Fix drag breaking if scrolling while dragging

osu.Game.Rulesets.Mania/Edit/Blueprints/ManiaSelectionBlueprint.cs

@@ -3,6 +3,7 @@
 
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
+using osu.Framework.Input.Events;
 using osu.Framework.Timing;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
@@ -14,6 +15,9 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
 {
     public class ManiaSelectionBlueprint : SelectionBlueprint
     {
+        public Vector2 ScreenSpaceMouseDownPosition { get; private set; }
+        public Vector2 MouseDownPosition { get; private set; }
+
         protected new DrawableManiaHitObject HitObject => (DrawableManiaHitObject)base.HitObject;
 
         protected IClock EditorClock { get; private set; }
@@ -43,6 +47,24 @@ namespace osu.Game.Rulesets.Mania.Edit.Blueprints
             Position = Parent.ToLocalSpace(HitObject.ToScreenSpace(Vector2.Zero));
         }
 
+        protected override bool OnMouseDown(MouseDownEvent e)
+        {
+            ScreenSpaceMouseDownPosition = e.ScreenSpaceMousePosition;
+            MouseDownPosition = HitObject.ToLocalSpace(e.ScreenSpaceMousePosition);
+
+            return base.OnMouseDown(e);
+        }
+
+        protected override bool OnDrag(DragEvent e)
+        {
+            var result = base.OnDrag(e);
+
+            ScreenSpaceMouseDownPosition = e.ScreenSpaceMousePosition;
+            MouseDownPosition = HitObject.ToLocalSpace(e.ScreenSpaceMousePosition);
+
+            return result;
+        }
+
         public override void Show()
         {
             HitObject.AlwaysAlive = true;

osu.Game.Rulesets.Mania/Edit/ManiaSelectionHandler.cs

@@ -5,6 +5,8 @@ using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Input.Events;
 using osu.Framework.Timing;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Mania.Edit.Blueprints;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.UI;
 using osu.Game.Rulesets.UI.Scrolling;
@@ -29,11 +31,42 @@ namespace osu.Game.Rulesets.Mania.Edit
             editorClock = clock;
         }
 
-        public override void HandleDrag(DragEvent dragEvent)
+        public override void HandleDrag(SelectionBlueprint blueprint, DragEvent dragEvent)
         {
-            foreach (var blueprint in SelectedBlueprints)
+            adjustOrigins((ManiaSelectionBlueprint)blueprint);
+            performDragMovement(dragEvent);
+            performColumnMovement(dragEvent);
+
+            base.HandleDrag(blueprint, dragEvent);
+        }
+
+        /// <summary>
+        /// Ensures that the position of hitobjects remains centred to the mouse position.
+        /// E.g. The hitobject position will change if the editor scrolls while a hitobject is dragged.
+        /// </summary>
+        /// <param name="reference">The <see cref="ManiaSelectionBlueprint"/> that received the drag event.</param>
+        private void adjustOrigins(ManiaSelectionBlueprint reference)
         {
-                var hitObject = blueprint.HitObject;
+            var referenceParent = (HitObjectContainer)reference.HitObject.Parent;
+
+            float offsetFromReferenceOrigin = reference.MouseDownPosition.Y - reference.HitObject.OriginPosition.Y;
+            float targetPosition = referenceParent.ToLocalSpace(reference.ScreenSpaceMouseDownPosition).Y - offsetFromReferenceOrigin;
+
+            // Flip the vertical coordinate space when scrolling downwards
+            if (scrollingInfo.Direction.Value == ScrollingDirection.Down)
+                targetPosition = targetPosition - referenceParent.DrawHeight;
+
+            float movementDelta = targetPosition - reference.HitObject.Position.Y;
+
+            foreach (var b in SelectedBlueprints.OfType<ManiaSelectionBlueprint>())
+                b.HitObject.Y += movementDelta;
+        }
+
+        private void performDragMovement(DragEvent dragEvent)
+        {
+            foreach (var b in SelectedBlueprints)
+            {
+                var hitObject = b.HitObject;
 
                 var objectParent = (HitObjectContainer)hitObject.Parent;
 
@@ -59,11 +92,9 @@ namespace osu.Game.Rulesets.Mania.Edit
 
                 objectParent.Add(hitObject);
             }
-
-            adjustColumn(dragEvent);
         }
 
-        private void adjustColumn(DragEvent dragEvent)
+        private void performColumnMovement(DragEvent dragEvent)
         {
             var lastColumn = composer.ColumnAt(dragEvent.ScreenSpaceLastMousePosition);
             var currentColumn = composer.ColumnAt(dragEvent.ScreenSpaceMousePosition);

osu.Game.Rulesets.Osu/Edit/OsuSelectionHandler.cs

@@ -3,6 +3,7 @@
 
 using System.Linq;
 using osu.Framework.Input.Events;
+using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Screens.Edit.Compose.Components;
 
@@ -10,10 +11,8 @@ namespace osu.Game.Rulesets.Osu.Edit
 {
     public class OsuSelectionHandler : SelectionHandler
     {
-        public override void HandleDrag(DragEvent dragEvent)
+        public override void HandleDrag(SelectionBlueprint blueprint, DragEvent dragEvent)
         {
-            base.HandleDrag(dragEvent);
-
             foreach (var h in SelectedHitObjects.OfType<OsuHitObject>())
             {
                 if (h is Spinner)
@@ -24,6 +23,8 @@ namespace osu.Game.Rulesets.Osu.Edit
 
                 h.Position += dragEvent.Delta;
             }
+
+            base.HandleDrag(blueprint, dragEvent);
         }
     }
 }

osu.Game/Rulesets/Edit/SelectionBlueprint.cs

@@ -38,7 +38,7 @@ namespace osu.Game.Rulesets.Edit
         /// <summary>
         /// Invoked when this <see cref="SelectionBlueprint"/> has requested drag.
         /// </summary>
-        public event Action<DragEvent> DragRequested;
+        public event Action<SelectionBlueprint, DragEvent> DragRequested;
 
         /// <summary>
         /// The <see cref="DrawableHitObject"/> which this <see cref="SelectionBlueprint"/> applies to.
@@ -130,7 +130,7 @@ namespace osu.Game.Rulesets.Edit
 
         protected override bool OnDrag(DragEvent e)
         {
-            DragRequested?.Invoke(e);
+            DragRequested?.Invoke(this, e);
             return true;
         }
 

osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs

@@ -180,7 +180,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         private void onSelectionRequested(SelectionBlueprint blueprint, InputState state) => selectionHandler.HandleSelectionRequested(blueprint, state);
 
-        private void onDragRequested(DragEvent dragEvent) => selectionHandler.HandleDrag(dragEvent);
+        private void onDragRequested(SelectionBlueprint blueprint, DragEvent dragEvent) => selectionHandler.HandleDrag(blueprint, dragEvent);
 
         private class SelectionBlueprintContainer : Container<SelectionBlueprint>
         {

osu.Game/Screens/Edit/Compose/Components/SelectionHandler.cs

@@ -13,6 +13,7 @@ using osu.Framework.Input.States;
 using osu.Game.Graphics;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
 using osuTK;
 using osuTK.Input;
 
@@ -66,8 +67,9 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// <summary>
         /// Handles the selected <see cref="DrawableHitObject"/>s being dragged.
         /// </summary>
+        /// <param name="blueprint">The <see cref="SelectionBlueprint"/> that received the drag event.</param>
         /// <param name="dragEvent">The drag event.</param>
-        public virtual void HandleDrag(DragEvent dragEvent)
+        public virtual void HandleDrag(SelectionBlueprint blueprint, DragEvent dragEvent)
         {
         }