fix(file-list): scroll position

app/src/androidTest/java/com/owncloud/android/ui/fragment/OCFileListFragmentStaticServerIT.kt

@@ -398,13 +398,27 @@ class OCFileListFragmentStaticServerIT : AbstractIT() {
 
             testFolder.richWorkspace = " "
             activity.storageManager.saveFile(testFolder)
-            sut.adapter.swapDirectory(user, testFolder, activity.storageManager, false, "")
+            sut.adapter.swapDirectory(
+                user,
+                testFolder,
+                activity.storageManager,
+                false,
+                ""
+            ) {
+            }
 
             Assert.assertFalse(sut.adapter.shouldShowHeader())
 
             testFolder.richWorkspace = null
             activity.storageManager.saveFile(testFolder)
-            sut.adapter.swapDirectory(user, testFolder, activity.storageManager, false, "")
+            sut.adapter.swapDirectory(
+                user,
+                testFolder,
+                activity.storageManager,
+                false,
+                ""
+            ) {
+            }
             Assert.assertFalse(sut.adapter.shouldShowHeader())
 
             EspressoIdlingResource.increment()

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

@@ -1591,7 +1591,11 @@ class FileDisplayActivity :
             return
         }
 
-        ocFileListFragment.listDirectory(currentDir, MainApp.isOnlyOnDevice())
+        ocFileListFragment.listDirectory(currentDir, MainApp.isOnlyOnDevice()) {
+            if (ocFileListFragment.isBrowseUp) {
+                ocFileListFragment.restoreIndexAndTopPosition()
+            }
+        }
     }
 
     private fun handleScrollBehaviour(ocFileListFragment: OCFileListFragment?) {

app/src/main/java/com/owncloud/android/ui/adapter/CommonOCFileListAdapterInterface.kt

@@ -22,7 +22,8 @@ interface CommonOCFileListAdapterInterface {
         directory: OCFile,
         storageManager: FileDataStorageManager,
         onlyOnDevice: Boolean,
-        mLimitToMimeType: String
+        mLimitToMimeType: String,
+        onComplete: () -> Unit
     )
 
     fun setHighlightedItem(file: OCFile)

app/src/main/java/com/owncloud/android/ui/adapter/GalleryAdapter.kt

@@ -387,7 +387,8 @@ class GalleryAdapter(
         directory: OCFile,
         storageManager: FileDataStorageManager,
         onlyOnDevice: Boolean,
-        mLimitToMimeType: String
+        mLimitToMimeType: String,
+        onComplete: () -> Unit
     ) = Unit
 
     override fun setHighlightedItem(file: OCFile) = Unit

app/src/main/java/com/owncloud/android/ui/adapter/OCFileListAdapter.java

@@ -87,6 +87,7 @@
 import androidx.recyclerview.widget.RecyclerView;
 import kotlin.Pair;
 import kotlin.Unit;
+import kotlin.jvm.functions.Function0;
 import me.zhanghai.android.fastscroll.PopupTextProvider;
 
 /**
@@ -832,7 +833,8 @@ public void swapDirectory(
         @NonNull OCFile directory,
         @NonNull FileDataStorageManager updatedStorageManager,
         boolean onlyOnDevice,
-        @NonNull String limitToMimeType) {
+        @NonNull String limitToMimeType,
+        @NonNull Function0<Unit> onComplete) {
 
         this.onlyOnDevice = onlyOnDevice;
 
@@ -861,6 +863,7 @@ public void swapDirectory(
                                (newList, fileSortOrder) ->
         {
             updateAdapter((List<OCFile>) newList, directory);
+            onComplete.invoke();
             return Unit.INSTANCE;
         });
     }

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

@@ -415,10 +415,6 @@ open class ExtendedListFragment :
         if (savedInstanceState.getBoolean(KEY_IS_GRID_VISIBLE, false) && recyclerView?.adapter != null) {
             switchToGridView()
         }
-
-        val referencePosition = savedInstanceState.getInt(KEY_SAVED_LIST_POSITION)
-        Log_OC.v(TAG, "Setting grid position $referencePosition")
-        scrollToPosition(referencePosition)
     }
 
     override fun onSaveInstanceState(savedInstanceState: Bundle) {
@@ -445,16 +441,12 @@ open class ExtendedListFragment :
             return mScale.roundToInt()
         }
 
-    /*
-     * Restore index and position
-     */
-    protected fun restoreIndexAndTopPosition() {
+    fun restoreIndexAndTopPosition() {
         if (mIndexes.isEmpty()) {
             Log_OC.d(TAG, "Indexes is null or empty")
             return
         }
 
-        // needs to be checked; not every browse-up had a browse-down before
         val index = mIndexes.removeAt(mIndexes.size - 1)
         val firstPosition = mFirstPositions.removeAt(mFirstPositions.size - 1)
         val top = mTops.removeAt(mTops.size - 1)
@@ -467,30 +459,41 @@ open class ExtendedListFragment :
                 )
         )
 
-        firstPosition?.let { scrollToPosition(it) }
+        if (firstPosition != null && firstPosition >= 0) {
+            mainThread(delay = 0L) {
+                scrollToPosition(firstPosition, top ?: 0)
+            }
+        }
     }
 
-    private fun scrollToPosition(position: Int) {
+    private fun scrollToPosition(position: Int, top: Int = 0) {
         val layoutManager = mRecyclerView?.layoutManager
 
-        if (layoutManager is LinearLayoutManager) {
-            val visibleItemCount = layoutManager.findLastCompletelyVisibleItemPosition() -
-                layoutManager.findFirstCompletelyVisibleItemPosition()
-            layoutManager.scrollToPositionWithOffset(position, (visibleItemCount / 2) * mHeightCell)
+        if (position < 0) {
+            return
+        }
+
+        when (layoutManager) {
+            is GridLayoutManager -> {
+                layoutManager.scrollToPositionWithOffset(position, top)
+            }
+
+            is LinearLayoutManager -> {
+                val visibleItemCount = layoutManager.findLastCompletelyVisibleItemPosition() -
+                    layoutManager.findFirstCompletelyVisibleItemPosition()
+                val offsetTop = if (top != 0) top else (visibleItemCount / 2) * mHeightCell
+                layoutManager.scrollToPositionWithOffset(position, offsetTop)
+            }
         }
     }
 
-    /*
-     * Save index and top position
-     */
     protected fun saveIndexAndTopPosition(index: Int) {
         mIndexes.add(index)
 
-        val layoutManager = mRecyclerView?.layoutManager
-        val firstPosition: Int = if (layoutManager is GridLayoutManager) {
-            layoutManager.findFirstCompletelyVisibleItemPosition()
-        } else {
-            (layoutManager as LinearLayoutManager).findFirstCompletelyVisibleItemPosition()
+        val firstPosition: Int = when (val layoutManager = mRecyclerView?.layoutManager) {
+            is GridLayoutManager -> layoutManager.findFirstCompletelyVisibleItemPosition()
+            is LinearLayoutManager -> layoutManager.findFirstCompletelyVisibleItemPosition()
+            else -> RecyclerView.NO_POSITION
         }
 
         mFirstPositions.add(firstPosition)
@@ -504,9 +507,7 @@ open class ExtendedListFragment :
         mHeightCell = if (view == null || mHeightCell != 0) mHeightCell else view.height
     }
 
-    override fun onItemClick(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
-        // to be @overridden
-    }
+    override fun onItemClick(parent: AdapterView<*>?, view: View?, position: Int, id: Long) = Unit
 
     override fun onRefresh() {
         if (searchView != null) {
@@ -803,8 +804,6 @@ open class ExtendedListFragment :
     companion object {
         protected val TAG: String = ExtendedListFragment::class.java.getSimpleName()
 
-        protected const val KEY_SAVED_LIST_POSITION: String = "SAVED_LIST_POSITION"
-
         private const val KEY_INDEXES = "INDEXES"
         private const val KEY_FIRST_POSITIONS = "FIRST_POSITIONS"
         private const val KEY_TOPS = "TOPS"

app/src/main/java/com/owncloud/android/ui/fragment/OCFileListFragment.java

@@ -80,7 +80,6 @@
 import com.owncloud.android.lib.resources.e2ee.ToggleEncryptionRemoteOperation;
 import com.owncloud.android.lib.resources.files.SearchRemoteOperation;
 import com.owncloud.android.lib.resources.files.ToggleFavoriteRemoteOperation;
-import com.owncloud.android.lib.resources.files.model.RemoteFile;
 import com.owncloud.android.lib.resources.status.E2EVersion;
 import com.owncloud.android.lib.resources.status.OCCapability;
 import com.owncloud.android.lib.resources.status.Type;
@@ -148,6 +147,7 @@
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 import kotlin.Unit;
+import kotlin.jvm.functions.Function0;
 
 import static com.owncloud.android.datamodel.OCFile.ROOT_PATH;
 import static com.owncloud.android.ui.dialog.setupEncryption.SetupEncryptionDialogFragment.SETUP_ENCRYPTION_DIALOG_TAG;
@@ -228,6 +228,7 @@ public class OCFileListFragment extends ExtendedListFragment implements
     protected String mLimitToMimeType;
     private FloatingActionButton mFabMain;
     public static boolean isMultipleFileSelectedForCopyOrMove = false;
+    private static boolean isBrowseUp = false;
 
     private static final Intent scanIntentExternalApp = new Intent("org.fairscan.app.action.SCAN_TO_PDF");
 
@@ -246,6 +247,10 @@ protected enum MenuItemAddRemove {
 
     private static OCFileDepth fileDepth = OCFileDepth.Root;
 
+    public boolean isBrowseUp() {
+        return isBrowseUp;
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -1042,6 +1047,7 @@ public int onBrowseUp() {
             searchFragment = true;
         }
 
+        isBrowseUp = true;
         updateFileList();
         return result.first;
     }
@@ -1088,9 +1094,11 @@ private String ensureTrailingSeparator(String path) {
     }
 
     private void updateFileList() {
-        listDirectory(mFile, MainApp.isOnlyOnDevice());
-        onRefresh(false);
-        restoreIndexAndTopPosition();
+        listDirectory(mFile, MainApp.isOnlyOnDevice(), () -> {
+            Log_OC.d(TAG, "list directory completed");
+            onRefresh(false);
+            return Unit.INSTANCE;
+        });
     }
 
     /**
@@ -1306,6 +1314,9 @@ private void browseToFolder(OCFile file, int position) {
         listDirectory(file, MainApp.isOnlyOnDevice());
         // then, notify parent activity to let it update its state and view
         mContainerActivity.onBrowsedDownTo(file);
+
+        isBrowseUp = false;
+
         // save index and top position
         saveIndexAndTopPosition(position);
     }
@@ -1551,7 +1562,15 @@ public void refreshDirectory() {
     }
 
     public void listDirectory(@Nullable OCFile directory, boolean onlyOnDevice) {
-        listDirectory(directory, null, onlyOnDevice);
+        listDirectory(directory, null, onlyOnDevice, () -> Unit.INSTANCE);
+    }
+
+    public void listDirectory(@Nullable OCFile directory, OCFile file, boolean onlyOnDevice) {
+        listDirectory(directory, file, onlyOnDevice, () -> Unit.INSTANCE);
+    }
+
+    public void listDirectory(@Nullable OCFile directory, boolean onlyOnDevice, @NonNull Function0<Unit> onComplete) {
+        listDirectory(directory, null, onlyOnDevice, onComplete);
     }
 
     private OCFile getDirectoryForListDirectory(@Nullable OCFile directory, FileDataStorageManager storageManager) {
@@ -1578,7 +1597,10 @@ private OCFile getDirectoryForListDirectory(@Nullable OCFile directory, FileData
      *
      * @param directory File to be listed
      */
-    public void listDirectory(@Nullable OCFile directory, OCFile file, boolean onlyOnDevice) {
+    public void listDirectory(@Nullable OCFile directory,
+                              OCFile file,
+                              boolean onlyOnDevice,
+                              @NonNull Function0<Unit> onComplete) {
         if (!searchFragment) {
             FileDataStorageManager storageManager = mContainerActivity.getStorageManager();
             if (storageManager == null) {
@@ -1607,7 +1629,8 @@ public void listDirectory(@Nullable OCFile directory, OCFile file, boolean onlyO
                 directory,
                 storageManager,
                 onlyOnDevice,
-                mLimitToMimeType);
+                mLimitToMimeType,
+                onComplete);
 
             OCFile previousDirectory = mFile;
             mFile = directory;