Proper go top, refactoring

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -160,8 +160,9 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
     private boolean authentication;
     private boolean debug;
 
+    private boolean gotop = false;
+    private AsyncPagedListDiffer<TupleMessageEx> differ;
     private SelectionTracker<Long> selectionTracker = null;
-    private AsyncPagedListDiffer<TupleMessageEx> differ = new AsyncPagedListDiffer<>(this, DIFF_CALLBACK);
 
     enum ViewType {UNIFIED, FOLDER, THREAD, SEARCH}
 
@@ -3143,7 +3144,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
     }
 
     AdapterMessage(Context context, LifecycleOwner owner,
-                   ViewType viewType, boolean compact, int zoom, String sort, boolean filter_duplicates, IProperties properties) {
+                   ViewType viewType, boolean compact, int zoom, String sort, boolean filter_duplicates, final IProperties properties) {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
 
         this.TF = Helper.getTimeInstance(context, SimpleDateFormat.SHORT);
@@ -3189,9 +3190,21 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
         this.autoimages = (this.contacts && prefs.getBoolean("autoimages", false));
         this.authentication = prefs.getBoolean("authentication", false);
         this.debug = prefs.getBoolean("debug", false);
+
+        this.differ = new AsyncPagedListDiffer<>(this, DIFF_CALLBACK);
+        this.differ.addPagedListListener(new AsyncPagedListDiffer.PagedListListener<TupleMessageEx>() {
+            @Override
+            public void onCurrentListChanged(@Nullable PagedList<TupleMessageEx> previousList, @Nullable PagedList<TupleMessageEx> currentList) {
+                if (gotop) {
+                    gotop = false;
+                    properties.scrollTo(0);
+                }
+            }
+        });
     }
 
-    void submitList(PagedList<TupleMessageEx> list) {
+    void submitList(PagedList<TupleMessageEx> list, boolean gotop) {
+        this.gotop = gotop;
         differ.submitList(list);
     }
 

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -1788,7 +1788,7 @@ public class FragmentMessages extends FragmentBase {
                 break;
         }
 
-        loadMessages();
+        loadMessages(false);
 
         if (selectionTracker != null && selectionTracker.hasSelection())
             fabMore.show();
@@ -2079,7 +2079,7 @@ public class FragmentMessages extends FragmentBase {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
         prefs.edit().putString("sort", sort).apply();
         adapter.setSort(sort);
-        loadMessages();
+        loadMessages(true);
     }
 
     private void onMenuFilterRead(boolean filter) {
@@ -2088,7 +2088,7 @@ public class FragmentMessages extends FragmentBase {
         getActivity().invalidateOptionsMenu();
         if (selectionTracker != null)
             selectionTracker.clearSelection();
-        loadMessages();
+        loadMessages(true);
     }
 
     private void onMenuFilterSnoozed(boolean filter) {
@@ -2097,7 +2097,7 @@ public class FragmentMessages extends FragmentBase {
         getActivity().invalidateOptionsMenu();
         if (selectionTracker != null)
             selectionTracker.clearSelection();
-        loadMessages();
+        loadMessages(true);
     }
 
     private void onMenuFilterDuplicates(boolean filter) {
@@ -2198,13 +2198,7 @@ public class FragmentMessages extends FragmentBase {
         if (lastUnseen == null || lastUnseen != unseen) {
             if ((!refreshing && manual) ||
                     (autoscroll && lastUnseen != null && lastUnseen < unseen))
-                // Delay to let list update
+                loadMessages(true);
-                new Handler().postDelayed(new Runnable() {
-                    @Override
-                    public void run() {
-                        rvMessage.scrollToPosition(0);
-                    }
-                }, 3000);
             manual = false;
             lastUnseen = unseen;
         }
@@ -2221,7 +2215,7 @@ public class FragmentMessages extends FragmentBase {
         swipeRefresh.setRefreshing(refreshing);
     }
 
-    private void loadMessages() {
+    private void loadMessages(final boolean top) {
         if (viewType == AdapterMessage.ViewType.THREAD && autonext) {
             ViewModelMessages model = ViewModelProviders.of(getActivity()).get(ViewModelMessages.class);
             model.observePrevNext(getViewLifecycleOwner(), id, found, new ViewModelMessages.IPrevNext() {
@@ -2238,7 +2232,7 @@ public class FragmentMessages extends FragmentBase {
                         closeNext = id;
                         if (!once) {
                             once = true;
-                            loadMessagesNext();
+                            loadMessagesNext(top);
                         }
                     }
                 }
@@ -2249,10 +2243,10 @@ public class FragmentMessages extends FragmentBase {
                 }
             });
         } else
-            loadMessagesNext();
+            loadMessagesNext(top);
     }
 
-    private void loadMessagesNext() {
+    private void loadMessagesNext(final boolean top) {
         ViewModelBrowse modelBrowse = ViewModelProviders.of(getActivity()).get(ViewModelBrowse.class);
         modelBrowse.set(getContext(), folder, search, REMOTE_PAGE_SIZE);
 
@@ -2344,20 +2338,52 @@ public class FragmentMessages extends FragmentBase {
         builder.setFetchExecutor(executor);
 
         modelMessages.setMessages(viewType, getViewLifecycleOwner(), builder.build());
-        modelMessages.observe(viewType, getViewLifecycleOwner(), observer);
+        modelMessages.observe(viewType, getViewLifecycleOwner(), new Observer<PagedList<TupleMessageEx>>() {
-    }
+            private boolean topped = false;
 
-    private Observer<PagedList<TupleMessageEx>> observer = new Observer<PagedList<TupleMessageEx>>() {
             @Override
             public void onChanged(@Nullable PagedList<TupleMessageEx> messages) {
-            if (messages == null ||
+                if (messages == null)
-                    (viewType == AdapterMessage.ViewType.THREAD && messages.size() == 0 &&
+                    return;
-                            (autoclose || autonext))) {
+
-                handleAutoClose();
+                if (viewType == AdapterMessage.ViewType.THREAD)
+                    if (handleThreadActions(messages))
                         return;
+
+                boolean gotop = (top && !topped);
+                topped = true;
+                Log.i("Submit messages=" + messages.size() + " top=" + gotop);
+                adapter.submitList(messages, gotop);
+
+                // This is to workaround not drawing when the search is expanded
+                new Handler().post(new Runnable() {
+                    @Override
+                    public void run() {
+                        rvMessage.requestLayout();
+                    }
+                });
+
+                rvMessage.setTag(messages.size());
+
+                if (boundaryCallback == null || !boundaryCallback.isLoading())
+                    pbWait.setVisibility(View.GONE);
+                if (boundaryCallback == null && messages.size() == 0)
+                    tvNoEmail.setVisibility(View.VISIBLE);
+                if (messages.size() > 0) {
+                    tvNoEmail.setVisibility(View.GONE);
+                    grpReady.setVisibility(View.VISIBLE);
+                }
+            }
+        });
+    }
+
+    private boolean handleThreadActions(@NonNull PagedList<TupleMessageEx> messages) {
+        // Auto close / next
+        if (messages.size() == 0 && (autoclose || autonext)) {
+            handleAutoClose();
+            return true;
         }
 
-            if (viewType == AdapterMessage.ViewType.THREAD) {
         // Mark duplicates
         Map<String, List<TupleMessageEx>> duplicates = new HashMap<>();
         for (TupleMessageEx message : messages)
@@ -2459,7 +2485,7 @@ public class FragmentMessages extends FragmentBase {
 
                 if (count == 0) {
                     handleAutoClose();
-                            return;
+                    return true;
                 }
             }
         }
@@ -2521,32 +2547,9 @@ public class FragmentMessages extends FragmentBase {
                 }
             }.execute(FragmentMessages.this, args, "messages:navigation");
         }
+        return false;
     }
 
-            Log.i("Submit messages=" + messages.size());
-            adapter.submitList(messages);
-
-            // This is to workaround not drawing when the search is expanded
-            new Handler().post(new Runnable() {
-                @Override
-                public void run() {
-                    rvMessage.requestLayout();
-                }
-            });
-
-            rvMessage.setTag(messages.size());
-
-            if (boundaryCallback == null || !boundaryCallback.isLoading())
-                pbWait.setVisibility(View.GONE);
-            if (boundaryCallback == null && messages.size() == 0)
-                tvNoEmail.setVisibility(View.VISIBLE);
-            if (messages.size() > 0) {
-                tvNoEmail.setVisibility(View.GONE);
-                grpReady.setVisibility(View.VISIBLE);
-            }
-        }
-    };
-
     private void handleExpand(long id) {
         Bundle args = new Bundle();
         args.putLong("id", id);