Add support for kotlin

Documentation/technical/Kotlin_Policy.md

@@ -0,0 +1,9 @@
+### Kotlin Policy
+
+xDrip supports both Java and Kotlin source files.
+
+New class files in Java or Kotlin are accepted but there is no intention to convert existing Java files to Kotlin.
+
+Kotlin classes should be mindful to maintain as much java compatibility as possible where they may need to interact with existing classes.
+
+Overhead in terms of additional libraries and any performance related issues (such as threading and component lifecycle) should be carefully monitored.

app/build.gradle

@@ -12,6 +12,7 @@ buildscript {
 apply plugin: 'com.android.application'
 apply from: 'token-replace.gradle'
 apply from: '../common.gradle'
+apply plugin: 'kotlin-android'
 
 if (project.file('local.gradle').exists()) {
     apply from: 'local.gradle'
@@ -160,6 +161,7 @@ android {
         exclude 'META-INF/NOTICE'
         exclude 'org/apache/http/version.properties'
         exclude 'org/apache/http/client/version.properties'
+        //exclude 'META-INF/androidx.core_core.version'
         exclude 'META-INF/com.android.tools/proguard/coroutines.pro'
         exclude 'META-INF/ASL2.0'
     }
@@ -259,6 +261,9 @@ dependencies {
         exclude group: 'androidx.core', module: 'core' // fix INotificationSideChannel // android.support.v4.app
     }
 
+    //implementation 'androidx.core:core-ktx:1.9.0'
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.7.21'
+
     implementation 'com.android.support:appcompat-v7:26.1.0'
     implementation 'com.android.support:design:26.1.0'
     implementation 'com.android.support:support-v13:26.1.0'
@@ -336,7 +341,7 @@ dependencies {
     testImplementation 'junit:junit:4.13.2'
     testImplementation 'org.objenesis:objenesis:2.5.1'
     testImplementation 'org.hamcrest:hamcrest-library:1.3'
-    testImplementation "org.robolectric:robolectric:4.2.1"
+    testImplementation "org.robolectric:robolectric:4.4.1"
     testImplementation "com.google.truth:truth:1.1.3"
 
     testImplementation 'org.mockito:mockito-core:2.4.0'

app/src/main/java/com/eveningoutpost/dexdrip/utils/framework/TestKot.kt

@@ -0,0 +1,18 @@
+package com.eveningoutpost.dexdrip.utils.framework
+
+/**
+ * JamOrHam
+ *
+ * Simple test to ensure compilation success
+ */
+
+class TestKot {
+
+    companion object {
+        @JvmStatic
+        fun compileOkay() : Boolean {
+            return true;
+        }
+    }
+
+}

app/src/test/java/com/eveningoutpost/dexdrip/utils/framework/TestKotTest.kt

@@ -0,0 +1,14 @@
+package com.eveningoutpost.dexdrip.utils.framework
+
+import org.junit.Assert.*
+
+import org.junit.Test
+
+class TestKotTest {
+
+    @Test
+    fun compileOkayTest() {
+        assert(TestKot.compileOkay())
+
+    }
+}

build.gradle

@@ -13,6 +13,7 @@ buildscript {
         classpath 'com.google.gms:google-services:4.3.3'
         classpath 'com.github.jamorham:ReplaceTokenPreprocessor:1.5'
         classpath 'com.google.android.gms:oss-licenses-plugin:0.9.5'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.21"
 
         apply plugin: 'java'
         apply plugin: 'maven'