Fixed NPE in EmptyViewHandler

1 files changed, 34 insertions, 10 deletions

diff --git a/app/src/main/java/de/danoeh/antennapod/view/EmptyViewHandler.java b/app/src/main/java/de/danoeh/antennapod/view/EmptyViewHandler.java
index 0bfd0247f..a2d8ec091 100644
--- a/app/src/main/java/de/danoeh/antennapod/view/EmptyViewHandler.java
+++ b/app/src/main/java/de/danoeh/antennapod/view/EmptyViewHandler.java
@@ -1,8 +1,10 @@
 package de.danoeh.antennapod.view;

 

 import android.content.Context;

+import android.database.DataSetObserver;

 import android.graphics.drawable.Drawable;

 import android.widget.AbsListView;

+import android.widget.ListAdapter;

 import androidx.annotation.AttrRes;

 import androidx.core.content.ContextCompat;

 import androidx.recyclerview.widget.RecyclerView;

@@ -17,8 +19,9 @@ import de.danoeh.antennapod.R;
 

 public class EmptyViewHandler {

     private boolean layoutAdded = false;

-    private RecyclerView recyclerView;

-    private RecyclerView.Adapter adapter;

+    private View list;

+    private ListAdapter listAdapter;

+    private RecyclerView.Adapter recyclerAdapter;

 

     private final Context context;

     private final View emptyView;

@@ -60,7 +63,9 @@ public class EmptyViewHandler {
         }

         addToParentView(listView);

         layoutAdded = true;

+        this.list = listView;

         listView.setEmptyView(emptyView);

+        updateAdapter(listView.getAdapter());

     }

 

     public void attachToRecyclerView(RecyclerView recyclerView) {

@@ -69,7 +74,7 @@ public class EmptyViewHandler {
         }

         addToParentView(recyclerView);

         layoutAdded = true;

-        this.recyclerView = recyclerView;

+        this.list = recyclerView;

         updateAdapter(recyclerView.getAdapter());

     }

 

@@ -85,16 +90,27 @@ public class EmptyViewHandler {
     }

 

     public void updateAdapter(RecyclerView.Adapter adapter) {

-        if (this.adapter != null) {

-            this.adapter.unregisterAdapterDataObserver(adapterObserver);

+        if (this.recyclerAdapter != null) {

+            this.recyclerAdapter.unregisterAdapterDataObserver(adapterObserver);

         }

-        this.adapter = adapter;

+        this.recyclerAdapter = adapter;

         if (adapter != null) {

             adapter.registerAdapterDataObserver(adapterObserver);

         }

         updateVisibility();

     }

 

+    private void updateAdapter(ListAdapter adapter) {

+        if (this.listAdapter != null) {

+            this.listAdapter.unregisterDataSetObserver(listAdapterObserver);

+        }

+        this.listAdapter = adapter;

+        if (adapter != null) {

+            adapter.registerDataSetObserver(listAdapterObserver);

+        }

+        updateVisibility();

+    }

+

     private final SimpleAdapterDataObserver adapterObserver = new SimpleAdapterDataObserver() {

         @Override

         public void anythingChanged() {

@@ -102,14 +118,22 @@ public class EmptyViewHandler {
         }

     };

 

+    private final DataSetObserver listAdapterObserver = new DataSetObserver() {

+        public void onChanged() {

+            updateVisibility();

+        }

+    };

+

     public void updateVisibility() {

         boolean empty;

-        if (adapter == null) {

-            empty = true;

+        if (recyclerAdapter != null) {

+            empty = recyclerAdapter.getItemCount() == 0;

+        } else if (listAdapter != null) {

+            empty = listAdapter.isEmpty();

         } else {

-            empty = adapter.getItemCount() == 0;

+            empty = true;

         }

-        recyclerView.setVisibility(empty ? View.GONE : View.VISIBLE);

+        list.setVisibility(empty ? View.GONE : View.VISIBLE);

         emptyView.setVisibility(empty ? View.VISIBLE : View.GONE);

     }

 }