Delegate the creation of the Session to MainActivity instead of VectorApplication to unblock the main thread.

This fix is not necessary anymore, since the session is restored either in `MainActivity` or in `VectorMessagingReceiver`.
Ref: b7a54ead68

vector/src/debug/java/im/vector/app/features/MainViewModel.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2022 New Vector Ltd
+ *
+ * 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 im.vector.app.features
+
+import com.airbnb.mvrx.MavericksViewModelFactory
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedFactory
+import dagger.assisted.AssistedInject
+import im.vector.app.core.di.ActiveSessionSetter
+import im.vector.app.core.di.MavericksAssistedViewModelFactory
+import im.vector.app.core.di.hiltMavericksViewModelFactory
+import im.vector.app.core.platform.VectorDummyViewState
+import im.vector.app.core.platform.VectorViewEvents
+import im.vector.app.core.platform.VectorViewModel
+import im.vector.app.core.platform.VectorViewModelAction
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+
+sealed interface MainViewAction : VectorViewModelAction {
+    object StartApp : MainViewAction
+}
+
+sealed interface MainViewEvent : VectorViewEvents {
+    object AppStarted : MainViewEvent
+}
+
+class MainViewModel @AssistedInject constructor(
+        @Assisted val initialState: VectorDummyViewState,
+        private val activeSessionSetter: ActiveSessionSetter,
+) : VectorViewModel<VectorDummyViewState, MainViewAction, MainViewEvent>(initialState) {
+
+    @AssistedFactory
+    interface Factory : MavericksAssistedViewModelFactory<MainViewModel, VectorDummyViewState> {
+        override fun create(initialState: VectorDummyViewState): MainViewModel
+    }
+
+    companion object : MavericksViewModelFactory<MainViewModel, VectorDummyViewState> by hiltMavericksViewModelFactory()
+
+    override fun handle(action: MainViewAction) {
+        when (action) {
+            MainViewAction.StartApp -> handleStartApp()
+        }
+    }
+
+    private fun handleStartApp() {
+        viewModelScope.launch(Dispatchers.IO) {
+            // This can take time because of DB migration(s), so do it in a background task.
+            activeSessionSetter.tryToSetActiveSession(startSync = true)
+            _viewEvents.post(MainViewEvent.AppStarted)
+        }
+    }
+}

vector/src/main/java/im/vector/app/VectorApplication.kt

@@ -41,8 +41,6 @@ import com.vanniktech.emoji.EmojiManager
 import com.vanniktech.emoji.google.GoogleEmojiProvider
 import dagger.hilt.android.HiltAndroidApp
 import im.vector.app.core.di.ActiveSessionHolder
-import im.vector.app.core.extensions.configureAndStart
-import im.vector.app.core.extensions.startSyncing
 import im.vector.app.features.analytics.VectorAnalytics
 import im.vector.app.features.call.webrtc.WebRtcCallManager
 import im.vector.app.features.configuration.VectorConfiguration
@@ -165,14 +163,6 @@ class VectorApplication :
             doNotShowDisclaimerDialog(this)
         }
 
-        if (authenticationService.hasAuthenticatedSessions() && !activeSessionHolder.hasActiveSession()) {
-            val lastAuthenticatedSession = authenticationService.getLastAuthenticatedSession()!!
-            activeSessionHolder.setActiveSession(lastAuthenticatedSession)
-            lastAuthenticatedSession.configureAndStart(applicationContext, startSyncing = false)
-        }
-
-        ProcessLifecycleOwner.get().lifecycle.addObserver(startSyncOnFirstStart)
-
         ProcessLifecycleOwner.get().lifecycle.addObserver(object : DefaultLifecycleObserver {
             override fun onResume(owner: LifecycleOwner) {
                 Timber.i("App entered foreground")
@@ -205,14 +195,6 @@ class VectorApplication :
         Mapbox.getInstance(this)
     }
 
-    private val startSyncOnFirstStart = object : DefaultLifecycleObserver {
-        override fun onStart(owner: LifecycleOwner) {
-            Timber.i("App process started")
-            authenticationService.getLastAuthenticatedSession()?.startSyncing(appContext)
-            ProcessLifecycleOwner.get().lifecycle.removeObserver(this)
-        }
-    }
-
     private fun enableStrictModeIfNeeded() {
         if (BuildConfig.ENABLE_STRICT_MODE_LOGS) {
             StrictMode.setThreadPolicy(

vector/src/main/java/im/vector/app/core/di/ActiveSessionSetter.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2022 New Vector Ltd
+ *
+ * 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 im.vector.app.core.di
+
+import android.content.Context
+import im.vector.app.core.extensions.configureAndStart
+import org.matrix.android.sdk.api.auth.AuthenticationService
+import javax.inject.Inject
+
+class ActiveSessionSetter @Inject constructor(
+        private val activeSessionHolder: ActiveSessionHolder,
+        private val authenticationService: AuthenticationService,
+        private val applicationContext: Context,
+) {
+    fun tryToSetActiveSession(startSync: Boolean) {
+        if (authenticationService.hasAuthenticatedSessions() && !activeSessionHolder.hasActiveSession()) {
+            val lastAuthenticatedSession = authenticationService.getLastAuthenticatedSession()!!
+            activeSessionHolder.setActiveSession(lastAuthenticatedSession)
+            lastAuthenticatedSession.configureAndStart(applicationContext, startSyncing = startSync)
+            activeSessionHolder.setActiveSession(lastAuthenticatedSession)
+        }
+    }
+}

vector/src/main/java/im/vector/app/core/di/MavericksViewModelModule.kt

@@ -20,6 +20,7 @@ import dagger.Binds
 import dagger.Module
 import dagger.hilt.InstallIn
 import dagger.multibindings.IntoMap
+import im.vector.app.features.MainViewModel
 import im.vector.app.features.analytics.accountdata.AnalyticsAccountDataViewModel
 import im.vector.app.features.analytics.ui.consent.AnalyticsConsentViewModel
 import im.vector.app.features.auth.ReAuthViewModel
@@ -483,6 +484,11 @@ interface MavericksViewModelModule {
     @MavericksViewModelKey(AnalyticsAccountDataViewModel::class)
     fun analyticsAccountDataViewModelFactory(factory: AnalyticsAccountDataViewModel.Factory): MavericksAssistedViewModelFactory<*, *>
 
+    @Binds
+    @IntoMap
+    @MavericksViewModelKey(MainViewModel::class)
+    fun mainViewModelFactory(factory: MainViewModel.Factory): MavericksAssistedViewModelFactory<*, *>
+
     @Binds
     @IntoMap
     @MavericksViewModelKey(HomeServerCapabilitiesViewModel::class)

vector/src/main/java/im/vector/app/core/pushers/VectorMessagingReceiver.kt

@@ -27,6 +27,7 @@ import androidx.localbroadcastmanager.content.LocalBroadcastManager
 import dagger.hilt.android.AndroidEntryPoint
 import im.vector.app.BuildConfig
 import im.vector.app.core.di.ActiveSessionHolder
+import im.vector.app.core.di.ActiveSessionSetter
 import im.vector.app.core.network.WifiDetector
 import im.vector.app.core.pushers.model.PushData
 import im.vector.app.core.services.GuardServiceStarter
@@ -59,6 +60,7 @@ class VectorMessagingReceiver : MessagingReceiver() {
     @Inject lateinit var notificationDrawerManager: NotificationDrawerManager
     @Inject lateinit var notifiableEventResolver: NotifiableEventResolver
     @Inject lateinit var pushersManager: PushersManager
+    @Inject lateinit var activeSessionSetter: ActiveSessionSetter
     @Inject lateinit var activeSessionHolder: ActiveSessionHolder
     @Inject lateinit var vectorPreferences: VectorPreferences
     @Inject lateinit var vectorDataStore: VectorDataStore
@@ -177,6 +179,11 @@ class VectorMessagingReceiver : MessagingReceiver() {
             }
 
             val session = activeSessionHolder.getSafeActiveSession()
+                    ?: run {
+                        // Active session may not exist yet, if MainActivity has not been launched
+                        activeSessionSetter.tryToSetActiveSession(startSync = false)
+                        activeSessionHolder.getSafeActiveSession()
+                    }
 
             if (session == null) {
                 Timber.tag(loggerTag.value).w("## Can't sync from push, no current session")

vector/src/main/java/im/vector/app/features/MainActivity.kt

@@ -22,6 +22,7 @@ import android.os.Bundle
 import android.os.Parcelable
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
+import com.airbnb.mvrx.viewModel
 import com.bumptech.glide.Glide
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import dagger.hilt.android.AndroidEntryPoint
@@ -47,6 +48,8 @@ import im.vector.app.features.signout.hard.SignedOutActivity
 import im.vector.app.features.themes.ActivityOtherThemes
 import im.vector.app.features.ui.UiStateRepository
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlinx.parcelize.Parcelize
@@ -84,6 +87,8 @@ class MainActivity : VectorBaseActivity<ActivityMainBinding>(), UnlockedActivity
         }
     }
 
+    private val mainViewModel: MainViewModel by viewModel()
+
     override fun getBinding() = ActivityMainBinding.inflate(layoutInflater)
 
     override fun getOtherThemes() = ActivityOtherThemes.Launcher
@@ -103,6 +108,21 @@ class MainActivity : VectorBaseActivity<ActivityMainBinding>(), UnlockedActivity
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+
+        mainViewModel.viewEvents.stream()
+                .onEach(::handleViewEvents)
+                .launchIn(lifecycleScope)
+
+        mainViewModel.handle(MainViewAction.StartApp)
+    }
+
+    private fun handleViewEvents(event: MainViewEvent) {
+        when (event) {
+            MainViewEvent.AppStarted -> handleAppStarted()
+        }
+    }
+
+    private fun handleAppStarted() {
         args = parseArgs()
         if (args.clearCredentials || args.isUserLoggedOut || args.clearCache) {
             clearNotifications()