Resolves Issue #5413 Crash when opening Nearby when location permission hasn't been granted yet (#5418)

* Resolves Issue #5413

* Added Javadoc and formatted code

Author: ShashwatKedia

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

@@ -304,37 +304,28 @@ public void onActivityResult(Map<String, Boolean> result) {
             }
         });
 
-    private ActivityResultLauncher<String[]> locationPermissionLauncher = registerForActivityResult(
-        new ActivityResultContracts.RequestMultiplePermissions(),
-        new ActivityResultCallback<Map<String, Boolean>>() {
-            @Override
-            public void onActivityResult(Map<String, Boolean> result) {
-                boolean areAllGranted = true;
-                for (final boolean b : result.values()) {
-                    areAllGranted = areAllGranted && b;
-                }
-
-                if (areAllGranted) {
-                    locationPermissionGranted();
+    private ActivityResultLauncher<String> locationPermissionLauncher = registerForActivityResult(
+        new ActivityResultContracts.RequestPermission(), isGranted -> {
+            if (isGranted) {
+                locationPermissionGranted();
+            } else {
+                if (shouldShowRequestPermissionRationale(permission.ACCESS_FINE_LOCATION)) {
+                    DialogUtil.showAlertDialog(getActivity(),
+                        getActivity().getString(R.string.location_permission_title),
+                        getActivity().getString(R.string.location_permission_rationale_nearby),
+                        getActivity().getString(android.R.string.ok),
+                        getActivity().getString(android.R.string.cancel),
+                        () -> {
+                            if (!(locationManager.isNetworkProviderEnabled()
+                                || locationManager.isGPSProviderEnabled())) {
+                                showLocationOffDialog();
+                            }
+                        },
+                        () -> isPermissionDenied = true,
+                        null,
+                        false);
                 } else {
-                    if (shouldShowRequestPermissionRationale(permission.ACCESS_FINE_LOCATION)) {
-                        DialogUtil.showAlertDialog(getActivity(),
-                            getActivity().getString(R.string.location_permission_title),
-                            getActivity().getString(R.string.location_permission_rationale_nearby),
-                            getActivity().getString(android.R.string.ok),
-                            getActivity().getString(android.R.string.cancel),
-                            () -> {
-                                if (!(locationManager.isNetworkProviderEnabled()
-                                    || locationManager.isGPSProviderEnabled())) {
-                                    showLocationOffDialog();
-                                }
-                            },
-                            () -> isPermissionDenied = true,
-                            null,
-                            false);
-                    } else {
-                        isPermissionDenied = true;
-                    }
+                    isPermissionDenied = true;
                 }
             }
         });
@@ -1037,10 +1028,28 @@ public fr.free.nrw.commons.location.LatLng getLastMapFocus() {
         return latLng;
     }
 
+    /**
+     * Computes location where map should be centered
+     *
+     * @return returns the last location, if available, else returns default location
+     */
     @Override
     public fr.free.nrw.commons.location.LatLng getMapCenter() {
-        fr.free.nrw.commons.location.LatLng latLnge = new fr.free.nrw.commons.location.LatLng(
-            mapCenter.getLatitude(), mapCenter.getLongitude(), 100);
+        if (applicationKvStore.getString("LastLocation") != null) {
+            final String[] locationLatLng
+                = applicationKvStore.getString("LastLocation").split(",");
+            lastKnownLocation
+                = new fr.free.nrw.commons.location.LatLng(Double.parseDouble(locationLatLng[0]),
+                Double.parseDouble(locationLatLng[1]), 1f);
+        } else {
+            lastKnownLocation = new fr.free.nrw.commons.location.LatLng(51.50550,
+                -0.07520, 1f);
+        }
+        fr.free.nrw.commons.location.LatLng latLnge = lastKnownLocation;
+        if (mapCenter != null) {
+            latLnge = new fr.free.nrw.commons.location.LatLng(
+                mapCenter.getLatitude(), mapCenter.getLongitude(), 100);
+        }
         return latLnge;
     }
 
@@ -1320,7 +1329,7 @@ public void setTabItemContributions() {
     @Override
     public void checkPermissionsAndPerformAction() {
         Timber.d("Checking permission and perfoming action");
-        locationPermissionLauncher.launch(new String[]{permission.ACCESS_FINE_LOCATION});
+        locationPermissionLauncher.launch(permission.ACCESS_FINE_LOCATION);
     }
 
     /**
@@ -1625,7 +1634,7 @@ public fr.free.nrw.commons.location.LatLng getCameraTarget() {
      */
     public void updateMarker(final boolean isBookmarked, final Place place,
         @Nullable final fr.free.nrw.commons.location.LatLng curLatLng) {
-            addMarkerToMap(place, isBookmarked);
+        addMarkerToMap(place, isBookmarked);
     }
 
     /**
@@ -1770,7 +1779,7 @@ private void removeMarker(Place place){
                     mapView.invalidate();
                     break;
                 }
-           }
+            }
         }
     }