From 36fdce5ecab9a845b75d827d705cf4deab9c170f Mon Sep 17 00:00:00 2001
From: Andreas <6977712+AndreasK79@users.noreply.github.com>
Date: Sun, 2 Jul 2023 16:50:06 +0200
Subject: [PATCH] [Gridsquare Map] Added display of coordinates, gridsquare,
 distance and bearing when mouseover

---
 application/controllers/Gridmap.php |   4 +
 application/views/gridmap/index.php |  23 +++++-
 assets/js/leaflet/geocoding.js      | 121 ++++++++++++++++++++++++++++
 assets/js/sections/gridmap.js       |   2 +
 4 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 assets/js/leaflet/geocoding.js

diff --git a/application/controllers/Gridmap.php b/application/controllers/Gridmap.php
index d4e32e6a..7594b98d 100644
--- a/application/controllers/Gridmap.php
+++ b/application/controllers/Gridmap.php
@@ -11,6 +11,9 @@ class Gridmap extends CI_Controller {
 
         $this->load->model('bands');
         $this->load->model('gridmap_model');
+		$this->load->model('stations');
+
+		$data['homegrid'] = explode(',', $this->stations->find_gridsquare());
 
         $data['modes'] = $this->gridmap_model->get_worked_modes();
 		$data['bands'] = $this->bands->get_worked_bands();
@@ -27,6 +30,7 @@ class Gridmap extends CI_Controller {
 
         $footerData = [];
 		$footerData['scripts'] = [
+			'assets/js/leaflet/geocoding.js',
 			'assets/js/leaflet/L.MaidenheadColouredGridMap.js',
 			'assets/js/sections/gridmap.js?'
 		];
diff --git a/application/views/gridmap/index.php b/application/views/gridmap/index.php
index 93a2cdeb..74ebaefc 100644
--- a/application/views/gridmap/index.php
+++ b/application/views/gridmap/index.php
@@ -6,9 +6,9 @@
   padding: 6px 8px;
   font: 14px Arial, Helvetica, sans-serif;
   background: white;
-  background: rgba(255, 255, 255, 0.8);
   line-height: 24px;
   color: #555;
+  border-radius: 10px;
 }
 .legend h4 {
   text-align: center;
@@ -25,7 +25,13 @@
   height: 18px;
   float: left;
   margin: 0 8px 0 0;
-  opacity: 0.7;
+}
+.coordinates {
+    justify-content: center; 
+    align-items: stretch;
+}
+.cohidden {
+    display:none;
 }
 </style>
 <div class="container">
@@ -94,10 +100,23 @@
 <div id="gridmapcontainer">
 	<div id="gridsquare_map" style="width: 100%; height: 800px"></div>
 </div>
+<div class="coordinates text-center d-flex">
+        <div class="cohidden">Latitude: </div>
+        <div class="cohidden col-auto text-success font-weight-bold" id="latDeg"></div>
+        <div class="cohidden">Longitude: </div>
+        <div class="cohidden col-auto text-success font-weight-bold" id="lngDeg"></div>
+        <div class="cohidden">Gridsquare: </div>
+        <div class="cohidden col-auto text-success font-weight-bold" id="locator"></div>
+        <div class="cohidden">Distance: </div>
+        <div class="cohidden col-auto text-success font-weight-bold" id="distance"></div>
+        <div class="cohidden">Bearing: </div>
+        <div class="cohidden col-auto text-success font-weight-bold" id="bearing"></div>
+</div>
 <script>var gridsquaremap = true;
 <?php
     echo 'var jslayer ="' . $layer .'";';
     echo "var jsattribution ='" . $attribution . "';";
+    echo "var homegrid ='" . strtoupper($homegrid[0]) . "';";
 
     echo 'var gridsquares_gridsquares = "' . $gridsquares_gridsquares . '";';
     echo 'var gridsquares_gridsquares_confirmed = "' . $gridsquares_gridsquares_confirmed . '";';
diff --git a/assets/js/leaflet/geocoding.js b/assets/js/leaflet/geocoding.js
new file mode 100644
index 00000000..a7efb8d7
--- /dev/null
+++ b/assets/js/leaflet/geocoding.js
@@ -0,0 +1,121 @@
+const isValidLocatorString = locatorString => locatorString.match(/^[A-Ra-r][A-Ra-r]\d\d[A-Xa-x][A-Xa-x]/) !== null;
+const charToNumber = char => char.toUpperCase().charCodeAt(0) - CHAR_CODE_OFFSET;
+const numberToChar = number => String.fromCharCode(number + CHAR_CODE_OFFSET);
+const CHAR_CODE_OFFSET = 65;
+const degToRad = deg => (deg % 360) * Math.PI / 180;
+const radToDeg = rad => (rad / Math.PI *180) % 360;
+const isValidPoint = (lat, lng) => (lat >= -90 && lat <= 90) && (lng >= -180 && lng <= 180);
+
+function ConvertDDToDMS(lat, lng) {
+	var LatLng = [];
+
+	if (lng < -180) {
+		lng = lng + 360;
+	}
+	if (lng > 180)  {
+		lng = lng - 360;
+	}
+	
+	LatLng['latDeg'] = (lat < 0 ? "S" : "N") + " " + (0 | (lat < 0 ? (lat = -lat) : lat)) + "° " + (0 | (((lat += 1e-9) % 1) * 60)) + "' " + ((0 | (((lat * 60) % 1) * 6000)) / 100) + "\"";
+
+	LatLng['lngDeg'] = (lng < 0 ? "W" : "E") + " " + (0 | (lng < 0 ? (lng = -lng) : lng)) + "° " + (0 | (((lng += 1e-9) % 1) * 60)) + "' " + ((0 | (((lng * 60) % 1) * 6000)) / 100) + "\"";
+
+	return LatLng;
+}
+
+const latLngToLocator = (lat, lng) => {
+	if (lng < -180) {
+		lng = lng + 360;
+	}
+	if (lng > 180)  {
+		lng = lng - 360;
+	}
+	if (!isValidPoint(lat, lng)) {
+		throw new Error('Input is not a valid coordinate');
+	}
+
+	const longitude = lng + 180;
+	const latitude = lat + 90;
+
+	const fieldLng = numberToChar(Math.floor(longitude / 20));
+	const fieldLat = numberToChar(Math.floor(latitude / 10));
+
+	const squareLng = Math.floor(longitude % 20 / 2);
+	const squareLat = Math.floor(latitude % 10);
+
+	const subsquareLng = numberToChar(Math.floor((longitude % 20 % 2) * 12)).toLowerCase();
+	const subsquareLat = numberToChar((latitude % 10 - squareLat) * 24).toLowerCase();
+
+	return fieldLng + fieldLat + squareLng + squareLat + subsquareLng + subsquareLat;
+};
+
+function onMapMove(event) {
+	var LatLng = event.latlng;
+	var lat = LatLng.lat; 
+	var lng = LatLng.lng; 					
+	var LatLng2 = ConvertDDToDMS(lat, lng);
+	$('#latDeg').html(LatLng2.latDeg);
+	$('#lngDeg').html(LatLng2.lngDeg);
+	var locator = latLngToLocator(lat,lng);
+	$('#locator').html(locator);
+	var distance = bearingDistance(homegrid, locator);
+
+	$('#bearing').html(distance.deg + ' deg');
+	$('#distance').html(Math.round(distance.km * 10) / 10 + ' km');
+};
+
+const bearingDistance = (from, to) => {
+	const fromCoords = locatorToLatLng(from);
+	const toCoords = locatorToLatLng(to);
+	const dLat = degToRad(toCoords[0] - fromCoords[0]);
+	const dLon = degToRad(toCoords[1] - fromCoords[1]);
+	const fromLat = degToRad(fromCoords[0]);
+	const toLat = degToRad(toCoords[0]);
+	const a = Math.pow(Math.sin(dLat / 2), 2) + Math.pow(Math.sin(dLon / 2), 2) * Math.cos(fromLat) * Math.cos(toLat);
+	const b = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+	
+	const y = (dLon) * Math.cos(fromLat) * Math.cos(toLat);
+	const x = Math.sin(toLat) - Math.sin(fromLat) * Math.cos(b);
+	
+	let az = Math.atan2(y, x);
+	
+	if (az < 0) {
+		az += 2 * Math.PI;
+	}
+	
+	return {
+		km: b * 6371,
+		deg: calcAngle(fromCoords, toCoords)
+	};
+};
+
+var calcAngle = function (p1, p2) {
+	var lat1 = p1[0] / 180 * Math.PI;
+	var lat2 = p2[0] / 180 * Math.PI;
+	var lng1 = p1[1] / 180 * Math.PI;
+	var lng2 = p2[1] / 180 * Math.PI;
+	var y = Math.sin(lng2-lng1) * Math.cos(lat2);
+	var x = Math.cos(lat1)*Math.sin(lat2) - Math.sin(lat1)*Math.cos(lat2)*Math.cos(lng2-lng1);
+	var brng = (Math.atan2(y, x) * 180 / Math.PI + 360).toFixed(0);
+
+	return (brng % 360);
+}
+
+const locatorToLatLng = (locatorString) => {
+	locatorString += 'll'; // append subsquare in case is 4 chars long...  If not, is ignored.
+	if (!isValidLocatorString(locatorString)) {
+		throw new Error('Input is not valid locator string');
+	}
+	
+	const fieldLng = charToNumber(locatorString[0]) * 20;
+	const fieldLat = charToNumber(locatorString[1]) * 10;
+	const squareLng = Number.parseInt(locatorString[2]) * 2;
+	const squareLat = Number.parseInt(locatorString[3]);
+	const subsquareLng = (charToNumber(locatorString[4]) + 0.5) / 12;
+	const subsquareLat = (charToNumber(locatorString[5]) + 0.5) / 24;
+	
+	return [
+		fieldLat + squareLat + subsquareLat - 90,
+		fieldLng + squareLng + subsquareLng - 180
+	];
+};
\ No newline at end of file
diff --git a/assets/js/sections/gridmap.js b/assets/js/sections/gridmap.js
index cec89f61..084ed5e3 100644
--- a/assets/js/sections/gridmap.js
+++ b/assets/js/sections/gridmap.js
@@ -40,6 +40,7 @@ function gridPlot(form) {
             sat: $("#sats").val(),
 		},
 		success: function (data) {
+            $('.cohidden').show();
             $(".ld-ext-right").removeClass('running');
             $(".ld-ext-right").prop('disabled', false);
             $('#plot').prop("disabled", false);
@@ -89,6 +90,7 @@ function gridPlot(form) {
             legend.addTo(map);
 
             var maidenhead = L.maidenhead().addTo(map);
+            map.on('mousemove', onMapMove);
 		},
 		error: function (data) {
 		},