Fix commons-app#2245: Correct back button behaviour from nearby fragment (commons-app#2301)

Author: vanshikaarora

app/src/main/java/fr/free/nrw/commons/contributions/MainActivity.java

@@ -269,9 +269,16 @@ public void onBackPressed() {
                 finish();
             }
         } else if (getSupportFragmentManager().findFragmentByTag(nearbyFragmentTag) != null && !isContributionsFragmentVisible) {
-            // Meas that nearby fragment is visible (not contributions fragment)
-            // Set current item to contributions activity instead of closing the activity
-            viewPager.setCurrentItem(0);
+            // Means that nearby fragment is visible (not contributions fragment)
+            NearbyFragment nearbyFragment = (NearbyFragment) contributionsActivityPagerAdapter.getItem(1);
+
+            if(nearbyFragment.isBottomSheetExpanded()) {
+                // Back should first hide the bottom sheet if it is expanded
+                nearbyFragment.listOptionMenuItemClicked();
+            } else {
+                // Otherwise go back to contributions fragment
+                viewPager.setCurrentItem(0);
+            }
         } else {
             super.onBackPressed();
         }
@@ -347,7 +354,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
                 return true;
             case R.id.list_sheet:
                 if (contributionsActivityPagerAdapter.getItem(1) != null) {
-                    ((NearbyFragment)contributionsActivityPagerAdapter.getItem(1)).listOptionMenuIteClicked();
+                    ((NearbyFragment)contributionsActivityPagerAdapter.getItem(1)).listOptionMenuItemClicked();
                 }
                 return true;
             default:

app/src/main/java/fr/free/nrw/commons/nearby/NearbyFragment.java

@@ -132,14 +132,13 @@ public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceStat
     /**
      * Hide or expand bottom sheet according to states of all sheets
      */
-    public void listOptionMenuIteClicked() {
+    public void listOptionMenuItemClicked() {
         if(bottomSheetBehavior.getState()==BottomSheetBehavior.STATE_COLLAPSED || bottomSheetBehavior.getState()==BottomSheetBehavior.STATE_HIDDEN){
             bottomSheetBehaviorForDetails.setState(BottomSheetBehavior.STATE_HIDDEN);
             bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
         }else if(bottomSheetBehavior.getState()==BottomSheetBehavior.STATE_EXPANDED){
             bottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
         }
-
     }
 
     /**
@@ -822,6 +821,9 @@ public void onPause() {
             locationManager.unregisterLocationManager();
         }
     }
+
+    public boolean isBottomSheetExpanded() { return bottomSheetBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED;
+    }
 }