RT state managment and rectangle support

dotnet/AipsRT/Model/Whiteboard/Whiteboard.cs

@@ -0,0 +1,41 @@
+using AipsRT.Model.Whiteboard.Shapes;
+
+namespace AipsRT.Model.Whiteboard;
+
+public class Whiteboard
+{
+    public Guid WhiteboardId { get; set; }
+    
+    public Guid OwnerId { get; set; }
+
+    public List<Shape> Shapes { get; } = [];
+
+    public List<Rectangle> Rectangles { get; } = [];
+    public List<Arrow> Arrows { get; } = [];
+    public List<Line> Lines { get; } = [];
+    public List<TextShape> TextShapes { get; } = [];
+
+    public void AddRectangle(Rectangle shape)
+    {
+        Shapes.Add(shape);
+        Rectangles.Add(shape);
+    }
+    
+    public void AddArrow(Arrow shape)
+    {
+        Shapes.Add(shape);
+        Arrows.Add(shape);
+    }
+    
+    public void AddLine(Line shape)
+    {
+        Shapes.Add(shape);
+        Lines.Add(shape);
+    }
+    
+    public void AddTextShape(TextShape shape)
+    {
+        Shapes.Add(shape);
+        TextShapes.Add(shape);
+    }
+}