Merge branch 'master' into visible-playfield-boundary

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

@@ -24,15 +24,15 @@ namespace osu.Game.Screens.Edit.Compose.Components
 {
     /// <summary>
     /// A container which provides a "blueprint" display of hitobjects.
-    /// Includes selection and manipulation support via a <see cref="SelectionHandler"/>.
+    /// Includes selection and manipulation support via a <see cref="Components.SelectionHandler"/>.
     /// </summary>
     public abstract class BlueprintContainer : CompositeDrawable, IKeyBindingHandler<PlatformAction>
     {
         protected DragBox DragBox { get; private set; }
 
-        protected Container<SelectionBlueprint> SelectionBlueprints { get; private set; }
+        public Container<SelectionBlueprint> SelectionBlueprints { get; private set; }
 
-        private SelectionHandler selectionHandler;
+        protected SelectionHandler SelectionHandler { get; private set; }
 
         [Resolved(CanBeNull = true)]
         private IEditorChangeHandler changeHandler { get; set; }
@@ -41,7 +41,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
         private EditorClock editorClock { get; set; }
 
         [Resolved]
-        private EditorBeatmap beatmap { get; set; }
+        protected EditorBeatmap Beatmap { get; private set; }
 
         private readonly BindableList<HitObject> selectedHitObjects = new BindableList<HitObject>();
 
@@ -56,22 +56,22 @@ namespace osu.Game.Screens.Edit.Compose.Components
         [BackgroundDependencyLoader]
         private void load()
         {
-            selectionHandler = CreateSelectionHandler();
-            selectionHandler.DeselectAll = deselectAll;
+            SelectionHandler = CreateSelectionHandler();
+            SelectionHandler.DeselectAll = deselectAll;
 
             AddRangeInternal(new[]
             {
-                DragBox = CreateDragBox(select),
-                selectionHandler,
+                DragBox = CreateDragBox(selectBlueprintsFromDragRectangle),
+                SelectionHandler,
                 SelectionBlueprints = CreateSelectionBlueprintContainer(),
-                selectionHandler.CreateProxy(),
+                SelectionHandler.CreateProxy(),
                 DragBox.CreateProxy().With(p => p.Depth = float.MinValue)
             });
 
-            foreach (var obj in beatmap.HitObjects)
+            foreach (var obj in Beatmap.HitObjects)
                 AddBlueprintFor(obj);
 
-            selectedHitObjects.BindTo(beatmap.SelectedHitObjects);
+            selectedHitObjects.BindTo(Beatmap.SelectedHitObjects);
             selectedHitObjects.CollectionChanged += (selectedObjects, args) =>
             {
                 switch (args.Action)
@@ -94,15 +94,15 @@ namespace osu.Game.Screens.Edit.Compose.Components
         {
             base.LoadComplete();
 
-            beatmap.HitObjectAdded += AddBlueprintFor;
-            beatmap.HitObjectRemoved += removeBlueprintFor;
+            Beatmap.HitObjectAdded += AddBlueprintFor;
+            Beatmap.HitObjectRemoved += removeBlueprintFor;
         }
 
         protected virtual Container<SelectionBlueprint> CreateSelectionBlueprintContainer() =>
             new Container<SelectionBlueprint> { RelativeSizeAxes = Axes.Both };
 
         /// <summary>
-        /// Creates a <see cref="SelectionHandler"/> which outlines <see cref="DrawableHitObject"/>s and handles movement of selections.
+        /// Creates a <see cref="Components.SelectionHandler"/> which outlines <see cref="DrawableHitObject"/>s and handles movement of selections.
         /// </summary>
         protected virtual SelectionHandler CreateSelectionHandler() => new SelectionHandler();
 
@@ -130,7 +130,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 return false;
 
             // store for double-click handling
-            clickedBlueprint = selectionHandler.SelectedBlueprints.FirstOrDefault(b => b.IsHovered);
+            clickedBlueprint = SelectionHandler.SelectedBlueprints.FirstOrDefault(b => b.IsHovered);
 
             // Deselection should only occur if no selected blueprints are hovered
             // A special case for when a blueprint was selected via this click is added since OnClick() may occur outside the hitobject and should not trigger deselection
@@ -147,7 +147,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 return false;
 
             // ensure the blueprint which was hovered for the first click is still the hovered blueprint.
-            if (clickedBlueprint == null || selectionHandler.SelectedBlueprints.FirstOrDefault(b => b.IsHovered) != clickedBlueprint)
+            if (clickedBlueprint == null || SelectionHandler.SelectedBlueprints.FirstOrDefault(b => b.IsHovered) != clickedBlueprint)
                 return false;
 
             editorClock?.SeekTo(clickedBlueprint.HitObject.StartTime);
@@ -201,6 +201,10 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
             if (isDraggingBlueprint)
             {
+                // handle positional change etc.
+                foreach (var obj in selectedHitObjects)
+                    Beatmap.Update(obj);
+
                 changeHandler?.EndChange();
                 isDraggingBlueprint = false;
             }
@@ -208,7 +212,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             if (DragBox.State == Visibility.Visible)
             {
                 DragBox.Hide();
-                selectionHandler.UpdateVisibility();
+                SelectionHandler.UpdateVisibility();
             }
         }
 
@@ -217,7 +221,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             switch (e.Key)
             {
                 case Key.Escape:
-                    if (!selectionHandler.SelectedBlueprints.Any())
+                    if (!SelectionHandler.SelectedBlueprints.Any())
                         return false;
 
                     deselectAll();
@@ -271,6 +275,9 @@ namespace osu.Game.Screens.Edit.Compose.Components
             blueprint.Selected += onBlueprintSelected;
             blueprint.Deselected += onBlueprintDeselected;
 
+            if (Beatmap.SelectedHitObjects.Contains(hitObject))
+                blueprint.Select();
+
             SelectionBlueprints.Add(blueprint);
         }
 
@@ -295,14 +302,14 @@ namespace osu.Game.Screens.Edit.Compose.Components
             bool allowDeselection = e.ControlPressed && e.Button == MouseButton.Left;
 
             // Todo: This is probably incorrectly disallowing multiple selections on stacked objects
-            if (!allowDeselection && selectionHandler.SelectedBlueprints.Any(s => s.IsHovered))
+            if (!allowDeselection && SelectionHandler.SelectedBlueprints.Any(s => s.IsHovered))
                 return;
 
             foreach (SelectionBlueprint blueprint in SelectionBlueprints.AliveChildren)
             {
                 if (blueprint.IsHovered)
                 {
-                    selectionHandler.HandleSelectionRequested(blueprint, e.CurrentState);
+                    SelectionHandler.HandleSelectionRequested(blueprint, e.CurrentState);
                     clickSelectionBegan = true;
                     break;
                 }
@@ -326,7 +333,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// Select all masks in a given rectangle selection area.
         /// </summary>
         /// <param name="rect">The rectangle to perform a selection on in screen-space coordinates.</param>
-        private void select(RectangleF rect)
+        private void selectBlueprintsFromDragRectangle(RectangleF rect)
         {
             foreach (var blueprint in SelectionBlueprints)
             {
@@ -355,26 +362,24 @@ namespace osu.Game.Screens.Edit.Compose.Components
         private void selectAll()
         {
             SelectionBlueprints.ToList().ForEach(m => m.Select());
-            selectionHandler.UpdateVisibility();
+            SelectionHandler.UpdateVisibility();
         }
 
         /// <summary>
         /// Deselects all selected <see cref="SelectionBlueprint"/>s.
         /// </summary>
-        private void deselectAll() => selectionHandler.SelectedBlueprints.ToList().ForEach(m => m.Deselect());
+        private void deselectAll() => SelectionHandler.SelectedBlueprints.ToList().ForEach(m => m.Deselect());
 
         private void onBlueprintSelected(SelectionBlueprint blueprint)
         {
-            selectionHandler.HandleSelected(blueprint);
+            SelectionHandler.HandleSelected(blueprint);
             SelectionBlueprints.ChangeChildDepth(blueprint, 1);
-            beatmap.SelectedHitObjects.Add(blueprint.HitObject);
         }
 
         private void onBlueprintDeselected(SelectionBlueprint blueprint)
         {
-            selectionHandler.HandleDeselected(blueprint);
+            SelectionHandler.HandleDeselected(blueprint);
             SelectionBlueprints.ChangeChildDepth(blueprint, 0);
-            beatmap.SelectedHitObjects.Remove(blueprint.HitObject);
         }
 
         #endregion
@@ -390,16 +395,16 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// </summary>
         private void prepareSelectionMovement()
         {
-            if (!selectionHandler.SelectedBlueprints.Any())
+            if (!SelectionHandler.SelectedBlueprints.Any())
                 return;
 
             // Any selected blueprint that is hovered can begin the movement of the group, however only the earliest hitobject is used for movement
             // A special case is added for when a click selection occurred before the drag
-            if (!clickSelectionBegan && !selectionHandler.SelectedBlueprints.Any(b => b.IsHovered))
+            if (!clickSelectionBegan && !SelectionHandler.SelectedBlueprints.Any(b => b.IsHovered))
                 return;
 
             // Movement is tracked from the blueprint of the earliest hitobject, since it only makes sense to distance snap from that hitobject
-            movementBlueprint = selectionHandler.SelectedBlueprints.OrderBy(b => b.HitObject.StartTime).First();
+            movementBlueprint = SelectionHandler.SelectedBlueprints.OrderBy(b => b.HitObject.StartTime).First();
             movementBlueprintOriginalPosition = movementBlueprint.ScreenSpaceSelectionPoint; // todo: unsure if correct
         }
 
@@ -424,15 +429,19 @@ namespace osu.Game.Screens.Edit.Compose.Components
             var result = snapProvider.SnapScreenSpacePositionToValidTime(movePosition);
 
             // Move the hitobjects.
-            if (!selectionHandler.HandleMovement(new MoveSelectionEvent(movementBlueprint, result.ScreenSpacePosition)))
+            if (!SelectionHandler.HandleMovement(new MoveSelectionEvent(movementBlueprint, result.ScreenSpacePosition)))
                 return true;
 
             if (result.Time.HasValue)
             {
                 // Apply the start time at the newly snapped-to position
                 double offset = result.Time.Value - draggedObject.StartTime;
-                foreach (HitObject obj in selectionHandler.SelectedHitObjects)
+
+                foreach (HitObject obj in Beatmap.SelectedHitObjects)
+                {
                     obj.StartTime += offset;
+                    Beatmap.Update(obj);
+                }
             }
 
             return true;
@@ -459,10 +468,10 @@ namespace osu.Game.Screens.Edit.Compose.Components
         {
             base.Dispose(isDisposing);
 
-            if (beatmap != null)
+            if (Beatmap != null)
             {
-                beatmap.HitObjectAdded -= AddBlueprintFor;
-                beatmap.HitObjectRemoved -= removeBlueprintFor;
+                Beatmap.HitObjectAdded -= AddBlueprintFor;
+                Beatmap.HitObjectRemoved -= removeBlueprintFor;
             }
         }
     }

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

@@ -3,14 +3,21 @@
 
 using System.Collections.Generic;
 using System.Linq;
+using Humanizer;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
 using osu.Framework.Input;
+using osu.Game.Audio;
+using osu.Game.Graphics.UserInterface;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Edit.Tools;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Screens.Edit.Components.TernaryButtons;
 using osuTK;
 
 namespace osu.Game.Screens.Edit.Compose.Components
@@ -46,6 +53,8 @@ namespace osu.Game.Screens.Edit.Compose.Components
         [BackgroundDependencyLoader]
         private void load()
         {
+            TernaryStates = CreateTernaryButtons().ToArray();
+
             AddInternal(placementBlueprintContainer);
         }
 
@@ -54,6 +63,90 @@ namespace osu.Game.Screens.Edit.Compose.Components
             base.LoadComplete();
 
             inputManager = GetContainingInputManager();
+
+            // updates to selected are handled for us by SelectionHandler.
+            NewCombo.BindTo(SelectionHandler.SelectionNewComboState);
+
+            // we are responsible for current placement blueprint updated based on state changes.
+            NewCombo.ValueChanged += _ => updatePlacementNewCombo();
+
+            // we own SelectionHandler so don't need to worry about making bindable copies (for simplicity)
+            foreach (var kvp in SelectionHandler.SelectionSampleStates)
+            {
+                kvp.Value.BindValueChanged(_ => updatePlacementSamples());
+            }
+        }
+
+        private void updatePlacementNewCombo()
+        {
+            if (currentPlacement?.HitObject is IHasComboInformation c)
+                c.NewCombo = NewCombo.Value == TernaryState.True;
+        }
+
+        private void updatePlacementSamples()
+        {
+            if (currentPlacement == null) return;
+
+            foreach (var kvp in SelectionHandler.SelectionSampleStates)
+                sampleChanged(kvp.Key, kvp.Value.Value);
+        }
+
+        private void sampleChanged(string sampleName, TernaryState state)
+        {
+            if (currentPlacement == null) return;
+
+            var samples = currentPlacement.HitObject.Samples;
+
+            var existingSample = samples.FirstOrDefault(s => s.Name == sampleName);
+
+            switch (state)
+            {
+                case TernaryState.False:
+                    if (existingSample != null)
+                        samples.Remove(existingSample);
+                    break;
+
+                case TernaryState.True:
+                    if (existingSample == null)
+                        samples.Add(new HitSampleInfo { Name = sampleName });
+                    break;
+            }
+        }
+
+        public readonly Bindable<TernaryState> NewCombo = new Bindable<TernaryState> { Description = "New Combo" };
+
+        /// <summary>
+        /// A collection of states which will be displayed to the user in the toolbox.
+        /// </summary>
+        public TernaryButton[] TernaryStates { get; private set; }
+
+        /// <summary>
+        /// Create all ternary states required to be displayed to the user.
+        /// </summary>
+        protected virtual IEnumerable<TernaryButton> CreateTernaryButtons()
+        {
+            //TODO: this should only be enabled (visible?) for rulesets that provide combo-supporting HitObjects.
+            yield return new TernaryButton(NewCombo, "New combo", () => new SpriteIcon { Icon = FontAwesome.Regular.DotCircle });
+
+            foreach (var kvp in SelectionHandler.SelectionSampleStates)
+                yield return new TernaryButton(kvp.Value, kvp.Key.Replace("hit", string.Empty).Titleize(), () => getIconForSample(kvp.Key));
+        }
+
+        private Drawable getIconForSample(string sampleName)
+        {
+            switch (sampleName)
+            {
+                case HitSampleInfo.HIT_CLAP:
+                    return new SpriteIcon { Icon = FontAwesome.Solid.Hands };
+
+                case HitSampleInfo.HIT_WHISTLE:
+                    return new SpriteIcon { Icon = FontAwesome.Solid.Bullhorn };
+
+                case HitSampleInfo.HIT_FINISH:
+                    return new SpriteIcon { Icon = FontAwesome.Solid.DrumSteelpan };
+            }
+
+            return null;
         }
 
         #region Placement
@@ -86,7 +179,9 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 removePlacement();
 
             if (currentPlacement != null)
+            {
                 updatePlacementPosition();
+            }
         }
 
         protected sealed override SelectionBlueprint CreateBlueprintFor(HitObject hitObject)
@@ -104,7 +199,12 @@ namespace osu.Game.Screens.Edit.Compose.Components
         protected override void AddBlueprintFor(HitObject hitObject)
         {
             refreshTool();
+
             base.AddBlueprintFor(hitObject);
+
+            // on successful placement, the new combo button should be reset as this is the most common user interaction.
+            if (Beatmap.SelectedHitObjects.Count == 0)
+                NewCombo.Value = TernaryState.False;
         }
 
         private void createPlacement()
@@ -115,10 +215,17 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
             if (blueprint != null)
             {
+                // doing this post-creations as adding the default hit sample should be the case regardless of the ruleset.
+                blueprint.HitObject.Samples.Add(new HitSampleInfo { Name = HitSampleInfo.HIT_NORMAL });
+
                 placementBlueprintContainer.Child = currentPlacement = blueprint;
 
                 // Fixes a 1-frame position discrepancy due to the first mouse move event happening in the next frame
                 updatePlacementPosition();
+
+                updatePlacementSamples();
+
+                updatePlacementNewCombo();
             }
         }
 

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

@@ -45,7 +45,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
         {
             Masking = true,
             BorderColour = Color4.White,
-            BorderThickness = SelectionHandler.BORDER_RADIUS,
+            BorderThickness = SelectionBox.BORDER_RADIUS,
             Child = new Box
             {
                 RelativeSizeAxes = Axes.Both,

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

@@ -0,0 +1,235 @@
+// 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.Shapes;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Graphics;
+using osuTK;
+
+namespace osu.Game.Screens.Edit.Compose.Components
+{
+    public class SelectionBox : CompositeDrawable
+    {
+        public Action<float> OnRotation;
+        public Action<Vector2, Anchor> OnScale;
+        public Action<Direction> OnFlip;
+        public Action OnReverse;
+
+        public Action OperationStarted;
+        public Action OperationEnded;
+
+        private bool canReverse;
+
+        /// <summary>
+        /// Whether pattern reversing support should be enabled.
+        /// </summary>
+        public bool CanReverse
+        {
+            get => canReverse;
+            set
+            {
+                if (canReverse == value) return;
+
+                canReverse = value;
+                recreate();
+            }
+        }
+
+        private bool canRotate;
+
+        /// <summary>
+        /// Whether rotation support should be enabled.
+        /// </summary>
+        public bool CanRotate
+        {
+            get => canRotate;
+            set
+            {
+                if (canRotate == value) return;
+
+                canRotate = value;
+                recreate();
+            }
+        }
+
+        private bool canScaleX;
+
+        /// <summary>
+        /// Whether vertical scale support should be enabled.
+        /// </summary>
+        public bool CanScaleX
+        {
+            get => canScaleX;
+            set
+            {
+                if (canScaleX == value) return;
+
+                canScaleX = value;
+                recreate();
+            }
+        }
+
+        private bool canScaleY;
+
+        /// <summary>
+        /// Whether horizontal scale support should be enabled.
+        /// </summary>
+        public bool CanScaleY
+        {
+            get => canScaleY;
+            set
+            {
+                if (canScaleY == value) return;
+
+                canScaleY = value;
+                recreate();
+            }
+        }
+
+        private FillFlowContainer buttons;
+
+        public const float BORDER_RADIUS = 3;
+
+        [Resolved]
+        private OsuColour colours { get; set; }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            RelativeSizeAxes = Axes.Both;
+
+            recreate();
+        }
+
+        private void recreate()
+        {
+            if (LoadState < LoadState.Loading)
+                return;
+
+            InternalChildren = new Drawable[]
+            {
+                new Container
+                {
+                    Masking = true,
+                    BorderThickness = BORDER_RADIUS,
+                    BorderColour = colours.YellowDark,
+                    RelativeSizeAxes = Axes.Both,
+                    Children = new Drawable[]
+                    {
+                        new Box
+                        {
+                            RelativeSizeAxes = Axes.Both,
+
+                            AlwaysPresent = true,
+                            Alpha = 0
+                        },
+                    }
+                },
+                buttons = new FillFlowContainer
+                {
+                    Y = 20,
+                    AutoSizeAxes = Axes.Both,
+                    Direction = FillDirection.Horizontal,
+                    Anchor = Anchor.BottomCentre,
+                    Origin = Anchor.Centre
+                }
+            };
+
+            if (CanScaleX) addXScaleComponents();
+            if (CanScaleX && CanScaleY) addFullScaleComponents();
+            if (CanScaleY) addYScaleComponents();
+            if (CanRotate) addRotationComponents();
+            if (CanReverse) addButton(FontAwesome.Solid.Backward, "Reverse pattern", () => OnReverse?.Invoke());
+        }
+
+        private void addRotationComponents()
+        {
+            const float separation = 40;
+
+            addButton(FontAwesome.Solid.Undo, "Rotate 90 degrees counter-clockwise", () => OnRotation?.Invoke(-90));
+            addButton(FontAwesome.Solid.Redo, "Rotate 90 degrees clockwise", () => OnRotation?.Invoke(90));
+
+            AddRangeInternal(new Drawable[]
+            {
+                new Box
+                {
+                    Depth = float.MaxValue,
+                    Colour = colours.YellowLight,
+                    Blending = BlendingParameters.Additive,
+                    Alpha = 0.3f,
+                    Size = new Vector2(BORDER_RADIUS, separation),
+                    Anchor = Anchor.TopCentre,
+                    Origin = Anchor.BottomCentre,
+                },
+                new SelectionBoxDragHandleButton(FontAwesome.Solid.Redo, "Free rotate")
+                {
+                    Anchor = Anchor.TopCentre,
+                    Y = -separation,
+                    HandleDrag = e => OnRotation?.Invoke(e.Delta.X),
+                    OperationStarted = operationStarted,
+                    OperationEnded = operationEnded
+                }
+            });
+        }
+
+        private void addYScaleComponents()
+        {
+            addButton(FontAwesome.Solid.ArrowsAltV, "Flip vertically", () => OnFlip?.Invoke(Direction.Vertical));
+
+            addDragHandle(Anchor.TopCentre);
+            addDragHandle(Anchor.BottomCentre);
+        }
+
+        private void addFullScaleComponents()
+        {
+            addDragHandle(Anchor.TopLeft);
+            addDragHandle(Anchor.TopRight);
+            addDragHandle(Anchor.BottomLeft);
+            addDragHandle(Anchor.BottomRight);
+        }
+
+        private void addXScaleComponents()
+        {
+            addButton(FontAwesome.Solid.ArrowsAltH, "Flip horizontally", () => OnFlip?.Invoke(Direction.Horizontal));
+
+            addDragHandle(Anchor.CentreLeft);
+            addDragHandle(Anchor.CentreRight);
+        }
+
+        private void addButton(IconUsage icon, string tooltip, Action action)
+        {
+            buttons.Add(new SelectionBoxDragHandleButton(icon, tooltip)
+            {
+                OperationStarted = operationStarted,
+                OperationEnded = operationEnded,
+                Action = action
+            });
+        }
+
+        private void addDragHandle(Anchor anchor) => AddInternal(new SelectionBoxDragHandle
+        {
+            Anchor = anchor,
+            HandleDrag = e => OnScale?.Invoke(e.Delta, anchor),
+            OperationStarted = operationStarted,
+            OperationEnded = operationEnded
+        });
+
+        private int activeOperations;
+
+        private void operationEnded()
+        {
+            if (--activeOperations == 0)
+                OperationEnded?.Invoke();
+        }
+
+        private void operationStarted()
+        {
+            if (activeOperations++ == 0)
+                OperationStarted?.Invoke();
+        }
+    }
+}

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

@@ -0,0 +1,105 @@
+// 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.Shapes;
+using osu.Framework.Input.Events;
+using osu.Game.Graphics;
+using osuTK;
+
+namespace osu.Game.Screens.Edit.Compose.Components
+{
+    public class SelectionBoxDragHandle : Container
+    {
+        public Action OperationStarted;
+        public Action OperationEnded;
+
+        public Action<DragEvent> HandleDrag { get; set; }
+
+        private Circle circle;
+
+        [Resolved]
+        private OsuColour colours { get; set; }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            Size = new Vector2(10);
+            Origin = Anchor.Centre;
+
+            InternalChildren = new Drawable[]
+            {
+                circle = new Circle
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                },
+            };
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+            UpdateHoverState();
+        }
+
+        protected override bool OnHover(HoverEvent e)
+        {
+            UpdateHoverState();
+            return base.OnHover(e);
+        }
+
+        protected override void OnHoverLost(HoverLostEvent e)
+        {
+            base.OnHoverLost(e);
+            UpdateHoverState();
+        }
+
+        protected bool HandlingMouse;
+
+        protected override bool OnMouseDown(MouseDownEvent e)
+        {
+            HandlingMouse = true;
+            UpdateHoverState();
+            return true;
+        }
+
+        protected override bool OnDragStart(DragStartEvent e)
+        {
+            OperationStarted?.Invoke();
+            return true;
+        }
+
+        protected override void OnDrag(DragEvent e)
+        {
+            HandleDrag?.Invoke(e);
+            base.OnDrag(e);
+        }
+
+        protected override void OnDragEnd(DragEndEvent e)
+        {
+            HandlingMouse = false;
+            OperationEnded?.Invoke();
+
+            UpdateHoverState();
+            base.OnDragEnd(e);
+        }
+
+        protected override void OnMouseUp(MouseUpEvent e)
+        {
+            HandlingMouse = false;
+            UpdateHoverState();
+            base.OnMouseUp(e);
+        }
+
+        protected virtual void UpdateHoverState()
+        {
+            circle.Colour = HandlingMouse ? colours.GrayF : (IsHovered ? colours.Red : colours.YellowDark);
+            this.ScaleTo(HandlingMouse || IsHovered ? 1.5f : 1, 100, Easing.OutQuint);
+        }
+    }
+}

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

@@ -0,0 +1,66 @@
+// 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.Cursor;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Input.Events;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Screens.Edit.Compose.Components
+{
+    /// <summary>
+    /// A drag "handle" which shares the visual appearance but behaves more like a clickable button.
+    /// </summary>
+    public sealed class SelectionBoxDragHandleButton : SelectionBoxDragHandle, IHasTooltip
+    {
+        private SpriteIcon icon;
+
+        private readonly IconUsage iconUsage;
+
+        public Action Action;
+
+        public SelectionBoxDragHandleButton(IconUsage iconUsage, string tooltip)
+        {
+            this.iconUsage = iconUsage;
+
+            TooltipText = tooltip;
+
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            Size *= 2;
+            AddInternal(icon = new SpriteIcon
+            {
+                RelativeSizeAxes = Axes.Both,
+                Size = new Vector2(0.5f),
+                Icon = iconUsage,
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+            });
+        }
+
+        protected override bool OnClick(ClickEvent e)
+        {
+            OperationStarted?.Invoke();
+            Action?.Invoke();
+            OperationEnded?.Invoke();
+            return true;
+        }
+
+        protected override void UpdateHoverState()
+        {
+            base.UpdateHoverState();
+            icon.Colour = !HandlingMouse && IsHovered ? Color4.White : Color4.Black;
+        }
+
+        public string TooltipText { get; }
+    }
+}

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

@@ -4,7 +4,9 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Humanizer;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Cursor;
@@ -20,6 +22,7 @@ using osu.Game.Graphics.UserInterface;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Objects.Types;
 using osuTK;
 
 namespace osu.Game.Screens.Edit.Compose.Components
@@ -29,22 +32,22 @@ namespace osu.Game.Screens.Edit.Compose.Components
     /// </summary>
     public class SelectionHandler : CompositeDrawable, IKeyBindingHandler<PlatformAction>, IHasContextMenu
     {
-        public const float BORDER_RADIUS = 2;
-
         public IEnumerable<SelectionBlueprint> SelectedBlueprints => selectedBlueprints;
         private readonly List<SelectionBlueprint> selectedBlueprints;
 
-        public IEnumerable<HitObject> SelectedHitObjects => selectedBlueprints.Select(b => b.HitObject);
+        public int SelectedCount => selectedBlueprints.Count;
 
         private Drawable content;
 
         private OsuSpriteText selectionDetailsText;
 
-        [Resolved(CanBeNull = true)]
+        protected SelectionBox SelectionBox { get; private set; }
+
+        [Resolved]
         protected EditorBeatmap EditorBeatmap { get; private set; }
 
         [Resolved(CanBeNull = true)]
-        private IEditorChangeHandler changeHandler { get; set; }
+        protected IEditorChangeHandler ChangeHandler { get; private set; }
 
         public SelectionHandler()
         {
@@ -58,23 +61,13 @@ namespace osu.Game.Screens.Edit.Compose.Components
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
+            createStateBindables();
+
             InternalChild = content = new Container
             {
                 Children = new Drawable[]
                 {
-                    new Container
-                    {
-                        RelativeSizeAxes = Axes.Both,
-                        Masking = true,
-                        BorderThickness = BORDER_RADIUS,
-                        BorderColour = colours.YellowDark,
-                        Child = new Box
-                        {
-                            RelativeSizeAxes = Axes.Both,
-                            AlwaysPresent = true,
-                            Alpha = 0
-                        }
-                    },
+                    // todo: should maybe be inside the SelectionBox?
                     new Container
                     {
                         Name = "info text",
@@ -93,11 +86,40 @@ namespace osu.Game.Screens.Edit.Compose.Components
                                 Font = OsuFont.Default.With(size: 11)
                             }
                         }
-                    }
+                    },
+                    SelectionBox = CreateSelectionBox(),
                 }
             };
         }
 
+        public SelectionBox CreateSelectionBox()
+            => new SelectionBox
+            {
+                OperationStarted = OnOperationBegan,
+                OperationEnded = OnOperationEnded,
+
+                OnRotation = angle => HandleRotation(angle),
+                OnScale = (amount, anchor) => HandleScale(amount, anchor),
+                OnFlip = direction => HandleFlip(direction),
+                OnReverse = () => HandleReverse(),
+            };
+
+        /// <summary>
+        /// Fired when a drag operation ends from the selection box.
+        /// </summary>
+        protected virtual void OnOperationBegan()
+        {
+            ChangeHandler.BeginChange();
+        }
+
+        /// <summary>
+        /// Fired when a drag operation begins from the selection box.
+        /// </summary>
+        protected virtual void OnOperationEnded()
+        {
+            ChangeHandler.EndChange();
+        }
+
         #region User Input Handling
 
         /// <summary>
@@ -112,7 +134,35 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// Whether any <see cref="DrawableHitObject"/>s could be moved.
         /// Returning true will also propagate StartTime changes provided by the closest <see cref="IPositionSnapProvider.SnapScreenSpacePositionToValidTime"/>.
         /// </returns>
-        public virtual bool HandleMovement(MoveSelectionEvent moveEvent) => true;
+        public virtual bool HandleMovement(MoveSelectionEvent moveEvent) => false;
+
+        /// <summary>
+        /// Handles the selected <see cref="DrawableHitObject"/>s being rotated.
+        /// </summary>
+        /// <param name="angle">The delta angle to apply to the selection.</param>
+        /// <returns>Whether any <see cref="DrawableHitObject"/>s could be rotated.</returns>
+        public virtual bool HandleRotation(float angle) => false;
+
+        /// <summary>
+        /// Handles the selected <see cref="DrawableHitObject"/>s being scaled.
+        /// </summary>
+        /// <param name="scale">The delta scale to apply, in playfield local coordinates.</param>
+        /// <param name="anchor">The point of reference where the scale is originating from.</param>
+        /// <returns>Whether any <see cref="DrawableHitObject"/>s could be scaled.</returns>
+        public virtual bool HandleScale(Vector2 scale, Anchor anchor) => false;
+
+        /// <summary>
+        /// Handles the selected <see cref="DrawableHitObject"/>s being flipped.
+        /// </summary>
+        /// <param name="direction">The direction to flip</param>
+        /// <returns>Whether any <see cref="DrawableHitObject"/>s could be flipped.</returns>
+        public virtual bool HandleFlip(Direction direction) => false;
+
+        /// <summary>
+        /// Handles the selected <see cref="DrawableHitObject"/>s being reversed pattern-wise.
+        /// </summary>
+        /// <returns>Whether any <see cref="DrawableHitObject"/>s could be reversed.</returns>
+        public virtual bool HandleReverse() => false;
 
         public bool OnPressed(PlatformAction action)
         {
@@ -146,7 +196,10 @@ namespace osu.Game.Screens.Edit.Compose.Components
         internal void HandleSelected(SelectionBlueprint blueprint)
         {
             selectedBlueprints.Add(blueprint);
-            EditorBeatmap.SelectedHitObjects.Add(blueprint.HitObject);
+
+            // there are potentially multiple SelectionHandlers active, but we only want to add hitobjects to the selected list once.
+            if (!EditorBeatmap.SelectedHitObjects.Contains(blueprint.HitObject))
+                EditorBeatmap.SelectedHitObjects.Add(blueprint.HitObject);
 
             UpdateVisibility();
         }
@@ -158,6 +211,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
         internal void HandleDeselected(SelectionBlueprint blueprint)
         {
             selectedBlueprints.Remove(blueprint);
+
             EditorBeatmap.SelectedHitObjects.Remove(blueprint.HitObject);
 
             UpdateVisibility();
@@ -189,12 +243,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         private void deleteSelected()
         {
-            changeHandler?.BeginChange();
-
-            foreach (var h in selectedBlueprints.ToList())
-                EditorBeatmap?.Remove(h.HitObject);
-
-            changeHandler?.EndChange();
+            EditorBeatmap.RemoveRange(selectedBlueprints.Select(b => b.HitObject));
         }
 
         #endregion
@@ -211,11 +260,22 @@ namespace osu.Game.Screens.Edit.Compose.Components
             selectionDetailsText.Text = count > 0 ? count.ToString() : string.Empty;
 
             if (count > 0)
+            {
                 Show();
+                OnSelectionChanged();
+            }
             else
                 Hide();
         }
 
+        /// <summary>
+        /// Triggered whenever more than one object is selected, on each change.
+        /// Should update the selection box's state to match supported operations.
+        /// </summary>
+        protected virtual void OnSelectionChanged()
+        {
+        }
+
         protected override void Update()
         {
             base.Update();
@@ -250,9 +310,9 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// <param name="sampleName">The name of the hit sample.</param>
         public void AddHitSample(string sampleName)
         {
-            changeHandler?.BeginChange();
+            EditorBeatmap.BeginChange();
 
-            foreach (var h in SelectedHitObjects)
+            foreach (var h in EditorBeatmap.SelectedHitObjects)
             {
                 // Make sure there isn't already an existing sample
                 if (h.Samples.Any(s => s.Name == sampleName))
@@ -261,7 +321,29 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 h.Samples.Add(new HitSampleInfo { Name = sampleName });
             }
 
-            changeHandler?.EndChange();
+            EditorBeatmap.EndChange();
+        }
+
+        /// <summary>
+        /// Set the new combo state of all selected <see cref="HitObject"/>s.
+        /// </summary>
+        /// <param name="state">Whether to set or unset.</param>
+        /// <exception cref="InvalidOperationException">Throws if any selected object doesn't implement <see cref="IHasComboInformation"/></exception>
+        public void SetNewCombo(bool state)
+        {
+            EditorBeatmap.BeginChange();
+
+            foreach (var h in EditorBeatmap.SelectedHitObjects)
+            {
+                var comboInfo = h as IHasComboInformation;
+
+                if (comboInfo == null || comboInfo.NewCombo == state) continue;
+
+                comboInfo.NewCombo = state;
+                EditorBeatmap.Update(h);
+            }
+
+            EditorBeatmap.EndChange();
         }
 
         /// <summary>
@@ -270,12 +352,99 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// <param name="sampleName">The name of the hit sample.</param>
         public void RemoveHitSample(string sampleName)
         {
-            changeHandler?.BeginChange();
+            EditorBeatmap.BeginChange();
 
-            foreach (var h in SelectedHitObjects)
+            foreach (var h in EditorBeatmap.SelectedHitObjects)
                 h.SamplesBindable.RemoveAll(s => s.Name == sampleName);
 
-            changeHandler?.EndChange();
+            EditorBeatmap.EndChange();
+        }
+
+        #endregion
+
+        #region Selection State
+
+        /// <summary>
+        /// The state of "new combo" for all selected hitobjects.
+        /// </summary>
+        public readonly Bindable<TernaryState> SelectionNewComboState = new Bindable<TernaryState>();
+
+        /// <summary>
+        /// The state of each sample type for all selected hitobjects. Keys match with <see cref="HitSampleInfo"/> constant specifications.
+        /// </summary>
+        public readonly Dictionary<string, Bindable<TernaryState>> SelectionSampleStates = new Dictionary<string, Bindable<TernaryState>>();
+
+        /// <summary>
+        /// Set up ternary state bindables and bind them to selection/hitobject changes (in both directions)
+        /// </summary>
+        private void createStateBindables()
+        {
+            foreach (var sampleName in HitSampleInfo.AllAdditions)
+            {
+                var bindable = new Bindable<TernaryState>
+                {
+                    Description = sampleName.Replace("hit", string.Empty).Titleize()
+                };
+
+                bindable.ValueChanged += state =>
+                {
+                    switch (state.NewValue)
+                    {
+                        case TernaryState.False:
+                            RemoveHitSample(sampleName);
+                            break;
+
+                        case TernaryState.True:
+                            AddHitSample(sampleName);
+                            break;
+                    }
+                };
+
+                SelectionSampleStates[sampleName] = bindable;
+            }
+
+            // new combo
+            SelectionNewComboState.ValueChanged += state =>
+            {
+                switch (state.NewValue)
+                {
+                    case TernaryState.False:
+                        SetNewCombo(false);
+                        break;
+
+                    case TernaryState.True:
+                        SetNewCombo(true);
+                        break;
+                }
+            };
+
+            // bring in updates from selection changes
+            EditorBeatmap.HitObjectUpdated += _ => UpdateTernaryStates();
+            EditorBeatmap.SelectedHitObjects.CollectionChanged += (sender, args) => UpdateTernaryStates();
+        }
+
+        /// <summary>
+        /// Called when context menu ternary states may need to be recalculated (selection changed or hitobject updated).
+        /// </summary>
+        protected virtual void UpdateTernaryStates()
+        {
+            SelectionNewComboState.Value = GetStateFromSelection(EditorBeatmap.SelectedHitObjects.OfType<IHasComboInformation>(), h => h.NewCombo);
+
+            foreach (var (sampleName, bindable) in SelectionSampleStates)
+            {
+                bindable.Value = GetStateFromSelection(EditorBeatmap.SelectedHitObjects, h => h.Samples.Any(s => s.Name == sampleName));
+            }
+        }
+
+        /// <summary>
+        /// Given a selection target and a function of truth, retrieve the correct ternary state for display.
+        /// </summary>
+        protected TernaryState GetStateFromSelection<T>(IEnumerable<T> selection, Func<T, bool> func)
+        {
+            if (selection.Any(func))
+                return selection.All(func) ? TernaryState.True : TernaryState.Indeterminate;
+
+            return TernaryState.False;
         }
 
         #endregion
@@ -293,6 +462,11 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
                 items.AddRange(GetContextMenuItemsForSelection(selectedBlueprints));
 
+                if (selectedBlueprints.All(b => b.HitObject is IHasComboInformation))
+                {
+                    items.Add(new TernaryStateMenuItem("New combo") { State = { BindTarget = SelectionNewComboState } });
+                }
+
                 if (selectedBlueprints.Count == 1)
                     items.AddRange(selectedBlueprints[0].ContextMenuItems);
 
@@ -300,12 +474,8 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 {
                     new OsuMenuItem("Sound")
                     {
-                        Items = new[]
-                        {
-                            createHitSampleMenuItem("Whistle", HitSampleInfo.HIT_WHISTLE),
-                            createHitSampleMenuItem("Clap", HitSampleInfo.HIT_CLAP),
-                            createHitSampleMenuItem("Finish", HitSampleInfo.HIT_FINISH)
-                        }
+                        Items = SelectionSampleStates.Select(kvp =>
+                            new TernaryStateMenuItem(kvp.Value.Description) { State = { BindTarget = kvp.Value } }).ToArray()
                     },
                     new OsuMenuItem("Delete", MenuItemType.Destructive, deleteSelected),
                 });
@@ -322,41 +492,6 @@ namespace osu.Game.Screens.Edit.Compose.Components
         protected virtual IEnumerable<MenuItem> GetContextMenuItemsForSelection(IEnumerable<SelectionBlueprint> selection)
             => Enumerable.Empty<MenuItem>();
 
-        private MenuItem createHitSampleMenuItem(string name, string sampleName)
-        {
-            return new TernaryStateMenuItem(name, MenuItemType.Standard, setHitSampleState)
-            {
-                State = { Value = getHitSampleState() }
-            };
-
-            void setHitSampleState(TernaryState state)
-            {
-                switch (state)
-                {
-                    case TernaryState.False:
-                        RemoveHitSample(sampleName);
-                        break;
-
-                    case TernaryState.True:
-                        AddHitSample(sampleName);
-                        break;
-                }
-            }
-
-            TernaryState getHitSampleState()
-            {
-                int countExisting = SelectedHitObjects.Count(h => h.Samples.Any(s => s.Name == sampleName));
-
-                if (countExisting == 0)
-                    return TernaryState.False;
-
-                if (countExisting < SelectedHitObjects.Count())
-                    return TernaryState.Indeterminate;
-
-                return TernaryState.True;
-            }
-        }
-
         #endregion
     }
 }

osu.Game/Screens/Edit/Compose/Components/Timeline/DifficultyPointPiece.cs

@@ -0,0 +1,67 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osuTK.Graphics;
+
+namespace osu.Game.Screens.Edit.Compose.Components.Timeline
+{
+    public class DifficultyPointPiece : CompositeDrawable
+    {
+        private readonly DifficultyControlPoint difficultyPoint;
+
+        private OsuSpriteText speedMultiplierText;
+        private readonly BindableNumber<double> speedMultiplier;
+
+        public DifficultyPointPiece(DifficultyControlPoint difficultyPoint)
+        {
+            this.difficultyPoint = difficultyPoint;
+            speedMultiplier = difficultyPoint.SpeedMultiplierBindable.GetBoundCopy();
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            RelativeSizeAxes = Axes.Y;
+            AutoSizeAxes = Axes.X;
+
+            Color4 colour = difficultyPoint.GetRepresentingColour(colours);
+
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    Colour = colour,
+                    Width = 2,
+                    RelativeSizeAxes = Axes.Y,
+                },
+                new Container
+                {
+                    AutoSizeAxes = Axes.Both,
+                    Children = new Drawable[]
+                    {
+                        new Box
+                        {
+                            Colour = colour,
+                            RelativeSizeAxes = Axes.Both,
+                        },
+                        speedMultiplierText = new OsuSpriteText
+                        {
+                            Font = OsuFont.Default.With(weight: FontWeight.Bold),
+                            Colour = Color4.White,
+                        }
+                    }
+                },
+            };
+
+            speedMultiplier.BindValueChanged(multiplier => speedMultiplierText.Text = $"{multiplier.NewValue:n2}x", true);
+        }
+    }
+}

osu.Game/Screens/Edit/Compose/Components/Timeline/SamplePointPiece.cs

@@ -0,0 +1,85 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Colour;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osuTK.Graphics;
+
+namespace osu.Game.Screens.Edit.Compose.Components.Timeline
+{
+    public class SamplePointPiece : CompositeDrawable
+    {
+        private readonly SampleControlPoint samplePoint;
+
+        private readonly Bindable<string> bank;
+        private readonly BindableNumber<int> volume;
+
+        private OsuSpriteText text;
+        private Box volumeBox;
+
+        public SamplePointPiece(SampleControlPoint samplePoint)
+        {
+            this.samplePoint = samplePoint;
+            volume = samplePoint.SampleVolumeBindable.GetBoundCopy();
+            bank = samplePoint.SampleBankBindable.GetBoundCopy();
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            Origin = Anchor.TopLeft;
+            Anchor = Anchor.TopLeft;
+
+            AutoSizeAxes = Axes.X;
+            RelativeSizeAxes = Axes.Y;
+
+            Color4 colour = samplePoint.GetRepresentingColour(colours);
+
+            InternalChildren = new Drawable[]
+            {
+                new Container
+                {
+                    RelativeSizeAxes = Axes.Y,
+                    Width = 20,
+                    Children = new Drawable[]
+                    {
+                        volumeBox = new Box
+                        {
+                            X = 2,
+                            Anchor = Anchor.BottomLeft,
+                            Origin = Anchor.BottomLeft,
+                            Colour = ColourInfo.GradientVertical(colour, Color4.Black),
+                            RelativeSizeAxes = Axes.Both,
+                        },
+                        new Box
+                        {
+                            Colour = colour.Lighten(0.2f),
+                            Width = 2,
+                            RelativeSizeAxes = Axes.Y,
+                        },
+                    }
+                },
+                text = new OsuSpriteText
+                {
+                    X = 2,
+                    Y = -5,
+                    Anchor = Anchor.BottomLeft,
+                    Alpha = 0.9f,
+                    Rotation = -90,
+                    Font = OsuFont.Default.With(weight: FontWeight.SemiBold)
+                }
+            };
+
+            volume.BindValueChanged(volume => volumeBox.Height = volume.NewValue / 100f, true);
+            bank.BindValueChanged(bank => text.Text = bank.NewValue, true);
+        }
+    }
+}

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

@@ -8,6 +8,7 @@ using osu.Framework.Bindables;
 using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Audio;
+using osu.Framework.Graphics.Containers;
 using osu.Framework.Input.Events;
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
@@ -21,6 +22,11 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
     public class Timeline : ZoomableScrollContainer, IPositionSnapProvider
     {
         public readonly Bindable<bool> WaveformVisible = new Bindable<bool>();
+
+        public readonly Bindable<bool> ControlPointsVisible = new Bindable<bool>();
+
+        public readonly Bindable<bool> TicksVisible = new Bindable<bool>();
+
         public readonly IBindable<WorkingBeatmap> Beatmap = new Bindable<WorkingBeatmap>();
 
         [Resolved]
@@ -57,23 +63,41 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
         private WaveformGraph waveform;
 
+        private TimelineTickDisplay ticks;
+
+        private TimelineControlPointDisplay controlPoints;
+
         [BackgroundDependencyLoader]
         private void load(IBindable<WorkingBeatmap> beatmap, OsuColour colours)
         {
-            Add(waveform = new WaveformGraph
+            AddRange(new Drawable[]
             {
-                RelativeSizeAxes = Axes.Both,
-                Colour = colours.Blue.Opacity(0.2f),
-                LowColour = colours.BlueLighter,
-                MidColour = colours.BlueDark,
-                HighColour = colours.BlueDarker,
-                Depth = float.MaxValue
+                new Container
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Depth = float.MaxValue,
+                    Children = new Drawable[]
+                    {
+                        waveform = new WaveformGraph
+                        {
+                            RelativeSizeAxes = Axes.Both,
+                            Colour = colours.Blue.Opacity(0.2f),
+                            LowColour = colours.BlueLighter,
+                            MidColour = colours.BlueDark,
+                            HighColour = colours.BlueDarker,
+                        },
+                        ticks = new TimelineTickDisplay(),
+                        controlPoints = new TimelineControlPointDisplay(),
+                    }
+                },
             });
 
             // We don't want the centre marker to scroll
             AddInternal(new CentreMarker { Depth = float.MaxValue });
 
             WaveformVisible.ValueChanged += visible => waveform.FadeTo(visible.NewValue ? 1 : 0, 200, Easing.OutQuint);
+            ControlPointsVisible.ValueChanged += visible => controlPoints.FadeTo(visible.NewValue ? 1 : 0, 200, Easing.OutQuint);
+            TicksVisible.ValueChanged += visible => ticks.FadeTo(visible.NewValue ? 1 : 0, 200, Easing.OutQuint);
 
             Beatmap.BindTo(beatmap);
             Beatmap.BindValueChanged(b =>

osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineArea.cs

@@ -14,9 +14,9 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 {
     public class TimelineArea : Container
     {
-        private readonly Timeline timeline = new Timeline { RelativeSizeAxes = Axes.Both };
+        public readonly Timeline Timeline = new Timeline { RelativeSizeAxes = Axes.Both };
 
-        protected override Container<Drawable> Content => timeline;
+        protected override Container<Drawable> Content => Timeline;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -25,6 +25,8 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             CornerRadius = 5;
 
             OsuCheckbox waveformCheckbox;
+            OsuCheckbox controlPointsCheckbox;
+            OsuCheckbox ticksCheckbox;
 
             InternalChildren = new Drawable[]
             {
@@ -57,12 +59,26 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                                         Origin = Anchor.CentreLeft,
                                         AutoSizeAxes = Axes.Y,
                                         Width = 160,
-                                        Padding = new MarginPadding { Horizontal = 15 },
+                                        Padding = new MarginPadding { Horizontal = 10 },
                                         Direction = FillDirection.Vertical,
                                         Spacing = new Vector2(0, 4),
                                         Children = new[]
                                         {
-                                            waveformCheckbox = new OsuCheckbox { LabelText = "Waveform" }
+                                            waveformCheckbox = new OsuCheckbox
+                                            {
+                                                LabelText = "Waveform",
+                                                Current = { Value = true },
+                                            },
+                                            controlPointsCheckbox = new OsuCheckbox
+                                            {
+                                                LabelText = "Control Points",
+                                                Current = { Value = true },
+                                            },
+                                            ticksCheckbox = new OsuCheckbox
+                                            {
+                                                LabelText = "Ticks",
+                                                Current = { Value = true },
+                                            }
                                         }
                                     }
                                 }
@@ -107,7 +123,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                                     }
                                 }
                             },
-                            timeline
+                            Timeline
                         },
                     },
                     ColumnDimensions = new[]
@@ -119,11 +135,11 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 }
             };
 
-            waveformCheckbox.Current.Value = true;
-
-            timeline.WaveformVisible.BindTo(waveformCheckbox.Current);
+            Timeline.WaveformVisible.BindTo(waveformCheckbox.Current);
+            Timeline.ControlPointsVisible.BindTo(controlPointsCheckbox.Current);
+            Timeline.TicksVisible.BindTo(ticksCheckbox.Current);
         }
 
-        private void changeZoom(float change) => timeline.Zoom += change;
+        private void changeZoom(float change) => Timeline.Zoom += change;
     }
 }

osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineControlPointDisplay.cs

@@ -0,0 +1,57 @@
+// 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.Collections.Specialized;
+using System.Linq;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Screens.Edit.Components.Timelines.Summary.Parts;
+
+namespace osu.Game.Screens.Edit.Compose.Components.Timeline
+{
+    /// <summary>
+    /// The part of the timeline that displays the control points.
+    /// </summary>
+    public class TimelineControlPointDisplay : TimelinePart<TimelineControlPointGroup>
+    {
+        private IBindableList<ControlPointGroup> controlPointGroups;
+
+        public TimelineControlPointDisplay()
+        {
+            RelativeSizeAxes = Axes.Both;
+        }
+
+        protected override void LoadBeatmap(WorkingBeatmap beatmap)
+        {
+            base.LoadBeatmap(beatmap);
+
+            controlPointGroups = beatmap.Beatmap.ControlPointInfo.Groups.GetBoundCopy();
+            controlPointGroups.BindCollectionChanged((sender, args) =>
+            {
+                switch (args.Action)
+                {
+                    case NotifyCollectionChangedAction.Reset:
+                        Clear();
+                        break;
+
+                    case NotifyCollectionChangedAction.Add:
+                        foreach (var group in args.NewItems.OfType<ControlPointGroup>())
+                            Add(new TimelineControlPointGroup(group));
+                        break;
+
+                    case NotifyCollectionChangedAction.Remove:
+                        foreach (var group in args.OldItems.OfType<ControlPointGroup>())
+                        {
+                            var matching = Children.SingleOrDefault(gv => gv.Group == group);
+
+                            matching?.Expire();
+                        }
+
+                        break;
+                }
+            }, true);
+        }
+    }
+}

osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineControlPointGroup.cs

@@ -0,0 +1,62 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Graphics;
+
+namespace osu.Game.Screens.Edit.Compose.Components.Timeline
+{
+    public class TimelineControlPointGroup : CompositeDrawable
+    {
+        public readonly ControlPointGroup Group;
+
+        private BindableList<ControlPoint> controlPoints;
+
+        [Resolved]
+        private OsuColour colours { get; set; }
+
+        public TimelineControlPointGroup(ControlPointGroup group)
+        {
+            Group = group;
+
+            RelativePositionAxes = Axes.X;
+            RelativeSizeAxes = Axes.Y;
+            AutoSizeAxes = Axes.X;
+
+            X = (float)group.Time;
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            controlPoints = (BindableList<ControlPoint>)Group.ControlPoints.GetBoundCopy();
+            controlPoints.BindCollectionChanged((_, __) =>
+            {
+                ClearInternal();
+
+                foreach (var point in controlPoints)
+                {
+                    switch (point)
+                    {
+                        case DifficultyControlPoint difficultyPoint:
+                            AddInternal(new DifficultyPointPiece(difficultyPoint) { Depth = -2 });
+                            break;
+
+                        case TimingControlPoint timingPoint:
+                            AddInternal(new TimingPointPiece(timingPoint));
+                            break;
+
+                        case SampleControlPoint samplePoint:
+                            AddInternal(new SamplePointPiece(samplePoint) { Depth = -1 });
+                            break;
+                    }
+                }
+            }, true);
+        }
+    }
+}

osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineHitObjectBlueprint.cs

@@ -3,18 +3,23 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Colour;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Effects;
 using osu.Framework.Graphics.Primitives;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Input.Events;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Objects.Types;
 using osuTK;
 using osuTK.Graphics;
@@ -34,11 +39,21 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
         private readonly List<Container> shadowComponents = new List<Container>();
 
+        private DrawableHitObject drawableHitObject;
+
+        private Bindable<Color4> comboColour;
+
+        private readonly Container mainComponents;
+
+        private readonly OsuSpriteText comboIndexText;
+
+        private Bindable<int> comboIndex;
+
         private const float thickness = 5;
 
         private const float shadow_radius = 5;
 
-        private const float circle_size = 16;
+        private const float circle_size = 24;
 
         public TimelineHitObjectBlueprint(HitObject hitObject)
             : base(hitObject)
@@ -54,14 +69,28 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             RelativeSizeAxes = Axes.X;
             AutoSizeAxes = Axes.Y;
 
+            AddRangeInternal(new Drawable[]
+            {
+                mainComponents = new Container
+                {
+                    Anchor = Anchor.CentreLeft,
+                    Origin = Anchor.CentreLeft,
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                },
+                comboIndexText = new OsuSpriteText
+                {
+                    Anchor = Anchor.CentreLeft,
+                    Origin = Anchor.Centre,
+                    Font = OsuFont.Numeric.With(size: circle_size / 2, weight: FontWeight.Black),
+                },
+            });
+
             circle = new Circle
             {
                 Size = new Vector2(circle_size),
                 Anchor = Anchor.CentreLeft,
                 Origin = Anchor.Centre,
-                RelativePositionAxes = Axes.X,
-                AlwaysPresent = true,
-                Colour = Color4.White,
                 EdgeEffect = new EdgeEffectParameters
                 {
                     Type = EdgeEffectType.Shadow,
@@ -77,7 +106,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 DragBar dragBarUnderlay;
                 Container extensionBar;
 
-                AddRangeInternal(new Drawable[]
+                mainComponents.AddRange(new Drawable[]
                 {
                     extensionBar = new Container
                     {
@@ -117,18 +146,93 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             }
             else
             {
-                AddInternal(circle);
+                mainComponents.Add(circle);
             }
 
             updateShadows();
         }
 
+        [BackgroundDependencyLoader(true)]
+        private void load(HitObjectComposer composer)
+        {
+            if (composer != null)
+            {
+                // best effort to get the drawable representation for grabbing colour and what not.
+                drawableHitObject = composer.HitObjects.FirstOrDefault(d => d.HitObject == HitObject);
+            }
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            if (HitObject is IHasComboInformation comboInfo)
+            {
+                comboIndex = comboInfo.IndexInCurrentComboBindable.GetBoundCopy();
+                comboIndex.BindValueChanged(combo =>
+                {
+                    comboIndexText.Text = (combo.NewValue + 1).ToString();
+                }, true);
+            }
+
+            if (drawableHitObject != null)
+            {
+                comboColour = drawableHitObject.AccentColour.GetBoundCopy();
+                comboColour.BindValueChanged(colour =>
+                {
+                    if (HitObject is IHasDuration)
+                        mainComponents.Colour = ColourInfo.GradientHorizontal(drawableHitObject.AccentColour.Value, Color4.White);
+                    else
+                        mainComponents.Colour = drawableHitObject.AccentColour.Value;
+
+                    var col = mainComponents.Colour.TopLeft.Linear;
+                    float brightness = col.R + col.G + col.B;
+
+                    // decide the combo index colour based on brightness?
+                    comboIndexText.Colour = brightness > 0.5f ? Color4.Black : Color4.White;
+                }, true);
+            }
+        }
+
         protected override void Update()
         {
             base.Update();
 
             // no bindable so we perform this every update
-            Width = (float)(HitObject.GetEndTime() - HitObject.StartTime);
+            float duration = (float)(HitObject.GetEndTime() - HitObject.StartTime);
+
+            if (Width != duration)
+            {
+                Width = duration;
+
+                // kind of haphazard but yeah, no bindables.
+                if (HitObject is IHasRepeats repeats)
+                    updateRepeats(repeats);
+            }
+        }
+
+        private Container repeatsContainer;
+
+        private void updateRepeats(IHasRepeats repeats)
+        {
+            repeatsContainer?.Expire();
+
+            mainComponents.Add(repeatsContainer = new Container
+            {
+                RelativeSizeAxes = Axes.Both,
+            });
+
+            for (int i = 0; i < repeats.RepeatCount; i++)
+            {
+                repeatsContainer.Add(new Circle
+                {
+                    Size = new Vector2(circle_size / 2),
+                    Anchor = Anchor.CentreLeft,
+                    Origin = Anchor.Centre,
+                    RelativePositionAxes = Axes.X,
+                    X = (float)(i + 1) / (repeats.RepeatCount + 1),
+                });
+            }
         }
 
         protected override bool ShouldBeConsideredForInput(Drawable child) => true;
@@ -288,6 +392,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                                 return;
 
                             repeatHitObject.RepeatCount = proposedCount;
+                            beatmap.Update(hitObject);
                             break;
 
                         case IHasDuration endTimeHitObject:
@@ -297,10 +402,9 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                                 return;
 
                             endTimeHitObject.Duration = snappedTime - hitObject.StartTime;
+                            beatmap.Update(hitObject);
                             break;
                     }
-
-                    beatmap.UpdateHitObject(hitObject);
                 }
             }
 

osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineTickDisplay.cs

@@ -1,9 +1,11 @@
 // 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 System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Caching;
 using osu.Framework.Graphics;
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
@@ -12,7 +14,7 @@ using osu.Game.Screens.Edit.Components.Timelines.Summary.Visualisations;
 
 namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 {
-    public class TimelineTickDisplay : TimelinePart
+    public class TimelineTickDisplay : TimelinePart<PointVisualisation>
     {
         [Resolved]
         private EditorBeatmap beatmap { get; set; }
@@ -31,15 +33,63 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             RelativeSizeAxes = Axes.Both;
         }
 
+        private readonly Cached tickCache = new Cached();
+
         [BackgroundDependencyLoader]
         private void load()
         {
-            beatDivisor.BindValueChanged(_ => createLines(), true);
+            beatDivisor.BindValueChanged(_ => tickCache.Invalidate());
         }
 
-        private void createLines()
+        /// <summary>
+        /// The visible time/position range of the timeline.
+        /// </summary>
+        private (float min, float max) visibleRange = (float.MinValue, float.MaxValue);
+
+        /// <summary>
+        /// The next time/position value to the left of the display when tick regeneration needs to be run.
+        /// </summary>
+        private float? nextMinTick;
+
+        /// <summary>
+        /// The next time/position value to the right of the display when tick regeneration needs to be run.
+        /// </summary>
+        private float? nextMaxTick;
+
+        [Resolved(canBeNull: true)]
+        private Timeline timeline { get; set; }
+
+        protected override void Update()
         {
-            Clear();
+            base.Update();
+
+            if (timeline != null)
+            {
+                var newRange = (
+                    (ToLocalSpace(timeline.ScreenSpaceDrawQuad.TopLeft).X - PointVisualisation.WIDTH * 2) / DrawWidth * Content.RelativeChildSize.X,
+                    (ToLocalSpace(timeline.ScreenSpaceDrawQuad.TopRight).X + PointVisualisation.WIDTH * 2) / DrawWidth * Content.RelativeChildSize.X);
+
+                if (visibleRange != newRange)
+                {
+                    visibleRange = newRange;
+
+                    // actual regeneration only needs to occur if we've passed one of the known next min/max tick boundaries.
+                    if (nextMinTick == null || nextMaxTick == null || (visibleRange.min < nextMinTick || visibleRange.max > nextMaxTick))
+                        tickCache.Invalidate();
+                }
+            }
+
+            if (!tickCache.IsValid)
+                createTicks();
+        }
+
+        private void createTicks()
+        {
+            int drawableIndex = 0;
+            int highestDivisor = BindableBeatDivisor.VALID_DIVISORS.Last();
+
+            nextMinTick = null;
+            nextMaxTick = null;
 
             for (var i = 0; i < beatmap.ControlPointInfo.TimingPoints.Count; i++)
             {
@@ -50,41 +100,70 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
                 for (double t = point.Time; t < until; t += point.BeatLength / beatDivisor.Value)
                 {
-                    var indexInBeat = beat % beatDivisor.Value;
+                    float xPos = (float)t;
 
-                    if (indexInBeat == 0)
-                    {
-                        Add(new PointVisualisation(t)
-                        {
-                            Colour = BindableBeatDivisor.GetColourFor(1, colours),
-                            Origin = Anchor.TopCentre,
-                        });
-                    }
+                    if (t < visibleRange.min)
+                        nextMinTick = xPos;
+                    else if (t > visibleRange.max)
+                        nextMaxTick ??= xPos;
                     else
                     {
+                        // if this is the first beat in the beatmap, there is no next min tick
+                        if (beat == 0 && i == 0)
+                            nextMinTick = float.MinValue;
+
+                        var indexInBar = beat % ((int)point.TimeSignature * beatDivisor.Value);
+
                         var divisor = BindableBeatDivisor.GetDivisorForBeatIndex(beat, beatDivisor.Value);
                         var colour = BindableBeatDivisor.GetColourFor(divisor, colours);
-                        var height = 0.1f - (float)divisor / BindableBeatDivisor.VALID_DIVISORS.Last() * 0.08f;
 
-                        Add(new PointVisualisation(t)
-                        {
-                            Colour = colour,
-                            Height = height,
-                            Origin = Anchor.TopCentre,
-                        });
+                        // even though "bar lines" take up the full vertical space, we render them in two pieces because it allows for less anchor/origin churn.
+                        var height = indexInBar == 0 ? 0.5f : 0.1f - (float)divisor / highestDivisor * 0.08f;
 
-                        Add(new PointVisualisation(t)
-                        {
-                            Colour = colour,
-                            Anchor = Anchor.BottomLeft,
-                            Origin = Anchor.BottomCentre,
-                            Height = height,
-                        });
+                        var topPoint = getNextUsablePoint();
+                        topPoint.X = xPos;
+                        topPoint.Colour = colour;
+                        topPoint.Height = height;
+                        topPoint.Anchor = Anchor.TopLeft;
+                        topPoint.Origin = Anchor.TopCentre;
+
+                        var bottomPoint = getNextUsablePoint();
+                        bottomPoint.X = xPos;
+                        bottomPoint.Colour = colour;
+                        bottomPoint.Anchor = Anchor.BottomLeft;
+                        bottomPoint.Origin = Anchor.BottomCentre;
+                        bottomPoint.Height = height;
                     }
 
                     beat++;
                 }
             }
+
+            int usedDrawables = drawableIndex;
+
+            // save a few drawables beyond the currently used for edge cases.
+            while (drawableIndex < Math.Min(usedDrawables + 16, Count))
+                Children[drawableIndex++].Hide();
+
+            // expire any excess
+            while (drawableIndex < Count)
+                Children[drawableIndex++].Expire();
+
+            tickCache.Validate();
+
+            Drawable getNextUsablePoint()
+            {
+                PointVisualisation point;
+                if (drawableIndex >= Count)
+                    Add(point = new PointVisualisation());
+                else
+                    point = Children[drawableIndex];
+
+                drawableIndex++;
+                point.Show();
+
+                return point;
+            }
         }
     }
 }

osu.Game/Screens/Edit/Compose/Components/Timeline/TimingPointPiece.cs

@@ -0,0 +1,63 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Colour;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osuTK.Graphics;
+
+namespace osu.Game.Screens.Edit.Compose.Components.Timeline
+{
+    public class TimingPointPiece : CompositeDrawable
+    {
+        private readonly TimingControlPoint point;
+
+        private readonly BindableNumber<double> beatLength;
+        private OsuSpriteText bpmText;
+
+        public TimingPointPiece(TimingControlPoint point)
+        {
+            this.point = point;
+            beatLength = point.BeatLengthBindable.GetBoundCopy();
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            Origin = Anchor.CentreLeft;
+            Anchor = Anchor.CentreLeft;
+
+            AutoSizeAxes = Axes.Both;
+
+            Color4 colour = point.GetRepresentingColour(colours);
+
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    Alpha = 0.9f,
+                    Colour = ColourInfo.GradientHorizontal(colour, colour.Opacity(0.5f)),
+                    RelativeSizeAxes = Axes.Both,
+                },
+                bpmText = new OsuSpriteText
+                {
+                    Alpha = 0.9f,
+                    Padding = new MarginPadding(3),
+                    Font = OsuFont.Default.With(size: 40)
+                }
+            };
+
+            beatLength.BindValueChanged(beatLength =>
+            {
+                bpmText.Text = $"{60000 / beatLength.NewValue:n1} BPM";
+            }, true);
+        }
+    }
+}

osu.Game/Screens/Edit/Compose/ComposeScreen.cs

@@ -1,8 +1,12 @@
 // 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Screens.Edit.Compose.Components.Timeline;
 using osu.Game.Skinning;
@@ -13,11 +17,28 @@ namespace osu.Game.Screens.Edit.Compose
     {
         private HitObjectComposer composer;
 
-        protected override Drawable CreateMainContent()
+        public ComposeScreen()
+            : base(EditorScreenMode.Compose)
         {
-            var ruleset = Beatmap.Value.BeatmapInfo.Ruleset?.CreateInstance();
+        }
+
+        private Ruleset ruleset;
+
+        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
+        {
+            var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
+
+            ruleset = parent.Get<IBindable<WorkingBeatmap>>().Value.BeatmapInfo.Ruleset?.CreateInstance();
             composer = ruleset?.CreateHitObjectComposer();
 
+            // make the composer available to the timeline and other components in this screen.
+            dependencies.CacheAs(composer);
+
+            return dependencies;
+        }
+
+        protected override Drawable CreateMainContent()
+        {
             if (ruleset == null || composer == null)
                 return new ScreenWhiteBox.UnderConstructionMessage(ruleset == null ? "This beatmap" : $"{ruleset.Description}'s composer");