fix(backup-list-fragment): permission handling

app/src/main/java/com/owncloud/android/ui/fragment/contactsbackup/BackupListAdapter.kt

@@ -126,6 +126,12 @@ class BackupListAdapter(
         notifyItemInserted(calendarFiles.lastIndex)
     }
 
+    @SuppressLint("NotifyDataSetChanged")
+    fun reloadCalendars() {
+        cachedAndroidCalendars = AndroidCalendar.loadAll(context.contentResolver)
+        notifyDataSetChanged()
+    }
+
     @SuppressLint("NotifyDataSetChanged")
     fun replaceVcards(vCards: List<VCard>) {
         contacts.clear()

app/src/main/java/com/owncloud/android/ui/fragment/contactsbackup/BackupListFragment.java

@@ -58,6 +58,8 @@
 
 import javax.inject.Inject;
 
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.ActionBar;
 import androidx.recyclerview.widget.LinearLayoutManager;
@@ -218,6 +220,10 @@ public View onCreateView(@NonNull final LayoutInflater inflater, ViewGroup conta
             }
         }
 
+        if (listAdapter.hasCalendarEntry()) {
+            checkAndAskForCalendarReadPermission();
+        }
+
         binding.restoreSelected.setOnClickListener(v -> {
             if (checkAndAskForCalendarWritePermission()) {
                 importCalendar();
@@ -408,58 +414,72 @@ private void closeFragment() {
         }
     }
 
+    // region permission check result listener
+    private final ActivityResultLauncher<String> contactsWritePermissionLauncher =
+        registerForActivityResult(new ActivityResultContracts.RequestPermission(), isGranted -> {
+            if (isGranted) {
+                importContacts(selectedAccount);
+            } else {
+                showPermissionErrorMessage();
+            }
+        });
+
+    private final ActivityResultLauncher<String> calendarReadPermissionLauncher =
+        registerForActivityResult(new ActivityResultContracts.RequestPermission(), isGranted -> {
+            if (isGranted) {
+                listAdapter.reloadCalendars();
+            }
+        });
+
+    private final ActivityResultLauncher<String> calendarWritePermissionLauncher =
+        registerForActivityResult(new ActivityResultContracts.RequestPermission(), isGranted -> {
+            if (isGranted) {
+                importCalendar();
+            } else {
+                showPermissionErrorMessage();
+            }
+        });
+    // endregion
+
+    // region permission checks
     private boolean checkAndAskForContactsWritePermission() {
-        // check permissions
-        if (!PermissionUtil.checkSelfPermission(getContext(), Manifest.permission.WRITE_CONTACTS)) {
-            requestPermissions(new String[]{Manifest.permission.WRITE_CONTACTS},
-                               PermissionUtil.PERMISSIONS_WRITE_CONTACTS);
+        final var context = getContext();
+        if (context == null) {
             return false;
-        } else {
-            return true;
         }
-    }
 
-    private boolean checkAndAskForCalendarWritePermission() {
-        // check permissions
-        if (!PermissionUtil.checkSelfPermission(getContext(), Manifest.permission.WRITE_CALENDAR)) {
-            requestPermissions(new String[]{Manifest.permission.WRITE_CALENDAR},
-                               PermissionUtil.PERMISSIONS_WRITE_CALENDAR);
+        if (!PermissionUtil.checkSelfPermission(context, Manifest.permission.WRITE_CONTACTS)) {
+            contactsWritePermissionLauncher.launch(Manifest.permission.WRITE_CONTACTS);
             return false;
-        } else {
-            return true;
         }
+
+        return true;
     }
 
-    @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
-        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
-
-        if (requestCode == PermissionUtil.PERMISSIONS_WRITE_CONTACTS) {
-            for (int index = 0; index < permissions.length; index++) {
-                if (Manifest.permission.WRITE_CONTACTS.equalsIgnoreCase(permissions[index])) {
-                    if (grantResults[index] >= 0) {
-                        importContacts(selectedAccount);
-                    } else {
-                        showPermissionErrorMessage();
-                    }
-                    break;
-                }
-            }
+    private void checkAndAskForCalendarReadPermission() {
+        final var context = getContext();
+        if (context == null) {
+            return;
         }
 
-        if (requestCode == PermissionUtil.PERMISSIONS_WRITE_CALENDAR) {
-            for (int index = 0; index < permissions.length; index++) {
-                if (Manifest.permission.WRITE_CALENDAR.equalsIgnoreCase(permissions[index])) {
-                    if (grantResults[index] >= 0) {
-                        importContacts(selectedAccount);
-                    } else {
-                        showPermissionErrorMessage();
-                    }
-                    break;
-                }
-            }
+        if (!PermissionUtil.checkSelfPermission(context, Manifest.permission.READ_CALENDAR)) {
+            calendarReadPermissionLauncher.launch(Manifest.permission.READ_CALENDAR);
+        }
+    }
+
+    private boolean checkAndAskForCalendarWritePermission() {
+        final var context = getContext();
+        if (context == null) {
+            return false;
+        }
+
+        if (!PermissionUtil.checkSelfPermission(context, Manifest.permission.WRITE_CALENDAR)) {
+            calendarWritePermissionLauncher.launch(Manifest.permission.WRITE_CALENDAR);
+            return false;
         }
+        return true;
     }
+    // endregion
 
     private void showPermissionErrorMessage() {
         DisplayUtils.showSnackMessage(this, R.string.contactlist_no_permission);

app/src/main/java/third_parties/sufficientlysecure/AndroidCalendar.java

@@ -112,9 +112,14 @@ private static String getString(Cursor cur, String dbName) {
     }
 
     private static boolean missing(ContentResolver resolver, Uri uri) {
-        // Determine if a provider is missing
+        // Determine if a provider is missing or inaccessible.
+        // acquireContentProviderClient throws SecurityException when the calendar
+        // permission has not been granted, so treat that as missing too.
         try (ContentProviderClient provider = resolver.acquireContentProviderClient(uri)) {
             return provider == null;
+        } catch (SecurityException e) {
+            Log_OC.w(TAG, "Calendar provider is not accessible: " + e.getMessage());
+            return true;
         }
     }