Fixed changing view model type

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

@@ -71,7 +71,6 @@ import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
 import androidx.lifecycle.Lifecycle;
 import androidx.lifecycle.LifecycleOwner;
-import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProviders;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
@@ -2620,78 +2619,82 @@ public class FragmentMessages extends FragmentBase {
 
         ViewModelMessages model = ViewModelProviders.of(getActivity()).get(ViewModelMessages.class);
 
-        LiveData<PagedList<TupleMessageEx>> liveMessages = model.getPagedList(
+        ViewModelMessages.Model vmodel = model.getModel(
                 getContext(), getViewLifecycleOwner(),
-                viewType, account, folder, thread, id, query, server,
+                viewType, account, folder, thread, id, query, server);
-                new BoundaryCallbackMessages.IBoundaryCallbackMessages() {
-                    @Override
-                    public void onLoading() {
-                        loading = true;
-                        pbWait.setVisibility(View.VISIBLE);
-                    }
-
-                    @Override
-                    public void onLoaded(int fetched) {
-                        loading = false;
-                        pbWait.setVisibility(View.GONE);
-
-                        Integer submitted = (Integer) rvMessage.getTag();
-                        if (submitted == null)
-                            submitted = 0;
-                        if (submitted + fetched == 0)
-                            tvNoEmail.setVisibility(View.VISIBLE);
-                    }
 
-                    @Override
+        vmodel.setCallback(callback);
-                    public void onError(Throwable ex) {
+        vmodel.setObserver(getViewLifecycleOwner(), observer);
-                        if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.RESUMED))
+    }
-                            if (ex instanceof IllegalArgumentException)
-                                Snackbar.make(view, ex.getMessage(), Snackbar.LENGTH_LONG).show();
-                            else
-                                new DialogBuilderLifecycle(getContext(), getViewLifecycleOwner())
-                                        .setMessage(Helper.formatThrowable(ex))
-                                        .setPositiveButton(android.R.string.cancel, null)
-                                        .create()
-                                        .show();
-                    }
-                });
 
-        liveMessages.observe(getViewLifecycleOwner(), new Observer<PagedList<TupleMessageEx>>() {
+    private BoundaryCallbackMessages.IBoundaryCallbackMessages callback = new BoundaryCallbackMessages.IBoundaryCallbackMessages() {
-            @Override
+        @Override
-            public void onChanged(@Nullable PagedList<TupleMessageEx> messages) {
+        public void onLoading() {
-                if (messages == null)
+            loading = true;
-                    return;
+            pbWait.setVisibility(View.VISIBLE);
+        }
 
-                if (viewType == AdapterMessage.ViewType.THREAD)
+        @Override
-                    if (handleThreadActions(messages))
+        public void onLoaded(int fetched) {
-                        return;
+            loading = false;
+            pbWait.setVisibility(View.GONE);
+
+            Integer submitted = (Integer) rvMessage.getTag();
+            if (submitted == null)
+                submitted = 0;
+            if (submitted + fetched == 0)
+                tvNoEmail.setVisibility(View.VISIBLE);
+        }
 
-                Log.i("Submit messages=" + messages.size());
+        @Override
-                adapter.submitList(messages);
+        public void onError(Throwable ex) {
+            if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.RESUMED))
+                if (ex instanceof IllegalArgumentException)
+                    Snackbar.make(view, ex.getMessage(), Snackbar.LENGTH_LONG).show();
+                else
+                    new DialogBuilderLifecycle(getContext(), getViewLifecycleOwner())
+                            .setMessage(Helper.formatThrowable(ex))
+                            .setPositiveButton(android.R.string.cancel, null)
+                            .create()
+                            .show();
+        }
+    };
 
-                // This is to workaround not drawing when the search is expanded
+    private Observer<PagedList<TupleMessageEx>> observer = new Observer<PagedList<TupleMessageEx>>() {
-                new Handler().post(new Runnable() {
+        @Override
-                    @Override
+        public void onChanged(@Nullable PagedList<TupleMessageEx> messages) {
-                    public void run() {
+            if (messages == null)
-                        rvMessage.requestLayout();
+                return;
-                    }
-                });
 
-                rvMessage.setTag(messages.size());
+            if (viewType == AdapterMessage.ViewType.THREAD)
+                if (handleThreadActions(messages))
+                    return;
 
-                boolean hasBoundary = (viewType == AdapterMessage.ViewType.FOLDER || viewType == AdapterMessage.ViewType.SEARCH);
+            Log.i("Submit messages=" + messages.size());
+            adapter.submitList(messages);
 
-                if (!hasBoundary || !loading)
+            // This is to workaround not drawing when the search is expanded
-                    pbWait.setVisibility(View.GONE);
+            new Handler().post(new Runnable() {
-                if (!hasBoundary && messages.size() == 0)
+                @Override
-                    tvNoEmail.setVisibility(View.VISIBLE);
+                public void run() {
-                if (messages.size() > 0) {
+                    rvMessage.requestLayout();
-                    tvNoEmail.setVisibility(View.GONE);
-                    grpReady.setVisibility(View.VISIBLE);
                 }
+            });
+
+            rvMessage.setTag(messages.size());
+
+            boolean hasBoundary = (viewType == AdapterMessage.ViewType.FOLDER || viewType == AdapterMessage.ViewType.SEARCH);
+
+            if (!hasBoundary || !loading)
+                pbWait.setVisibility(View.GONE);
+            if (!hasBoundary && 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

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

@@ -52,12 +52,11 @@ public class ViewModelMessages extends ViewModel {
     private static final int LOCAL_PAGE_SIZE = 100;
     private static final int REMOTE_PAGE_SIZE = 10;
 
-    LiveData<PagedList<TupleMessageEx>> getPagedList(
+    Model getModel(
-            Context context, LifecycleOwner owner,
+            Context context, final LifecycleOwner owner,
             final AdapterMessage.ViewType viewType,
             long account, long folder, String thread, long id,
-            String query, boolean server,
+            String query, boolean server) {
-            BoundaryCallbackMessages.IBoundaryCallbackMessages callback) {
 
         Args args = new Args(context, account, folder, thread, id, query, server);
         Log.i("Get model " + viewType + " " + args);
@@ -67,8 +66,10 @@ public class ViewModelMessages extends ViewModel {
         if (model == null || !model.args.equals(args)) {
             Log.i("Creating model");
 
-            if (model != null)
+            if (model != null) {
                 model.clear();
+                model.list.removeObservers(owner);
+            }
 
             DB db = DB.getInstance(context);
 
@@ -168,9 +169,6 @@ public class ViewModelMessages extends ViewModel {
                 });
         }
 
-        if (model.boundary != null)
-            model.boundary.setCallback(callback);
-
         if (viewType == AdapterMessage.ViewType.UNIFIED) {
             remove(AdapterMessage.ViewType.FOLDER);
             remove(AdapterMessage.ViewType.SEARCH);
@@ -182,7 +180,7 @@ public class ViewModelMessages extends ViewModel {
         Log.i("Returning model=" + viewType);
         dump();
 
-        return model.list;
+        return model;
     }
 
     @Override
@@ -193,10 +191,8 @@ public class ViewModelMessages extends ViewModel {
 
     private void remove(AdapterMessage.ViewType viewType) {
         Model model = models.get(viewType);
-        if (model != null) {
+        if (model != null)
-            model.clear();
             models.remove(viewType);
-        }
     }
 
     void observePrevNext(LifecycleOwner owner, final long id, final IPrevNext intf) {
@@ -321,7 +317,7 @@ public class ViewModelMessages extends ViewModel {
         Log.i("Current models=" + TextUtils.join(", ", models.keySet()));
     }
 
-    private class Model {
+    class Model {
         private Args args;
         private LiveData<PagedList<TupleMessageEx>> list;
         private BoundaryCallbackMessages boundary;
@@ -332,6 +328,15 @@ public class ViewModelMessages extends ViewModel {
             this.boundary = boundary;
         }
 
+        void setCallback(BoundaryCallbackMessages.IBoundaryCallbackMessages callback) {
+            if (boundary != null)
+                boundary.setCallback(callback);
+        }
+
+        void setObserver(LifecycleOwner owner, @NonNull Observer<PagedList<TupleMessageEx>> observer) {
+            list.observe(owner, observer);
+        }
+
         private void clear() {
             if (this.boundary != null)
                 this.boundary.clear();