Store and restore session

app/src/main/java/io/element/android/x/MainActivity.kt

@@ -4,8 +4,11 @@ import android.content.Intent
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.activity.viewModels
+import androidx.lifecycle.lifecycleScope
 import io.element.android.x.ui.screen.login.LoginActivity
 import io.element.android.x.ui.screen.login.RoomListActivity
+import kotlinx.coroutines.launch
 
 class MainActivity : ComponentActivity() {
     private val launcher =
@@ -18,11 +21,17 @@ class MainActivity : ComponentActivity() {
             }
         }
 
+    private val viewModel: MainViewModel by viewModels()
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        // Just start the LoginActivity for now.
-        // TODO if a session exist, start the room list
-        launcher.launch(Intent(this, LoginActivity::class.java))
+        lifecycleScope.launch {
+            if (viewModel.hasSession()) {
+                startRoomActivityAndFinish()
+            } else {
+                launcher.launch(Intent(this@MainActivity, LoginActivity::class.java))
+            }
+        }
     }
 
     private fun startRoomActivityAndFinish() {

app/src/main/java/io/element/android/x/MainViewModel.kt

@@ -0,0 +1,12 @@
+package io.element.android.x
+
+import androidx.lifecycle.ViewModel
+import io.element.android.x.sdk.matrix.MatrixInstance
+
+class MainViewModel : ViewModel() {
+    private val matrix = MatrixInstance.getInstance()
+
+    suspend fun hasSession(): Boolean {
+        return matrix.restoreSession() != null
+    }
+}