CMCL-0000: Spline roll cleanup (#997)

* Spline roll cleanup

* Add button in inspector to engage the scene view tool

* Prettier SplineRoll inspector - requires minor API change

* Add missing tooltips

* Update CinemachineSplineRollEditor.cs

* Fix broken roll data list

* Add tooltips in scene view

* Add SplineDataInspectorUtility

* Refactor spline roll to work with scaled splines

* Refactor ISplineReferencer

* Update SplineSettings.cs

* Update CinemachineSplineCart.cs

* Fix missing doc and remove finalizer

* Remove some infrastructure editor classes from public

* New spline roll tool icons

* Update CinemachineSplineDolly.cs

com.unity.cinemachine/Editor/Editors/CinemachineSplineCartEditor.cs

@@ -13,7 +13,9 @@ class CinemachineSplineCartEditor : UnityEditor.Editor
         public override VisualElement CreateInspectorGUI()
         {
             var ux = new VisualElement();
-            ux.Add(new PropertyField(serializedObject.FindProperty(() => Target.SplineSettings)));
+
+            var splineIsChildHelp = ux.AddChild(new HelpBox("Spline should not be a child of this object.", HelpBoxMessageType.Error));
+            ux.Add(new PropertyField(serializedObject.FindProperty("m_SplineSettings")));
             ux.Add(new PropertyField(serializedObject.FindProperty(() => Target.UpdateMethod)));
 
             var autoDollyProp = serializedObject.FindProperty(() => Target.AutomaticDolly);
@@ -26,6 +28,18 @@ public override VisualElement CreateInspectorGUI()
                 targetField.SetVisible(autodolly != null && autodolly.RequiresTrackingTarget);
             });
 
+            ux.TrackAnyUserActivity(() =>
+            {
+                bool isChild = false;
+                for (int i = 0; !isChild && i < targets.Length; ++i)
+                {
+                    var t = targets[i] as CinemachineSplineCart;
+                    if (t != null && t.Spline != null)
+                        isChild = t.transform.IsAncestorOf(t.Spline.transform);
+                }
+                splineIsChildHelp.SetVisible(isChild);
+            });
+
             return ux;
         }
     }

com.unity.cinemachine/Editor/Editors/CinemachineSplineDollyEditor.cs

@@ -1,7 +1,6 @@
 using UnityEditor;
 using UnityEditor.UIElements;
 using UnityEngine.UIElements;
-using UnityEngine.Splines;
 
 namespace Unity.Cinemachine.Editor
 {
@@ -17,8 +16,9 @@ public override VisualElement CreateInspectorGUI()
 
             this.AddMissingCmCameraHelpBox(ux);
             var noSplineHelp = ux.AddChild(new HelpBox("A Spline is required.", HelpBoxMessageType.Warning));
+            var splineIsChildHelp = ux.AddChild(new HelpBox("Spline should not be a child of this object.", HelpBoxMessageType.Error));
 
-            var splineProp = serializedObject.FindProperty(() => Target.SplineSettings);
+            var splineProp = serializedObject.FindProperty("m_SplineSettings");
             ux.Add(new PropertyField(splineProp));
             ux.Add(new PropertyField(serializedObject.FindProperty(() => Target.SplineOffset)));
             ux.Add(new PropertyField(serializedObject.FindProperty(() => Target.CameraRotation)));
@@ -33,6 +33,18 @@ public override VisualElement CreateInspectorGUI()
                 noSplineHelp.SetVisible(noSpline);
             });
 
+            ux.TrackAnyUserActivity(() =>
+            {
+                bool isChild = false;
+                for (int i = 0; !isChild && i < targets.Length; ++i)
+                {
+                    var t = targets[i] as CinemachineSplineDolly;
+                    if (t != null && t.Spline != null)
+                        isChild = t.transform.IsAncestorOf(t.Spline.transform);
+                }
+                splineIsChildHelp.SetVisible(isChild);
+            });
+
             return ux;
         }
     }