Add missing OffsetX and OffsetY events to MouseEventArgs.

Author: Valks

src/Components/Web.JS/src/Rendering/EventForDotNet.ts

@@ -201,6 +201,8 @@ function parseMouseEvent(event: MouseEvent) {
     screenY: event.screenY,
     clientX: event.clientX,
     clientY: event.clientY,
+    offsetX: event.offsetX,
+    offsetY: event.offsetY,
     button: event.button,
     buttons: event.buttons,
     ctrlKey: event.ctrlKey,
@@ -317,6 +319,8 @@ interface UIMouseEventArgs extends UIEventArgs {
   screenY: number;
   clientX: number;
   clientY: number;
+  offsetX: number;
+  offsetY: number;
   button: number;
   buttons: number;
   ctrlKey: boolean;

src/Components/Web/src/Web/MouseEventArgs.cs

@@ -35,6 +35,16 @@ public class MouseEventArgs : EventArgs
         /// </summary>
         public double ClientY { get; set; }
 
+        /// <summary>
+        /// The X coordinate of the mouse pointer in relative (Target Element) coordinates.
+        /// </summary>
+        public double OffsetX { get; set; }
+
+        /// <summary>
+        /// The Y coordinate of the mouse pointer in relative (Target Element) coordinates.
+        /// </summary>
+        public double OffsetY { get; set; }
+
         /// <summary>
         /// The button number that was pressed when the mouse event was fired:
         /// Left button=0,