Restore elements between tabs

app/src/main/java/app/fedilab/android/BaseMainActivity.java

@@ -122,6 +122,7 @@ public abstract class BaseMainActivity extends BaseActivity implements NetworkSt
     private ActivityMainBinding binding;
     private Pinned pinned;
 
+
     private final BroadcastReceiver broadcast_data = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {

app/src/main/java/app/fedilab/android/client/entities/app/SavedValues.java

@@ -0,0 +1,76 @@
+package app.fedilab.android.client.entities.app;
+/* Copyright 2022 Thomas Schneider
+ *
+ * This file is a part of Fedilab
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Fedilab is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Fedilab; if not,
+ * see <http://www.gnu.org/licenses>. */
+
+import java.util.HashMap;
+import java.util.List;
+
+import app.fedilab.android.client.entities.Timeline;
+import app.fedilab.android.client.mastodon.entities.Status;
+
+public class SavedValues {
+
+    public static HashMap<String, SavedValues> storedStates = new HashMap<>();
+    public int position;
+    public List<Status> statusList;
+
+    /**
+     * Retrieves saved values
+     *
+     * @param timeLineType - Timeline.TimeLineEnum
+     * @param ident        - the name for pinned timeline
+     * @return SavedValues
+     */
+    public static SavedValues getSavedValue(Timeline.TimeLineEnum timeLineType, String ident) {
+        if (!canBestored(timeLineType)) {
+            return null;
+        }
+        String key = timeLineType.getValue();
+        if (ident != null) {
+            key += "|" + ident;
+        }
+        return storedStates.get(key);
+    }
+
+    /**
+     * Check if the current timeline can be stored
+     *
+     * @param timeLineType - Timeline.TimeLineEnum
+     * @return boolean
+     */
+    private static boolean canBestored(Timeline.TimeLineEnum timeLineType) {
+        return timeLineType == Timeline.TimeLineEnum.HOME || timeLineType == Timeline.TimeLineEnum.LOCAL || timeLineType == Timeline.TimeLineEnum.PUBLIC || timeLineType == Timeline.TimeLineEnum.REMOTE || timeLineType == Timeline.TimeLineEnum.LIST || timeLineType == Timeline.TimeLineEnum.TAG;
+    }
+
+    /**
+     * @param position     - current position in timeline
+     * @param timeLineType - Timeline.TimeLineEnum
+     * @param statusList   - List<Status> to save
+     * @param ident        - the name for pinned timeline
+     */
+    public static void storeTimeline(int position, Timeline.TimeLineEnum timeLineType, List<Status> statusList, String ident) {
+        if (!canBestored(timeLineType)) {
+            return;
+        }
+        String key = timeLineType.getValue();
+        if (ident != null) {
+            key += "|" + ident;
+        }
+        SavedValues savedValues = new SavedValues();
+        savedValues.position = position;
+        savedValues.statusList = statusList;
+        storedStates.put(key, savedValues);
+    }
+}

app/src/main/java/app/fedilab/android/ui/fragment/timeline/FragmentMastodonTimeline.java

@@ -42,6 +42,7 @@ import java.util.List;
 import app.fedilab.android.BaseMainActivity;
 import app.fedilab.android.R;
 import app.fedilab.android.client.entities.Timeline;
+import app.fedilab.android.client.entities.app.SavedValues;
 import app.fedilab.android.client.entities.app.TagTimeline;
 import app.fedilab.android.client.mastodon.entities.Account;
 import app.fedilab.android.client.mastodon.entities.Marker;
@@ -78,6 +79,8 @@ public class FragmentMastodonTimeline extends Fragment {
     private Account accountTimeline;
     private boolean exclude_replies, exclude_reblogs, show_pinned, media_only, minified;
     private String viewModelKey, remoteInstance;
+    private String ident;
+
 
     //Handle actions that can be done in other fragments
     private final BroadcastReceiver receive_action = new BroadcastReceiver() {
@@ -161,6 +164,15 @@ public class FragmentMastodonTimeline extends Fragment {
             minified = getArguments().getBoolean(Helper.ARG_MINIFIED, false);
             statusReport = (Status) getArguments().getSerializable(Helper.ARG_STATUS_REPORT);
         }
+        if (tagTimeline != null) {
+            ident = tagTimeline.name;
+        } else if (list_id != null) {
+            ident = list_id;
+        } else if (remoteInstance != null) {
+            ident = remoteInstance;
+        } else {
+            ident = null;
+        }
         LocalBroadcastManager.getInstance(requireActivity()).registerReceiver(receive_action, new IntentFilter(Helper.RECEIVE_STATUS_ACTION));
         binding = FragmentPaginationBinding.inflate(inflater, container, false);
         binding.getRoot().setBackgroundColor(ThemeHelper.getBackgroundColor(requireActivity()));
@@ -340,6 +352,11 @@ public class FragmentMastodonTimeline extends Fragment {
     @Override
     public void onDestroyView() {
         super.onDestroyView();
+
+        if (mLayoutManager != null) {
+            int position = mLayoutManager.findFirstVisibleItemPosition();
+            new Thread(() -> SavedValues.storeTimeline(position, timelineType, statuses, ident)).start();
+        }
         //Update last read id for home timeline
         storeMarker();
         if (binding != null) {
@@ -384,6 +401,26 @@ public class FragmentMastodonTimeline extends Fragment {
      * @param direction - DIRECTION null if first call, then is set to TOP or BOTTOM depending of scroll
      */
     private void route(DIRECTION direction) {
+
+        new Thread(() -> {
+            SavedValues savedValues = SavedValues.getSavedValue(timelineType, ident);
+            if (savedValues != null && savedValues.statusList != null && savedValues.statusList.size() > 0) {
+                Statuses statuses = new Statuses();
+                statuses.statuses = savedValues.statusList;
+                statuses.pagination = new Pagination();
+                statuses.pagination.max_id = savedValues.statusList.get(savedValues.statusList.size() - 1).id;
+                statuses.pagination.min_id = savedValues.statusList.get(0).id;
+                try {
+                    Thread.sleep(200);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+                Handler mainHandler = new Handler(Looper.getMainLooper());
+                Runnable myRunnable = () -> initializeStatusesCommonView(statuses);
+                mainHandler.post(myRunnable);
+            } else {
+                Handler mainHandler = new Handler(Looper.getMainLooper());
+                Runnable myRunnable = () -> {
                     // --- HOME TIMELINE ---
                     if (timelineType == Timeline.TimeLineEnum.HOME) {
                         //for more visibility it's done through loadHomeStrategy method
@@ -508,6 +545,12 @@ public class FragmentMastodonTimeline extends Fragment {
                             flagLoading = false;
                         }
                     }
+                };
+                mainHandler.post(myRunnable);
+            }
+
+        }).start();
+
     }
 
     /**