Merge pull request #15996 from nextcloud/perf/gallery-adapter-full-refresh-after-delete

fix(gallery): prevent multiple onRefresh calls during multi-image delete to avoid flicker

Author: alperozturk96

app/src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.kt

@@ -117,6 +117,7 @@ import com.owncloud.android.ui.asynctasks.CheckAvailableSpaceTask
 import com.owncloud.android.ui.asynctasks.CheckAvailableSpaceTask.CheckAvailableSpaceListener
 import com.owncloud.android.ui.asynctasks.FetchRemoteFileTask
 import com.owncloud.android.ui.asynctasks.GetRemoteFileTask
+import com.owncloud.android.ui.dialog.DeleteBatchTracker
 import com.owncloud.android.ui.dialog.SendShareDialog
 import com.owncloud.android.ui.dialog.SendShareDialog.SendShareDialogDownloader
 import com.owncloud.android.ui.dialog.SortingOrderDialogFragment.OnSortingOrderListener
@@ -2083,13 +2084,22 @@ class FileDisplayActivity :
         }
     }
 
+    val deleteBatchTracker = DeleteBatchTracker(onAllDeletesFinished = {
+        if (leftFragment is GalleryFragment) {
+            val galleryFragment = leftFragment as GalleryFragment
+            galleryFragment.onRefresh()
+        }
+    })
+
     /**
      * Updates the view associated to the activity after the finish of an operation trying to remove a file.
      *
      * @param operation Removal operation performed.
      * @param result    Result of the removal.
      */
     private fun onRemoveFileOperationFinish(operation: RemoveFileOperation, result: RemoteOperationResult<*>) {
+        deleteBatchTracker.onSingleDeleteFinished()
+
         if (!operation.isInBackground) {
             DisplayUtils.showSnackMessage(
                 this,
@@ -2111,9 +2121,6 @@ class FileDisplayActivity :
             val parentFile = storageManager.getFileById(removedFile.parentId)
             if (parentFile != null && parentFile == getCurrentDir()) {
                 updateListOfFilesFragment(false)
-            } else if (this.leftFragment is GalleryFragment) {
-                val galleryFragment = leftFragment as GalleryFragment
-                galleryFragment.onRefresh()
             } else if (leftFragment is OCFileListFragment &&
                 SearchRemoteOperation.SearchType.FAVORITE_SEARCH == leftFragment.searchEvent?.searchType
             ) {
@@ -2127,7 +2134,6 @@ class FileDisplayActivity :
                 }
             }
             supportInvalidateOptionsMenu()
-            refreshGalleryFragmentIfNeeded()
             fetchRecommendedFilesIfNeeded(ignoreETag = true, currentDir)
         } else {
             if (result.isSslRecoverableException) {

app/src/main/java/com/owncloud/android/ui/dialog/DeleteBatchTracker.kt

@@ -0,0 +1,32 @@
+/*
+ * Nextcloud - Android Client
+ *
+ * SPDX-FileCopyrightText: 2025 Alper Ozturk <[email protected]>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package com.owncloud.android.ui.dialog
+
+class DeleteBatchTracker(private val onAllDeletesFinished: () -> Unit) {
+    private var expectedDeletes: Int = -1
+    private var completedDeletes: Int = 0
+
+    fun startBatchDelete(fileCount: Int) {
+        expectedDeletes = fileCount
+        completedDeletes = 0
+    }
+
+    fun onSingleDeleteFinished() {
+        if (expectedDeletes < 0) return // batch not active
+
+        completedDeletes++
+
+        if (completedDeletes == expectedDeletes) {
+            // Reset so it can handle the next batch
+            expectedDeletes = -1
+            completedDeletes = 0
+
+            onAllDeletesFinished()
+        }
+    }
+}

app/src/main/java/com/owncloud/android/ui/dialog/RemoveFilesDialogFragment.kt

@@ -100,6 +100,8 @@ class RemoveFilesDialogFragment :
             if (result) {
                 fileActivity.showLoadingDialog(fileActivity.getString(R.string.wait_a_moment))
 
+                fda?.deleteBatchTracker?.startBatchDelete(files.size)
+
                 if (files.isNotEmpty()) {
                     // Display the snackbar message only when a single file is deleted.
                     val inBackground = (files.size != 1)