Test for 9-slice image set usage.

osrs-toolbox/Controls/NineSlicePanel.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Media;
+
+namespace osrs_toolbox
+{
+    public class NineSlicePanel : FrameworkElement
+    {
+        public static string[] SliceNames =
+        {
+            "top_left", "top", "top_right",
+            "left", "center", "right",
+            "bottom_left", "bottom", "bottom_right"
+        };
+        public ImageSource[] Slices = new ImageSource[9];
+        public int BorderSize { get; set; } = 16;
+        protected override void OnRender(DrawingContext dc)
+        {
+            if (Slices.Length != 9)
+                return;
+            foreach (ImageSource Slice in Slices)
+            {
+                if (Slice == null) return;
+            }
+
+            double width = ActualWidth;
+            double height = ActualHeight;
+            double b = BorderSize;
+
+            Rect[] targets = 
+            {
+                new(0, 0, b, b),                     // TopLeft
+                new(b, 0, width - 2 * b, b),         // Top
+                new(width - b, 0, b, b),             // TopRight
+                new(0, b, b, height - 2 * b),        // Left
+                new(b, b, width - 2 * b, height - 2 * b), // Center
+                new(width - b, b, b, height - 2 * b),     // Right
+                new(0, height - b, b, b),            // BottomLeft
+                new(b, height - b, width - 2 * b, b),// Bottom
+                new(width - b, height - b, b, b)     // BottomRight
+            };
+
+            for (int i = 0; i < 9; i++)
+            {
+                if (Slices[i] != null)
+                    dc.DrawImage(Slices[i], targets[i]);
+            }
+        }
+    }
+}