Nearby: Move handling map scroll to presenter

app/src/main/java/fr/free/nrw/commons/nearby/contract/NearbyParentFragmentContract.java

@@ -122,8 +122,6 @@ public interface NearbyParentFragmentContract {
         void filterByMarkerType(List<Label> selectedLabels, int state, boolean filterForPlaceState,
             boolean filterForAllNoneType);
 
-        void updateMapMarkersToController(List<BaseMarker> baseMarkers);
-
         void searchViewGainedFocus();
 
         void setCheckboxUnknown();
@@ -131,5 +129,7 @@ public interface NearbyParentFragmentContract {
         void setAdvancedQuery(String query);
 
         void toggleBookmarkedStatus(Place place);
+
+        void handleMapScrolled(LifecycleCoroutineScope scope);
     }
 }

app/src/main/java/fr/free/nrw/commons/nearby/fragments/NearbyParentFragment.java

@@ -55,6 +55,7 @@ import androidx.appcompat.app.AlertDialog.Builder;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.core.content.ContextCompat;
 import androidx.core.content.FileProvider;
+import androidx.lifecycle.LifecycleCoroutineScope;
 import androidx.lifecycle.LifecycleOwnerKt;
 import androidx.recyclerview.widget.DividerItemDecoration;
 import androidx.recyclerview.widget.GridLayoutManager;
@@ -208,6 +209,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
     private boolean isNetworkErrorOccurred;
     private Snackbar snackbar;
     private View view;
+    private LifecycleCoroutineScope scope;
     private NearbyParentFragmentPresenter presenter;
     private boolean isDarkTheme;
     private boolean isFABsExpanded;
@@ -231,10 +233,8 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
     private Place nearestPlace;
     private volatile boolean stopQuery;
 
-    private boolean isSearchInProgress = false;
     private final Handler searchHandler = new Handler();
     private Runnable searchRunnable;
-    private static final long SCROLL_DELAY = 800; // Delay for debounce of onscroll, in milliseconds.
 
     private LatLng updatedLatLng;
     private boolean searchable;
@@ -341,6 +341,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
         view = binding.getRoot();
 
         initNetworkBroadCastReceiver();
+        scope = LifecycleOwnerKt.getLifecycleScope(getViewLifecycleOwner());
         presenter = new NearbyParentFragmentPresenter(bookmarkLocationDao, placesRepository, nearbyController);
         progressDialog = new ProgressDialog(getActivity());
         progressDialog.setCancelable(false);
@@ -471,28 +472,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
         binding.map.addMapListener(new MapListener() {
             @Override
             public boolean onScroll(ScrollEvent event) {
-
-                // Remove any pending search runnables
-                searchHandler.removeCallbacks(searchRunnable);
-
-                // Set a runnable to call the Search after a delay
-                searchRunnable = new Runnable() {
-                    @Override
-                    public void run() {
-                        if (!isSearchInProgress) {
-                            isSearchInProgress = true; // search executing flag
-                            // Start Search
-                            try {
-                                presenter.searchInTheArea();
-                            } finally {
-                                isSearchInProgress = false;
-                            }
-                        }
-                    }
-                };
-                // post runnable with configured SCROLL_DELAY
-                searchHandler.postDelayed(searchRunnable, SCROLL_DELAY);
-
+                presenter.handleMapScrolled(scope);
                 return true;
             }
 
@@ -1477,8 +1457,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
      */
     private void updateMapMarkers(final List<Place> nearbyPlaces, final LatLng curLatLng,
         final boolean shouldUpdateSelectedMarker) {
-        presenter.updateMapMarkers(nearbyPlaces, curLatLng,
-            LifecycleOwnerKt.getLifecycleScope(getViewLifecycleOwner()));
+        presenter.updateMapMarkers(nearbyPlaces, curLatLng, scope);
     }
 
 

app/src/main/java/fr/free/nrw/commons/nearby/presenter/NearbyParentFragmentPresenter.kt

@@ -52,6 +52,9 @@ class NearbyParentFragmentPresenter
 
     private var nearbyParentFragmentView: NearbyParentFragmentContract.View = DUMMY
 
+    private var placeSearchJob: Job? = null
+    private var isSearchInProgress = false
+
     private val clickedPlaces = CopyOnWriteArrayList<Place>()
 
     /**
@@ -489,17 +492,21 @@ class NearbyParentFragmentPresenter
         }
     }
 
-    @MainThread
-    override fun updateMapMarkersToController(baseMarkers: MutableList<BaseMarker>) {
-        NearbyController.markerLabelList.clear()
-        for (i in baseMarkers.indices) {
-            val nearbyBaseMarker = baseMarkers[i]
-            NearbyController.markerLabelList.add(
-                MarkerPlaceGroup(
-                    bookmarkLocationDao.findBookmarkLocation(nearbyBaseMarker.place),
-                    nearbyBaseMarker.place
-                )
-            )
+    @Override
+    override fun handleMapScrolled(scope: LifecycleCoroutineScope?) {
+        scope ?: return
+        placeSearchJob?.cancel()
+        placeSearchJob = scope.launch {
+            delay(SCROLL_DELAY)
+            if (!isSearchInProgress) {
+                isSearchInProgress = true; // search executing flag
+                // Start Search
+                try {
+                    searchInTheArea();
+                } finally {
+                    isSearchInProgress = false;
+                }
+            }
         }
     }
 
@@ -575,6 +582,7 @@ class NearbyParentFragmentPresenter
     }
 
     companion object {
+        private const val SCROLL_DELAY = 800L; // Delay for debounce of onscroll, in milliseconds.
         private val DUMMY = Proxy.newProxyInstance(
             NearbyParentFragmentContract.View::class.java.getClassLoader(),
             arrayOf<Class<*>>(NearbyParentFragmentContract.View::class.java),