Show which note is locked and how to unlock it

app/src/main/java/it/niedermann/owncloud/notes/exception/tips/TipsAdapter.java

@@ -36,6 +36,8 @@
 
 import it.niedermann.owncloud.notes.BuildConfig;
 import it.niedermann.owncloud.notes.R;
+import it.niedermann.owncloud.notes.persistence.NoteSyncException;
+import it.niedermann.owncloud.notes.persistence.SyncFailureReason;
 
 public class TipsAdapter extends RecyclerView.Adapter<TipsViewHolder> {
 
@@ -89,6 +91,9 @@ public void setThrowables(@NonNull List<Throwable> throwables) {
                 add(R.string.error_dialog_timeout_toggle, new Intent(Settings.ACTION_WIFI_SETTINGS).putExtra(INTENT_EXTRA_BUTTON_TEXT, R.string.error_action_open_network));
             } else if (throwable instanceof JSONException || throwable instanceof NullPointerException) {
                 add(R.string.error_dialog_check_server);
+            } else if (throwable instanceof NoteSyncException syncException && syncException.getReason() == SyncFailureReason.LOCKED) {
+                add(R.string.error_dialog_tip_note_locked_close);
+                add(R.string.error_dialog_tip_note_locked_unlock);
             } else if (throwable instanceof NextcloudHttpRequestFailedException) {
                 final int statusCode = ((NextcloudHttpRequestFailedException) throwable).getStatusCode();
                 switch (statusCode) {

app/src/main/java/it/niedermann/owncloud/notes/main/MainActivity.java

@@ -216,7 +216,7 @@ protected void onCreate(Bundle savedInstanceState) {
         mainViewModel.getSyncStatus().observe(this, syncStatus -> swipeRefreshLayout.setRefreshing(syncStatus));
         mainViewModel.getSyncErrors().observe(this, exceptions -> {
             if (mainViewModel.containsNonInfrastructureRelatedItems(exceptions)) {
-                BrandedSnackbar.make(coordinatorLayout, SyncErrorMessage.of(exceptions), Snackbar.LENGTH_LONG)
+                BrandedSnackbar.make(coordinatorLayout, SyncErrorMessage.of(MainActivity.this, exceptions), Snackbar.LENGTH_LONG)
                         .setAnchorView(binding.activityNotesListView.fabCreate)
                         .setAction(R.string.simple_more, v -> ExceptionDialogFragment.newInstance(exceptions)
                                 .show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName()))
@@ -325,7 +325,7 @@ public void onError(@NonNull Throwable t) {
                                     .setAnchorView(binding.activityNotesListView.fabCreate)
                                     .show();
                         } else {
-                            BrandedSnackbar.make(coordinatorLayout, SyncErrorMessage.of(t), Snackbar.LENGTH_LONG)
+                            BrandedSnackbar.make(coordinatorLayout, SyncErrorMessage.of(MainActivity.this, t), Snackbar.LENGTH_LONG)
                                     .setAction(R.string.simple_more, v -> ExceptionDialogFragment.newInstance(t)
                                             .show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName()))
                                     .setAnchorView(binding.activityNotesListView.fabCreate)
@@ -609,7 +609,7 @@ public void onError(@NonNull Throwable t) {
                                         .setAnchorView(binding.activityNotesListView.fabCreate)
                                         .show();
                             } else {
-                                BrandedSnackbar.make(coordinatorLayout, SyncErrorMessage.of(t), Snackbar.LENGTH_LONG)
+                                BrandedSnackbar.make(coordinatorLayout, SyncErrorMessage.of(MainActivity.this, t), Snackbar.LENGTH_LONG)
                                         .setAction(R.string.simple_more, v -> ExceptionDialogFragment.newInstance(t)
                                                 .show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName()))
                                         .setAnchorView(binding.activityNotesListView.fabCreate)

app/src/main/java/it/niedermann/owncloud/notes/main/SyncErrorMessage.kt

@@ -6,27 +6,48 @@
  */
 package it.niedermann.owncloud.notes.main
 
-import androidx.annotation.StringRes
+import android.content.Context
 import com.nextcloud.android.sso.exceptions.NextcloudApiNotRespondingException
 import com.nextcloud.android.sso.exceptions.NextcloudHttpRequestFailedException
 import com.nextcloud.android.sso.exceptions.NextcloudNetworkException
 import com.nextcloud.android.sso.exceptions.TokenMismatchException
+import it.niedermann.owncloud.notes.R
 import it.niedermann.owncloud.notes.persistence.NoteSyncException
 import it.niedermann.owncloud.notes.persistence.SyncFailureReason
 
 object SyncErrorMessage {
     @JvmStatic
-    @StringRes
-    fun of(exceptions: Collection<Throwable>): Int =
-        (exceptions.map { it.syncFailureReason() }.distinct().singleOrNull() ?: SyncFailureReason.UNKNOWN).message
+    fun of(context: Context, exceptions: Collection<Throwable>): String {
+        val reasons = exceptions.map { it.syncFailureReason() }.distinct()
+        val reason = reasons.singleOrNull() ?: SyncFailureReason.UNKNOWN
+        if (reason != SyncFailureReason.LOCKED) {
+            return context.getString(reason.message)
+        }
+        return lockedMessage(context, exceptions.mapNotNull { it.lockedNoteTitle() }.distinct())
+    }
 
     @JvmStatic
-    @StringRes
-    fun of(exception: Throwable): Int = exception.syncFailureReason().message
+    fun of(context: Context, exception: Throwable): String = of(context, listOf(exception))
+
+    private fun lockedMessage(context: Context, lockedNoteTitles: List<String>): String = when (lockedNoteTitles.size) {
+        0 -> context.getString(SyncFailureReason.LOCKED.message)
+        1 -> context.getString(R.string.error_sync_note_locked, lockedNoteTitles.single())
+        else -> context.resources.getQuantityString(
+            R.plurals.error_sync_notes_locked,
+            lockedNoteTitles.size,
+            lockedNoteTitles.size,
+        )
+    }
+
+    private fun Throwable.lockedNoteTitle(): String? = causeChain()
+        .filterIsInstance<NoteSyncException>()
+        .firstOrNull { it.reason == SyncFailureReason.LOCKED }
+        ?.noteTitle
 
     private fun Throwable.syncFailureReason(): SyncFailureReason =
-        generateSequence(this) { it.cause }.firstNotNullOfOrNull { it.directSyncFailureReason() }
-            ?: SyncFailureReason.UNKNOWN
+        causeChain().firstNotNullOfOrNull { it.directSyncFailureReason() } ?: SyncFailureReason.UNKNOWN
+
+    private fun Throwable.causeChain(): Sequence<Throwable> = generateSequence(this) { it.cause }
 
     private fun Throwable.directSyncFailureReason(): SyncFailureReason? = when (this) {
         is NoteSyncException -> reason

app/src/main/java/it/niedermann/owncloud/notes/persistence/NoteSyncException.kt

@@ -8,7 +8,7 @@ package it.niedermann.owncloud.notes.persistence
 
 import retrofit2.Response
 
-class NoteSyncException(noteTitle: String, response: Response<*>) :
+class NoteSyncException(val noteTitle: String, response: Response<*>) :
     Exception("Could not sync \"$noteTitle\" (HTTP ${response.code()}): ${response.message()}") {
     val reason = SyncFailureReason.fromStatusCode(response.code())
 }

app/src/main/java/it/niedermann/owncloud/notes/persistence/SyncFailureReason.kt

@@ -18,7 +18,7 @@ enum class SyncFailureReason(@StringRes val message: Int) {
     UNAUTHORIZED(R.string.error_sync_unauthorized),
     PERMISSION(R.string.error_sync_permission),
     NOTES_APP_UNAVAILABLE(R.string.error_sync_notes_app_unavailable),
-    LOCKED(R.string.error_sync_locked),
+    LOCKED(R.string.error_sync_unknown_note_locked),
     SERVER_ERROR(R.string.error_sync_server_error),
     MAINTENANCE(R.string.error_sync_maintenance),
     INSUFFICIENT_STORAGE(R.string.error_sync_insufficient_storage),

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

@@ -195,7 +195,12 @@
 
     <string name="error_sync">Synchronization failed: %1$s</string>
     <string name="error_synchronization">Synchronization failed</string>
-    <string name="error_sync_locked">A note is open in another app. Close it there to sync your changes.</string>
+    <string name="error_sync_unknown_note_locked">A note is locked on the server. Close it in the other app, or unlock it in the web interface.</string>
+    <string name="error_sync_note_locked">“%1$s” is locked on the server. Close it in the other app, or unlock it in the web interface.</string>
+    <plurals name="error_sync_notes_locked">
+        <item quantity="one">%d note is locked on the server. Close it in the other app, or unlock it in the web interface.</item>
+        <item quantity="other">%d notes are locked on the server. Close them in the other app, or unlock them in the web interface.</item>
+    </plurals>
     <string name="error_sync_unauthorized">Your login is no longer valid. Log in again in the Nextcloud Files app.</string>
     <string name="error_sync_permission">You don’t have permission to save this note. Please check your access and try again.</string>
     <string name="error_sync_notes_app_unavailable">The Notes app is not available on your server.</string>
@@ -354,6 +359,8 @@
     <string name="error_dialog_redirect">Your server did respond with a HTTP 302 status code, which implies, that you do not have installed the Notes app on your server or something is misconfigured. This can be caused by custom overrides in a .htaccess-file or by Nextcloud apps like OID Client.</string>
     <string name="error_dialog_tip_disable_battery_optimizations">Please disable all battery optimizations for Nextcloud and the Notes app.</string>
     <string name="error_dialog_min_version">The Notes Android app requires the Nextcloud Android app to be at least version 3.18.</string>
+    <string name="error_dialog_tip_note_locked_close">The note is locked on the server. This usually means it is open in the Text editor or in another app. Close it there and sync again.</string>
+    <string name="error_dialog_tip_note_locked_unlock">If the note is not open anywhere, the lock is stale. In the Nextcloud web interface, open Files, find the note in the Notes folder, open its menu and choose Unlock. If that is not offered, ask your administrator to remove the lock.</string>
     <string name="added_content">Added "%1$s"</string>
     <string name="shared_text_empty">Shared text was empty</string>
     <string name="append_to_note">Append to note</string>

app/src/test/java/it/niedermann/owncloud/notes/main/SyncErrorMessageTest.kt

@@ -0,0 +1,83 @@
+/*
+ * Nextcloud Notes - Android Client
+ *
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package it.niedermann.owncloud.notes.main
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import it.niedermann.owncloud.notes.R
+import it.niedermann.owncloud.notes.persistence.NoteSyncException
+import okhttp3.ResponseBody.Companion.toResponseBody
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import retrofit2.Response
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [36])
+class SyncErrorMessageTest {
+
+    private val context: Context = ApplicationProvider.getApplicationContext()
+
+    @Test
+    fun singleLockedNoteIsNamed() {
+        val message = SyncErrorMessage.of(context, listOf(noteSyncException(GROCERIES, HTTP_LOCKED)))
+
+        assertEquals(context.getString(R.string.error_sync_note_locked, GROCERIES), message)
+    }
+
+    @Test
+    fun severalLockedNotesAreCounted() {
+        val exceptions = listOf(
+            noteSyncException(GROCERIES, HTTP_LOCKED),
+            noteSyncException(INVOICES, HTTP_LOCKED),
+        )
+
+        val message = SyncErrorMessage.of(context, exceptions)
+
+        assertEquals(context.resources.getQuantityString(R.plurals.error_sync_notes_locked, 2, 2), message)
+    }
+
+    @Test
+    fun lockedNoteIsFoundInCauseChain() {
+        val wrapped = RuntimeException(IllegalStateException(noteSyncException(GROCERIES, HTTP_LOCKED)))
+
+        val message = SyncErrorMessage.of(context, wrapped)
+
+        assertEquals(context.getString(R.string.error_sync_note_locked, GROCERIES), message)
+    }
+
+    @Test
+    fun lockedTogetherWithOtherFailuresFallsBackToGenericMessage() {
+        val exceptions = listOf(
+            noteSyncException(GROCERIES, HTTP_LOCKED),
+            noteSyncException(INVOICES, HTTP_INSUFFICIENT_STORAGE),
+        )
+
+        val message = SyncErrorMessage.of(context, exceptions)
+
+        assertEquals(context.getString(R.string.error_synchronization), message)
+    }
+
+    @Test
+    fun otherFailureReasonsKeepTheirMessage() {
+        val message = SyncErrorMessage.of(context, noteSyncException(GROCERIES, HTTP_INSUFFICIENT_STORAGE))
+
+        assertEquals(context.getString(R.string.error_sync_insufficient_storage), message)
+    }
+
+    private fun noteSyncException(title: String, statusCode: Int) =
+        NoteSyncException(title, Response.error<Any>(statusCode, "".toResponseBody()))
+
+    companion object {
+        private const val GROCERIES = "Groceries"
+        private const val INVOICES = "Invoices"
+        private const val HTTP_LOCKED = 423
+        private const val HTTP_INSUFFICIENT_STORAGE = 507
+    }
+}