#145 Zoom on the map when Selecting Paths

backend/src/models.ts

@@ -66,6 +66,7 @@ export interface Road {
   way_name: string;
   branches: OSMWayId[][];
   geometries: Record<OSMWayId, LatLng[]>;
+  length: number;
 }
 
 /**

backend/src/roads/road.service.ts

@@ -97,7 +97,18 @@ export class RoadService {
     Object.values(ways).forEach((way) => {
       geometries[way.osm_id] = way.section_geom;
     });
-    return { way_name: wayName, branches: branches, geometries: geometries };
+
+    const sumLength = longestBranches.reduce(
+      (total, branch) => total + branch.length,
+      0,
+    );
+
+    return {
+      way_name: wayName,
+      branches: branches,
+      geometries: geometries,
+      length: sumLength,
+    };
   }
 
   /**

frontend/src/Components/Map/Hooks/ForceMapUpdate.tsx

@@ -7,14 +7,20 @@ interface Props {
   triggerUpdate?: number;
   /** The coordinates of the map center*/
   position?: LatLng;
+  /** Zoom level for the map */
+  zoomLevel?: number;
 }
 
 /**
  * This component is used to force an update of the map. It is used in conjunction with the useMap hook.
  *
- * @author Kerbourc'h
+ * @author Kerbourc'h, Chen
  */
-const ForceMapUpdate: React.FC<Props> = ({ triggerUpdate, position }) => {
+const ForceMapUpdate: React.FC<Props> = ({
+  triggerUpdate,
+  position,
+  zoomLevel,
+}) => {
   const map = useMap();
 
   useEffect(() => {
@@ -24,9 +30,9 @@ const ForceMapUpdate: React.FC<Props> = ({ triggerUpdate, position }) => {
   // TODO: not working when moving too little
   useEffect(() => {
     if (position) {
-      map.flyTo(position);
+      map.flyTo(position, zoomLevel);
     }
-  }, [position]);
+  }, [position, zoomLevel]);
 
   return null;
 };

frontend/src/models/path.ts

@@ -47,6 +47,7 @@ export interface IRoad {
   branches: WayId[][];
   // the geometry of each way
   geometries: Record<WayId, LatLng[]>;
+  length: number;
 }
 
 export enum ImageType {

frontend/src/pages/Main.tsx

@@ -3,6 +3,7 @@ import Hamburger from '../Components/Map/Inputs/Hamburger';
 import { IRoad } from '../models/path';
 import { getRoadsPaths } from '../queries/road';
 import { LatLng, SurveyListItem } from '../models/models';
+import { LatLng as LatLngLeaflet } from 'leaflet';
 import { FeatureCollection } from 'geojson';
 import { getAllConditions } from '../queries/conditions';
 
@@ -32,6 +33,39 @@ import InfoButton from '../Components/Conditions/InfoButton';
 import UploadPanel from '../Components/Conditions/UploadPanel';
 import ProgressCircle from '../Components/ProgressCircle';
 
+/**
+/* Function to calculate the zoom level
+/*
+/* @author Chen
+*/
+const calculateZoomLevel = (maxDistance: number): number => {
+  let slope = -7.8e-5; // Default
+  let intercept = 12.6; // Default
+  if (maxDistance <= 900) {
+    slope = -7.8e-5;
+    intercept = 16.5;
+  } else if (maxDistance > 900 && maxDistance <= 2500) {
+    slope = -7.8e-5;
+    intercept = 14.1;
+  } else if (maxDistance > 2500 && maxDistance <= 8000) {
+    slope = -7.9e-5;
+    intercept = 13.8;
+  } else if (maxDistance > 8000 && maxDistance <= 20000) {
+    slope = -7.8e-5;
+    intercept = 14;
+  } else if (maxDistance > 20000 && maxDistance <= 40000) {
+    slope = -6.7e-5;
+    intercept = 14;
+  } else if (maxDistance > 40000 && maxDistance <= 100000) {
+    slope = -5e-5;
+    intercept = 14;
+  } else {
+    return 10;
+  }
+  const ZoomInParam = slope * maxDistance + intercept;
+  return ZoomInParam;
+};
+
 /**
  * Component rendering the main page
  *
@@ -196,6 +230,9 @@ const Main: FC = () => {
     });
   }, []);
 
+  // Control Zoom level by the length of roads when selecting a road on the map
+  const [zoomLevel, setZoomLevel] = useState<number>(13); // Default zoom level
+
   return (
     <>
       <div className="nav-wrapper">
@@ -207,6 +244,17 @@ const Main: FC = () => {
               survey.geometry[Math.floor(survey.geometry.length / 2)];
             setMoveToPosition({ lat: coord[1], lng: coord[0] });
 
+            const path = survey.geometry.map(
+              (coord) => new LatLngLeaflet(coord[1], coord[0]),
+            );
+
+            let len = 0;
+            for (let i = 0; i < path.length - 1; i++) {
+              len += path[i].distanceTo(path[i + 1]);
+            }
+            const zoomParam = calculateZoomLevel(len);
+            setZoomLevel(zoomParam);
+
             setSelectedSurvey(survey);
           }}
         />
@@ -313,6 +361,11 @@ const Main: FC = () => {
             if (selectedRoadIdx === -1 && selectedSurvey == null) {
               // If no road is selected, select the road
               setSelectedRoadIdx(index);
+              // Get information of road branches for Zoom in
+              const selectedRoad = roads[index];
+              const sumLength = selectedRoad.length;
+              const zoomParam = calculateZoomLevel(sumLength);
+              setZoomLevel(zoomParam);
             } else if (selectedRoadIdx != -1) {
               // if a road is selected, go to the inspect page for the clicked road branch
               navigate(
@@ -344,7 +397,7 @@ const Main: FC = () => {
             }
           }}
         />
-        <ForceMapUpdate position={moveToPosition} />
+        <ForceMapUpdate position={moveToPosition} zoomLevel={zoomLevel} />
       </ConditionsMap>
       {isUploadPanelOpened && (
         <UploadPanel