fixed stale state after logout and replayed or lost share intents

android/app/src/main/AndroidManifest.xml

@@ -9,7 +9,7 @@
         <activity
             android:name=".MainActivity"
             android:exported="true"
-            android:launchMode="singleTop"
+            android:launchMode="singleTask"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"

android/app/src/main/kotlin/eu/mhsl/marianum/mobile/client/MainActivity.kt

@@ -1,15 +1,38 @@
 package eu.mhsl.marianum.mobile.client
 
 import android.content.Intent
+import android.os.Bundle
 import io.flutter.embedding.android.FlutterActivity
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.MethodChannel
 
 class MainActivity : FlutterActivity() {
     private val widgetChannel = "eu.mhsl.marianum.widget"
+    private val shareChannel = "eu.mhsl.marianum.share"
     /// Last seen widget tap target. Cleared by Dart via `consumePendingNavigation`
     /// so the same intent isn't replayed on every resume.
     private var pendingTimetableTap: Boolean = false
+    private val shareActions = setOf(Intent.ACTION_SEND, Intent.ACTION_SEND_MULTIPLE)
+
+    /// receive_sharing_intent only emits warm shares to a live Dart listener and
+    /// does not buffer them. After a relaunch into an existing task the share
+    /// arrives via onNewIntent before Dart subscribed, so it is held here until
+    /// Dart reports `listenerReady`.
+    private var shareListenerReady = false
+    private var bufferedShare: Intent? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        // Android replays the original launch intent when the activity is
+        // recreated from recents or after process death. A share or widget tap
+        // that was already handled would otherwise run again — for shares with
+        // temp files that are long gone.
+        val replayed = savedInstanceState != null ||
+            (intent.flags and Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY) != 0
+        if (replayed && (intent.action in shareActions || isWidgetTap(intent))) {
+            intent = Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_LAUNCHER)
+        }
+        super.onCreate(savedInstanceState)
+    }
 
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
@@ -26,17 +49,35 @@ class MainActivity : FlutterActivity() {
                 else -> result.notImplemented()
             }
         }
+        MethodChannel(
+            flutterEngine.dartExecutor.binaryMessenger,
+            shareChannel
+        ).setMethodCallHandler { call, result ->
+            when (call.method) {
+                "listenerReady" -> {
+                    shareListenerReady = true
+                    bufferedShare?.let { flutterEngine.activityControlSurface.onNewIntent(it) }
+                    bufferedShare = null
+                    result.success(null)
+                }
+                else -> result.notImplemented()
+            }
+        }
         consumeIntentData(intent)
     }
 
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
+        if (!shareListenerReady && intent.action in shareActions) {
+            bufferedShare = intent
+        }
         consumeIntentData(intent)
     }
 
+    private fun isWidgetTap(intent: Intent?): Boolean =
+        intent?.getBooleanExtra("widget_open_timetable", false) == true
+
     private fun consumeIntentData(intent: Intent?) {
-        if (intent?.getBooleanExtra("widget_open_timetable", false) == true) {
-            pendingTimetableTap = true
-        }
+        if (isWidgetTap(intent)) pendingTimetableTap = true
     }
 }