Changed class Location to readonly struct

MapControl/Avalonia/MapBase.Avalonia.cs

@@ -21,13 +21,13 @@ namespace MapControl
             DependencyPropertyHelper.Register<MapBase, Easing>(nameof(AnimationEasing), new QuadraticEaseOut());
 
         public static readonly StyledProperty<Location> CenterProperty =
-            DependencyPropertyHelper.Register<MapBase, Location>(nameof(Center), new Location(),
+            DependencyPropertyHelper.Register<MapBase, Location>(nameof(Center), new Location(0d, 0d),
                 (map, oldValue, newValue) => map.CenterPropertyChanged(newValue),
                 (map, value) => map.CoerceCenterProperty(value),
                 true);
 
         public static readonly StyledProperty<Location> TargetCenterProperty =
-           DependencyPropertyHelper.Register<MapBase, Location>(nameof(TargetCenter), new Location(),
+           DependencyPropertyHelper.Register<MapBase, Location>(nameof(TargetCenter), new Location(0d, 0d),
                 async (map, oldValue, newValue) => await map.TargetCenterPropertyChanged(newValue),
                 (map, value) => map.CoerceCenterProperty(value),
                 true);

MapControl/Avalonia/MapContentControl.Avalonia.cs

@@ -1,42 +0,0 @@
-using Avalonia;
-using Avalonia.Controls;
-
-namespace MapControl
-{
-    /// <summary>
-    /// ContentControl placed on a MapPanel at a geographic location specified by the Location property.
-    /// </summary>
-    public class MapContentControl : ContentControl
-    {
-        public static readonly StyledProperty<bool> AutoCollapseProperty =
-            MapPanel.AutoCollapseProperty.AddOwner<MapContentControl>();
-
-        public static readonly StyledProperty<Location> LocationProperty =
-            MapPanel.LocationProperty.AddOwner<MapContentControl>();
-
-        /// <summary>
-        /// Gets/sets MapPanel.AutoCollapse.
-        /// </summary>
-        public bool AutoCollapse
-        {
-            get => GetValue(AutoCollapseProperty);
-            set => SetValue(AutoCollapseProperty, value);
-        }
-
-        /// <summary>
-        /// Gets/sets MapPanel.Location.
-        /// </summary>
-        public Location Location
-        {
-            get => GetValue(LocationProperty);
-            set => SetValue(LocationProperty, value);
-        }
-    }
-
-    /// <summary>
-    /// MapContentControl with a Pushpin Style.
-    /// </summary>
-    public class Pushpin : MapContentControl
-    {
-    }
-}

MapControl/Avalonia/MapItem.Avalonia.cs

@@ -1,22 +1,10 @@
-using Avalonia;
+using Avalonia.Controls;
-using Avalonia.Controls;
 using Avalonia.Input;
 
 namespace MapControl
 {
     public partial class MapItem
     {
-        public static readonly StyledProperty<bool> AutoCollapseProperty =
-            MapPanel.AutoCollapseProperty.AddOwner<MapItem>();
-
-        public static readonly StyledProperty<Location> LocationProperty =
-            MapPanel.LocationProperty.AddOwner<MapItem>();
-
-        static MapItem()
-        {
-            LocationProperty.Changed.AddClassHandler<MapItem, Location>((item, e) => item.UpdateMapTransform());
-        }
-
         protected override void OnPointerPressed(PointerPressedEventArgs e)
         {
             if (e.Pointer.Type != PointerType.Mouse &&

MapControl/Avalonia/MapPanel.Avalonia.cs

@@ -7,8 +7,8 @@ namespace MapControl
         public static readonly AttachedProperty<bool> AutoCollapseProperty =
             DependencyPropertyHelper.RegisterAttached<bool>("AutoCollapse", typeof(MapPanel));
 
-        public static readonly AttachedProperty<Location> LocationProperty =
+        public static readonly AttachedProperty<Location?> LocationProperty =
-            DependencyPropertyHelper.RegisterAttached<Location>("Location", typeof(MapPanel));
+            DependencyPropertyHelper.RegisterAttached<Location?>("Location", typeof(MapPanel));
 
         public static readonly AttachedProperty<BoundingBox> BoundingBoxProperty =
             DependencyPropertyHelper.RegisterAttached<BoundingBox>("BoundingBox", typeof(MapPanel));

MapControl/Avalonia/MapPolypoint.Avalonia.cs

@@ -14,7 +14,7 @@ namespace MapControl
 
             if (ParentMap != null && locations != null)
             {
-                var longitudeOffset = GetLongitudeOffset(Location ?? locations.FirstOrDefault());
+                var longitudeOffset = GetLongitudeOffset(locations);
 
                 AddPolylinePoints(figures, locations, longitudeOffset, closed);
             }
@@ -28,7 +28,7 @@ namespace MapControl
 
             if (ParentMap != null && polygons != null)
             {
-                var longitudeOffset = GetLongitudeOffset(Location);
+                var longitudeOffset = GetLongitudeOffset(polygons.FirstOrDefault());
 
                 foreach (var locations in polygons)
                 {

MapControl/Shared/Location.cs

@@ -5,35 +5,20 @@ namespace MapControl
 {
     /// <summary>
     /// A geographic location with latitude and longitude values in degrees.
-    /// For calculations with azimuth and distance on great circles, see
-    /// https://en.wikipedia.org/wiki/Great_circle,
-    /// https://en.wikipedia.org/wiki/Great-circle_distance,
-    /// https://en.wikipedia.org/wiki/Great-circle_navigation.
     /// </summary>
 #if UWP || WINUI
     [Windows.Foundation.Metadata.CreateFromString(MethodName = "Parse")]
 #else
     [System.ComponentModel.TypeConverter(typeof(LocationConverter))]
 #endif
-    public class Location : IEquatable<Location>
+    public readonly struct Location(double latitude, double longitude) : IEquatable<Location>
     {
-        // Arithmetic mean radius (2*a + b) / 3 == (1 - f/3) * a.
+        public double Latitude { get; } = Math.Min(Math.Max(latitude, -90d), 90d);
-        // See https://en.wikipedia.org/wiki/Earth_radius#Arithmetic_mean_radius.
+        public double Longitude => longitude;
-        //
-        public const double Wgs84MeanRadius = (1d - MapProjection.Wgs84Flattening / 3d) * MapProjection.Wgs84EquatorialRadius;
 
-        public Location()
+        public static bool operator ==(Location loc1, Location loc2) => loc1.Equals(loc2);
-        {
-        }
 
-        public Location(double latitude, double longitude)
+        public static bool operator !=(Location loc1, Location loc2) => !loc1.Equals(loc2);
-        {
-            Latitude = Math.Min(Math.Max(latitude, -90d), 90d);
-            Longitude = longitude;
-        }
-
-        public double Latitude { get; }
-        public double Longitude { get; }
 
         public bool LatitudeEquals(double latitude) => Math.Abs(Latitude - latitude) < 1e-9;
 
@@ -41,9 +26,9 @@ namespace MapControl
 
         public bool Equals(double latitude, double longitude) => LatitudeEquals(latitude) && LongitudeEquals(longitude);
 
-        public bool Equals(Location location) => location != null && Equals(location.Latitude, location.Longitude);
+        public bool Equals(Location location) => Equals(location.Latitude, location.Longitude);
 
-        public override bool Equals(object obj) => Equals(obj as Location);
+        public override bool Equals(object obj) => obj is Location location && Equals(location);
 
         public override int GetHashCode() => Latitude.GetHashCode() ^ Longitude.GetHashCode();
 
@@ -81,8 +66,14 @@ namespace MapControl
             return x < 0d ? x + 180d : x - 180d;
         }
 
+        // Arithmetic mean radius (2*a + b) / 3 == (1 - f/3) * a.
+        // See https://en.wikipedia.org/wiki/Earth_radius#Arithmetic_mean_radius.
+        //
+        public const double Wgs84MeanRadius = (1d - MapProjection.Wgs84Flattening / 3d) * MapProjection.Wgs84EquatorialRadius;
+
         /// <summary>
         /// Calculates great circle azimuth in degrees and distance in meters between this and the specified Location.
+        /// See https://en.wikipedia.org/wiki/Great-circle_navigation#Course.
         /// </summary>
         public (double, double) GetAzimuthDistance(Location location, double earthRadius = Wgs84MeanRadius)
         {
@@ -108,6 +99,7 @@ namespace MapControl
 
         /// <summary>
         /// Calculates great distance in meters between this and the specified Location.
+        /// See https://en.wikipedia.org/wiki/Great-circle_navigation#Course.
         /// </summary>
         public double GetDistance(Location location, double earthRadius = Wgs84MeanRadius)
         {
@@ -118,6 +110,7 @@ namespace MapControl
 
         /// <summary>
         /// Calculates the Location on a great circle at the specified azimuth in degrees and distance in meters from this Location.
+        /// See https://en.wikipedia.org/wiki/Great-circle_navigation#Finding_way-points.
         /// </summary>
         public Location GetLocation(double azimuth, double distance, double earthRadius = Wgs84MeanRadius)
         {

MapControl/Shared/MapBase.cs

@@ -43,7 +43,7 @@ namespace MapControl
             DependencyPropertyHelper.Register<MapBase, MapProjection>(nameof(MapProjection), new WebMercatorProjection(),
                 (map, oldValue, newValue) => map.MapProjectionPropertyChanged(newValue));
 
-        private Location transformCenter;
+        private Location? transformCenter;
         private Point viewCenter;
         private double centerLongitude;
         private double maxLatitude = 85.05112878; // default WebMercatorProjection
@@ -326,12 +326,7 @@ namespace MapControl
 
         private Location CoerceCenterProperty(Location center)
         {
-            if (center == null)
+            if (center.Latitude < -maxLatitude || center.Latitude > maxLatitude ||
-            {
-                center = new Location();
-            }
-            else if (
-                center.Latitude < -maxLatitude || center.Latitude > maxLatitude ||
                 center.Longitude < -180d || center.Longitude > 180d)
             {
                 center = new Location(
@@ -391,7 +386,7 @@ namespace MapControl
 
             ViewTransform.SetTransform(mapCenter, viewCenter, viewScale, -Heading);
 
-            if (transformCenter != null)
+            if (transformCenter.HasValue)
             {
                 var center = ViewToLocation(new Point(ActualWidth / 2d, ActualHeight / 2d));
                 var latitude = center.Latitude;
@@ -419,7 +414,7 @@ namespace MapControl
                 {
                     // Check if transform center has moved across 180° longitude.
                     //
-                    transformCenterChanged = Math.Abs(center.Longitude - transformCenter.Longitude) > 180d;
+                    transformCenterChanged = Math.Abs(center.Longitude - transformCenter.Value.Longitude) > 180d;
                     ResetTransformCenter();
                     mapCenter = MapProjection.LocationToMap(center);
                     ViewTransform.SetTransform(mapCenter, viewCenter, viewScale, -Heading);

MapControl/Shared/MapContentControl.cs

@@ -0,0 +1,54 @@
+#if WPF
+using System.Windows;
+using System.Windows.Controls;
+#elif UWP
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+#elif WINUI
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+#elif AVALONIA
+using Avalonia.Controls;
+#endif
+
+namespace MapControl
+{
+    /// <summary>
+    /// ContentControl placed on a MapPanel at a geographic location specified by the Location property.
+    /// </summary>
+    public partial class MapContentControl : ContentControl
+    {
+        public static readonly DependencyProperty LocationProperty =
+            DependencyPropertyHelper.Register<MapContentControl, Location>(nameof(Location), default,
+                (control, oldValue, newValue) => MapPanel.SetLocation(control, newValue));
+
+        public static readonly DependencyProperty AutoCollapseProperty =
+            DependencyPropertyHelper.Register<MapContentControl, bool>(nameof(AutoCollapse), false,
+                (control, oldValue, newValue) => MapPanel.SetAutoCollapse(control, newValue));
+
+        /// <summary>
+        /// Gets/sets MapPanel.Location.
+        /// </summary>
+        public Location Location
+        {
+            get => (Location)GetValue(LocationProperty);
+            set => SetValue(LocationProperty, value);
+        }
+
+        /// <summary>
+        /// Gets/sets MapPanel.AutoCollapse.
+        /// </summary>
+        public bool AutoCollapse
+        {
+            get => (bool)GetValue(AutoCollapseProperty);
+            set => SetValue(AutoCollapseProperty, value);
+        }
+    }
+
+    /// <summary>
+    /// MapContentControl with a Pushpin Style.
+    /// </summary>
+    public partial class Pushpin : MapContentControl
+    {
+    }
+}

MapControl/Shared/MapItem.cs

@@ -1,10 +1,13 @@
 #if WPF
+using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
 #elif UWP
+using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Media;
 #elif WINUI
+using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Media;
 #elif AVALONIA
@@ -19,14 +22,17 @@ namespace MapControl
     /// </summary>
     public partial class MapItem : ListBoxItem, IMapElement
     {
-        /// <summary>
+        public static readonly DependencyProperty LocationProperty =
-        /// Gets/sets MapPanel.AutoCollapse.
+            DependencyPropertyHelper.Register<MapItem, Location>(nameof(Location), default,
-        /// </summary>
+                (item, oldValue, newValue) =>
-        public bool AutoCollapse
+                {
-        {
+                    MapPanel.SetLocation(item, newValue);
-            get => (bool)GetValue(AutoCollapseProperty);
+                    item.UpdateMapTransform();
-            set => SetValue(AutoCollapseProperty, value);
+                });
-        }
+
+        public static readonly DependencyProperty AutoCollapseProperty =
+            DependencyPropertyHelper.Register<MapItem, bool>(nameof(AutoCollapse), false,
+                (item, oldValue, newValue) => MapPanel.SetAutoCollapse(item, newValue));
 
         /// <summary>
         /// Gets/sets MapPanel.Location.
@@ -37,6 +43,15 @@ namespace MapControl
             set => SetValue(LocationProperty, value);
         }
 
+        /// <summary>
+        /// Gets/sets MapPanel.AutoCollapse.
+        /// </summary>
+        public bool AutoCollapse
+        {
+            get => (bool)GetValue(AutoCollapseProperty);
+            set => SetValue(AutoCollapseProperty, value);
+        }
+
         /// <summary>
         /// Implements IMapElement.ParentMap.
         /// </summary>
@@ -94,7 +109,7 @@ namespace MapControl
 
         private void UpdateMapTransform()
         {
-            if (MapTransform != null && ParentMap != null && Location != null)
+            if (MapTransform != null && ParentMap != null)
             {
                 MapTransform.Matrix = ParentMap.GetMapToViewTransform(Location);
             }

MapControl/Shared/MapItemsControl.cs

@@ -68,7 +68,7 @@ namespace MapControl
             {
                 var location = MapPanel.GetLocation(ContainerFromItem(item));
 
-                return location != null && predicate(location);
+                return location.HasValue && predicate(location.Value);
             });
         }
 

MapControl/Shared/MapPanel.cs

@@ -99,15 +99,15 @@ namespace MapControl
         /// <summary>
         /// Gets the Location of an element.
         /// </summary>
-        public static Location GetLocation(FrameworkElement element)
+        public static Location? GetLocation(FrameworkElement element)
         {
-            return (Location)element.GetValue(LocationProperty);
+            return (Location?)element.GetValue(LocationProperty);
         }
 
         /// <summary>
         /// Sets the Location of an element.
         /// </summary>
-        public static void SetLocation(FrameworkElement element, Location value)
+        public static void SetLocation(FrameworkElement element, Location? value)
         {
             element.SetValue(LocationProperty, value);
         }
@@ -261,9 +261,9 @@ namespace MapControl
         {
             var location = GetLocation(element);
 
-            if (location != null)
+            if (location.HasValue)
             {
-                var position = SetViewPosition(element, GetViewPosition(location));
+                var position = SetViewPosition(element, GetViewPosition(location.Value));
 
                 if (GetAutoCollapse(element))
                 {

MapControl/Shared/MapPath.cs

@@ -17,15 +17,15 @@ namespace MapControl
     public partial class MapPath : IMapElement
     {
         public static readonly DependencyProperty LocationProperty =
-            DependencyPropertyHelper.Register<MapPath, Location>(nameof(Location), null,
+            DependencyPropertyHelper.Register<MapPath, Location>(nameof(Location), default,
                 (path, oldValue, newValue) => path.UpdateData());
 
         /// <summary>
-        /// Gets or sets a Location that is used as
+        /// Gets or sets a Location that is either used as
-        /// - either the origin point of a geometry specified in projected map coordinates (meters)
+        /// - the origin point of a geometry specified in projected map coordinates (meters) or
-        /// - or as an optional anchor point to constrain the view position of MapPaths with multiple
+        /// - as an optional anchor point to constrain the view position of MapPaths with
-        ///   Locations (like MapPolyline or MapPolygon) to the visible map viewport, as done
+        ///   multiple Locations (like MapPolyline or MapPolygon) to the visible map viewport,
-        ///   for elements where the MapPanel.Location property is set.
+        ///   as done for elements where the MapPanel.Location property is set.
         /// </summary>
         public Location Location
         {
@@ -64,7 +64,7 @@ namespace MapControl
 
         protected virtual void UpdateData()
         {
-            if (ParentMap != null && Location != null && Data != null)
+            if (ParentMap != null && Data != null)
             {
                 SetDataTransform(ParentMap.GetMapToViewTransform(Location));
             }
@@ -72,23 +72,6 @@ namespace MapControl
             MapPanel.SetLocation(this, Location);
         }
 
-        protected double GetLongitudeOffset(Location location)
-        {
-            var longitudeOffset = 0d;
-
-            if (location != null != ParentMap.MapProjection.IsNormalCylindrical)
-            {
-                var position = ParentMap.LocationToView(location);
-
-                if (!ParentMap.InsideViewBounds(position))
-                {
-                    longitudeOffset = ParentMap.NearestLongitude(location.Longitude) - location.Longitude;
-                }
-            }
-
-            return longitudeOffset;
-        }
-
         protected Point LocationToMap(Location location, double longitudeOffset)
         {
             var point = ParentMap.MapProjection.LocationToMap(location.Latitude, location.Longitude + longitudeOffset);

MapControl/Shared/MapPolypoint.cs

@@ -1,5 +1,8 @@
 using System.Collections;
+using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Linq;
+
 #if WPF
 using System.Windows;
 using System.Windows.Media;
@@ -37,6 +40,7 @@ namespace MapControl
         protected MapPolypoint()
         {
             Data = new PolypointGeometry();
+            Location = new Location(0d, double.NaN);
         }
 
         protected void DataCollectionPropertyChanged(IEnumerable oldValue, IEnumerable newValue)
@@ -58,5 +62,35 @@ namespace MapControl
         {
             UpdateData();
         }
+
+        protected double GetLongitudeOffset(IEnumerable<Location> locations)
+        {
+            if (!ParentMap.MapProjection.IsNormalCylindrical)
+            {
+                return 0d;
+            }
+
+            Location location;
+
+            if (!double.IsNaN(Location.Longitude))
+            {
+                location = Location;
+            }
+            else if (locations != null && locations.Any())
+            {
+                location = locations.First();
+            }
+            else
+            {
+                return 0d;
+            }
+
+            if (ParentMap.InsideViewBounds(ParentMap.LocationToView(location)))
+            {
+                return 0d;
+            }
+
+            return ParentMap.NearestLongitude(location.Longitude) - location.Longitude;
+        }
     }
 }

MapControl/WPF/MapBase.WPF.cs

@@ -15,13 +15,13 @@ namespace MapControl
                 new QuadraticEase { EasingMode = EasingMode.EaseOut });
 
         public static readonly DependencyProperty CenterProperty =
-            DependencyPropertyHelper.Register<MapBase, Location>(nameof(Center), new Location(),
+            DependencyPropertyHelper.Register<MapBase, Location>(nameof(Center), new Location(0d, 0d),
                 (map, oldValue, newValue) => map.CenterPropertyChanged(newValue),
                 (map, value) => map.CoerceCenterProperty(value),
                 true);
 
         public static readonly DependencyProperty TargetCenterProperty =
-           DependencyPropertyHelper.Register<MapBase, Location>(nameof(TargetCenter), new Location(),
+           DependencyPropertyHelper.Register<MapBase, Location>(nameof(TargetCenter), new Location(0d, 0d),
                 (map, oldValue, newValue) => map.TargetCenterPropertyChanged(newValue),
                 (map, value) => map.CoerceCenterProperty(value),
                 true);

MapControl/WPF/MapContentControl.WPF.cs

@@ -1,47 +1,16 @@
 using System.Windows;
-using System.Windows.Controls;
 
 namespace MapControl
 {
-    /// <summary>
+    public partial class MapContentControl
-    /// ContentControl placed on a MapPanel at a geographic location specified by the Location property.
-    /// </summary>
-    public class MapContentControl : ContentControl
     {
-        public static readonly DependencyProperty AutoCollapseProperty =
-            MapPanel.AutoCollapseProperty.AddOwner(typeof(MapContentControl));
-
-        public static readonly DependencyProperty LocationProperty =
-            MapPanel.LocationProperty.AddOwner(typeof(MapContentControl));
-
         static MapContentControl()
         {
             DefaultStyleKeyProperty.OverrideMetadata(typeof(MapContentControl), new FrameworkPropertyMetadata(typeof(MapContentControl)));
         }
-
-        /// <summary>
-        /// Gets/sets MapPanel.AutoCollapse.
-        /// </summary>
-        public bool AutoCollapse
-        {
-            get => (bool)GetValue(AutoCollapseProperty);
-            set => SetValue(AutoCollapseProperty, value);
-        }
-
-        /// <summary>
-        /// Gets/sets MapPanel.Location.
-        /// </summary>
-        public Location Location
-        {
-            get => (Location)GetValue(LocationProperty);
-            set => SetValue(LocationProperty, value);
-        }
     }
 
-    /// <summary>
+    public partial class Pushpin
-    /// MapContentControl with a Pushpin Style.
-    /// </summary>
-    public class Pushpin : MapContentControl
     {
         static Pushpin()
         {

MapControl/WPF/MapItem.WPF.cs

@@ -6,13 +6,6 @@ namespace MapControl
 {
     public partial class MapItem
     {
-        public static readonly DependencyProperty AutoCollapseProperty =
-            MapPanel.AutoCollapseProperty.AddOwner(typeof(MapItem));
-
-        public static readonly DependencyProperty LocationProperty =
-            MapPanel.LocationProperty.AddOwner(typeof(MapItem),
-                new FrameworkPropertyMetadata(null, (o, e) => ((MapItem)o).UpdateMapTransform()));
-
         static MapItem()
         {
             DefaultStyleKeyProperty.OverrideMetadata(typeof(MapItem), new FrameworkPropertyMetadata(typeof(MapItem)));

MapControl/WPF/MapPanel.WPF.cs

@@ -8,7 +8,7 @@ namespace MapControl
             DependencyPropertyHelper.RegisterAttached< bool>("AutoCollapse", typeof(MapPanel));
 
         public static readonly DependencyProperty LocationProperty =
-            DependencyPropertyHelper.RegisterAttached<Location>("Location", typeof(MapPanel), null,
+            DependencyPropertyHelper.RegisterAttached<Location?>("Location", typeof(MapPanel), null,
                 FrameworkPropertyMetadataOptions.AffectsParentArrange);
 
         public static readonly DependencyProperty BoundingBoxProperty =

MapControl/WPF/MapPolypoint.WPF.cs

@@ -13,7 +13,7 @@ namespace MapControl
 
             if (ParentMap != null && locations != null)
             {
-                var longitudeOffset = GetLongitudeOffset(Location ?? locations.FirstOrDefault());
+                var longitudeOffset = GetLongitudeOffset(locations);
 
                 AddPolylinePoints(context, locations, longitudeOffset, closed);
             }
@@ -25,7 +25,7 @@ namespace MapControl
 
             if (ParentMap != null && polygons != null)
             {
-                var longitudeOffset = GetLongitudeOffset(Location);
+                var longitudeOffset = GetLongitudeOffset(polygons.FirstOrDefault());
 
                 foreach (var locations in polygons)
                 {

MapControl/WinUI/MapBase.WinUI.cs

@@ -23,11 +23,11 @@ namespace MapControl
                 new QuadraticEase { EasingMode = EasingMode.EaseOut });
 
         public static readonly DependencyProperty CenterProperty =
-            DependencyPropertyHelper.Register<MapBase, Location>(nameof(Center), new Location(),
+            DependencyPropertyHelper.Register<MapBase, Location>(nameof(Center), new Location(0d, 0d),
                 (map, oldValue, newValue) => map.CenterPropertyChanged(newValue));
 
         public static readonly DependencyProperty TargetCenterProperty =
-           DependencyPropertyHelper.Register<MapBase, Location>(nameof(TargetCenter), new Location(),
+           DependencyPropertyHelper.Register<MapBase, Location>(nameof(TargetCenter), new Location(0d, 0d),
                 (map, oldValue, newValue) => map.TargetCenterPropertyChanged(newValue));
 
         public static readonly DependencyProperty MinZoomLevelProperty =

MapControl/WinUI/MapContentControl.WinUI.cs

@@ -1,52 +1,21 @@
 #if UWP
 using Windows.UI.Xaml;
-using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Data;
 #else
 using Microsoft.UI.Xaml;
-using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Data;
 #endif
 
 namespace MapControl
 {
-    /// <summary>
+    public partial class MapContentControl
-    /// ContentControl placed on a MapPanel at a geographic location specified by the Location property.
-    /// </summary>
-    public partial class MapContentControl : ContentControl
     {
-        public static readonly DependencyProperty AutoCollapseProperty =
-            DependencyPropertyHelper.Register<MapContentControl, bool>(nameof(AutoCollapse), false,
-                (control, oldValue, newValue) => MapPanel.SetAutoCollapse(control, newValue));
-
-        public static readonly DependencyProperty LocationProperty =
-            DependencyPropertyHelper.Register<MapContentControl, Location>(nameof(Location), null,
-                (control, oldValue, newValue) => MapPanel.SetLocation(control, newValue));
-
         public MapContentControl()
         {
             DefaultStyleKey = typeof(MapContentControl);
             MapPanel.InitMapElement(this);
         }
 
-        /// <summary>
-        /// Gets/sets MapPanel.AutoCollapse.
-        /// </summary>
-        public bool AutoCollapse
-        {
-            get => (bool)GetValue(AutoCollapseProperty);
-            set => SetValue(AutoCollapseProperty, value);
-        }
-
-        /// <summary>
-        /// Gets/sets MapPanel.Location.
-        /// </summary>
-        public Location Location
-        {
-            get => (Location)GetValue(LocationProperty);
-            set => SetValue(LocationProperty, value);
-        }
-
         protected override void OnApplyTemplate()
         {
             base.OnApplyTemplate();
@@ -76,10 +45,7 @@ namespace MapControl
         }
     }
 
-    /// <summary>
+    public partial class Pushpin : MapContentControl
-    /// MapContentControl with a Pushpin Style.
-    /// </summary>
-    public class Pushpin : MapContentControl
     {
         public Pushpin()
         {

MapControl/WinUI/MapItem.WinUI.cs

@@ -16,18 +16,6 @@ namespace MapControl
 {
     public partial class MapItem
     {
-        public static readonly DependencyProperty AutoCollapseProperty =
-            DependencyPropertyHelper.Register<MapItem, bool>(nameof(AutoCollapse), false,
-                (item, oldValue, newValue) => MapPanel.SetAutoCollapse(item, newValue));
-
-        public static readonly DependencyProperty LocationProperty =
-            DependencyPropertyHelper.Register<MapItem, Location>(nameof(Location), null,
-                (item, oldValue, newValue) =>
-                {
-                    MapPanel.SetLocation(item, newValue);
-                    item.UpdateMapTransform();
-                });
-
         private Windows.Foundation.Point? pointerPressedPosition;
 
         public MapItem()

MapControl/WinUI/MapPanel.WinUI.cs

@@ -14,7 +14,7 @@ namespace MapControl
             DependencyPropertyHelper.RegisterAttached<bool>("AutoCollapse", typeof(MapPanel));
 
         public static readonly DependencyProperty LocationProperty =
-            DependencyPropertyHelper.RegisterAttached<Location>("Location", typeof(MapPanel), null,
+            DependencyPropertyHelper.RegisterAttached<Location?>("Location", typeof(MapPanel), null,
                 (element, oldValue, newValue) => (element.Parent as MapPanel)?.InvalidateArrange());
 
         public static readonly DependencyProperty BoundingBoxProperty =

MapControl/WinUI/MapPolypoint.WinUI.cs

@@ -18,7 +18,7 @@ namespace MapControl
 
             if (ParentMap != null && locations != null)
             {
-                var longitudeOffset = GetLongitudeOffset(Location ?? locations.FirstOrDefault());
+                var longitudeOffset = GetLongitudeOffset(locations);
 
                 AddPolylinePoints(figures, locations, longitudeOffset, closed);
             }
@@ -31,7 +31,7 @@ namespace MapControl
 
             if (ParentMap != null && polygons != null)
             {
-                var longitudeOffset = GetLongitudeOffset(Location);
+                var longitudeOffset = GetLongitudeOffset(polygons.FirstOrDefault());
 
                 foreach (var locations in polygons)
                 {

MapControl/WinUI/Rect.WinUI.cs

@@ -5,28 +5,12 @@ namespace MapControl
     /// <summary>
     /// Replaces Windows.Foundation.Rect for double floating point precision.
     /// </summary>
-    public readonly struct Rect : IEquatable<Rect>
+    public readonly struct Rect(double x, double y, double width, double height) : IEquatable<Rect>
     {
-        public Rect(double x, double y, double width, double height)
+        public double X => x;
-        {
+        public double Y => y;
-            X = x;
+        public double Width => width;
-            Y = y;
+        public double Height => height;
-            Width = width;
-            Height = height;
-        }
-
-        public Rect(Point p1, Point p2)
-        {
-            X = Math.Min(p1.X, p2.X);
-            Y = Math.Min(p1.Y, p2.Y);
-            Width = Math.Max(p1.X, p2.X) - X;
-            Height = Math.Max(p1.Y, p2.Y) - Y;
-        }
-
-        public double X { get; }
-        public double Y { get; }
-        public double Width { get; }
-        public double Height { get; }
 
         public static implicit operator Windows.Foundation.Rect(Rect r) => new(r.X, r.Y, r.Width, r.Height);
 

SampleApps/AvaloniaApp/MainWindow.axaml.cs

@@ -63,12 +63,9 @@ namespace SampleApplication
                     e.Pointer.Capture(map);
                     var location = map.ViewToLocation(point.Position);
 
-                    if (location != null)
+                    map.Cursor = new Cursor(StandardCursorType.Cross);
-                    {
+                    measurementLine.IsVisible = true;
-                        map.Cursor = new Cursor(StandardCursorType.Cross);
+                    measurementLine.Locations = new LocationCollection(location);
-                        measurementLine.IsVisible = true;
-                        measurementLine.Locations = new LocationCollection(location);
-                    }
                 }
             }
         }
@@ -88,23 +85,14 @@ namespace SampleApplication
         {
             var location = map.ViewToLocation(e.GetPosition(map));
 
-            if (location != null)
+            mouseLocation.IsVisible = true;
-            {
+            mouseLocation.Text = GetLatLonText(location);
-                mouseLocation.IsVisible = true;
-                mouseLocation.Text = GetLatLonText(location);
 
-                var start = measurementLine.Locations?.FirstOrDefault();
+            if (measurementLine.Locations != null)
-
-                if (start != null)
-                {
-                    measurementLine.Locations = LocationCollection.GeodesicLocations(start, location);
-                    mouseLocation.Text += GetDistanceText(location.GetDistance(start));
-                }
-            }
-            else
             {
-                mouseLocation.IsVisible = false;
+                var start = measurementLine.Locations.First();
-                mouseLocation.Text = "";
+                measurementLine.Locations = LocationCollection.GeodesicLocations(start, location);
+                mouseLocation.Text += GetDistanceText(location.GetDistance(start));
             }
         }
 

SampleApps/WinUiApp/MainWindow.xaml.cs

@@ -59,11 +59,8 @@ namespace SampleApplication
                 {
                     var location = map.ViewToLocation(point.Position);
 
-                    if (location != null)
+                    measurementLine.Visibility = Visibility.Visible;
-                    {
+                    measurementLine.Locations = new LocationCollection(location);
-                        measurementLine.Visibility = Visibility.Visible;
-                        measurementLine.Locations = new LocationCollection(location);
-                    }
                 }
                 else if (e.KeyModifiers.HasFlag(VirtualKeyModifiers.Control) && map.MapLayer is WmsImageLayer wmsLayer)
                 {
@@ -87,23 +84,14 @@ namespace SampleApplication
             var point = e.GetCurrentPoint(map);
             var location = map.ViewToLocation(point.Position);
 
-            if (location != null)
+            mouseLocation.Visibility = Visibility.Visible;
-            {
+            mouseLocation.Text = GetLatLonText(location);
-                mouseLocation.Visibility = Visibility.Visible;
-                mouseLocation.Text = GetLatLonText(location);
 
-                var start = measurementLine.Locations?.FirstOrDefault();
+            if (measurementLine.Locations != null)
-
-                if (start != null)
-                {
-                    measurementLine.Locations = LocationCollection.GeodesicLocations(start, location);
-                    mouseLocation.Text += GetDistanceText(location.GetDistance(start));
-                }
-            }
-            else
             {
-                mouseLocation.Visibility = Visibility.Collapsed;
+                var start = measurementLine.Locations.First();
-                mouseLocation.Text = "";
+                measurementLine.Locations = LocationCollection.GeodesicLocations(start, location);
+                mouseLocation.Text += GetDistanceText(location.GetDistance(start));
             }
         }
 

SampleApps/WpfApplication/MainWindow.xaml.cs

@@ -80,7 +80,7 @@ namespace SampleApplication
         {
             var location = map.ViewToLocation(e.GetPosition(map));
 
-            if (location != null && map.CaptureMouse())
+            if (map.CaptureMouse())
             {
                 map.Cursor = Cursors.Cross;
                 measurementLine.Visibility = Visibility.Visible;
@@ -100,23 +100,14 @@ namespace SampleApplication
         {
             var location = map.ViewToLocation(e.GetPosition(map));
 
-            if (location != null)
+            mouseLocation.Visibility = Visibility.Visible;
-            {
+            mouseLocation.Text = GetLatLonText(location);
-                mouseLocation.Visibility = Visibility.Visible;
-                mouseLocation.Text = GetLatLonText(location);
 
-                var start = measurementLine.Locations?.FirstOrDefault();
+            if (measurementLine.Locations != null)
-
-                if (start != null)
-                {
-                    measurementLine.Locations = LocationCollection.GeodesicLocations(start, location);
-                    mouseLocation.Text += GetDistanceText(location.GetDistance(start));
-                }
-            }
-            else
             {
-                mouseLocation.Visibility = Visibility.Collapsed;
+                var start = measurementLine.Locations.First();
-                mouseLocation.Text = "";
+                measurementLine.Locations = LocationCollection.GeodesicLocations(start, location);
+                mouseLocation.Text += GetDistanceText(location.GetDistance(start));
             }
         }