alperozturk96 · Sep 28, 2026 · Sep 28, 2026 · Sep 28, 2026 · Sep 28, 2026 · Oct 5, 2026
diff --git a/app/src/main/java/com/nextcloud/utils/extensions/OCFileExtensions.kt b/app/src/main/java/com/nextcloud/utils/extensions/OCFileExtensions.kt
@@ -19,7 +19,6 @@ import com.owncloud.android.datamodel.OCFileDepth.Root
 import com.owncloud.android.ui.events.EncryptionEvent
 import com.owncloud.android.utils.FileStorageUtils
 import java.util.Calendar
-import java.util.Date
 
 fun List<OCFile>.filterFilenames(): List<OCFile> = distinctBy { it.fileName }
 
@@ -85,6 +84,19 @@ private fun transformToRows(list: List<OCFile>, layout: GalleryRowLayout): List<
         .map { chunk -> GalleryRow(chunk, layout.measure(chunk)) }
 }
 
+fun OCFile?.isDownloadedFileChanged(serverFile: OCFile): Boolean {
+    if (this == null || !isDown || serverFile.isFolder) {
+        return false
+    }
+
+    return etag.eTagChanged(serverFile.etag)
+}
+
+fun OCFile.isLocalETagOutdated(): Boolean {
+    val serverETag = etagInConflict
+    return !serverETag.isNullOrEmpty() && etag.eTagChanged(serverETag)
+}
+
 fun OCFile.toEncryptionEvent(encrypt: Boolean): EncryptionEvent = EncryptionEvent(
     localId,
     remoteId,

diff --git a/app/src/main/java/com/owncloud/android/operations/FolderRefreshScheduler.kt b/app/src/main/java/com/owncloud/android/operations/FolderRefreshScheduler.kt
@@ -20,11 +20,11 @@ import kotlinx.coroutines.delay
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
-import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.Duration.Companion.seconds
 
 class FolderRefreshScheduler(private val activity: FileDisplayActivity) {
     companion object {
-        private const val ETAG_POLL_INTERVAL_MS = 30_000L
+        private val ETAG_POLL_INTERVAL = 10.seconds
         private const val TAG = "FolderRefreshScheduler"
     }
 
@@ -35,12 +35,12 @@ class FolderRefreshScheduler(private val activity: FileDisplayActivity) {
 
         job = activity.lifecycleScope.launch {
             while (isActive) {
-                delay(ETAG_POLL_INTERVAL_MS.milliseconds)
+                delay(ETAG_POLL_INTERVAL)
                 checkAndRefreshIfETagChanged()
             }
         }
 
-        Log_OC.d(TAG, "eTag polling started interval 30 seconds")
+        Log_OC.d(TAG, "eTag polling started interval $ETAG_POLL_INTERVAL")
     }
 
     fun stop() {

diff --git a/app/src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java b/app/src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java
@@ -19,6 +19,7 @@
 import com.nextcloud.utils.ResultParser;
 import com.nextcloud.utils.e2ee.E2EVersionHelper;
 import com.nextcloud.utils.share.UnifiedShareSharees;
+import com.nextcloud.utils.extensions.OCFileExtensionsKt;
 import com.nextcloud.utils.extensions.StringExtensionsKt;
 import com.owncloud.android.datamodel.ArbitraryDataProvider;
 import com.owncloud.android.datamodel.ArbitraryDataProviderImpl;
@@ -55,6 +56,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Vector;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -113,12 +115,12 @@ public class RefreshFolderOperation extends RemoteOperation {
     /**
      * Counter of conflicts found between local and remote files
      */
-    private int mConflictsFound;
+    private final AtomicInteger mConflictsFound = new AtomicInteger();
 
     /**
      * Counter of failed operations in synchronization of kept-in-sync files
      */
-    private int mFailsInKeptInSyncFound;
+    private final AtomicInteger mFailsInKeptInSyncFound = new AtomicInteger();
 
     /**
      * Map of remote and local paths to files that where locally stored in a location out of the ownCloud folder and
@@ -134,7 +136,7 @@ public class RefreshFolderOperation extends RemoteOperation {
     /**
      * 'True' means that the remote folder changed and should be fetched
      */
-    private boolean mRemoteFolderChanged;
+    private volatile boolean mRemoteFolderChanged;
 
     /**
      * 'True' means that the sharees of at least one child of the folder changed
@@ -154,6 +156,8 @@ public class RefreshFolderOperation extends RemoteOperation {
     private final List<SynchronizeFileOperation> mFilesToSyncContents;
     // this will be used for every file when 'folder synchronization' replaces 'folder download'
 
+    private final boolean syncChangedDownloadedFiles;
+
 
     /**
      * Creates a new instance of {@link RefreshFolderOperation}.
@@ -174,6 +178,17 @@ public RefreshFolderOperation(OCFile folder,
                                   FileDataStorageManager dataStorageManager,
                                   User user,
                                   Context context) {
+        this(folder, currentSyncTime, syncFullAccount, ignoreETag, dataStorageManager, user, context, false);
+    }
+
+    public RefreshFolderOperation(OCFile folder,
+                                  long currentSyncTime,
+                                  boolean syncFullAccount,
+                                  boolean ignoreETag,
+                                  FileDataStorageManager dataStorageManager,
+                                  User user,
+                                  Context context,
+                                  boolean syncChangedDownloadedFiles) {
         mLocalFolder = folder;
         mCurrentSyncTime = currentSyncTime;
         mSyncFullAccount = syncFullAccount;
@@ -185,6 +200,7 @@ public RefreshFolderOperation(OCFile folder,
         mIgnoreETag = ignoreETag;
         mOnlyFileMetadata = false;
         mFilesToSyncContents = new Vector<>();
+        this.syncChangedDownloadedFiles = syncChangedDownloadedFiles;
     }
 
     /**
@@ -205,6 +221,7 @@ public RefreshFolderOperation(OCFile folder,
         mIgnoreETag = false;
         mOnlyFileMetadata = true;
         mFilesToSyncContents = new Vector<>();
+        syncChangedDownloadedFiles = false;
 
         // since metadata worker working in background for sub-folders no need send folder refresh event
         isMetadataSyncWorkerRunning = true;
@@ -229,14 +246,15 @@ public RefreshFolderOperation(OCFile folder,
         mIgnoreETag = ignoreETag;
         mOnlyFileMetadata = onlyFileMetadata;
         mFilesToSyncContents = new Vector<>();
+        syncChangedDownloadedFiles = false;
     }
 
     public int getConflictsFound() {
-        return mConflictsFound;
+        return mConflictsFound.get();
     }
 
     public int getFailsInKeptInSyncFound() {
-        return mFailsInKeptInSyncFound;
+        return mFailsInKeptInSyncFound.get();
     }
 
     public Map<String, String> getForgottenLocalFiles() {
@@ -261,8 +279,8 @@ public List<OCFile> getChildren() {
     @Override
     protected RemoteOperationResult run(OwnCloudClient client) {
         RemoteOperationResult result;
-        mFailsInKeptInSyncFound = 0;
-        mConflictsFound = 0;
+        mFailsInKeptInSyncFound.set(0);
+        mConflictsFound.set(0);
         mForgottenLocalFiles.clear();
 
         if (mLocalFolder == null) {
@@ -470,7 +488,7 @@ private RemoteOperationResult fetchAndSyncRemoteFolder(OwnCloudClient client) {
 
         if (result.isSuccess()) {
             synchronizeData(result.getData());
-            if (mConflictsFound > 0 || mFailsInKeptInSyncFound > 0) {
+            if (mConflictsFound.get() > 0 || mFailsInKeptInSyncFound.get() > 0) {
                 result = new RemoteOperationResult(ResultCode.SYNC_CONFLICT);
                 // should be a different result code, but will do the job
             }
@@ -619,6 +637,12 @@ private void synchronizeData(List<Object> folderAndFiles) {
             updatedFile.setEncrypted(encrypted);
             updatedFile.setReadOnly(localFile != null && localFile.isReadOnly());
 
+            if (syncChangedDownloadedFiles && !encrypted &&
+                OCFileExtensionsKt.isDownloadedFileChanged(localFile, remoteFile)) {
+                mFilesToSyncContents.add(new SynchronizeFileOperation(updatedFile, remoteFile, user, true, mContext,
+                                                                      fileDataStorageManager, true));
+            }
+
             updatedFiles.add(updatedFile);
         }
 
@@ -817,26 +841,37 @@ public static Map<String, OCFile> prefillLocalFilesMap(Object metadata, List<OCF
      * @param filesToSyncContents Synchronization operations to execute.
      */
     private void startContentSynchronizations(List<SynchronizeFileOperation> filesToSyncContents) {
-        RemoteOperationResult contentsResult;
-        for (SynchronizeFileOperation op : filesToSyncContents) {
-            contentsResult = op.execute(mContext);   // async
-            if (!contentsResult.isSuccess()) {
-                if (contentsResult.getCode() == ResultCode.SYNC_CONFLICT) {
-                    mConflictsFound++;
-                } else {
-                    mFailsInKeptInSyncFound++;
-                    if (contentsResult.getException() != null) {
-                        Log_OC.e(TAG, "Error while synchronizing favourites : "
-                            + contentsResult.getLogMessage(), contentsResult.getException());
-                    } else {
-                        Log_OC.e(TAG, "Error while synchronizing favourites : "
-                            + contentsResult.getLogMessage());
-                    }
-                }
-            }   // won't let these fails break the synchronization process
+        // won't let these fails break the synchronization process
+        for (SynchronizeFileOperation operation : filesToSyncContents) {
+            final RemoteOperationResult<?> result = operation.execute(mContext);
+            if (result.isSuccess()) {
+                operation.printSuccess();
+                continue;
+            }
+
+            if (result.getCode() == ResultCode.SYNC_CONFLICT) {
+                operation.printConflict();
+                mConflictsFound.incrementAndGet();
+                continue;
+            }
+
+            operation.printFailure();
+            mFailsInKeptInSyncFound.incrementAndGet();
+            logContentSynchronizationFailure(result);
         }
     }
 
+    private void logContentSynchronizationFailure(RemoteOperationResult<?> result) {
+        final String message = "Error while synchronizing favourites : " + result.getLogMessage(mContext);
+        final Exception exception = result.getException();
+        if (exception == null) {
+            Log_OC.e(TAG, message);
+            return;
+        }
+
+        Log_OC.e(TAG, message, exception);
+    }
+
     /**
      * Sends a message to any application component interested in the progress of the synchronization.
      *

diff --git a/app/src/main/java/com/owncloud/android/operations/SynchronizeFileOperation.kt b/app/src/main/java/com/owncloud/android/operations/SynchronizeFileOperation.kt
@@ -257,6 +257,18 @@ class SynchronizeFileOperation : SyncOperation {
         }
     }
 
+    fun printSuccess() {
+        Log_OC.i(TAG, "content synchronized, remote path: $remotePath")
+    }
+
+    fun printConflict() {
+        Log_OC.w(TAG, "content has conflict, remote path: $remotePath")
+    }
+
+    fun printFailure() {
+        Log_OC.e(TAG, "content not synchronized, remote path: $remotePath")
+    }
+
     companion object {
         private val TAG: String = SynchronizeFileOperation::class.java.simpleName
     }

diff --git a/app/src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.kt b/app/src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.kt
@@ -2014,7 +2014,7 @@ class FileDisplayActivity :
     override fun onBrowsedDownTo(directory: OCFile?) {
         file = directory
         resetScrollingAndUpdateActionBar()
-        startSyncFolderOperation(directory, false)
+        startSyncFolderOperation(directory, ignoreETag = false, syncChangedDownloadedFiles = true)
         startMetadataSyncForCurrentDir()
     }
 
@@ -2090,6 +2090,10 @@ class FileDisplayActivity :
     fun canPreviewInMediaPager(file: OCFile?): Boolean =
         PreviewImageFragment.canBePreviewed(file) || (file != null && MimeTypeUtil.isVideo(file))
 
+    /**
+     * Downloaded and non-downloaded images are handled later in
+     * [com.owncloud.android.ui.preview.PreviewMediaPagerAdapter.fragmentFor]
+     */
     fun previewImageWithSearchContext(
         file: OCFile,
         searchFragment: Boolean,
@@ -2112,8 +2116,7 @@ class FileDisplayActivity :
             null
         }
 
-        val showPreview = file.isDown || MimeTypeUtil.isVideo(file)
-        startImagePreview(file, showPreview, type, mediaState, sourceView)
+        startImagePreview(file, true, type, mediaState, sourceView)
     }
 
     fun previewFile(file: OCFile, setFabVisible: CompletionCallback?) {
@@ -2128,10 +2131,14 @@ class FileDisplayActivity :
             startPdfPreview(file)
         } else if (PreviewTextFileFragment.canBePreviewed(file)) {
             setFabVisible?.onComplete(false)
-            startTextPreview(file, false)
+            fileOperationsHelper.startSyncForOutdatedFileAndIntent(file, textPreviewIntent(file))
         } else if (canPreviewInAudioPlayer(file)) {
             setFabVisible?.onComplete(false)
-            startAudioPreview(file, true, false)
+            if (file.isDownloading) {
+                fileOperationsHelper.startSyncForOutdatedFileAndIntent(file, audioPreviewIntent(file))
+            } else {
+                startAudioPlayer(file)
+            }
         } else {
             fileOperationsHelper.openFile(file)
         }
@@ -2598,14 +2605,19 @@ class FileDisplayActivity :
      * @param ignoreFocus reloads file list even without focus, e.g. on tablet mode, focus can still be in detail view
      */
     @JvmOverloads
-    fun startSyncFolderOperation(folder: OCFile?, ignoreETag: Boolean, ignoreFocus: Boolean = false) {
+    fun startSyncFolderOperation(
+        folder: OCFile?,
+        ignoreETag: Boolean,
+        ignoreFocus: Boolean = false,
+        syncChangedDownloadedFiles: Boolean = false
+    ) {
         Log_OC.d(TAG, "startSyncFolderOperation called, ignoreEtag: $ignoreETag, ignoreFocus: $ignoreFocus")
 
         if (!searchQuery.isNullOrEmpty() || !user.isPresent) {
             return
         }
 
-        val syncFolder = Runnable { executeSyncFolderOperation(folder, ignoreETag) }
+        val syncFolder = Runnable { executeSyncFolderOperation(folder, ignoreETag, syncChangedDownloadedFiles) }
 
         // The refresh must not run while another window floats over the activity, e.g. a dialog that is being
         // dismissed or a rotation. Rather than waiting a fixed delay run right away when it already has focus
@@ -2631,7 +2643,7 @@ class FileDisplayActivity :
         }
     }
 
-    private fun executeSyncFolderOperation(folder: OCFile?, ignoreETag: Boolean) {
+    private fun executeSyncFolderOperation(folder: OCFile?, ignoreETag: Boolean, syncChangedDownloadedFiles: Boolean) {
         val folder = folder ?: return
 
         user.ifPresent { user ->
@@ -2644,7 +2656,8 @@ class FileDisplayActivity :
                 ignoreETag,
                 storageManager,
                 user,
-                applicationContext
+                applicationContext,
+                syncChangedDownloadedFiles
             ).execute(
                 account,
                 this,
@@ -2773,15 +2786,17 @@ class FileDisplayActivity :
         if ((showPreview && file.isDown && !file.isDownloading) || streamMedia) {
             startAudioPlayer(file)
         } else {
-            val previewIntent = Intent()
-            previewIntent.putExtra(EXTRA_FILE, file)
-            previewIntent.putExtra(AUDIO_PREVIEW, true)
             val fileOperationsHelper =
                 FileOperationsHelper(this, userAccountManager, connectivityService, editorUtils)
-            fileOperationsHelper.startSyncForFileAndIntent(file, previewIntent)
+            fileOperationsHelper.startSyncForFileAndIntent(file, audioPreviewIntent(file))
         }
     }
 
+    private fun audioPreviewIntent(file: OCFile): Intent = Intent().apply {
+        putExtra(EXTRA_FILE, file)
+        putExtra(AUDIO_PREVIEW, true)
+    }
+
     private fun startAudioPlayer(file: OCFile) {
         val collection = listOfFilesFragment?.currentSearchType.toPlaybackCollection()
         audioPlayerLauncher.launch(this, file, collection)
@@ -2810,15 +2825,17 @@ class FileDisplayActivity :
             configureToolbarForPreview(file)
             showBottomNavigationBar(false)
         } else {
-            val previewIntent = Intent()
-            previewIntent.putExtra(EXTRA_FILE, file)
-            previewIntent.putExtra(TEXT_PREVIEW, true)
             val fileOperationsHelper =
                 FileOperationsHelper(this, userAccountManager, connectivityService, editorUtils)
-            fileOperationsHelper.startSyncForFileAndIntent(file, previewIntent)
+            fileOperationsHelper.startSyncForFileAndIntent(file, textPreviewIntent(file))
         }
     }
 
+    private fun textPreviewIntent(file: OCFile?): Intent = Intent().apply {
+        putExtra(EXTRA_FILE, file)
+        putExtra(TEXT_PREVIEW, true)
+    }
+
     /**
      * Starts rich workspace preview for a folder.
      *