Merge pull request #81 from Franz1960/LatLngBoundsLiteral_Extend

Added several convenience methods to LatLngBoundsLiteral.

.gitignore

@@ -330,3 +330,4 @@ ASALocalRun/
 .mfractor/
 GoogleMapsComponents/.vscode/*
 .gitignore
+.vscode

GoogleMapsComponents/Maps/Coordinates/LatLngBoundsLiteral.cs

@@ -11,6 +11,40 @@ namespace GoogleMapsComponents.Maps
     /// </summary>
     public class LatLngBoundsLiteral
     {
+        /// <summary>
+        /// Default constructor. Set East, North, South and West explicitely because here they are initialized to zero.
+        /// </summary>
+        public LatLngBoundsLiteral() {
+        }
+
+        /// <summary>
+        /// Constructor with one or two given coordinate points.
+        /// If the second point is null, the bounds are set to the first point.
+        /// The points may be positioned arbitrarily.
+        /// </summary>
+        public LatLngBoundsLiteral(LatLngLiteral latLng1,LatLngLiteral latLng2=null) {
+            East=latLng1.Lng;
+            West=latLng1.Lng;
+            South=latLng1.Lat;
+            North=latLng1.Lat;
+            if (latLng2!=null) {
+              Extend(latLng2);
+            }
+        }
+
+        /// <summary>
+        /// Create or extend a LatLngBoundsLiteral with a given coordinate point.
+        /// Using this method you can initialize a LatLngBoundsLiteral reference with null and call 
+        /// subsequently this method to extend the boundaries by given points.
+        /// </summary>
+        public static void CreateOrExtend(ref LatLngBoundsLiteral latLngBoundsLiteral,LatLngLiteral latLng) {
+            if (latLngBoundsLiteral == null) {
+                latLngBoundsLiteral = new LatLngBoundsLiteral(latLng);
+            } else {
+                latLngBoundsLiteral.Extend(latLng);
+            }
+        }
+
         /// <summary>
         /// East longitude in degrees. Values outside the range [-180, 180] will be wrapped to the range [-180, 180). 
         /// For example, a value of -190 will be converted to 170. 
@@ -42,6 +76,38 @@ public class LatLngBoundsLiteral
         /// </summary>
         public double West { get; set; }
 
+        /// <summary>
+        /// Extend these boundaries by a given coordinate point.
+        /// </summary>
+        public void Extend(double lng, double lat) {
+            if (lng < West) {
+              West = lng;
+            }
+            if (lng > East) {
+              East = lng;
+            }
+            if (lat < South) {
+              South = lat;
+            }
+            if (lat > North) {
+              North = lat;
+            }
+        }
+
+        /// <summary>
+        /// Extend these boundaries by a given coordinate point.
+        /// </summary>
+        public void Extend(LatLngLiteral latLng) {
+            Extend(latLng.Lng,latLng.Lat);
+        }
+
+        /// <summary>
+        /// Is the area zero?
+        /// </summary>
+        public bool IsEmpty() {
+            return (West == East || South == North);
+        }
+
         public override string ToString()
         {
             return $"{North} {East} {South} {West}";