fix compatibility issue with androids older than 10 after introducing the MediaStore workaround for people who deleted/disabled their com.android.documentsui

Author: alzwded

CHANGELOG.md

@@ -1,3 +1,13 @@
+13.0
+====
+
+- Fix permission issue for Androids < 10 introduced by the workaround
+  introduced in version 10.0 which uses the MediaStore to output audiobooks to
+  a default directory
+- Add a LaunchedEffect to re-check if permissions were gained/lost, in case
+  they were gained/lost since the app was started and since we last checked
+  and the activity wasn't reaped by the system
+
 12.0
 ====
 

app/build.gradle.kts

@@ -12,8 +12,8 @@ android {
         applicationId = "alzwded.openaudiobookify"
         minSdk = 24
         targetSdk = 35
-        versionCode = 12
-        versionName = "12.0"
+        versionCode = 13
+        versionName = "13.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables {

app/src/main/AndroidManifest.xml

@@ -7,6 +7,9 @@
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <!-- compatibility with older Androids -->
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+                     android:maxSdkVersion="28" />
 
     <queries>
         <intent>

app/src/main/java/alzwded/openaudiobookify/MainActivity.kt

@@ -281,6 +281,35 @@ fun OpenAudioBookifyApp(viewModel: MainViewModel) {
         )
     }
 
+    var hasWriteExternalPermission by remember {
+        mutableStateOf(
+            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
+                ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
+            } else {
+                // permission no longer necessary starting in Q when using MediaStore;
+                // if an output directory is set with SAF, you grant permission then, any version
+                true
+            }
+        )
+    }
+
+    // Re-verify permission whenever the Composable comes into the foreground
+    // (in case the user changed permissions in system settings)
+    LaunchedEffect(Unit) {
+        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
+            hasWriteExternalPermission = ContextCompat.checkSelfPermission(
+                context, 
+                Manifest.permission.WRITE_EXTERNAL_STORAGE
+            ) == PackageManager.PERMISSION_GRANTED
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            hasNotificationPermission = ContextCompat.checkSelfPermission(
+                context,
+                Manifest.permission.POST_NOTIFICATIONS
+            ) == PackageManager.PERMISSION_GRANTED
+        }
+    }
+
     val permissionLauncher = rememberLauncherForActivityResult(
         contract = ActivityResultContracts.RequestPermission(),
         onResult = { isGranted ->
@@ -291,6 +320,16 @@ fun OpenAudioBookifyApp(viewModel: MainViewModel) {
         }
     )
 
+    val writeExternalPermissionLauncher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+        onResult = { isGranted ->
+            hasWriteExternalPermission = isGranted
+            if (!isGranted) {
+                Toast.makeText(context, context.getString(R.string.write_external_permission_required), Toast.LENGTH_SHORT).show()
+            }
+        }
+    )
+
     val filePickerLauncher = rememberLauncherForActivityResult(
         contract = ActivityResultContracts.OpenMultipleDocuments(),
         onResult = { uris ->
@@ -387,6 +426,8 @@ fun OpenAudioBookifyApp(viewModel: MainViewModel) {
                 if (selectedBooks.isNotEmpty()) {
                     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU && !hasNotificationPermission) {
                         permissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS)
+                    } else if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P && !hasWriteExternalPermission) {
+                        writeExternalPermissionLauncher.launch(Manifest.permission.WRITE_EXTERNAL_STORAGE);
                     } else {
                         startProcessingService()
                     }

app/src/main/res/values-ro/strings.xml

@@ -2,6 +2,7 @@
     <string name="about">Despre</string>
     <string name="settings">Setări</string>
     <string name="notification_permission_required">Aplicația are nevoie de permisiunea de a afișa notificări pentru procesarea datelor în fundal</string>
+    <string name="write_external_permission_required">Aplicația are nevoie de permisiunea de a scrie pe mediul de stocare extern ("Write External Storage"), cu excepția cazului în care alegeți explicit un dosar de ieșire</string>
     <string name="processing_started">Procesarea a început în fundal</string>
     <string name="error_no_output_folder">Nu a fost selectat niciun dosar pentru datele de ieșire</string>
     <string name="error_no_books_added">Trebuie să adăugați cărți</string>

app/src/main/res/values/strings.xml

@@ -2,6 +2,7 @@
     <string name="about">About</string>
     <string name="settings">Settings</string>
     <string name="notification_permission_required">Notification permission required for background processing</string>
+    <string name="write_external_permission_required">Write External Storage permission required, unless you explicitly set an output directory</string>
     <string name="processing_started">Processing started in background</string>
     <string name="error_no_output_folder">No output folder selected</string>
     <string name="error_no_books_added">Add some books first</string>