Add ability to change slider length by dragging slider tail

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

@@ -163,6 +163,44 @@ public void TestMultipleControlPointDeselectionViaClickOutside()
             checkControlPointSelected(1, false);
         }
 
+        [Test]
+        public void TestAdjustLength()
+        {
+            AddStep("move mouse to drag marker", () =>
+            {
+                Vector2 position = slider.Position + slider.Path.PositionAt(1) + new Vector2(60, 0);
+                InputManager.MoveMouseTo(drawableObject.Parent!.ToScreenSpace(position));
+            });
+            AddStep("start drag", () => InputManager.PressButton(MouseButton.Left));
+            AddStep("move mouse to control point 1", () =>
+            {
+                Vector2 position = slider.Position + slider.Path.ControlPoints[1].Position + new Vector2(60, 0);
+                InputManager.MoveMouseTo(drawableObject.Parent!.ToScreenSpace(position));
+            });
+            AddStep("end adjust length", () => InputManager.ReleaseButton(MouseButton.Left));
+            AddAssert("expected distance halved",
+                () => Precision.AlmostEquals(slider.Path.Distance, 172.2, 0.1));
+
+            AddStep("move mouse to drag marker", () =>
+            {
+                Vector2 position = slider.Position + slider.Path.PositionAt(1) + new Vector2(60, 0);
+                InputManager.MoveMouseTo(drawableObject.Parent!.ToScreenSpace(position));
+            });
+            AddStep("start drag", () => InputManager.PressButton(MouseButton.Left));
+            AddStep("move mouse beyond last control point", () =>
+            {
+                Vector2 position = slider.Position + slider.Path.ControlPoints[2].Position + new Vector2(100, 0);
+                InputManager.MoveMouseTo(drawableObject.Parent!.ToScreenSpace(position));
+            });
+            AddStep("end adjust length", () => InputManager.ReleaseButton(MouseButton.Left));
+            AddAssert("expected distance is calculated distance",
+                () => Precision.AlmostEquals(slider.Path.Distance, slider.Path.CalculatedDistance, 0.1));
+
+            moveMouseToControlPoint(1);
+            AddAssert("expected distance is unchanged",
+                () => Precision.AlmostEquals(slider.Path.Distance, slider.Path.CalculatedDistance, 0.1));
+        }
+
         private void moveHitObject()
         {
             AddStep("move hitobject", () =>

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

@@ -1,19 +1,43 @@
 // 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;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Lines;
+using osu.Framework.Graphics.Primitives;
+using osu.Framework.Input.Events;
+using osu.Framework.Utils;
+using osu.Game.Graphics;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components;
 using osu.Game.Rulesets.Osu.Objects;
+using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
 {
     public partial class SliderCircleOverlay : CompositeDrawable
     {
+        public RectangleF VisibleQuad
+        {
+            get
+            {
+                var result = CirclePiece.ScreenSpaceDrawQuad.AABBFloat;
+
+                if (endDragMarkerContainer == null) return result;
+
+                var size = result.Size * 1.4f;
+                var location = result.TopLeft - result.Size * 0.2f;
+                return new RectangleF(location, size);
+            }
+        }
+
         protected readonly HitCirclePiece CirclePiece;
 
         private readonly Slider slider;
         private readonly SliderPosition position;
         private readonly HitCircleOverlapMarker? marker;
+        private readonly Container? endDragMarkerContainer;
 
         public SliderCircleOverlay(Slider slider, SliderPosition position)
         {
@@ -24,26 +48,121 @@ public SliderCircleOverlay(Slider slider, SliderPosition position)
                 AddInternal(marker = new HitCircleOverlapMarker());
 
             AddInternal(CirclePiece = new HitCirclePiece());
+
+            if (position == SliderPosition.End)
+            {
+                AddInternal(endDragMarkerContainer = new Container
+                {
+                    AutoSizeAxes = Axes.Both,
+                    Anchor = Anchor.CentreLeft,
+                    Origin = Anchor.CentreLeft,
+                    Padding = new MarginPadding(-2.5f),
+                    Child = EndDragMarker = new SliderEndDragMarker()
+                });
+            }
         }
 
+        public SliderEndDragMarker? EndDragMarker { get; }
+
         protected override void Update()
         {
             base.Update();
 
-            var circle = position == SliderPosition.Start ? (HitCircle)slider.HeadCircle : slider.TailCircle;
+            var circle = position == SliderPosition.Start ? (HitCircle)slider.HeadCircle :
+                slider.RepeatCount % 2 == 0 ? slider.TailCircle : slider.LastRepeat!;
 
             CirclePiece.UpdateFrom(circle);
             marker?.UpdateFrom(circle);
+
+            if (endDragMarkerContainer != null)
+            {
+                endDragMarkerContainer.Position = circle.Position;
+                endDragMarkerContainer.Scale = CirclePiece.Scale * 1.2f;
+                var diff = slider.Path.PositionAt(1) - slider.Path.PositionAt(0.99f);
+                endDragMarkerContainer.Rotation = float.RadiansToDegrees(MathF.Atan2(diff.Y, diff.X));
+            }
         }
 
         public override void Hide()
         {
             CirclePiece.Hide();
+            endDragMarkerContainer?.Hide();
         }
 
         public override void Show()
         {
             CirclePiece.Show();
+            endDragMarkerContainer?.Show();
+        }
+
+        public partial class SliderEndDragMarker : SmoothPath
+        {
+            public Action<DragStartEvent>? StartDrag { get; set; }
+            public Action<DragEvent>? Drag { get; set; }
+            public Action? EndDrag { get; set; }
+
+            [Resolved]
+            private OsuColour colours { get; set; } = null!;
+
+            [BackgroundDependencyLoader]
+            private void load()
+            {
+                var path = PathApproximator.CircularArcToPiecewiseLinear([
+                    new Vector2(0, OsuHitObject.OBJECT_RADIUS),
+                    new Vector2(OsuHitObject.OBJECT_RADIUS, 0),
+                    new Vector2(0, -OsuHitObject.OBJECT_RADIUS)
+                ]);
+
+                Anchor = Anchor.CentreLeft;
+                Origin = Anchor.CentreLeft;
+                PathRadius = 5;
+                Vertices = path;
+            }
+
+            protected override void LoadComplete()
+            {
+                base.LoadComplete();
+
+                updateState();
+            }
+
+            protected override bool OnHover(HoverEvent e)
+            {
+                updateState();
+                return true;
+            }
+
+            protected override void OnHoverLost(HoverLostEvent e)
+            {
+                updateState();
+                base.OnHoverLost(e);
+            }
+
+            protected override bool OnDragStart(DragStartEvent e)
+            {
+                updateState();
+                StartDrag?.Invoke(e);
+                return true;
+            }
+
+            protected override void OnDrag(DragEvent e)
+            {
+                updateState();
+                base.OnDrag(e);
+                Drag?.Invoke(e);
+            }
+
+            protected override void OnDragEnd(DragEndEvent e)
+            {
+                updateState();
+                EndDrag?.Invoke();
+                base.OnDragEnd(e);
+            }
+
+            private void updateState()
+            {
+                Colour = IsHovered || IsDragged ? colours.Red : colours.Yellow;
+            }
         }
     }
 }