Make the hitobject masks move within their placement/selection

# Conflicts:
#	osu.Game.Rulesets.Osu/Edit/Masks/HitCircleMasks/Components/HitCircleMask.cs
#	osu.Game.Rulesets.Osu/Edit/Masks/HitCircleMasks/HitCircleSelectionMask.cs
#	osu.Game.Rulesets.Osu/Edit/Masks/HitCirclePlacementMask.cs
#	osu.Game/Rulesets/Edit/PlacementMask.cs

osu.Game.Rulesets.Osu/Edit/Masks/HitCircleMasks/Components/HitCircleMask.cs

@@ -13,23 +13,30 @@ namespace osu.Game.Rulesets.Osu.Edit.Masks.HitCircleMasks.Components
 {
     public class HitCircleMask : CompositeDrawable
     {
+        private readonly HitCircle hitCircle;
+
         public HitCircleMask(HitCircle hitCircle)
         {
-            Anchor = Anchor.Centre;
+            this.hitCircle = hitCircle;
             Origin = Anchor.Centre;
 
             Size = new Vector2((float)OsuHitObject.OBJECT_RADIUS * 2);
             Scale = new Vector2(hitCircle.Scale);
-
             CornerRadius = Size.X / 2;
 
-            AddInternal(new RingPiece());
+            InternalChild = new RingPiece();
+
+            hitCircle.PositionChanged += _ => UpdatePosition();
         }
 
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
             Colour = colours.Yellow;
+
+            UpdatePosition();
         }
+
+        protected virtual void UpdatePosition() => Position = hitCircle.StackedPosition;
     }
 }

osu.Game.Rulesets.Osu/Edit/Masks/HitCircleMasks/HitCircleSelectionMask.cs

@@ -1,7 +1,6 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using osu.Framework.Graphics;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Osu.Edit.Masks.HitCircleMasks.Components;
 using osu.Game.Rulesets.Osu.Objects;
@@ -14,13 +13,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Masks.HitCircleMasks
         public HitCircleSelectionMask(DrawableHitCircle hitCircle)
             : base(hitCircle)
         {
-            Origin = Anchor.Centre;
-            AutoSizeAxes = Axes.Both;
-            Position = hitCircle.Position;
-
             InternalChild = new HitCircleMask((HitCircle)hitCircle.HitObject);
-
-            hitCircle.HitObject.PositionChanged += _ => Position = hitCircle.Position;
         }
     }
 }

osu.Game.Rulesets.Osu/Edit/Masks/SliderMasks/Components/SliderBodyMask.cs

@@ -0,0 +1,51 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Framework.Allocation;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Rulesets.Osu.Objects.Drawables.Pieces;
+using OpenTK.Graphics;
+
+namespace osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks.Components
+{
+    public class SliderBodyMask : CompositeDrawable
+    {
+        private readonly Slider slider;
+        private readonly SliderBody body;
+
+        public SliderBodyMask(Slider slider)
+        {
+            this.slider = slider;
+            InternalChild = body = new SliderBody(slider)
+            {
+                AccentColour = Color4.Transparent,
+                PathWidth = slider.Scale * 64
+            };
+
+            slider.PositionChanged += _ => updatePosition();
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            body.BorderColour = colours.Yellow;
+
+            updatePosition();
+        }
+
+        private void updatePosition() => Position = slider.StackedPosition;
+
+        protected override void Update()
+        {
+            base.Update();
+
+            Size = body.Size;
+            OriginPosition = body.PathOffset;
+
+            // Need to cause one update
+            body.UpdateProgress(0);
+        }
+    }
+}

osu.Game.Rulesets.Osu/Edit/Masks/SliderMasks/Components/SliderCircleMask.cs

@@ -0,0 +1,34 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Game.Rulesets.Osu.Edit.Masks.HitCircleMasks.Components;
+using osu.Game.Rulesets.Osu.Objects;
+
+namespace osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks.Components
+{
+    public class SliderCircleMask : HitCircleMask
+    {
+        private readonly Slider slider;
+        private readonly SliderPosition position;
+
+        public SliderCircleMask(Slider slider, SliderPosition position)
+            : base(slider.HeadCircle)
+        {
+            this.slider = slider;
+            this.position = position;
+        }
+
+        protected override void UpdatePosition()
+        {
+            switch (position)
+            {
+                case SliderPosition.Start:
+                    Position = slider.StackedPosition + slider.Curve.PositionAt(0);
+                    break;
+                case SliderPosition.End:
+                    Position = slider.StackedPosition + slider.Curve.PositionAt(1);
+                    break;
+            }
+        }
+    }
+}

osu.Game.Rulesets.Osu/Edit/Masks/SliderMasks/SliderCircleSelectionMask.cs

@@ -1,60 +1,23 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using osu.Framework.Allocation;
-using osu.Framework.Graphics;
-using osu.Game.Graphics;
 using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks.Components;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Osu.Objects.Drawables;
-using osu.Game.Rulesets.Osu.Objects.Drawables.Pieces;
-using OpenTK;
 
 namespace osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks
 {
     public class SliderCircleSelectionMask : SelectionMask
     {
-        public SliderCircleSelectionMask(DrawableHitCircle sliderHead, DrawableSlider slider)
+        public SliderCircleSelectionMask(DrawableOsuHitObject hitObject, Slider slider, SliderPosition position)
-            : this(sliderHead, Vector2.Zero, slider)
-        {
-        }
-
-        public SliderCircleSelectionMask(DrawableSliderTail sliderTail, DrawableSlider slider)
-            : this(sliderTail, ((Slider)slider.HitObject).Curve.PositionAt(1), slider)
-        {
-        }
-
-        private readonly DrawableOsuHitObject hitObject;
-
-        private SliderCircleSelectionMask(DrawableOsuHitObject hitObject, Vector2 position, DrawableSlider slider)
             : base(hitObject)
         {
-            this.hitObject = hitObject;
+            InternalChild = new SliderCircleMask(slider, position);
-
-            Origin = Anchor.Centre;
-
-            Position = position;
-            Size = slider.HeadCircle.Size;
-            Scale = slider.HeadCircle.Scale;
-
-            AddInternal(new RingPiece());
 
             Select();
         }
 
-        [BackgroundDependencyLoader]
-        private void load(OsuColour colours)
-        {
-            Colour = colours.Yellow;
-        }
-
-        protected override void Update()
-        {
-            base.Update();
-
-            RelativeAnchorPosition = hitObject.RelativeAnchorPosition;
-        }
-
         // Todo: This is temporary, since the slider circle masks don't do anything special yet. In the future they will handle input.
         public override bool HandlePositionalInput => false;
     }

osu.Game.Rulesets.Osu/Edit/Masks/SliderMasks/SliderPosition.cs

@@ -0,0 +1,11 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+namespace osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks
+{
+    public enum SliderPosition
+    {
+        Start,
+        End
+    }
+}

osu.Game.Rulesets.Osu/Edit/Masks/SliderMasks/SliderSelectionMask.cs

@@ -1,67 +1,32 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using osu.Framework.Allocation;
 using osu.Framework.Graphics;
-using osu.Framework.Graphics.Primitives;
-using osu.Game.Graphics;
 using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks.Components;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Osu.Objects.Drawables;
-using osu.Game.Rulesets.Osu.Objects.Drawables.Pieces;
 using OpenTK;
-using OpenTK.Graphics;
 
 namespace osu.Game.Rulesets.Osu.Edit.Masks.SliderMasks
 {
     public class SliderSelectionMask : SelectionMask
     {
-        private readonly SliderBody body;
+        private readonly SliderCircleSelectionMask headMask;
-        private readonly DrawableSlider slider;
 
         public SliderSelectionMask(DrawableSlider slider)
             : base(slider)
         {
-            this.slider = slider;
-
-            Position = slider.Position;
-
             var sliderObject = (Slider)slider.HitObject;
 
             InternalChildren = new Drawable[]
             {
-                body = new SliderBody(sliderObject)
+                new SliderBodyMask(sliderObject),
-                {
+                headMask = new SliderCircleSelectionMask(slider.HeadCircle, sliderObject, SliderPosition.Start),
-                    AccentColour = Color4.Transparent,
+                new SliderCircleSelectionMask(slider.TailCircle, sliderObject, SliderPosition.End),
-                    PathWidth = sliderObject.Scale * 64
-                },
-                new SliderCircleSelectionMask(slider.HeadCircle, slider),
-                new SliderCircleSelectionMask(slider.TailCircle, slider),
             };
-
-            sliderObject.PositionChanged += _ => Position = slider.Position;
         }
 
-        [BackgroundDependencyLoader]
+        public override Vector2 SelectionPoint => headMask.SelectionPoint;
-        private void load(OsuColour colours)
-        {
-            body.BorderColour = colours.Yellow;
-        }
-
-        protected override void Update()
-        {
-            base.Update();
-
-            Size = slider.Size;
-            OriginPosition = slider.OriginPosition;
-
-            // Need to cause one update
-            body.UpdateProgress(0);
-        }
-
-        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => body.ReceivePositionalInputAt(screenSpacePos);
-
-        public override Vector2 SelectionPoint => ToScreenSpace(OriginPosition);
-        public override Quad SelectionQuad => body.PathDrawQuad;
     }
 }

osu.Game.Rulesets.Osu/Objects/OsuHitObject.cs

@@ -22,7 +22,7 @@ namespace osu.Game.Rulesets.Osu.Objects
 
         private Vector2 position;
 
-        public Vector2 Position
+        public virtual Vector2 Position
         {
             get => position;
             set

osu.Game.Rulesets.Osu/Objects/Slider.cs

@@ -70,6 +70,21 @@ namespace osu.Game.Rulesets.Osu.Objects
             set { Curve.Distance = value; }
         }
 
+        public override Vector2 Position
+        {
+            get => base.Position;
+            set
+            {
+                base.Position = value;
+
+                if (HeadCircle != null)
+                    HeadCircle.Position = value;
+
+                if (TailCircle != null)
+                    TailCircle.Position = EndPosition;
+            }
+        }
+
         public double? LegacyLastTickOffset { get; set; }
 
         /// <summary>

osu.Game/Rulesets/Edit/SelectionMask.cs

@@ -3,6 +3,7 @@
 
 using System;
 using osu.Framework;
+using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Primitives;
 using osu.Framework.Input.Events;
@@ -52,6 +53,8 @@ namespace osu.Game.Rulesets.Edit
         {
             HitObject = hitObject;
 
+            RelativeSizeAxes = Axes.Both;
+
             AlwaysPresent = true;
             Alpha = 0;
         }
@@ -94,6 +97,8 @@ namespace osu.Game.Rulesets.Edit
 
         public bool IsSelected => State == SelectionState.Selected;
 
+        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => HitObject.ReceivePositionalInputAt(screenSpacePos);
+
         private bool selectionRequested;
 
         protected override bool OnMouseDown(MouseDownEvent e)
@@ -132,11 +137,11 @@ namespace osu.Game.Rulesets.Edit
         /// <summary>
         /// The screen-space point that causes this <see cref="SelectionMask"/> to be selected.
         /// </summary>
-        public virtual Vector2 SelectionPoint => ScreenSpaceDrawQuad.Centre;
+        public virtual Vector2 SelectionPoint => HitObject.ScreenSpaceDrawQuad.Centre;
 
         /// <summary>
         /// The screen-space quad that outlines this <see cref="SelectionMask"/> for selections.
         /// </summary>
-        public virtual Quad SelectionQuad => ScreenSpaceDrawQuad;
+        public virtual Quad SelectionQuad => HitObject.ScreenSpaceDrawQuad;
     }
 }