Diagram creation is solid

src/Dsl/CustomCode/Partials/ClassShape.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
+using System.Windows.Forms;
 
 using Sawczyn.EFDesigner.EFModel.Extensions;
 
@@ -370,5 +371,6 @@ public override void OnDoubleClick(DiagramPointEventArgs e)
             ErrorDisplay.Show($"Can't open generated file for {modelClass.Name}");
          }
       }
+
    }
 }

src/Dsl/CustomCode/Partials/EFModelDiagram.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Windows.Forms;
 
+using Microsoft.VisualStudio.Modeling;
 using Microsoft.VisualStudio.Modeling.Diagrams;
 using Microsoft.VisualStudio.Modeling.Diagrams.GraphObject;
 
@@ -16,7 +17,7 @@ public partial class EFModelDiagram: IHasStore
       public override void OnInitialize()
       {
          base.OnInitialize();
-         ModelRoot modelRoot = Store.GetAll<ModelRoot>().FirstOrDefault();
+         ModelRoot modelRoot = Store.ModelRoot();
 
          // because we can hide elements, line routing looks odd when it thinks it's jumping over lines
          // that really aren't visible. Since replacing the routing algorithm is too hard (impossible?)
@@ -28,6 +29,18 @@ public override void OnInitialize()
          GridColor = modelRoot?.GridColor ?? Color.Gainsboro;
          SnapToGrid = modelRoot?.SnapToGrid ?? true;
          GridSize = modelRoot?.GridSize ?? 0.125;
+
+      }
+
+      /// <summary>
+      /// Called during view fixup to ask the parent whether a shape should be created for the given child element.
+      /// </summary>
+      /// <remarks>
+      /// Always return true, since we assume there is only one diagram per model file for DSL scenarios.
+      /// </remarks>
+      protected override bool ShouldAddShapeForElement(ModelElement element)
+      {
+         return base.ShouldAddShapeForElement(element) || NestedChildShapes.Any(s => s.ModelElement == element);
       }
 
       public static bool IsDropping { get; private set; }
@@ -36,8 +49,15 @@ public override void OnDragOver(DiagramDragEventArgs diagramDragEventArgs)
       {
          base.OnDragOver(diagramDragEventArgs);
 
-         if (diagramDragEventArgs.Effect == DragDropEffects.None && IsAcceptableDropItem(diagramDragEventArgs))
+         if (diagramDragEventArgs.Handled)
+            return;
+
+         if (diagramDragEventArgs.Data.GetData(typeof(ModelElement)) is ModelElement)
+            diagramDragEventArgs.Effect = DragDropEffects.Move;
+         else if (IsAcceptableDropItem(diagramDragEventArgs))
             diagramDragEventArgs.Effect = DragDropEffects.Copy;
+         else
+            diagramDragEventArgs.Effect = DragDropEffects.None;
       }
 
       private bool IsAcceptableDropItem(DiagramDragEventArgs diagramDragEventArgs)
@@ -48,16 +68,30 @@ private bool IsAcceptableDropItem(DiagramDragEventArgs diagramDragEventArgs)
          return IsDropping;
       }
 
+      public bool DropTarget { get; private set; }
       public override void OnDragDrop(DiagramDragEventArgs diagramDragEventArgs)
       {
          try
          {
+            DropTarget = true;
             base.OnDragDrop(diagramDragEventArgs);
          }
          catch (ArgumentException)
          {
             // ignore. byproduct of multiple diagrams
          }
+         finally
+         {
+            DropTarget = false;
+         }
+
+         // came from model explorer?
+         if (diagramDragEventArgs.Effect == DragDropEffects.Move && diagramDragEventArgs.Data.GetData(typeof(ModelElement)) is ModelElement element)
+         {
+            FixUpAllDiagrams.FixUp(this, Store.ModelRoot(), element);
+
+            return;
+         }
 
          if (IsDropping)
          {
@@ -106,5 +140,46 @@ public override void OnMouseUp(DiagramMouseEventArgs e)
          IsDropping = false;
          base.OnMouseUp(e);
       }
+
+      /// <summary>
+      /// Called when a key is pressed when the Diagram itself has the focus.
+      /// </summary>
+      /// <param name="e">A DiagramKeyEventArgs that contains event data.</param>
+      public override void OnKeyDown(DiagramKeyEventArgs e)
+      {
+         //using (Transaction t = Store.TransactionManager.BeginTransaction("Diagram.OnKeyDown"))
+         //{
+
+         //   if (e.KeyCode == Keys.Delete)
+         //   {
+         //      SelectedShapesCollection selection = FocusedDiagramView.Selection;
+
+         //      string message = selection.Count == 1
+         //                          ? "Delete multiple elements from model? Are you sure?"
+         //                          : "Delete element from model? Are you sure?";
+
+         //      if (e.Control && BooleanQuestionDisplay.Show(message) == true)
+         //      {
+         //         foreach (ModelElement modelElement in selection.RepresentedElements)
+         //            modelElement.Delete();
+         //         t.Commit();
+         //         e.Handled = true;
+         //      }
+         //      else if (!e.Control)
+         //      {
+         //         foreach (DiagramItem diagramItem in selection)
+         //         {
+         //            if (diagramItem.Shape is NodeShape nodeShape)
+         //               nodeShape.Delete();
+         //         }
+
+         //         t.Commit();
+         //         e.Handled = true;
+         //      }
+         //   }
+         //}
+
+         base.OnKeyDown(e);
+      }
    }
 }

src/Dsl/CustomCode/Partials/FixUpAllDiagrams.cs

@@ -0,0 +1,18 @@
+//using System;
+//using System.Collections.Generic;
+//using System.Linq;
+//using System.Text;
+//using System.Threading.Tasks;
+
+//using Microsoft.VisualStudio.Modeling;
+
+//namespace Sawczyn.EFDesigner.EFModel
+//{
+//   partial class FixUpAllDiagrams
+//   {
+//      protected override bool SkipFixup(ModelElement childElement)
+//      {
+//         return childElement.IsDeleted || childElement.Store.TransactionManager.CurrentTransaction.IsSerializing;
+//      }
+//   }
+//}

src/Dsl/CustomCode/Partials/UnidirectionalConnector.cs

@@ -1,16 +1,17 @@
-//using Microsoft.VisualStudio.Modeling.Diagrams;
+using Microsoft.VisualStudio.Modeling.Diagrams;
 
-//namespace Sawczyn.EFDesigner.EFModel
-//{
-//   public partial class UnidirectionalConnector
-//   {
-//      public override bool HasToolTip => true;
+namespace Sawczyn.EFDesigner.EFModel
+{
+   partial class ClassShape
+   {
+      /// <summary>Called when a key is pressed.</summary>
+      /// <param name="e">A DiagramKeyEventArgs that contains event data.</param>
+      public override void OnKeyDown(DiagramKeyEventArgs e)
+      {
+         base.OnKeyDown(e);
+      }
+   }
+
+
+}
 
-//      public override string GetToolTipText(DiagramItem item)
-//      {
-//         return item.Shape.ModelElement is Association association
-//                   ? association.GetDisplayText()
-//                   : string.Empty;
-//      }
-//   }
-//}

src/Dsl/Dsl.csproj

@@ -139,6 +139,7 @@
     <Compile Include="CustomCode\Name Providers\ModelDiagramDataNameProvider.cs" />
     <Compile Include="CustomCode\Partials\AssociationConnector.cs" />
     <Compile Include="CustomCode\Domain Types\Namespaces.cs" />
+    <Compile Include="CustomCode\Partials\FixUpAllDiagrams.cs" />
     <Compile Include="CustomCode\Partials\ModelDiagramData.cs" />
     <Compile Include="CustomCode\Rules\AssociationDeletingRules.cs" />
     <Compile Include="CustomCode\Rules\BidirectionalAssociationAddRules.cs" />

src/Dsl/GeneratedCode/Diagram.cs

@@ -193,10 +193,10 @@ private void CompartmentItemRolePlayerOrderChanged(object sender, DslModeling::R
 		/// <remarks>
 		/// Always return true, since we assume there is only one diagram per model file for DSL scenarios.
 		/// </remarks>
-		protected override bool ShouldAddShapeForElement(DslModeling::ModelElement element)
-		{
-		   return true;
-		}
+		//protected override bool ShouldAddShapeForElement(DslModeling::ModelElement element)
+		//{
+		//   return true;
+		//}
 
 		internal bool ShouldSupport(DslModeling::ModelElement element) // HACK : MEXEDGE
 		{