Fix compile warnings on AOSP 11

app/src/main/java/com/stevesoltys/seedvault/UsbIntentReceiver.kt

@@ -11,6 +11,7 @@ import android.hardware.usb.UsbManager.ACTION_USB_DEVICE_DETACHED
 import android.hardware.usb.UsbManager.EXTRA_DEVICE
 import android.net.Uri
 import android.os.Handler
+import android.os.Looper
 import android.provider.DocumentsContract
 import android.util.Log
 import com.stevesoltys.seedvault.metadata.MetadataManager
@@ -74,7 +75,8 @@ abstract class UsbMonitor : BroadcastReceiver() {
 
             val rootsUri = DocumentsContract.buildRootsUri(AUTHORITY_STORAGE)
             val contentResolver = context.contentResolver
-            val observer = object : ContentObserver(Handler()) {
+            val handler = Handler(Looper.getMainLooper())
+            val observer = object : ContentObserver(handler) {
                 override fun onChange(selfChange: Boolean, uri: Uri?) {
                     super.onChange(selfChange, uri)
                     onStatusChanged(context, action, device)

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsStorage.kt

@@ -7,7 +7,6 @@ import android.content.pm.PackageInfo
 import android.database.ContentObserver
 import android.database.Cursor
 import android.net.Uri
-import android.os.FileUtils.closeQuietly
 import android.provider.DocumentsContract.Document.COLUMN_DOCUMENT_ID
 import android.provider.DocumentsContract.EXTRA_LOADING
 import android.provider.DocumentsContract.buildChildDocumentsUriUsingTree
@@ -294,14 +293,14 @@ internal suspend fun getLoadedCursor(timeout: Long = 15_000, query: () -> Cursor
     withTimeout(timeout) {
         suspendCancellableCoroutine<Cursor> { cont ->
             val cursor = query() ?: throw IOException()
-            cont.invokeOnCancellation { closeQuietly(cursor) }
+            cont.invokeOnCancellation { cursor.close() }
             val loading = cursor.extras.getBoolean(EXTRA_LOADING, false)
             if (loading) {
                 Log.d(TAG, "Wait for children to get loaded...")
                 cursor.registerContentObserver(object : ContentObserver(null) {
                     override fun onChange(selfChange: Boolean, uri: Uri?) {
                         Log.d(TAG, "Children loaded. Continue...")
-                        closeQuietly(cursor)
+                        cursor.close()
                         val newCursor = query()
                         if (newCursor == null) cont.cancel(IOException("query returned no results"))
                         else cont.resume(newCursor)

app/src/main/java/com/stevesoltys/seedvault/restore/InstallProgressFragment.kt

@@ -32,8 +32,11 @@ class InstallProgressFragment : Fragment() {
     private lateinit var appList: RecyclerView
     private lateinit var button: Button
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
+    override fun onCreateView(
-                              savedInstanceState: Bundle?): View? {
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
         val v: View = inflater.inflate(R.layout.fragment_restore_progress, container, false)
 
         progressBar = v.findViewById(R.id.progressBar)
@@ -55,20 +58,16 @@ class InstallProgressFragment : Fragment() {
         }
         button.setText(R.string.restore_next)
         button.setOnClickListener { viewModel.onNextClicked() }
-    }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        viewModel.chosenRestorableBackup.observe(viewLifecycleOwner, Observer { restorableBackup ->
-        super.onActivityCreated(savedInstanceState)
-
-        viewModel.chosenRestorableBackup.observe(this, Observer { restorableBackup ->
             backupNameView.text = restorableBackup.name
         })
 
-        viewModel.installResult.observe(this, Observer { result ->
+        viewModel.installResult.observe(viewLifecycleOwner, Observer { result ->
             onInstallResult(result)
         })
 
-        viewModel.nextButtonEnabled.observe(this, Observer { enabled ->
+        viewModel.nextButtonEnabled.observe(viewLifecycleOwner, Observer { enabled ->
             button.isEnabled = enabled
         })
     }

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreActivity.kt

@@ -19,7 +19,7 @@ class RestoreActivity : RequireProvisioningActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        if (isSetupWizard) hideSystemUI()
+        if (isSetupWizard) hideSystemUiNavigation()
 
         setContentView(R.layout.activity_fragment_container)
 

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreProgressFragment.kt

@@ -59,25 +59,21 @@ class RestoreProgressFragment : Fragment() {
             requireActivity().setResult(RESULT_OK)
             requireActivity().finishAfterTransition()
         }
-    }
-
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
 
         // decryption will fail when the device is locked, so keep the screen on to prevent locking
         requireActivity().window.addFlags(FLAG_KEEP_SCREEN_ON)
 
-        viewModel.chosenRestorableBackup.observe(this, Observer { restorableBackup ->
+        viewModel.chosenRestorableBackup.observe(viewLifecycleOwner, Observer { restorableBackup ->
             backupNameView.text = restorableBackup.name
             progressBar.max = restorableBackup.packageMetadataMap.size
         })
 
-        viewModel.restoreProgress.observe(this, Observer { list ->
+        viewModel.restoreProgress.observe(viewLifecycleOwner, Observer { list ->
             stayScrolledAtTop { adapter.update(list) }
             progressBar.progress = list.size
         })
 
-        viewModel.restoreBackupResult.observe(this, Observer { finished ->
+        viewModel.restoreBackupResult.observe(viewLifecycleOwner, Observer { finished ->
             button.isEnabled = true
             if (finished.hasError()) {
                 backupNameView.text = finished.errorMsg

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreSetFragment.kt

@@ -24,8 +24,11 @@ class RestoreSetFragment : Fragment() {
     private lateinit var errorView: TextView
     private lateinit var backView: TextView
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
+    override fun onCreateView(
-                              savedInstanceState: Bundle?): View? {
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
         val v: View = inflater.inflate(R.layout.fragment_restore_set, container, false)
 
         listView = v.findViewById(R.id.listView)
@@ -36,13 +39,15 @@ class RestoreSetFragment : Fragment() {
         return v
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+        super.onViewCreated(view, savedInstanceState)
 
         // decryption will fail when the device is locked, so keep the screen on to prevent locking
         requireActivity().window.addFlags(FLAG_KEEP_SCREEN_ON)
 
-        viewModel.restoreSetResults.observe(this, Observer { result -> onRestoreResultsLoaded(result) })
+        viewModel.restoreSetResults.observe(viewLifecycleOwner, Observer { result ->
+            onRestoreResultsLoaded(result)
+        })
 
         backView.setOnClickListener { requireActivity().finishAfterTransition() }
     }

app/src/main/java/com/stevesoltys/seedvault/settings/AppStatusFragment.kt

@@ -43,8 +43,8 @@ class AppStatusFragment : Fragment(), AppStatusToggleListener {
         return v
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+        super.onViewCreated(view, savedInstanceState)
 
         activity?.setTitle(R.string.settings_backup_status_title)
 
@@ -54,7 +54,7 @@ class AppStatusFragment : Fragment(), AppStatusToggleListener {
         }
 
         progressBar.visibility = VISIBLE
-        viewModel.appStatusList.observe(this, Observer { result ->
+        viewModel.appStatusList.observe(viewLifecycleOwner, Observer { result ->
             adapter.update(result.appStatusList, result.diff)
             progressBar.visibility = INVISIBLE
         })
@@ -66,7 +66,7 @@ class AppStatusFragment : Fragment(), AppStatusToggleListener {
         appEditMenuItem = menu.findItem(R.id.edit_app_blacklist)
 
         // observe edit mode changes here where we are sure to have the MenuItem
-        viewModel.appEditMode.observe(this, Observer { enabled ->
+        viewModel.appEditMode.observe(viewLifecycleOwner, Observer { enabled ->
             appEditMenuItem.isChecked = enabled
             adapter.setEditMode(enabled)
         })

app/src/main/java/com/stevesoltys/seedvault/settings/SettingsActivity.kt

@@ -5,10 +5,10 @@ import androidx.annotation.CallSuper
 import androidx.preference.Preference
 import androidx.preference.PreferenceFragmentCompat
 import androidx.preference.PreferenceFragmentCompat.OnPreferenceStartFragmentCallback
-import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.ui.RequireProvisioningActivity
 import com.stevesoltys.seedvault.ui.RequireProvisioningViewModel
+import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
 import org.koin.android.ext.android.inject
 import org.koin.androidx.viewmodel.ext.android.viewModel
 
@@ -50,13 +50,16 @@ class SettingsActivity : RequireProvisioningActivity(), OnPreferenceStartFragmen
         }
     }
 
-    override fun onPreferenceStartFragment(caller: PreferenceFragmentCompat, pref: Preference): Boolean {
+    override fun onPreferenceStartFragment(
-        val fragment = supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
+        caller: PreferenceFragmentCompat,
-        fragment.setTargetFragment(caller, 0)
+        pref: Preference
+    ): Boolean {
+        val fragment =
+            supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
         supportFragmentManager.beginTransaction()
-                .replace(R.id.fragment, fragment)
+            .replace(R.id.fragment, fragment)
-                .addToBackStack(null)
+            .addToBackStack(null)
-                .commit()
+            .commit()
         return true
     }
 

app/src/main/java/com/stevesoltys/seedvault/settings/SettingsFragment.kt

@@ -16,6 +16,7 @@ import android.util.Log
 import android.view.Menu
 import android.view.MenuInflater
 import android.view.MenuItem
+import android.view.View
 import androidx.appcompat.app.AlertDialog
 import androidx.lifecycle.Observer
 import androidx.preference.Preference
@@ -117,8 +118,12 @@ class SettingsFragment : PreferenceFragmentCompat() {
             return@OnPreferenceChangeListener false
         }
         backupStatus = findPreference("backup_status")!!
+    }
 
-        viewModel.lastBackupTime.observe(this, Observer { time -> setAppBackupStatusSummary(time) })
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        viewModel.lastBackupTime.observe(viewLifecycleOwner, Observer { time -> setAppBackupStatusSummary(time) })
     }
 
     override fun onStart() {
@@ -162,7 +167,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
             true
         }
         R.id.action_about -> {
-            AboutDialogFragment().show(fragmentManager!!, AboutDialogFragment.TAG)
+            AboutDialogFragment().show(parentFragmentManager, AboutDialogFragment.TAG)
             true
         }
         else -> super.onOptionsItemSelected(item)

app/src/main/java/com/stevesoltys/seedvault/transport/backup/ApkBackup.kt

@@ -116,7 +116,7 @@ class ApkBackup(
         return PackageMetadata(
             state = packageState,
             version = version,
-            installer = pm.getInstallerPackageName(packageName),
+            installer = pm.getInstallSourceInfo(packageName).installingPackageName,
             sha256 = sha256,
             signatures = signatures
         )

app/src/main/java/com/stevesoltys/seedvault/ui/BackupActivity.kt

@@ -25,7 +25,7 @@ abstract class BackupActivity : AppCompatActivity() {
         fragmentTransaction.commit()
     }
 
-    protected fun hideSystemUI() {
+    protected fun hideSystemUiNavigation() {
         window.decorView.systemUiVisibility = SYSTEM_UI_FLAG_HIDE_NAVIGATION
     }
 

app/src/main/java/com/stevesoltys/seedvault/ui/RequireProvisioningActivity.kt

@@ -3,14 +3,11 @@ package com.stevesoltys.seedvault.ui
 import android.content.Intent
 import android.os.Bundle
 import android.util.Log
+import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult
 import androidx.annotation.CallSuper
 import com.stevesoltys.seedvault.ui.recoverycode.RecoveryCodeActivity
 import com.stevesoltys.seedvault.ui.storage.StorageActivity
 
-const val REQUEST_CODE_OPEN_DOCUMENT_TREE = 1
-const val REQUEST_CODE_BACKUP_LOCATION = 2
-const val REQUEST_CODE_RECOVERY_CODE = 3
-
 const val INTENT_EXTRA_IS_RESTORE = "isRestore"
 const val INTENT_EXTRA_IS_SETUP_WIZARD = "isSetupWizard"
 
@@ -24,6 +21,25 @@ private val TAG = RequireProvisioningActivity::class.java.name
  */
 abstract class RequireProvisioningActivity : BackupActivity() {
 
+    private val recoveryCodeRequest =
+        registerForActivityResult(StartActivityForResult()) { result ->
+            if (result.resultCode != RESULT_OK) {
+                Log.w(TAG, "Error in activity result for requesting recovery code")
+                if (!getViewModel().recoveryCodeIsSet()) {
+                    finishAfterTransition()
+                }
+            }
+        }
+    private val requestLocation =
+        registerForActivityResult(StartActivityForResult()) { result ->
+            if (result.resultCode != RESULT_OK) {
+                Log.w(TAG, "Error in activity result for requesting location")
+                if (!getViewModel().validLocationIsSet()) {
+                    finishAfterTransition()
+                }
+            }
+        }
+
     protected val isSetupWizard: Boolean
         get() = intent?.action == ACTION_SETUP_WIZARD
 
@@ -38,35 +54,18 @@ abstract class RequireProvisioningActivity : BackupActivity() {
         })
     }
 
-    @CallSuper
-    override fun onActivityResult(requestCode: Int, resultCode: Int, result: Intent?) {
-        if (requestCode == REQUEST_CODE_BACKUP_LOCATION && resultCode != RESULT_OK) {
-            Log.w(TAG, "Error in activity result: $requestCode")
-            if (!getViewModel().validLocationIsSet()) {
-                finishAfterTransition()
-            }
-        } else if (requestCode == REQUEST_CODE_RECOVERY_CODE && resultCode != RESULT_OK) {
-            Log.w(TAG, "Error in activity result: $requestCode")
-            if (!getViewModel().recoveryCodeIsSet()) {
-                finishAfterTransition()
-            }
-        } else {
-            super.onActivityResult(requestCode, resultCode, result)
-        }
-    }
-
     protected fun showStorageActivity() {
         val intent = Intent(this, StorageActivity::class.java)
         intent.putExtra(INTENT_EXTRA_IS_RESTORE, getViewModel().isRestoreOperation)
         intent.putExtra(INTENT_EXTRA_IS_SETUP_WIZARD, isSetupWizard)
-        startActivityForResult(intent, REQUEST_CODE_BACKUP_LOCATION)
+        requestLocation.launch(intent)
     }
 
     protected fun showRecoveryCodeActivity() {
         val intent = Intent(this, RecoveryCodeActivity::class.java)
         intent.putExtra(INTENT_EXTRA_IS_RESTORE, getViewModel().isRestoreOperation)
         intent.putExtra(INTENT_EXTRA_IS_SETUP_WIZARD, isSetupWizard)
-        startActivityForResult(intent, REQUEST_CODE_RECOVERY_CODE)
+        recoveryCodeRequest.launch(intent)
     }
 
 }

app/src/main/java/com/stevesoltys/seedvault/ui/recoverycode/RecoveryCodeActivity.kt

@@ -16,7 +16,7 @@ class RecoveryCodeActivity : BackupActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        if (isSetupWizard()) hideSystemUI()
+        if (isSetupWizard()) hideSystemUiNavigation()
 
         setContentView(R.layout.activity_recovery_code)
 

app/src/main/java/com/stevesoltys/seedvault/ui/recoverycode/RecoveryCodeInputFragment.kt

@@ -12,7 +12,7 @@ import android.widget.Button
 import android.widget.TextView
 import android.widget.Toast
 import android.widget.Toast.LENGTH_LONG
-import androidx.constraintlayout.widget.ConstraintLayout;
+import androidx.constraintlayout.widget.ConstraintLayout
 import androidx.fragment.app.Fragment
 import com.google.android.material.textfield.TextInputLayout
 import com.stevesoltys.seedvault.R
@@ -43,8 +43,11 @@ class RecoveryCodeInputFragment : Fragment() {
     private lateinit var wordLayout12: TextInputLayout
     private lateinit var wordList: ConstraintLayout
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
+    override fun onCreateView(
-                              savedInstanceState: Bundle?): View? {
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
         val v: View = inflater.inflate(R.layout.fragment_recovery_code_input, container, false)
 
         introText = v.findViewById(R.id.introText)
@@ -67,8 +70,8 @@ class RecoveryCodeInputFragment : Fragment() {
         return v
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+        super.onViewCreated(view, savedInstanceState)
 
         if (viewModel.isRestore) {
             introText.setText(R.string.recovery_code_input_intro)
@@ -137,6 +140,7 @@ class RecoveryCodeInputFragment : Fragment() {
         }
     }
 
+    @Suppress("MagicNumber")
     private fun getWordLayout(i: Int) = when (i + 1) {
         1 -> wordLayout1
         2 -> wordLayout2

app/src/main/java/com/stevesoltys/seedvault/ui/recoverycode/RecoveryCodeOutputFragment.kt

@@ -19,8 +19,11 @@ class RecoveryCodeOutputFragment : Fragment() {
     private lateinit var wordList: RecyclerView
     private lateinit var confirmCodeButton: Button
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
+    override fun onCreateView(
-                              savedInstanceState: Bundle?): View? {
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
         val v: View = inflater.inflate(R.layout.fragment_recovery_code_output, container, false)
 
         wordList = v.findViewById(R.id.wordList)
@@ -29,8 +32,8 @@ class RecoveryCodeOutputFragment : Fragment() {
         return v
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+        super.onViewCreated(view, savedInstanceState)
 
         setGridParameters(wordList)
         wordList.adapter = RecoveryCodeAdapter(viewModel.wordList)
@@ -38,6 +41,7 @@ class RecoveryCodeOutputFragment : Fragment() {
         confirmCodeButton.setOnClickListener { viewModel.onConfirmButtonClicked() }
     }
 
+    @Suppress("MagicNumber")
     private fun setGridParameters(list: RecyclerView) {
         val layoutManager = list.layoutManager as GridLayoutManager
         if (resources.configuration.orientation == ORIENTATION_LANDSCAPE) {

app/src/main/java/com/stevesoltys/seedvault/ui/storage/StorageActivity.kt

@@ -1,6 +1,5 @@
 package com.stevesoltys.seedvault.ui.storage
 
-import android.content.Intent
 import android.os.Bundle
 import android.util.Log
 import androidx.annotation.CallSuper
@@ -22,7 +21,7 @@ class StorageActivity : BackupActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        if (isSetupWizard()) hideSystemUI()
+        if (isSetupWizard()) hideSystemUiNavigation()
 
         setContentView(R.layout.activity_fragment_container)
 
@@ -52,16 +51,6 @@ class StorageActivity : BackupActivity() {
         }
     }
 
-    @CallSuper
-    override fun onActivityResult(requestCode: Int, resultCode: Int, result: Intent?) {
-        if (resultCode != RESULT_OK) {
-            Log.w(TAG, "Error in activity result: $requestCode")
-            onInvalidLocation(getString(R.string.storage_check_fragment_permission_error))
-        } else {
-            super.onActivityResult(requestCode, resultCode, result)
-        }
-    }
-
     override fun onBackPressed() {
         if (supportFragmentManager.backStackEntryCount > 0) {
             Log.d(TAG, "Blocking back button.")

app/src/main/java/com/stevesoltys/seedvault/ui/storage/StorageCheckFragment.kt

@@ -33,8 +33,11 @@ class StorageCheckFragment : Fragment() {
         }
     }
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
+    override fun onCreateView(
-                              savedInstanceState: Bundle?): View? {
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
         val v: View = inflater.inflate(R.layout.fragment_storage_check, container, false)
 
         titleView = v.findViewById(R.id.titleView)
@@ -45,12 +48,12 @@ class StorageCheckFragment : Fragment() {
         return v
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+        super.onViewCreated(view, savedInstanceState)
 
-        titleView.text = arguments!!.getString(TITLE)
+        titleView.text = requireArguments().getString(TITLE)
 
-        val errorMsg = arguments!!.getString(ERROR_MSG)
+        val errorMsg = requireArguments().getString(ERROR_MSG)
         if (errorMsg != null) {
             progressBar.visibility = INVISIBLE
             errorView.text = errorMsg

app/src/main/java/com/stevesoltys/seedvault/ui/storage/StorageRootFetcher.kt

@@ -12,6 +12,7 @@ import android.database.Cursor
 import android.graphics.drawable.Drawable
 import android.net.Uri
 import android.os.Handler
+import android.os.Looper
 import android.provider.DocumentsContract
 import android.provider.DocumentsContract.PROVIDER_INTERFACE
 import android.provider.DocumentsContract.Root.COLUMN_AVAILABLE_BYTES
@@ -72,7 +73,8 @@ internal class StorageRootFetcher(private val context: Context, private val isRe
     private val whitelistedAuthorities = context.resources.getStringArray(R.array.storage_authority_whitelist)
 
     private var listener: RemovableStorageListener? = null
-    private val observer = object : ContentObserver(Handler()) {
+    private val handler = Handler(Looper.getMainLooper())
+    private val observer = object : ContentObserver(handler) {
         override fun onChange(selfChange: Boolean, uri: Uri?) {
             super.onChange(selfChange, uri)
             listener?.onStorageChanged()

app/src/main/java/com/stevesoltys/seedvault/ui/storage/StorageRootsFragment.kt

@@ -1,9 +1,12 @@
 package com.stevesoltys.seedvault.ui.storage
 
+import android.annotation.SuppressLint
+import android.content.Context
 import android.content.Intent
 import android.content.Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION
 import android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION
 import android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION
+import android.net.Uri
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
@@ -13,13 +16,12 @@ import android.view.ViewGroup
 import android.widget.ImageView
 import android.widget.ProgressBar
 import android.widget.TextView
-import androidx.appcompat.app.AppCompatActivity.RESULT_OK
+import androidx.activity.result.contract.ActivityResultContracts.OpenDocumentTree
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
 import androidx.recyclerview.widget.RecyclerView
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.ui.INTENT_EXTRA_IS_RESTORE
-import com.stevesoltys.seedvault.ui.REQUEST_CODE_OPEN_DOCUMENT_TREE
 import org.koin.androidx.viewmodel.ext.android.getSharedViewModel
 
 internal class StorageRootsFragment : Fragment(), StorageRootClickedListener {
@@ -45,8 +47,11 @@ internal class StorageRootsFragment : Fragment(), StorageRootClickedListener {
 
     private val adapter by lazy { StorageRootAdapter(viewModel.isRestoreOperation, this) }
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
+    override fun onCreateView(
-                              savedInstanceState: Bundle?): View? {
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
         val v: View = inflater.inflate(R.layout.fragment_storage_root, container, false)
 
         titleView = v.findViewById(R.id.titleView)
@@ -60,10 +65,10 @@ internal class StorageRootsFragment : Fragment(), StorageRootClickedListener {
         return v
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+        super.onViewCreated(view, savedInstanceState)
 
-        viewModel = if (arguments!!.getBoolean(INTENT_EXTRA_IS_RESTORE)) {
+        viewModel = if (requireArguments().getBoolean(INTENT_EXTRA_IS_RESTORE)) {
             getSharedViewModel<RestoreStorageViewModel>()
         } else {
             getSharedViewModel<BackupStorageViewModel>()
@@ -81,7 +86,9 @@ internal class StorageRootsFragment : Fragment(), StorageRootClickedListener {
 
         listView.adapter = adapter
 
-        viewModel.storageRoots.observe(this, Observer { roots -> onRootsLoaded(roots) })
+        viewModel.storageRoots.observe(viewLifecycleOwner, Observer { roots ->
+            onRootsLoaded(roots)
+        })
     }
 
     override fun onStart() {
@@ -94,21 +101,13 @@ internal class StorageRootsFragment : Fragment(), StorageRootClickedListener {
         adapter.setItems(roots)
     }
 
-    override fun onClick(root: StorageRoot) {
+    private val openDocumentTree = registerForActivityResult(OpenSeedvaultTree()) { uri ->
-        viewModel.onStorageRootChosen(root)
+        viewModel.onUriPermissionResultReceived(uri)
-        val intent = Intent(requireContext(), PermissionGrantActivity::class.java)
-        intent.data = root.uri
-        intent.addFlags(FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
-                FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION)
-        startActivityForResult(intent, REQUEST_CODE_OPEN_DOCUMENT_TREE)
     }
 
-    override fun onActivityResult(requestCode: Int, resultCode: Int, result: Intent?) {
+    override fun onClick(root: StorageRoot) {
-        if (resultCode == RESULT_OK && requestCode == REQUEST_CODE_OPEN_DOCUMENT_TREE) {
+        viewModel.onStorageRootChosen(root)
-            viewModel.onUriPermissionGranted(result)
+        openDocumentTree.launch(root.uri)
-        } else {
-            super.onActivityResult(requestCode, resultCode, result)
-        }
     }
 
 }
@@ -116,3 +115,16 @@ internal class StorageRootsFragment : Fragment(), StorageRootClickedListener {
 internal interface StorageRootClickedListener {
     fun onClick(root: StorageRoot)
 }
+
+private class OpenSeedvaultTree : OpenDocumentTree() {
+    @SuppressLint("MissingSuperCall") // we are intentionally creating our own intent
+    override fun createIntent(context: Context, input: Uri?): Intent {
+        return Intent(context, PermissionGrantActivity::class.java).apply {
+            check(input != null) { "Uri was null, but is needed." }
+            data = input
+            val flags = FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
+                    FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION
+            addFlags(flags)
+        }
+    }
+}

app/src/main/java/com/stevesoltys/seedvault/ui/storage/StorageViewModel.kt

@@ -3,7 +3,6 @@ package com.stevesoltys.seedvault.ui.storage
 import android.app.Application
 import android.content.Context
 import android.content.Context.USB_SERVICE
-import android.content.Intent
 import android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION
 import android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION
 import android.hardware.usb.UsbManager
@@ -24,8 +23,8 @@ import com.stevesoltys.seedvault.ui.MutableLiveEvent
 private val TAG = StorageViewModel::class.java.simpleName
 
 internal abstract class StorageViewModel(
-        private val app: Application,
+    private val app: Application,
-        protected val settingsManager: SettingsManager
+    protected val settingsManager: SettingsManager
 ) : AndroidViewModel(app), RemovableStorageListener {
 
     private val mStorageRoots = MutableLiveData<List<StorageRoot>>()
@@ -44,7 +43,10 @@ internal abstract class StorageViewModel(
     abstract val isRestoreOperation: Boolean
 
     companion object {
-        internal fun validLocationIsSet(context: Context, settingsManager: SettingsManager): Boolean {
+        internal fun validLocationIsSet(
+            context: Context,
+            settingsManager: SettingsManager
+        ): Boolean {
             val storage = settingsManager.getStorage() ?: return false
             if (storage.isUsb) return true
             return storage.getDocumentFile(context).isDirectory
@@ -66,14 +68,18 @@ internal abstract class StorageViewModel(
         storageRoot = root
     }
 
-    internal fun onUriPermissionGranted(result: Intent?) {
+    internal fun onUriPermissionResultReceived(uri: Uri?) {
-        val uri = result?.data ?: return
+        if (uri == null) {
+            val msg = app.getString(R.string.storage_check_fragment_permission_error)
+            mLocationChecked.setEvent(LocationResult(msg))
+            return
+        }
 
         // inform UI that a location has been successfully selected
         mLocationSet.setEvent(true)
 
         // persist permission to access backup folder across reboots
-        val takeFlags = result.flags and (FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION)
+        val takeFlags = FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION
         app.contentResolver.takePersistableUriPermission(uri, takeFlags)
 
         onLocationSet(uri)