Merge pull request #16184 from bdach/move-many-slider-nodes-at-once

Allow dragging multiple slider path control points at once

osu.Game.Rulesets.Osu.Tests/Editor/TestSceneSliderControlPointPiece.cs

@@ -1,7 +1,10 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Linq;
+using Humanizer;
 using NUnit.Framework;
+using osu.Framework.Testing;
 using osu.Framework.Utils;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
@@ -47,6 +50,126 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
             AddBlueprint(new TestSliderBlueprint(slider), drawableObject);
         });
 
+        [Test]
+        public void TestSelection()
+        {
+            moveMouseToControlPoint(0);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+            assertSelectionCount(1);
+            assertSelected(0);
+
+            AddStep("click right mouse", () => InputManager.Click(MouseButton.Right));
+            assertSelectionCount(1);
+            assertSelected(0);
+
+            moveMouseToControlPoint(3);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+            assertSelectionCount(1);
+            assertSelected(3);
+
+            AddStep("press control", () => InputManager.PressKey(Key.ControlLeft));
+            moveMouseToControlPoint(2);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+            assertSelectionCount(2);
+            assertSelected(2);
+            assertSelected(3);
+
+            moveMouseToControlPoint(0);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+            assertSelectionCount(3);
+            assertSelected(0);
+            assertSelected(2);
+            assertSelected(3);
+
+            AddStep("click right mouse", () => InputManager.Click(MouseButton.Right));
+            assertSelectionCount(3);
+            assertSelected(0);
+            assertSelected(2);
+            assertSelected(3);
+
+            AddStep("release control", () => InputManager.ReleaseKey(Key.ControlLeft));
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+            assertSelectionCount(1);
+            assertSelected(0);
+
+            moveMouseToRelativePosition(new Vector2(350, 0));
+            AddStep("ctrl+click to create new point", () =>
+            {
+                InputManager.PressKey(Key.ControlLeft);
+                InputManager.PressButton(MouseButton.Left);
+            });
+            assertSelectionCount(1);
+            assertSelected(3);
+
+            AddStep("release ctrl+click", () =>
+            {
+                InputManager.ReleaseButton(MouseButton.Left);
+                InputManager.ReleaseKey(Key.ControlLeft);
+            });
+            assertSelectionCount(1);
+            assertSelected(3);
+        }
+
+        [Test]
+        public void TestNewControlPointCreation()
+        {
+            moveMouseToRelativePosition(new Vector2(350, 0));
+            AddStep("ctrl+click to create new point", () =>
+            {
+                InputManager.PressKey(Key.ControlLeft);
+                InputManager.PressButton(MouseButton.Left);
+            });
+            AddAssert("slider has 6 control points", () => slider.Path.ControlPoints.Count == 6);
+            AddStep("release ctrl+click", () =>
+            {
+                InputManager.ReleaseButton(MouseButton.Left);
+                InputManager.ReleaseKey(Key.ControlLeft);
+            });
+
+            // ensure that the next drag doesn't attempt to move the placement that just finished.
+            moveMouseToRelativePosition(new Vector2(0, 50));
+            AddStep("press left mouse", () => InputManager.PressButton(MouseButton.Left));
+            moveMouseToRelativePosition(new Vector2(0, 100));
+            AddStep("release left mouse", () => InputManager.ReleaseButton(MouseButton.Left));
+            assertControlPointPosition(3, new Vector2(350, 0));
+
+            moveMouseToRelativePosition(new Vector2(400, 75));
+            AddStep("ctrl+click to create new point", () =>
+            {
+                InputManager.PressKey(Key.ControlLeft);
+                InputManager.PressButton(MouseButton.Left);
+            });
+            AddAssert("slider has 7 control points", () => slider.Path.ControlPoints.Count == 7);
+            moveMouseToRelativePosition(new Vector2(350, 75));
+            AddStep("release ctrl+click", () =>
+            {
+                InputManager.ReleaseButton(MouseButton.Left);
+                InputManager.ReleaseKey(Key.ControlLeft);
+            });
+            assertControlPointPosition(5, new Vector2(350, 75));
+
+            // ensure that the next drag doesn't attempt to move the placement that just finished.
+            moveMouseToRelativePosition(new Vector2(0, 50));
+            AddStep("press left mouse", () => InputManager.PressButton(MouseButton.Left));
+            moveMouseToRelativePosition(new Vector2(0, 100));
+            AddStep("release left mouse", () => InputManager.ReleaseButton(MouseButton.Left));
+            assertControlPointPosition(5, new Vector2(350, 75));
+        }
+
+        private void assertSelectionCount(int count) =>
+            AddAssert($"{count} control point pieces selected", () => this.ChildrenOfType<PathControlPointPiece>().Count(piece => piece.IsSelected.Value) == count);
+
+        private void assertSelected(int index) =>
+            AddAssert($"{(index + 1).ToOrdinalWords()} control point piece selected",
+                () => this.ChildrenOfType<PathControlPointPiece>().Single(piece => piece.ControlPoint == slider.Path.ControlPoints[index]).IsSelected.Value);
+
+        private void moveMouseToRelativePosition(Vector2 relativePosition) =>
+            AddStep($"move mouse to {relativePosition}", () =>
+            {
+                Vector2 position = slider.Position + relativePosition;
+                InputManager.MoveMouseTo(drawableObject.Parent.ToScreenSpace(position));
+            });
+
         [Test]
         public void TestDragControlPoint()
         {
@@ -60,6 +183,83 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
             assertControlPointType(0, PathType.PerfectCurve);
         }
 
+        [Test]
+        public void TestDragMultipleControlPoints()
+        {
+            moveMouseToControlPoint(2);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+
+            AddStep("hold control", () => InputManager.PressKey(Key.LControl));
+
+            moveMouseToControlPoint(3);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+
+            moveMouseToControlPoint(4);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+
+            moveMouseToControlPoint(2);
+            AddStep("hold left mouse", () => InputManager.PressButton(MouseButton.Left));
+
+            AddAssert("three control point pieces selected", () => this.ChildrenOfType<PathControlPointPiece>().Count(piece => piece.IsSelected.Value) == 3);
+
+            addMovementStep(new Vector2(450, 50));
+            AddStep("release left mouse", () => InputManager.ReleaseButton(MouseButton.Left));
+
+            AddAssert("three control point pieces selected", () => this.ChildrenOfType<PathControlPointPiece>().Count(piece => piece.IsSelected.Value) == 3);
+
+            assertControlPointPosition(2, new Vector2(450, 50));
+            assertControlPointType(2, PathType.PerfectCurve);
+
+            assertControlPointPosition(3, new Vector2(550, 50));
+
+            assertControlPointPosition(4, new Vector2(550, 200));
+
+            AddStep("release control", () => InputManager.ReleaseKey(Key.LControl));
+        }
+
+        [Test]
+        public void TestDragMultipleControlPointsIncludingHead()
+        {
+            moveMouseToControlPoint(0);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+
+            AddStep("hold control", () => InputManager.PressKey(Key.LControl));
+
+            moveMouseToControlPoint(3);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+
+            moveMouseToControlPoint(4);
+            AddStep("click left mouse", () => InputManager.Click(MouseButton.Left));
+
+            moveMouseToControlPoint(3);
+            AddStep("hold left mouse", () => InputManager.PressButton(MouseButton.Left));
+
+            AddAssert("three control point pieces selected", () => this.ChildrenOfType<PathControlPointPiece>().Count(piece => piece.IsSelected.Value) == 3);
+
+            addMovementStep(new Vector2(550, 50));
+            AddStep("release left mouse", () => InputManager.ReleaseButton(MouseButton.Left));
+
+            AddAssert("three control point pieces selected", () => this.ChildrenOfType<PathControlPointPiece>().Count(piece => piece.IsSelected.Value) == 3);
+
+            // note: if the head is part of the selection being moved, the entire slider is moved.
+            // the unselected nodes will therefore change position relative to the slider head.
+
+            AddAssert("slider moved", () => Precision.AlmostEquals(slider.Position, new Vector2(256, 192) + new Vector2(150, 50)));
+
+            assertControlPointPosition(0, Vector2.Zero);
+            assertControlPointType(0, PathType.PerfectCurve);
+
+            assertControlPointPosition(1, new Vector2(0, 100));
+
+            assertControlPointPosition(2, new Vector2(150, -50));
+
+            assertControlPointPosition(3, new Vector2(400, 0));
+
+            assertControlPointPosition(4, new Vector2(400, 150));
+
+            AddStep("release control", () => InputManager.ReleaseKey(Key.LControl));
+        }
+
         [Test]
         public void TestDragControlPointAlmostLinearlyExterior()
         {

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/Components/PathControlPointPiece.cs

@@ -16,11 +16,9 @@ using osu.Framework.Input.Events;
 using osu.Framework.Localisation;
 using osu.Framework.Utils;
 using osu.Game.Graphics;
-using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Osu.Objects;
-using osu.Game.Screens.Edit;
 using osuTK;
 using osuTK.Graphics;
 using osuTK.Input;
@@ -33,6 +31,11 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
     public class PathControlPointPiece : BlueprintPiece<Slider>, IHasTooltip
     {
         public Action<PathControlPointPiece, MouseButtonEvent> RequestSelection;
+
+        public Action<PathControlPoint> DragStarted;
+        public Action<DragEvent> DragInProgress;
+        public Action DragEnded;
+
         public List<PathControlPoint> PointsInSegment;
 
         public readonly BindableBool IsSelected = new BindableBool();
@@ -42,12 +45,6 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
         private readonly Container marker;
         private readonly Drawable markerRing;
 
-        [Resolved(CanBeNull = true)]
-        private IEditorChangeHandler changeHandler { get; set; }
-
-        [Resolved(CanBeNull = true)]
-        private IPositionSnapProvider snapProvider { get; set; }
-
         [Resolved]
         private OsuColour colours { get; set; }
 
@@ -138,6 +135,10 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
             updateMarkerDisplay();
         }
 
+        // Used to pair up mouse down/drag events with their corresponding mouse up events,
+        // to avoid deselecting the piece by accident when the mouse up corresponding to the mouse down/drag fires.
+        private bool keepSelection;
+
         protected override bool OnMouseDown(MouseDownEvent e)
         {
             if (RequestSelection == null)
@@ -146,22 +147,41 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
             switch (e.Button)
             {
                 case MouseButton.Left:
+                    // if control is pressed, do not do anything as the user may be adding to current selection
+                    // or dragging all currently selected control points.
+                    // if it isn't and the user's intent is to deselect, deselection will happen on mouse up.
+                    if (e.ControlPressed && IsSelected.Value)
+                        return true;
+
                     RequestSelection.Invoke(this, e);
+                    keepSelection = true;
+
                     return true;
 
                 case MouseButton.Right:
                     if (!IsSelected.Value)
                         RequestSelection.Invoke(this, e);
+
+                    keepSelection = true;
                     return false; // Allow context menu to show
             }
 
             return false;
         }
 
-        protected override bool OnClick(ClickEvent e) => RequestSelection != null;
+        protected override void OnMouseUp(MouseUpEvent e)
+        {
+            base.OnMouseUp(e);
 
-        private Vector2 dragStartPosition;
+            // ctrl+click deselects this piece, but only if this event
-        private PathType? dragPathType;
+            // wasn't immediately preceded by a matching mouse down or drag.
+            if (IsSelected.Value && e.ControlPressed && !keepSelection)
+                IsSelected.Value = false;
+
+            keepSelection = false;
+        }
+
+        protected override bool OnClick(ClickEvent e) => RequestSelection != null;
 
         protected override bool OnDragStart(DragStartEvent e)
         {
@@ -170,54 +190,17 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
 
             if (e.Button == MouseButton.Left)
             {
-                dragStartPosition = ControlPoint.Position;
+                DragStarted?.Invoke(ControlPoint);
-                dragPathType = PointsInSegment[0].Type;
+                keepSelection = true;
-
-                changeHandler?.BeginChange();
                 return true;
             }
 
             return false;
         }
 
-        protected override void OnDrag(DragEvent e)
+        protected override void OnDrag(DragEvent e) => DragInProgress?.Invoke(e);
-        {
-            Vector2[] oldControlPoints = slider.Path.ControlPoints.Select(cp => cp.Position).ToArray();
-            var oldPosition = slider.Position;
-            double oldStartTime = slider.StartTime;
 
-            if (ControlPoint == slider.Path.ControlPoints[0])
+        protected override void OnDragEnd(DragEndEvent e) => DragEnded?.Invoke();
-            {
-                // Special handling for the head control point - the position of the slider changes which means the snapped position and time have to be taken into account
-                var result = snapProvider?.SnapScreenSpacePositionToValidTime(e.ScreenSpaceMousePosition);
-
-                Vector2 movementDelta = Parent.ToLocalSpace(result?.ScreenSpacePosition ?? e.ScreenSpaceMousePosition) - slider.Position;
-
-                slider.Position += movementDelta;
-                slider.StartTime = result?.Time ?? slider.StartTime;
-
-                // Since control points are relative to the position of the slider, they all need to be offset backwards by the delta
-                for (int i = 1; i < slider.Path.ControlPoints.Count; i++)
-                    slider.Path.ControlPoints[i].Position -= movementDelta;
-            }
-            else
-                ControlPoint.Position = dragStartPosition + (e.MousePosition - e.MouseDownPosition);
-
-            if (!slider.Path.HasValidLength)
-            {
-                for (int i = 0; i < slider.Path.ControlPoints.Count; i++)
-                    slider.Path.ControlPoints[i].Position = oldControlPoints[i];
-
-                slider.Position = oldPosition;
-                slider.StartTime = oldStartTime;
-                return;
-            }
-
-            // Maintain the path type in case it got defaulted to bezier at some point during the drag.
-            PointsInSegment[0].Type = dragPathType;
-        }
-
-        protected override void OnDragEnd(DragEndEvent e) => changeHandler?.EndChange();
 
         private void cachePoints(Slider slider) => PointsInSegment = slider.Path.PointsInSegment(ControlPoint);
 

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/Components/PathControlPointVisualiser.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics;
 using System.Linq;
 using Humanizer;
 using osu.Framework.Allocation;
@@ -16,6 +17,7 @@ using osu.Framework.Input;
 using osu.Framework.Input.Bindings;
 using osu.Framework.Input.Events;
 using osu.Game.Graphics.UserInterface;
+using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Osu.Objects;
@@ -40,6 +42,9 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
 
         public Action<List<PathControlPoint>> RemoveControlPointsRequested;
 
+        [Resolved(CanBeNull = true)]
+        private IPositionSnapProvider snapProvider { get; set; }
+
         public PathControlPointVisualiser(Slider slider, bool allowSelection)
         {
             this.slider = slider;
@@ -64,6 +69,39 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
             controlPoints.BindTo(slider.Path.ControlPoints);
         }
 
+        /// <summary>
+        /// Selects the <see cref="PathControlPointPiece"/> corresponding to the given <paramref name="pathControlPoint"/>,
+        /// and deselects all other <see cref="PathControlPointPiece"/>s.
+        /// </summary>
+        public void SetSelectionTo(PathControlPoint pathControlPoint)
+        {
+            foreach (var p in Pieces)
+                p.IsSelected.Value = p.ControlPoint == pathControlPoint;
+        }
+
+        /// <summary>
+        /// Delete all visually selected <see cref="PathControlPoint"/>s.
+        /// </summary>
+        /// <returns></returns>
+        public bool DeleteSelected()
+        {
+            List<PathControlPoint> toRemove = Pieces.Where(p => p.IsSelected.Value).Select(p => p.ControlPoint).ToList();
+
+            // Ensure that there are any points to be deleted
+            if (toRemove.Count == 0)
+                return false;
+
+            changeHandler?.BeginChange();
+            RemoveControlPointsRequested?.Invoke(toRemove);
+            changeHandler?.EndChange();
+
+            // Since pieces are re-used, they will not point to the deleted control points while remaining selected
+            foreach (var piece in Pieces)
+                piece.IsSelected.Value = false;
+
+            return true;
+        }
+
         private void onControlPointsChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
             switch (e.Action)
@@ -87,7 +125,11 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
                         Pieces.Add(new PathControlPointPiece(slider, point).With(d =>
                         {
                             if (allowSelection)
-                                d.RequestSelection = selectPiece;
+                                d.RequestSelection = selectionRequested;
+
+                            d.DragStarted = dragStarted;
+                            d.DragInProgress = dragInProgress;
+                            d.DragEnded = dragEnded;
                         }));
 
                         Connections.Add(new PathControlPointConnectionPiece(slider, e.NewStartingIndex + i));
@@ -119,6 +161,9 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
 
         protected override bool OnClick(ClickEvent e)
         {
+            if (Pieces.Any(piece => piece.IsHovered))
+                return false;
+
             foreach (var piece in Pieces)
             {
                 piece.IsSelected.Value = false;
@@ -142,15 +187,12 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
         {
         }
 
-        private void selectPiece(PathControlPointPiece piece, MouseButtonEvent e)
+        private void selectionRequested(PathControlPointPiece piece, MouseButtonEvent e)
         {
             if (e.Button == MouseButton.Left && inputManager.CurrentState.Keyboard.ControlPressed)
                 piece.IsSelected.Toggle();
             else
-            {
+                SetSelectionTo(piece.ControlPoint);
-                foreach (var p in Pieces)
-                    p.IsSelected.Value = p == piece;
-            }
         }
 
         /// <summary>
@@ -184,25 +226,82 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
         [Resolved(CanBeNull = true)]
         private IEditorChangeHandler changeHandler { get; set; }
 
-        public bool DeleteSelected()
+        #region Drag handling
-        {
-            List<PathControlPoint> toRemove = Pieces.Where(p => p.IsSelected.Value).Select(p => p.ControlPoint).ToList();
 
-            // Ensure that there are any points to be deleted
+        private Vector2[] dragStartPositions;
-            if (toRemove.Count == 0)
+        private PathType?[] dragPathTypes;
-                return false;
+        private int draggedControlPointIndex;
+        private HashSet<PathControlPoint> selectedControlPoints;
+
+        private void dragStarted(PathControlPoint controlPoint)
+        {
+            dragStartPositions = slider.Path.ControlPoints.Select(point => point.Position).ToArray();
+            dragPathTypes = slider.Path.ControlPoints.Select(point => point.Type).ToArray();
+            draggedControlPointIndex = slider.Path.ControlPoints.IndexOf(controlPoint);
+            selectedControlPoints = new HashSet<PathControlPoint>(Pieces.Where(piece => piece.IsSelected.Value).Select(piece => piece.ControlPoint));
+
+            Debug.Assert(draggedControlPointIndex >= 0);
 
             changeHandler?.BeginChange();
-            RemoveControlPointsRequested?.Invoke(toRemove);
-            changeHandler?.EndChange();
-
-            // Since pieces are re-used, they will not point to the deleted control points while remaining selected
-            foreach (var piece in Pieces)
-                piece.IsSelected.Value = false;
-
-            return true;
         }
 
+        private void dragInProgress(DragEvent e)
+        {
+            Vector2[] oldControlPoints = slider.Path.ControlPoints.Select(cp => cp.Position).ToArray();
+            var oldPosition = slider.Position;
+            double oldStartTime = slider.StartTime;
+
+            if (selectedControlPoints.Contains(slider.Path.ControlPoints[0]))
+            {
+                // Special handling for selections containing head control point - the position of the slider changes which means the snapped position and time have to be taken into account
+                Vector2 newHeadPosition = Parent.ToScreenSpace(e.MousePosition + (dragStartPositions[0] - dragStartPositions[draggedControlPointIndex]));
+                var result = snapProvider?.SnapScreenSpacePositionToValidTime(newHeadPosition);
+
+                Vector2 movementDelta = Parent.ToLocalSpace(result?.ScreenSpacePosition ?? newHeadPosition) - slider.Position;
+
+                slider.Position += movementDelta;
+                slider.StartTime = result?.Time ?? slider.StartTime;
+
+                for (int i = 1; i < slider.Path.ControlPoints.Count; i++)
+                {
+                    var controlPoint = slider.Path.ControlPoints[i];
+                    // Since control points are relative to the position of the slider, all points that are _not_ selected
+                    // need to be offset _back_ by the delta corresponding to the movement of the head point.
+                    // All other selected control points (if any) will move together with the head point
+                    // (and so they will not move at all, relative to each other).
+                    if (!selectedControlPoints.Contains(controlPoint))
+                        controlPoint.Position -= movementDelta;
+                }
+            }
+            else
+            {
+                for (int i = 0; i < controlPoints.Count; ++i)
+                {
+                    var controlPoint = controlPoints[i];
+                    if (selectedControlPoints.Contains(controlPoint))
+                        controlPoint.Position = dragStartPositions[i] + (e.MousePosition - e.MouseDownPosition);
+                }
+            }
+
+            if (!slider.Path.HasValidLength)
+            {
+                for (int i = 0; i < slider.Path.ControlPoints.Count; i++)
+                    slider.Path.ControlPoints[i].Position = oldControlPoints[i];
+
+                slider.Position = oldPosition;
+                slider.StartTime = oldStartTime;
+                return;
+            }
+
+            // Maintain the path types in case they got defaulted to bezier at some point during the drag.
+            for (int i = 0; i < slider.Path.ControlPoints.Count; i++)
+                slider.Path.ControlPoints[i].Type = dragPathTypes[i];
+        }
+
+        private void dragEnded() => changeHandler?.EndChange();
+
+        #endregion
+
         public MenuItem[] ContextMenuItems
         {
             get

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/SliderSelectionBlueprint.cs

@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
@@ -140,7 +139,9 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
                 case MouseButton.Left:
                     if (e.ControlPressed && IsSelected)
                     {
-                        placementControlPointIndex = addControlPoint(e.MousePosition);
+                        changeHandler?.BeginChange();
+                        placementControlPoint = addControlPoint(e.MousePosition);
+                        ControlPointVisualiser?.SetSelectionTo(placementControlPoint);
                         return true; // Stop input from being handled and modifying the selection
                     }
 
@@ -150,31 +151,22 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
             return false;
         }
 
-        private int? placementControlPointIndex;
+        [CanBeNull]
+        private PathControlPoint placementControlPoint;
 
-        protected override bool OnDragStart(DragStartEvent e)
+        protected override bool OnDragStart(DragStartEvent e) => placementControlPoint != null;
-        {
-            if (placementControlPointIndex != null)
-            {
-                changeHandler?.BeginChange();
-                return true;
-            }
-
-            return false;
-        }
 
         protected override void OnDrag(DragEvent e)
         {
-            Debug.Assert(placementControlPointIndex != null);
+            if (placementControlPoint != null)
-
+                placementControlPoint.Position = e.MousePosition - HitObject.Position;
-            HitObject.Path.ControlPoints[placementControlPointIndex.Value].Position = e.MousePosition - HitObject.Position;
         }
 
-        protected override void OnDragEnd(DragEndEvent e)
+        protected override void OnMouseUp(MouseUpEvent e)
         {
-            if (placementControlPointIndex != null)
+            if (placementControlPoint != null)
             {
-                placementControlPointIndex = null;
+                placementControlPoint = null;
                 changeHandler?.EndChange();
             }
         }
@@ -193,7 +185,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
             return false;
         }
 
-        private int addControlPoint(Vector2 position)
+        private PathControlPoint addControlPoint(Vector2 position)
         {
             position -= HitObject.Position;
 
@@ -211,10 +203,12 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
                 }
             }
 
-            // Move the control points from the insertion index onwards to make room for the insertion
+            var pathControlPoint = new PathControlPoint { Position = position };
-            controlPoints.Insert(insertionIndex, new PathControlPoint { Position = position });
 
-            return insertionIndex;
+            // Move the control points from the insertion index onwards to make room for the insertion
+            controlPoints.Insert(insertionIndex, pathControlPoint);
+
+            return pathControlPoint;
         }
 
         private void removeControlPoints(List<PathControlPoint> toRemove)