looper
 import android.util.TypedValue
 import android.view.View
 import android.view.animation.AnimationUtils
@@ -45,10 +47,33 @@ import androidx.core.content.ContextCompat
 import ca.allanwang.kau.R
 import ca.allanwang.kau.logging.KL
 import com.afollestad.materialdialogs.MaterialDialog
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
+import kotlin.coroutines.CoroutineContext
 
 /**
  * Created by Allan Wang on 2017-06-03.
  */
+private object ContextHelper: CoroutineScope {
+
+    val handler = Handler(Looper.getMainLooper())
+
+    override val coroutineContext: CoroutineContext
+        get() = Dispatchers.Main
+}
+
+/**
+ * Most context items implement [CoroutineScope] by default.
+ * We will add a fallback just in case.
+ * It is expected that the scope returned always has the Android main dispatcher as part of the context.
+ */
+internal inline val Context.ctxCoroutine: CoroutineScope
+    get() = this as? CoroutineScope ?: ContextHelper
+
+fun Context.runOnUiThread(f: Context.() -> Unit) {
+    if (Looper.getMainLooper() === Looper.myLooper()) f() else ContextHelper.handler.post { f() }
+}
 
 /**
  * Helper class to launch an activity from a context
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/FragmentUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/FragmentUtils.kt
index 1c97900..75dc1c1 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/FragmentUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/FragmentUtils.kt
@@ -16,12 +16,11 @@
 package ca.allanwang.kau.utils
 
 import androidx.fragment.app.Fragment
-import org.jetbrains.anko.bundleOf
 
 /**
  * Created by Allan Wang on 2017-07-02.
  */
-fun <T : Fragment> T.withArguments(vararg params: Pair<String, Any>): T {
+fun <T : Fragment> T.withArguments(vararg params: Pair<String, Any?>): T {
     arguments = bundleOf(*params)
     return this
 }
diff --git a/core/src/main/kotlin/ca/allanwang/kau/xml/Changelog.kt b/core/src/main/kotlin/ca/allanwang/kau/xml/Changelog.kt
index 6a75aa9..51e63f9 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/xml/Changelog.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/xml/Changelog.kt
@@ -26,11 +26,12 @@ import androidx.annotation.LayoutRes
 import androidx.annotation.XmlRes
 import androidx.recyclerview.widget.RecyclerView
 import ca.allanwang.kau.R
+import ca.allanwang.kau.utils.ctxCoroutine
 import ca.allanwang.kau.utils.materialDialog
 import ca.allanwang.kau.utils.use
 import com.afollestad.materialdialogs.MaterialDialog
-import org.jetbrains.anko.doAsync
-import org.jetbrains.anko.uiThread
+import kotlinx.coroutines.async
+import kotlinx.coroutines.launch
 import org.xmlpull.v1.XmlPullParser
 
 /**
@@ -39,15 +40,13 @@ import org.xmlpull.v1.XmlPullParser
  * Easy changelog loader
  */
 fun Context.showChangelog(@XmlRes xmlRes: Int, @ColorInt textColor: Int? = null, customize: MaterialDialog.Builder.() -> Unit = {}) {
-    doAsync {
-        val items = parse(this@showChangelog, xmlRes)
-        uiThread {
-            materialDialog {
-                title(R.string.kau_changelog)
-                positiveText(R.string.kau_great)
-                adapter(ChangelogAdapter(items, textColor), null)
-                customize()
-            }
+    ctxCoroutine.launch {
+        val items = async { parse(this@showChangelog, xmlRes) }.await()
+        materialDialog {
+            title(R.string.kau_changelog)
+            positiveText(R.string.kau_great)
+            adapter(ChangelogAdapter(items, textColor), null)
+            customize()
         }
     }
 }
diff --git a/core/src/main/kotlin/ca/allanwang/kau/xml/FAQ.kt b/core/src/main/kotlin/ca/allanwang/kau/xml/FAQ.kt
index cb57216..73d7d6c 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/xml/FAQ.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/xml/FAQ.kt
@@ -21,8 +21,6 @@ import android.text.Html
 import android.text.Spanned
 import androidx.annotation.XmlRes
 import ca.allanwang.kau.utils.use
-import org.jetbrains.anko.doAsync
-import org.jetbrains.anko.uiThread
 import org.xmlpull.v1.XmlPullParser
 
 /**
@@ -30,8 +28,8 @@ import org.xmlpull.v1.XmlPullParser
  */
 
 /**
- * Parse an xml asynchronously with two tags, <question>Text</question> and <answer>Text</answer>,
- * and invoke the [callback] on the ui thread
+ * Parse an xml asynchronously with two tags, <question>Text</question> and <answer>Text</answer>.
+ * Note that this should executed in a background thread.
  */
 @Suppress("DEPRECATION")
 fun Context.kauParseFaq(
@@ -39,47 +37,44 @@ fun Context.kauParseFaq(
     /**
      * If \n is used, it will automatically be converted to </br>
      */
-    parseNewLine: Boolean = true,
-    callback: (items: List<FaqItem>) -> Unit
-) {
-    doAsync {
-        val items = mutableListOf<FaqItem>()
-        resources.getXml(xmlRes).use { parser: XmlResourceParser ->
-            var eventType = parser.eventType
-            var question: Spanned? = null
-            var flag = -1 //-1, 0, 1 -> invalid, question, answer
-            while (eventType != XmlPullParser.END_DOCUMENT) {
-                if (eventType == XmlPullParser.START_TAG) {
-                    flag = when (parser.name) {
-                        "question" -> 0
-                        "answer" -> 1
-                        else -> -1
+    parseNewLine: Boolean = true
+): List<FaqItem> {
+    val items = mutableListOf<FaqItem>()
+    resources.getXml(xmlRes).use { parser: XmlResourceParser ->
+        var eventType = parser.eventType
+        var question: Spanned? = null
+        var flag = -1 //-1, 0, 1 -> invalid, question, answer
+        while (eventType != XmlPullParser.END_DOCUMENT) {
+            if (eventType == XmlPullParser.START_TAG) {
+                flag = when (parser.name) {
+                    "question" -> 0
+                    "answer" -> 1
+                    else -> -1
+                }
+            } else if (eventType == XmlPullParser.TEXT) {
+                when (flag) {
+                    0 -> {
+                        question = Html.fromHtml(parser.text.replace("\n", if (parseNewLine) "<br/>" else ""))
+                        flag = -1
                     }
-                } else if (eventType == XmlPullParser.TEXT) {
-                    when (flag) {
-                        0 -> {
-                            question = Html.fromHtml(parser.text.replace("\n", if (parseNewLine) "<br/>" else ""))
-                            flag = -1
-                        }
-                        1 -> {
-                            items.add(
-                                FaqItem(
-                                    items.size + 1,
-                                    question
-                                        ?: throw IllegalArgumentException("KAU FAQ answer found without a question"),
-                                    Html.fromHtml(parser.text.replace("\n", if (parseNewLine) "<br/>" else ""))
-                                )
+                    1 -> {
+                        items.add(
+                            FaqItem(
+                                items.size + 1,
+                                question
+                                    ?: throw IllegalArgumentException("KAU FAQ answer found without a question"),
+                                Html.fromHtml(parser.text.replace("\n", if (parseNewLine) "<br/>" else ""))
                             )
-                            question = null
-                            flag = -1
-                        }
+                        )
+                        question = null
+                        flag = -1
                     }
                 }
-                eventType = parser.next()
             }
+            eventType = parser.next()
         }
-        uiThread { callback(items) }
     }
+    return items
 }
 
 data class FaqItem(val number: Int, val question: Spanned, val answer: Spanned)