Unregister fragment update listener when destorying view

android_app/app/src/main/java/com/health/openscale/core/OpenScale.java

@@ -461,6 +461,10 @@ public class OpenScale {
         fragment.updateOnView(scaleMeasurementList);
     }
 
+    public void unregisterFragment(FragmentUpdateListener fragment) {
+        fragmentList.remove(fragment);
+    }
+
     public void updateScaleData() {
         int selectedUserId = getSelectedScaleUserId();
 

android_app/app/src/main/java/com/health/openscale/gui/fragments/GraphFragment.java

@@ -226,6 +226,12 @@ public class GraphFragment extends Fragment implements FragmentUpdateListener {
         return graphView;
     }
 
+    @Override
+    public void onDestroyView() {
+        OpenScale.getInstance(getContext()).unregisterFragment(this);
+        super.onDestroyView();
+    }
+
     @Override
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);

android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java

@@ -148,6 +148,12 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
         return overviewView;
     }
 
+    @Override
+    public void onDestroyView() {
+        OpenScale.getInstance(getContext()).unregisterFragment(this);
+        super.onDestroyView();
+    }
+
     @Override
     public void updateOnView(List<ScaleMeasurement> scaleMeasurementList) {
         if (scaleMeasurementList.isEmpty()) {

android_app/app/src/main/java/com/health/openscale/gui/fragments/StatisticsFragment.java

@@ -156,6 +156,12 @@ public class StatisticsFragment extends Fragment implements FragmentUpdateListen
         return statisticsView;
     }
 
+    @Override
+    public void onDestroyView() {
+        OpenScale.getInstance(getContext()).unregisterFragment(this);
+        super.onDestroyView();
+    }
+
     @Override
     public void updateOnView(List<ScaleMeasurement> scaleMeasurementList) {
         currentScaleUser = OpenScale.getInstance(getContext()).getSelectedScaleUser();

android_app/app/src/main/java/com/health/openscale/gui/fragments/TableFragment.java

@@ -97,6 +97,12 @@ public class TableFragment extends Fragment implements FragmentUpdateListener {
         return tableView;
     }
 
+    @Override
+    public void onDestroyView() {
+        OpenScale.getInstance(getContext()).unregisterFragment(this);
+        super.onDestroyView();
+    }
+
     @Override
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);