Add KOIN for dependency injection

gradle.properties

@@ -3,6 +3,7 @@ androidCompileSdkVersion=27
 androidBuildToolsVersion=27.0.3
 androidSupportLibraryVersion=27.0.2
 timberVersion=4.5.1
+koinVersion=0.9.1
 
 robolectricVersion=3.7.1
 junitVersion=4.12

k9mail/build.gradle

@@ -42,6 +42,7 @@ dependencies {
     implementation 'com.xwray:groupie:2.0.3'
     implementation 'com.xwray:groupie-kotlin-android-extensions:2.0.3'
     implementation "org.jetbrains.anko:anko-coroutines:0.10.4"
+    implementation "org.koin:koin-android-architecture:${koinVersion}"
 
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
 
@@ -50,6 +51,7 @@ dependencies {
     testImplementation "com.google.truth:truth:${truthVersion}"
     testImplementation "org.mockito:mockito-core:${mockitoVersion}"
     testImplementation "org.jdom:jdom2:2.0.6"
+    testImplementation "org.koin:koin-test:${koinVersion}"
 }
 
 android {

k9mail/src/main/java/com/fsck/k9/DI.kt

@@ -0,0 +1,43 @@
+package com.fsck.k9
+
+import android.app.Application
+import com.fsck.k9.ui.settings.settingsUiModule
+import org.koin.Koin
+import org.koin.KoinContext
+import org.koin.android.ext.koin.with
+import org.koin.android.logger.AndroidLogger
+import org.koin.core.parameter.Parameters
+import org.koin.dsl.module.applicationContext
+import org.koin.log.EmptyLogger
+import org.koin.standalone.StandAloneContext
+
+object DI {
+    private val mainModule = applicationContext {
+        bean { Preferences.getPreferences(get()) }
+    }
+
+    val appModules = listOf(
+        mainModule,
+        settingsUiModule
+    )
+
+    @JvmStatic fun start(application: Application) {
+        @Suppress("ConstantConditionIf")
+        Koin.logger = if (BuildConfig.DEBUG) AndroidLogger() else EmptyLogger()
+
+        StandAloneContext.startKoin(appModules) with application
+    }
+
+    @JvmOverloads
+    @JvmStatic
+    fun <T : Any> get(clazz: Class<T>, name: String = "", parameters: Parameters = { emptyMap() }): T {
+        val koinContext = StandAloneContext.koinContext as KoinContext
+        val kClass = clazz.kotlin
+
+        return if (name.isEmpty()) {
+            koinContext.resolveInstance(kClass, parameters) { koinContext.beanRegistry.searchAll(kClass) }
+        } else {
+            koinContext.resolveInstance(kClass, parameters) { koinContext.beanRegistry.searchByName(name) }
+        }
+    }
+}

k9mail/src/main/java/com/fsck/k9/K9.java

@@ -530,6 +530,7 @@ public class K9 extends Application {
 
         super.onCreate();
         app = this;
+        DI.start(this);
         Globals.setContext(this);
 
         K9MailLib.setDebugStatus(new K9MailLib.DebugStatus() {

k9mail/src/main/java/com/fsck/k9/ui/account/AccountsLiveData.kt

@@ -1,29 +1,28 @@
 package com.fsck.k9.ui.account
 
 import android.arch.lifecycle.LiveData
-import android.content.Context
 import com.fsck.k9.Account
 import com.fsck.k9.Preferences
 import kotlinx.coroutines.experimental.android.UI
 import kotlinx.coroutines.experimental.launch
 import org.jetbrains.anko.coroutines.experimental.bg
 
-class AccountsLiveData(context: Context) : LiveData<List<Account>>() {
+class AccountsLiveData(val preferences: Preferences) : LiveData<List<Account>>() {
     init {
-        loadAccountsAsync(context)
+        loadAccountsAsync()
     }
 
-    private fun loadAccountsAsync(context: Context) {
+    private fun loadAccountsAsync() {
         launch(UI) {
             val accounts = bg {
-                loadAccounts(context)
+                loadAccounts()
             }
 
             value = accounts.await()
         }
     }
 
-    private fun loadAccounts(context: Context): List<Account> {
-        return Preferences.getPreferences(context).accounts
+    private fun loadAccounts(): List<Account> {
+        return preferences.accounts
     }
 }

k9mail/src/main/java/com/fsck/k9/ui/settings/KoinModule.kt

@@ -0,0 +1,10 @@
+package com.fsck.k9.ui.settings
+
+import com.fsck.k9.ui.account.AccountsLiveData
+import org.koin.android.architecture.ext.viewModel
+import org.koin.dsl.module.applicationContext
+
+val settingsUiModule = applicationContext {
+    bean { AccountsLiveData(get()) }
+    viewModel { SettingsViewModel(get()) }
+}

k9mail/src/main/java/com/fsck/k9/ui/settings/SettingsActivity.kt

@@ -1,7 +1,6 @@
 package com.fsck.k9.ui.settings
 
 import android.app.Activity
-import android.arch.lifecycle.ViewModelProviders
 import android.content.Intent
 import android.os.Bundle
 import android.support.v7.widget.LinearLayoutManager
@@ -16,8 +15,11 @@ import com.xwray.groupie.Item
 import com.xwray.groupie.Section
 import com.xwray.groupie.kotlinandroidextensions.ViewHolder
 import kotlinx.android.synthetic.main.activity_settings.*
+import org.koin.android.architecture.ext.viewModel
 
 class SettingsActivity : K9Activity() {
+    private val viewModel: SettingsViewModel by viewModel()
+
     private lateinit var settingsAdapter: GroupAdapter<ViewHolder>
 
 
@@ -48,7 +50,6 @@ class SettingsActivity : K9Activity() {
     }
 
     private fun populateSettingsList() {
-        val viewModel = ViewModelProviders.of(this).get(SettingsViewModel::class.java)
         viewModel.accounts.observe(this) { accounts ->
             populateSettingsList(accounts)
         }

k9mail/src/main/java/com/fsck/k9/ui/settings/SettingsViewModel.kt

@@ -1,9 +1,6 @@
 package com.fsck.k9.ui.settings
 
-import android.app.Application
-import android.arch.lifecycle.AndroidViewModel
+import android.arch.lifecycle.ViewModel
 import com.fsck.k9.ui.account.AccountsLiveData
 
-internal class SettingsViewModel(application: Application) : AndroidViewModel(application) {
-    val accounts = AccountsLiveData(application)
-}
+internal class SettingsViewModel(val accounts: AccountsLiveData) : ViewModel()

k9mail/src/test/java/com/fsck/k9/DependencyInjectionTest.kt

@@ -0,0 +1,15 @@
+package com.fsck.k9
+
+import org.junit.Test
+import org.koin.Koin
+import org.koin.log.PrintLogger
+import org.koin.test.dryRun
+
+class DependencyInjectionTest : K9RobolectricTest() {
+    @Test
+    fun testDependencyTree() {
+        Koin.logger = PrintLogger()
+
+        dryRun()
+    }
+}

k9mail/src/test/java/com/fsck/k9/K9RobolectricTest.kt

@@ -0,0 +1,14 @@
+package com.fsck.k9
+
+import android.app.Application
+import org.junit.runner.RunWith
+import org.koin.test.AutoCloseKoinTest
+import org.robolectric.RobolectricTestRunner
+
+/**
+ * A Robolectric test that creates an instance of our [Application] class [K9].
+ *
+ * See also [RobolectricTest].
+ */
+@RunWith(RobolectricTestRunner::class)
+abstract class K9RobolectricTest : AutoCloseKoinTest()