Location info item in file details (#942)

lib/core/constants.dart

@@ -57,3 +57,5 @@ const double restrictedMaxWidth = 430;
 const double mobileSmallThreshold = 336;
 
 const publicLinkDeviceLimits = [50, 25, 10, 5, 2, 1];
+
+const kilometersPerDegree = 111.16;

lib/services/location_service.dart

@@ -1,6 +1,8 @@
 import "dart:collection";
 import "dart:convert";
+import "dart:math";
 
+import "package:photos/core/constants.dart";
 import "package:shared_preferences/shared_preferences.dart";
 
 class LocationService {
@@ -13,7 +15,7 @@ class LocationService {
     prefs ??= await SharedPreferences.getInstance();
   }
 
-  List<String> getLocations() {
+  List<String> getAllLocationTags() {
     var list = prefs!.getStringList('locations');
     list ??= [];
     return list;
@@ -22,22 +24,55 @@ class LocationService {
   Future<void> addLocation(
     String location,
     double lat,
-    double lon,
+    double long,
     int radius,
   ) async {
-    final list = getLocations();
+    final list = getAllLocationTags();
+    //The area enclosed by the location tag will be a circle on a 3D spherical
+    //globe and an ellipse on a 2D Mercator projection (2D map)
+    //a & b are the semi-major and semi-minor axes of the ellipse
+    //Converting the unit from kilometers to degrees for a and b as that is
+    //the unit on the caritesian plane
+    final a = (radius * _scaleFactor(lat)) / kilometersPerDegree;
+    final b = radius / kilometersPerDegree;
+    final center = [lat, long];
     final data = {
-      "id": list.length,
       "name": location,
-      "lat": lat,
-      "lon": lon,
       "radius": radius,
+      "aSquare": a * a,
+      "bSquare": b * b,
+      "center": center,
     };
     final encodedMap = json.encode(data);
     list.add(encodedMap);
     await prefs!.setStringList('locations', list);
   }
 
+  ///The area bounded by the location tag becomes more elliptical with increase
+  ///in the magnitude of the latitude on the caritesian plane. When latitude is
+  ///0 degrees, the ellipse is a circle with a = b = r. When latitude incrases,
+  ///the major axis (a) has to be scaled by the secant of the latitude.
+  double _scaleFactor(double lat) {
+    return 1 / cos(lat * (pi / 180));
+  }
+
+  List<String> enclosingLocationTags(List<double> coordinates) {
+    final result = List<String>.of([]);
+    final allLocationTags = getAllLocationTags();
+    for (var locationTag in allLocationTags) {
+      final locationJson = json.decode(locationTag);
+      final aSquare = locationJson["aSquare"];
+      final bSquare = locationJson["bSquare"];
+      final center = locationJson["center"];
+      final x = coordinates[0] - center[0];
+      final y = coordinates[1] - center[1];
+      if ((x * x) / (aSquare) + (y * y) / (bSquare) <= 1) {
+        result.add(locationJson["name"]);
+      }
+    }
+    return result;
+  }
+
   Future<void> addFileToLocation(int locationId, int fileId) async {
     final list = getFilesByLocation(locationId.toString());
     list.add(fileId.toString());
@@ -51,7 +86,7 @@ class LocationService {
   }
 
   List<String> getLocationsByFileID(int fileId) {
-    final locationList = getLocations();
+    final locationList = getAllLocationTags();
     final locations = List<dynamic>.of([]);
     for (String locationString in locationList) {
       final locationJson = json.decode(locationString);
@@ -81,3 +116,21 @@ class LocationService {
     return map;
   }
 }
+
+class GPSData {
+  final String latRef;
+  final List<double> lat;
+  final String longRef;
+  final List<double> long;
+
+  GPSData(this.latRef, this.lat, this.longRef, this.long);
+
+  List<double> toSignedDecimalDegreeCoordinates() {
+    final latSign = latRef == "N" ? 1 : -1;
+    final longSign = longRef == "E" ? 1 : -1;
+    return [
+      latSign * lat[0] + lat[1] / 60 + lat[2] / 3600,
+      longSign * long[0] + long[1] / 60 + long[2] / 3600
+    ];
+  }
+}

lib/services/search_service.dart

@@ -270,7 +270,7 @@ class SearchService {
     String query,
   ) async {
     final List<GenericSearchResult> searchResults = [];
-    final locations = LocationService.instance.getLocations();
+    final locations = LocationService.instance.getAllLocationTags();
     for (String location in locations) {
       final locationJson = json.decode(location);
       final locationName = locationJson["name"].toString();

lib/ui/components/buttons/chip_button_widget.dart

@@ -37,14 +37,16 @@ class ChipButtonWidget extends StatelessWidget {
                       size: 17,
                     )
                   : const SizedBox.shrink(),
-              const SizedBox(width: 4),
-              Padding(
-                padding: const EdgeInsets.symmetric(horizontal: 4),
-                child: Text(
-                  label ?? "",
-                  style: getEnteTextTheme(context).smallBold,
-                ),
-              )
+              if (label != null && leadingIcon != null)
+                const SizedBox(width: 4),
+              if (label != null)
+                Padding(
+                  padding: const EdgeInsets.symmetric(horizontal: 4),
+                  child: Text(
+                    label!,
+                    style: getEnteTextTheme(context).smallBold,
+                  ),
+                )
             ],
           ),
         ),

lib/ui/viewer/file/file_details_widget.dart

@@ -5,6 +5,7 @@ import "package:photos/core/configuration.dart";
 import "package:photos/models/file.dart";
 import "package:photos/models/file_type.dart";
 import "package:photos/services/feature_flag_service.dart";
+import "package:photos/services/location_service.dart";
 import 'package:photos/theme/ente_theme.dart';
 import 'package:photos/ui/components/buttons/icon_button_widget.dart';
 import "package:photos/ui/components/divider_widget.dart";
@@ -16,6 +17,7 @@ import 'package:photos/ui/viewer/file_details/backed_up_time_item_widget.dart';
 import "package:photos/ui/viewer/file_details/creation_time_item_widget.dart";
 import 'package:photos/ui/viewer/file_details/exif_item_widgets.dart';
 import "package:photos/ui/viewer/file_details/file_properties_item_widget.dart";
+import "package:photos/ui/viewer/file_details/location_tags_widget.dart";
 import "package:photos/ui/viewer/file_details/objects_item_widget.dart";
 import "package:photos/utils/exif_util.dart";
 
@@ -39,12 +41,17 @@ class _FileDetailsWidgetState extends State<FileDetailsWidget> {
     "takenOnDevice": null,
     "exposureTime": null,
     "ISO": null,
-    "megaPixels": null
+    "megaPixels": null,
+    "lat": null,
+    "long": null,
+    "latRef": null,
+    "longRef": null,
   };
 
   bool _isImage = false;
   late int _currentUserID;
   bool showExifListTile = false;
+  bool hasGPSData = false;
 
   @override
   void initState() {
@@ -52,6 +59,12 @@ class _FileDetailsWidgetState extends State<FileDetailsWidget> {
     _currentUserID = Configuration.instance.getUserID()!;
     _isImage = widget.file.fileType == FileType.image ||
         widget.file.fileType == FileType.livePhoto;
+    _exifNotifier.addListener(() {
+      if (_exifNotifier.value != null) {
+        _generateExifForLocation(_exifNotifier.value!);
+        hasGPSData = _haGPSData();
+      }
+    });
     if (_isImage) {
       _exifNotifier.addListener(() {
         if (_exifNotifier.value != null) {
@@ -63,10 +76,10 @@ class _FileDetailsWidgetState extends State<FileDetailsWidget> {
             _exifData["exposureTime"] != null ||
             _exifData["ISO"] != null;
       });
-      getExif(widget.file).then((exif) {
-        _exifNotifier.value = exif;
-      });
     }
+    getExif(widget.file).then((exif) {
+      _exifNotifier.value = exif;
+    });
     super.initState();
   }
 
@@ -125,6 +138,30 @@ class _FileDetailsWidgetState extends State<FileDetailsWidget> {
         },
       ),
     );
+    if (FeatureFlagService.instance.isInternalUserOrDebugBuild()) {
+      fileDetailsTiles.addAll([
+        ValueListenableBuilder(
+          valueListenable: _exifNotifier,
+          builder: (context, _, __) {
+            return hasGPSData
+                ? Column(
+                    children: [
+                      LocationTagsWidget(
+                        GPSData(
+                          _exifData["latRef"],
+                          _exifData["lat"],
+                          _exifData["longRef"],
+                          _exifData["long"],
+                        ).toSignedDecimalDegreeCoordinates(),
+                      ),
+                      const FileDetailsDivider(),
+                    ],
+                  )
+                : const SizedBox.shrink();
+          },
+        )
+      ]);
+    }
     if (_isImage) {
       fileDetailsTiles.addAll([
         ValueListenableBuilder(
@@ -200,6 +237,36 @@ class _FileDetailsWidgetState extends State<FileDetailsWidget> {
     );
   }
 
+  bool _haGPSData() {
+    return _exifData["lat"] != null &&
+        _exifData["long"] != null &&
+        _exifData["latRef"] != null &&
+        _exifData["longRef"] != null;
+  }
+
+  void _generateExifForLocation(Map<String, IfdTag> exif) {
+    if (exif["GPS GPSLatitude"] != null) {
+      _exifData["lat"] = exif["GPS GPSLatitude"]!
+          .values
+          .toList()
+          .map((e) => ((e as Ratio).numerator / e.denominator))
+          .toList();
+    }
+    if (exif["GPS GPSLongitude"] != null) {
+      _exifData["long"] = exif["GPS GPSLongitude"]!
+          .values
+          .toList()
+          .map((e) => ((e as Ratio).numerator / e.denominator))
+          .toList();
+    }
+    if (exif["GPS GPSLatitudeRef"] != null) {
+      _exifData["latRef"] = exif["GPS GPSLatitudeRef"].toString();
+    }
+    if (exif["GPS GPSLongitudeRef"] != null) {
+      _exifData["longRef"] = exif["GPS GPSLongitudeRef"].toString();
+    }
+  }
+
   _generateExifForDetails(Map<String, IfdTag> exif) {
     if (exif["EXIF FocalLength"] != null) {
       _exifData["focalLength"] =

lib/ui/viewer/file_details/location_tags_widget.dart

@@ -0,0 +1,59 @@
+import "dart:async";
+
+import "package:flutter/material.dart";
+import "package:photos/services/location_service.dart";
+import "package:photos/ui/components/buttons/chip_button_widget.dart";
+import "package:photos/ui/components/buttons/inline_button_widget.dart";
+import "package:photos/ui/components/info_item_widget.dart";
+
+class LocationTagsWidget extends StatefulWidget {
+  final List<double> coordinates;
+  const LocationTagsWidget(this.coordinates, {super.key});
+
+  @override
+  State<LocationTagsWidget> createState() => _LocationTagsWidgetState();
+}
+
+class _LocationTagsWidgetState extends State<LocationTagsWidget> {
+  String title = "Add location";
+  IconData leadingIcon = Icons.add_location_alt_outlined;
+  bool hasChipButtons = false;
+  late final Future<List<Widget>> locationTagChips;
+  @override
+  void initState() {
+    locationTagChips = _getLocationTags();
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return AnimatedSwitcher(
+      duration: const Duration(milliseconds: 500),
+      switchInCurve: Curves.easeInOutExpo,
+      switchOutCurve: Curves.easeInOutExpo,
+      child: InfoItemWidget(
+        key: ValueKey(title),
+        leadingIcon: Icons.add_location_alt_outlined,
+        title: title,
+        subtitleSection: locationTagChips,
+        hasChipButtons: hasChipButtons,
+      ),
+    );
+  }
+
+  Future<List<Widget>> _getLocationTags() async {
+    final locationTags =
+        LocationService.instance.enclosingLocationTags(widget.coordinates);
+    if (locationTags.isEmpty) {
+      return [
+        InlineButtonWidget("Group nearby photos", () {}),
+      ];
+    }
+    setState(() {
+      title = "Location";
+      leadingIcon = Icons.pin_drop_outlined;
+      hasChipButtons = true;
+    });
+    return locationTags.map((e) => ChipButtonWidget(e)).toList();
+  }
+}

pubspec.yaml

@@ -12,7 +12,7 @@ description: ente photos application
 # Read more about iOS versioning at
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 
-version: 0.7.37+437
+version: 0.7.38+438
 
 environment:
   sdk: '>=2.17.0 <3.0.0'