A bug fix in settings

Author: aidin36

app/src/main/java/com/aidinhut/simpletextcrypt/ui/screen/MainScreen.kt

@@ -43,6 +43,7 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
@@ -56,9 +57,9 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.activity.ComponentActivity
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
-import androidx.lifecycle.compose.LocalLifecycleOwner
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.aidinhut.simpletextcrypt.R
 import com.aidinhut.simpletextcrypt.viewmodel.MainViewModel
@@ -76,21 +77,26 @@ fun MainScreen(
     var showAbout by remember { mutableStateOf(false) }
     var showHelp by remember { mutableStateOf(false) }
 
-    // Handle lock timeout on lifecycle events.
-    val lifecycleOwner = LocalLifecycleOwner.current
-    LaunchedEffect(lifecycleOwner) {
+    // Check lock timeout every time this screen enters composition
+    // (returning from Settings or from background).
+    LaunchedEffect(Unit) {
+        viewModel.checkLockTimeout(context)
+    }
+
+    // Handle lock-on-background using the Activity lifecycle.
+    // Using Activity lifecycle (not NavBackStackEntry) so in-app navigation
+    // to Settings doesn't trigger the pause lock.
+    val activity = context as ComponentActivity
+    DisposableEffect(activity) {
         val observer = LifecycleEventObserver { _, event ->
-            when (event) {
-                Lifecycle.Event.ON_RESUME -> {
-                    viewModel.checkLockTimeout(context)
-                }
-                Lifecycle.Event.ON_PAUSE -> {
-                    viewModel.checkPauseLock(context)
-                }
-                else -> {}
+            if (event == Lifecycle.Event.ON_STOP) {
+                viewModel.checkPauseLock(context)
             }
         }
-        lifecycleOwner.lifecycle.addObserver(observer)
+        activity.lifecycle.addObserver(observer)
+        onDispose {
+            activity.lifecycle.removeObserver(observer)
+        }
     }
 
     // Navigate to lock when shouldLock triggers.

app/src/main/java/com/aidinhut/simpletextcrypt/ui/screen/SettingsScreen.kt

@@ -39,6 +39,7 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
@@ -48,9 +49,9 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.activity.ComponentActivity
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
-import androidx.lifecycle.compose.LocalLifecycleOwner
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.aidinhut.simpletextcrypt.R
 import com.aidinhut.simpletextcrypt.viewmodel.SettingsViewModel
@@ -77,17 +78,20 @@ fun SettingsScreen(
         }
     }
 
-    // This activity won't lock. So, if the user sends the app to the background while on
-    // the settings activity, anyone can get back to it without the need to enter passcode.
-    // So we finish (navigate back) on pause.
-    val lifecycleOwner = LocalLifecycleOwner.current
-    LaunchedEffect(lifecycleOwner) {
+    // Navigate back when the app goes to background (security: prevent returning
+    // to settings without passcode). Using Activity lifecycle so that in-app
+    // navigation doesn't trigger this.
+    val activity = context as ComponentActivity
+    DisposableEffect(activity) {
         val observer = LifecycleEventObserver { _, event ->
-            if (event == Lifecycle.Event.ON_PAUSE) {
+            if (event == Lifecycle.Event.ON_STOP) {
                 onNavigateBack()
             }
         }
-        lifecycleOwner.lifecycle.addObserver(observer)
+        activity.lifecycle.addObserver(observer)
+        onDispose {
+            activity.lifecycle.removeObserver(observer)
+        }
     }
 
     Scaffold(