update notify on dataset change

app/src/main/java/org/schabi/newpipe/fragments/detail/TabAdaptor.java

@@ -44,27 +44,20 @@ public class TabAdaptor extends FragmentPagerAdapter {
     public void addFragment(Fragment fragment, String title) {
         mFragmentList.add(fragment);
         mFragmentTitleList.add(title);
-        notifyDataSetChanged();
     }
 
     public void clearAllItems() {
         mFragmentList.clear();
         mFragmentTitleList.clear();
-        notifyDataSetChanged();
     }
 
     public void removeItem(int position){
         mFragmentList.remove(position == 0 ? 0 : position - 1);
         mFragmentTitleList.remove(position == 0 ? 0 : position - 1);
-        notifyDataSetChanged();
     }
 
     public void updateItem(int position, Fragment fragment){
         mFragmentList.set(position, fragment);
-        // shift the ID returned by getItemId outside the range of all previous fragments
-        // https://stackoverflow.com/questions/10396321/remove-fragment-page-from-viewpager-in-android
-        baseId += getCount() + 1;
-        notifyDataSetChanged();
     }
 
     public void updateItem(String title, Fragment fragment){
@@ -79,4 +72,20 @@ public class TabAdaptor extends FragmentPagerAdapter {
         if (mFragmentList.contains(object)) return mFragmentList.indexOf(object);
         else return POSITION_NONE;
     }
+
+    /**
+     * Notify that the position of a fragment has been changed.
+     * Create a new ID for each position to force recreation of the fragment
+     * @param n number of items which have been changed
+     */
+    public void notifyChangeInPosition(int n) {
+        // shift the ID returned by getItemId outside the range of all previous fragments
+        // https://stackoverflow.com/questions/10396321/remove-fragment-page-from-viewpager-in-android
+        baseId += getCount() + n;
+    }
+
+    public void notifyDataSetUpdate(){
+        notifyChangeInPosition(1);
+        notifyDataSetChanged();
+    }
 }

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -819,6 +819,8 @@ public class VideoDetailFragment
             pageAdapter.addFragment(new Fragment(), RELATED_TAB_TAG);
         }
 
+        pageAdapter.notifyDataSetUpdate();
+
         if(pageAdapter.getCount() < 2){
             tabLayout.setVisibility(View.GONE);
         }else{
@@ -1083,6 +1085,7 @@ public class VideoDetailFragment
 
         if(showRelatedStreams){
             pageAdapter.updateItem(RELATED_TAB_TAG, RelatedVideosFragment.getInstance(currentInfo));
+            pageAdapter.notifyDataSetUpdate();
         }
 
         pushToStack(serviceId, url, name);