Pause/Resume sync thread when app goes background/foreground

matrix-sdk-android/build.gradle

@@ -45,7 +45,6 @@ dependencies {
     def support_version = '28.0.0'
     def moshi_version = '1.7.0'
     def lifecycle_version = "1.1.1"
-    def work_version = "1.0.0-alpha10"
 
     implementation fileTree(dir: 'libs', include: ['*.aar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
@@ -65,7 +64,6 @@ dependencies {
     implementation 'com.squareup.okhttp3:logging-interceptor:3.10.0'
     implementation 'com.squareup.okio:okio:1.15.0'
     implementation 'com.novoda:merlin:1.1.6'
-
     implementation 'com.google.code.gson:gson:2.8.5'
     implementation "com.squareup.moshi:moshi-adapters:$moshi_version"
     kapt "com.squareup.moshi:moshi-kotlin-codegen:$moshi_version"
@@ -73,10 +71,7 @@ dependencies {
     // Paging
     implementation "android.arch.paging:runtime:1.0.1"
 
-    // Worker
-    implementation "android.arch.work:work-runtime-ktx:$work_version"
-    implementation 'com.evernote:android-job:1.2.6'
-
+    // FP
     implementation "io.arrow-kt:arrow-core:$arrow_version"
 
     // DI

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/Matrix.kt

@@ -1,12 +1,13 @@
 package im.vector.matrix.android.api
 
+import android.arch.lifecycle.ProcessLifecycleOwner
 import android.content.Context
-import com.evernote.android.job.JobManager
 import im.vector.matrix.android.api.auth.Authenticator
 import im.vector.matrix.android.api.session.Session
 import im.vector.matrix.android.internal.auth.AuthModule
 import im.vector.matrix.android.internal.di.MatrixModule
 import im.vector.matrix.android.internal.di.NetworkModule
+import im.vector.matrix.android.internal.util.BackgroundDetectionObserver
 import io.realm.Realm
 import org.koin.standalone.KoinComponent
 import org.koin.standalone.StandAloneContext.loadKoinModules
@@ -16,16 +17,17 @@ import org.koin.standalone.inject
 class Matrix(matrixOptions: MatrixOptions) : KoinComponent {
 
     private val authenticator by inject<Authenticator>()
+    private val backgroundDetectionObserver by inject<BackgroundDetectionObserver>()
 
     var currentSession: Session? = null
 
     init {
         Realm.init(matrixOptions.context)
-        JobManager.create(matrixOptions.context)
         val matrixModule = MatrixModule(matrixOptions)
         val networkModule = NetworkModule()
         val authModule = AuthModule()
         loadKoinModules(listOf(matrixModule, networkModule, authModule))
+        ProcessLifecycleOwner.get().lifecycle.addObserver(backgroundDetectionObserver)
     }
 
     fun authenticator(): Authenticator {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/di/MatrixModule.kt

@@ -2,6 +2,7 @@ package im.vector.matrix.android.internal.di
 
 import im.vector.matrix.android.api.MatrixOptions
 import im.vector.matrix.android.api.thread.MainThreadExecutor
+import im.vector.matrix.android.internal.util.BackgroundDetectionObserver
 import im.vector.matrix.android.internal.util.MatrixCoroutineDispatchers
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.IO
@@ -22,5 +23,10 @@ class MatrixModule(private val options: MatrixOptions) : Module {
         single {
             MatrixCoroutineDispatchers(io = Dispatchers.IO, computation = Dispatchers.IO, main = MainThreadExecutor().asCoroutineDispatcher())
         }
+
+        single {
+            BackgroundDetectionObserver()
+        }
+
     }.invoke()
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/events/sync/SyncModule.kt

@@ -34,7 +34,7 @@ class SyncModule : Module {
         }
 
         scope(DefaultSession.SCOPE) {
-            SyncThread(get(), get(), get())
+            SyncThread(get(), get(), get(), get())
         }
 
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/events/sync/job/SyncThread.kt

@@ -7,6 +7,7 @@ import im.vector.matrix.android.internal.events.sync.SyncRequest
 import im.vector.matrix.android.internal.events.sync.SyncTokenStore
 import im.vector.matrix.android.internal.events.sync.data.SyncResponse
 import im.vector.matrix.android.internal.network.NetworkConnectivityChecker
+import im.vector.matrix.android.internal.util.BackgroundDetectionObserver
 import timber.log.Timber
 import java.util.concurrent.CountDownLatch
 
@@ -14,8 +15,9 @@ private const val RETRY_WAIT_TIME_MS = 10_000L
 
 class SyncThread(private val syncRequest: SyncRequest,
                  private val networkConnectivityChecker: NetworkConnectivityChecker,
-                 private val syncTokenStore: SyncTokenStore
-) : Thread(), NetworkConnectivityChecker.Listener {
+                 private val syncTokenStore: SyncTokenStore,
+                 private val backgroundDetectionObserver: BackgroundDetectionObserver
+) : Thread(), NetworkConnectivityChecker.Listener, BackgroundDetectionObserver.Listener {
 
     enum class State {
         IDLE,
@@ -63,8 +65,9 @@ class SyncThread(private val syncRequest: SyncRequest,
 
     override fun run() {
         Timber.v("Start syncing...")
-        state = State.RUNNING
         networkConnectivityChecker.register(this)
+        backgroundDetectionObserver.register(this)
+        state = State.RUNNING
         while (state != State.KILLING) {
             if (!networkConnectivityChecker.isConnected() || state == State.PAUSED) {
                 Timber.v("Waiting...")
@@ -94,6 +97,7 @@ class SyncThread(private val syncRequest: SyncRequest,
         }
         Timber.v("Sync killed")
         state = State.KILLED
+        backgroundDetectionObserver.unregister(this)
         networkConnectivityChecker.unregister(this)
     }
 
@@ -103,6 +107,15 @@ class SyncThread(private val syncRequest: SyncRequest,
         }
     }
 
+    override fun onMoveToForeground() {
+        restart()
+    }
+
+    override fun onMoveToBackground() {
+        pause()
+    }
+
+
 }
 
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/BackgroundDetectionObserver.kt

@@ -0,0 +1,46 @@
+package im.vector.matrix.android.internal.util
+
+import android.arch.lifecycle.Lifecycle
+import android.arch.lifecycle.LifecycleObserver
+import android.arch.lifecycle.OnLifecycleEvent
+import timber.log.Timber
+
+/**
+ * To be attached to ProcessLifecycleOwner lifecycle
+ */
+class BackgroundDetectionObserver : LifecycleObserver {
+
+    var isIsBackground: Boolean = false
+        private set
+
+    private
+    val listeners = ArrayList<Listener>()
+
+    fun register(listener: Listener) {
+        listeners.add(listener)
+    }
+
+    fun unregister(listener: Listener) {
+        listeners.remove(listener)
+    }
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_START)
+    fun onMoveToForeground() {
+        Timber.d("App returning to foreground…")
+        isIsBackground = false
+        listeners.forEach { it.onMoveToForeground() }
+    }
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
+    fun onMoveToBackground() {
+        Timber.d("App going to background…")
+        isIsBackground = true
+        listeners.forEach { it.onMoveToBackground() }
+    }
+
+    interface Listener {
+        fun onMoveToForeground()
+        fun onMoveToBackground()
+    }
+
+}