Map with a current location and current heading

main.cljd

(ns acme.main
  (:require ["dart:async" :as da]
            ["package:flutter/material.dart" :as m]
            [cljd.flutter :as f]
            ["package:flutter_map/flutter_map.dart" :as fm]
            ["package:flutter_map_location_marker/flutter_map_location_marker.dart" :as fmlm]
            ["package:latlong2/latlong.dart" :as ll]
            #_["package:geolocator/geolocator.dart" :as geo]
            #_["package:flutter_rotation_sensor/flutter_rotation_sensor.dart" :as rs]
            ["package:url_launcher/url_launcher.dart" :as ul]))

; Position and Heading Streams
;; cljd port of flutter_map_location_marker default_stream_example.dart:
;; https://github.com/tlserver/flutter_map_location_marker/blob/main/example/lib/page/default_stream_example.dart

(defn map-view []
  (f/widget
   :let [factory (fmlm/LocationMarkerDataStreamFactory)
         align-position-stream-controller (da/StreamController)
         apou (atom fmlm/AlignOnUpdate.always)
         adou (atom fmlm/AlignOnUpdate.always)]
   
   :watch [position-stream (.asBroadcastStream (.fromGeolocatorPositionStream factory))
           heading-stream (.asBroadcastStream (.fromRotationSensorHeadingStream factory))
           align-position-stream (.-stream align-position-stream-controller)
           align-position-on-update apou
           align-direction-on-update adou]
   
    (fm/FlutterMap
     .options (fm/MapOptions
               .initialZoom 19
                                        ; Stop aligning the location marker to the center of the map widget
                                        ; if user interacted with the map.
               .onPositionChanged (fn [fmlm/MapCamera hasGesture]
                                    (if (and hasGesture (not= align-position-on-update fmlm/AlignOnUpdate.never)) ; maybe also check align-direction-on-update 
                                      (do
                                        (reset! apou fmlm/AlignOnUpdate.never)
                                        ; maybe also
                                        (reset! adou fmlm/AlignOnUpdate.never) ))))
    
     .children [(fm/TileLayer
                 .urlTemplate "https://tile.openstreetmap.org/{z}/{x}/{y}.png"
                 .userAgentPackageName "com.yilki.app")
                
                (fmlm/CurrentLocationLayer
                 .positionStream position-stream
                 .headingStream heading-stream
                 .alignPositionStream align-position-stream
                 .alignPositionOnUpdate  align-position-on-update
                 .alignDirectionOnUpdate align-direction-on-update
                 .style (fmlm/LocationMarkerStyle
                         .marker (fmlm/DefaultLocationMarker
                                  .child (m/Icon m/Icons.navigation .color m/Colors.white))
                         .markerSize (m/Size 40 40)
                         .markerDirection fmlm/MarkerDirection.heading))
                
                (m/Align
                 .alignment m/Alignment.bottomRight
                 .child (m/Padding
                         .padding (m/EdgeInsets.all 20.0)
                         .child (m/FloatingActionButton
                                 .onPressed (fn [] 
                                        ; Align the location marker to the center of the map widget
                                        ; on location update until user interact with the map.
                                              (reset! apou fmlm/AlignOnUpdate.always)
                                        ;maybe also
                                              (reset! adou fmlm/AlignOnUpdate.always)
                                        ;maybe also set the device location marker location to the last known location
                                        ; Align the location marker to the center of the map widget
                                        ; and zoom the map to level 18.
                                              (.add align-position-stream-controller 18))
                                 .child (m/Icon m/Icons.my_location .color m/Colors.white))))
                
                (fm/RichAttributionWidget
                 .attributions [(fm/TextSourceAttribution
                                 "OpenStreetMap contributors"
                                 #_#_.onTap (fn [] (ul/launchUrl (Uri.parse "https://openstreetmap.org/copyright"))))])])))


(defn main []
  (f/run
    (m/MaterialApp
     .title "Flutter Loc Marker with streams"
     .theme (m/ThemeData .primarySwatch m.Colors/pink))
    .home
    (m/Scaffold
     .appBar (m/AppBar
              .title (m/Text "Flutter Loc Marker with streams")))
    .body
    (m/Center
     .child (map-view))))