Merge branch 'VjDeleteUsedParamWarning' of https://github.com/xxSeys1/FlaxEngine into xxSeys1-VjDeleteUsedParamWarning

Source/Editor/Options/InterfaceOptions.cs

@@ -449,6 +449,13 @@ namespace FlaxEditor.Options
         [EditorDisplay("Visject", "Grid Snapping Size"), EditorOrder(551), Tooltip("Defines the size of the grid for nodes snapping."), VisibleIf(nameof(SurfaceGridSnapping))]
         public float SurfaceGridSnappingSize { get; set; } = 20.0f;
 
+        /// <summary>
+        /// Gets or sets a value that indicates if a warning should be displayed when deleting a Visject parameter that is used in a graph.
+        /// </summary>
+        [DefaultValue(true)]
+        [EditorDisplay("Visject", "Warn when deleting used parameter"), EditorOrder(552)]
+        public bool WarnOnDeletingUsedVisjectParameter { get; set; } = true;
+
         private static FontAsset DefaultFont => FlaxEngine.Content.LoadAsyncInternal<FontAsset>(EditorAssets.PrimaryFont);
         private static FontAsset ConsoleFont => FlaxEngine.Content.LoadAsyncInternal<FontAsset>(EditorAssets.InconsolataRegularFont);
 

Source/Editor/Surface/Archetypes/Parameters.cs

@@ -13,6 +13,7 @@ using FlaxEditor.Scripting;
 using FlaxEditor.Surface.Elements;
 using FlaxEngine;
 using FlaxEngine.Utilities;
+using System.Linq;
 
 namespace FlaxEditor.Surface.Archetypes
 {
@@ -425,6 +426,12 @@ namespace FlaxEditor.Surface.Archetypes
                 UpdateCombo();
             }
 
+            /// <inheritdoc />
+            public bool IsParamreferenced(SurfaceParameter param)
+            {
+                return (Guid)Values[0] == param.ID;
+            }
+
             /// <inheritdoc />
             public override void OnLoaded(SurfaceNodeActions action)
             {
@@ -937,13 +944,17 @@ namespace FlaxEditor.Surface.Archetypes
             {
                 // Deselect if that parameter is selected
                 if ((Guid)Values[0] == param.ID)
-                {
                     _combobox.SelectedIndex = -1;
-                }
 
                 UpdateCombo();
             }
 
+            /// <inheritdoc />
+            public bool IsParamreferenced(SurfaceParameter param)
+            {
+                return (Guid)Values[0] == param.ID;
+            }
+
             /// <inheritdoc />
             public override void OnLoaded(SurfaceNodeActions action)
             {

Source/Editor/Surface/IParametersDependantNode.cs

@@ -33,5 +33,12 @@ namespace FlaxEditor.Surface
         /// </summary>
         /// <param name="param">The parameter.</param>
         void OnParamDeleted(SurfaceParameter param);
+
+        /// <summary>
+        /// Get if the parameter is referenced in a graph. Referenced in this case means in a graph and at least one node in-/output connected to another node.
+        /// </summary>
+        /// <param name="param">The parameter.</param>
+        /// <returns>If the parameter is referenced.</returns>
+        bool IsParamreferenced(SurfaceParameter param);
     }
 }

Source/Editor/Surface/VisjectSurfaceWindow.cs

@@ -775,7 +775,34 @@ namespace FlaxEditor.Surface
 
         private void DeleteParameter(int index)
         {
+            bool displayWarning = Editor.Instance.Options.Options.Interface.WarnOnDeletingUsedVisjectParameter;
+
             var window = (IVisjectSurfaceWindow)Values[0];
+            SurfaceParameter param = window.VisjectSurface.Parameters[index];
+
+            int connectedParameterNodeCount = 0;
+
+            List<SurfaceNode> nodes = window.VisjectSurface.Nodes;
+
+            for (int i = 0; i < window.VisjectSurface.Nodes.Count; i++)
+            {
+                if (nodes[i] is IParametersDependantNode node)
+                {
+                    if (displayWarning && node.IsParamreferenced(param))
+                        connectedParameterNodeCount++;
+                }
+            }
+
+            if (displayWarning)
+            {
+                string singularPlural = connectedParameterNodeCount > 1 ? "s" : "";
+                string msg = $"Delete parameter {param.Name}?\nParameter is being used in a graph {connectedParameterNodeCount} time{singularPlural}.\n\nYou can disable this warning in the editor settings.";
+
+                if (connectedParameterNodeCount > 0)
+                    if (MessageBox.Show(msg, "Delete parameter", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) != DialogResult.OK)
+                        return;
+            }
+
             var action = new AddRemoveParamAction
             {
                 Window = window,