refactor: file and class names

app/lib/pages/default_page.dart

 import 'dart:async';
 import 'package:flutter/material.dart';
 import 'widgets/map_widget.dart';
-import 'marker_handler/marker_data.dart';
+import 'server_requests/data_classes.dart';
 import 'consts.dart';
-import 'marker_handler/get_markers.dart';
-import 'marker_handler/get_relation.dart';
+import 'server_requests/fetch_markers.dart';
+import 'server_requests/fetch_relation.dart';
 import 'dart:typed_data';
 
 class DefaultPage extends StatefulWidget {

app/lib/pages/marker_handler/get_markers.dart → app/lib/pages/server_requests/fetch_markers.dart

@@ -2,7 +2,7 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import '../consts.dart';
-import 'marker_data.dart';
+import 'data_classes.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:flutter/material.dart';

app/lib/pages/widgets/cloropleth_map.dart → app/lib/pages/widgets/choropleth_map.dart

 import 'dart:typed_data';
-import '../marker_handler/marker_data.dart';
+import '../server_requests/data_classes.dart';
 import 'package:flutter/material.dart';
 import 'package:syncfusion_flutter_maps/maps.dart';
 import 'dart:math';

app/lib/pages/widgets/map_widget.dart

 import 'package:flutter/material.dart';
-import '../marker_handler/marker_data.dart';
+import '../server_requests/data_classes.dart';
 import '../consts.dart';
 import 'quick_view_chart.dart';
 import 'stat_charts.dart';
 import 'sat_layer.dart';
 import 'package:flutter_map/flutter_map.dart';
-import 'cloropleth_map.dart';
+import 'choropleth_map.dart';
 import 'dart:typed_data';
 import 'package:google_fonts/google_fonts.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -27,8 +27,8 @@ class MapContainerWidget extends StatefulWidget {
 
 class _MapContainerWidgetState extends State<MapContainerWidget> {
 
-  Measurement? selectedMarker;  // Containing data for selected marker
-  int selectedMarkerIndex = 0;
+  Measurement? selectedTile;  // Containing data for selected marker
+  int selectedTileIndex = 0;
   bool isMinimized = true;      // Quick view box state tacker
   bool satLayer = false;        // Satellite layer visibility tracker
   bool isTapped = false;        // Button tap state tracker
@@ -57,14 +57,14 @@ class _MapContainerWidgetState extends State<MapContainerWidget> {
   // Tile selection handler
   void handleSelection(int index) {
     setState(() {
-      selectedMarkerIndex = index;
+      selectedTileIndex = index;
     });
   }
 
   @override
   Widget build(BuildContext context) {
     // Initialise selectedMarker to first element in markerList
-    selectedMarker ??= widget.markerList[selectedMarkerIndex];
+    selectedTile ??= widget.markerList[selectedTileIndex];
 
     checkAndSetLastUpdate();
 
@@ -180,7 +180,7 @@ class _MapContainerWidgetState extends State<MapContainerWidget> {
                         child: Stack(
                           children: [
                             Visibility( // Graph only visible when box is maximized and a marker is selected
-                              visible: !isMinimized && selectedMarker != null,
+                              visible: !isMinimized && selectedTile != null,
                               child: Center(
                                 child: Padding(
                                   padding: const EdgeInsets.only(right: 16.0, top: 17.0),
@@ -284,16 +284,16 @@ class _MapContainerWidgetState extends State<MapContainerWidget> {
                           style: subHeadingStyle,
                         ),
                         Text(
-                          'Date ${(selectedMarker?.timeMeasured.day ?? '-')}/${(selectedMarker?.timeMeasured.month ?? '-')}/${(selectedMarker?.timeMeasured.year ?? '-')}',
+                          'Date ${(selectedTile?.timeMeasured.day ?? '-')}/${(selectedTile?.timeMeasured.month ?? '-')}/${(selectedTile?.timeMeasured.year ?? '-')}',
                           style: regTextStyle,
                         ),
                         Text(
-                          'Time: ${selectedMarker?.timeMeasured.hour}:00',
+                          'Time: ${selectedTile?.timeMeasured.hour}:00',
                           style: regTextStyle,
                         ),
                         const SizedBox(height: contPadding),
                         Text(
-                          'Measuring point: (${selectedMarker?.measurementID}, ${selectedMarker?.measurementID})',
+                          'Measuring point: (${selectedTile?.measurementID}, ${selectedTile?.measurementID})',
                           style: regTextStyle,
                         ),
                         const SizedBox(height: contPadding),

app/lib/pages/widgets/osm_map.dart

 import 'package:flutter/material.dart';
-import '../marker_handler/marker_data.dart';
+import '../server_requests/data_classes.dart';
 import '../consts.dart';
 import 'package:flutter_map/flutter_map.dart';
 import 'package:latlong2/latlong.dart';

app/lib/pages/widgets/sat_layer.dart

 import 'package:flutter/material.dart';
-import '../marker_handler/marker_data.dart';
+import '../server_requests/data_classes.dart';
 import 'package:flutter_map/flutter_map.dart';
 import 'package:latlong2/latlong.dart';