Allow to adjust slider velocity on multiple objects simultaneously

osu.Game.Tests/Visual/Editing/TestSceneHitObjectDifficultyPointAdjustments.cs

@@ -136,7 +136,7 @@ namespace osu.Game.Tests.Visual.Editing
         private void velocityPopoverHasSingleValue(double velocity) => AddUntilStep($"velocity popover has {velocity}", () =>
         {
             var popover = this.ChildrenOfType<DifficultyPointPiece.DifficultyEditPopover>().SingleOrDefault();
-            var slider = popover?.ChildrenOfType<SliderWithTextBoxInput<double>>().Single();
+            var slider = popover?.ChildrenOfType<IndeterminateSliderWithTextBoxInput<double>>().Single();
 
             return slider?.Current.Value == velocity;
         });
@@ -144,7 +144,7 @@ namespace osu.Game.Tests.Visual.Editing
         private void velocityPopoverHasIndeterminateValue() => AddUntilStep("velocity popover has indeterminate value", () =>
         {
             var popover = this.ChildrenOfType<DifficultyPointPiece.DifficultyEditPopover>().SingleOrDefault();
-            var slider = popover?.ChildrenOfType<SliderWithTextBoxInput<double>>().Single();
+            var slider = popover?.ChildrenOfType<IndeterminateSliderWithTextBoxInput<double>>().Single();
 
             return slider != null && slider.Current.Value == null;
         });
@@ -158,7 +158,7 @@ namespace osu.Game.Tests.Visual.Editing
         private void setVelocityViaPopover(double velocity) => AddStep($"set {velocity} via popover", () =>
         {
             var popover = this.ChildrenOfType<DifficultyPointPiece.DifficultyEditPopover>().Single();
-            var slider = popover.ChildrenOfType<SliderWithTextBoxInput<double>>().Single();
+            var slider = popover.ChildrenOfType<IndeterminateSliderWithTextBoxInput<double>>().Single();
             slider.Current.Value = velocity;
         });
 

osu.Game/Screens/Edit/Compose/Components/Timeline/DifficultyPointPiece.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.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions;
+using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Cursor;
@@ -49,9 +51,8 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
         public class DifficultyEditPopover : OsuPopover
         {
             private readonly HitObject hitObject;
-            private readonly DifficultyControlPoint point;
 
-            private SliderWithTextBoxInput<double> sliderVelocitySlider;
+            private IndeterminateSliderWithTextBoxInput<double> sliderVelocitySlider;
 
             [Resolved(canBeNull: true)]
             private EditorBeatmap beatmap { get; set; }
@@ -59,7 +60,6 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
             public DifficultyEditPopover(HitObject hitObject)
             {
                 this.hitObject = hitObject;
-                point = hitObject.DifficultyControlPoint;
             }
 
             [BackgroundDependencyLoader]
@@ -74,9 +74,8 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                         AutoSizeAxes = Axes.Y,
                         Children = new Drawable[]
                         {
-                            sliderVelocitySlider = new SliderWithTextBoxInput<double>("Velocity")
+                            sliderVelocitySlider = new IndeterminateSliderWithTextBoxInput<double>("Velocity", new DifficultyControlPoint().SliderVelocityBindable)
                             {
-                                Current = new DifficultyControlPoint().SliderVelocityBindable,
                                 KeyboardStep = 0.1f
                             },
                             new OsuTextFlowContainer
@@ -89,17 +88,37 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                     }
                 };
 
-                var selectedPointBindable = point.SliderVelocityBindable;
+                // if the piece belongs to a currently selected object, assume that the user wants to change all selected objects.
+                // if the piece belongs to an unselected object, operate on that object alone, independently of the selection.
+                var relevantObjects = (beatmap.SelectedHitObjects.Contains(hitObject) ? beatmap.SelectedHitObjects : hitObject.Yield()).ToArray();
+                var relevantControlPoints = relevantObjects.Select(h => h.DifficultyControlPoint).ToArray();
 
-                // there may be legacy control points, which contain infinite precision for compatibility reasons (see LegacyDifficultyControlPoint).
+                // even if there are multiple objects selected, we can still display a value if they all have the same value.
-                // generally that level of precision could only be set by externally editing the .osu file, so at the point
+                var selectedPointBindable = relevantControlPoints.Select(point => point.SliderVelocity).Distinct().Count() == 1 ? relevantControlPoints.First().SliderVelocityBindable : null;
-                // a user is looking to update this within the editor it should be safe to obliterate this additional precision.
-                double expectedPrecision = new DifficultyControlPoint().SliderVelocityBindable.Precision;
-                if (selectedPointBindable.Precision < expectedPrecision)
-                    selectedPointBindable.Precision = expectedPrecision;
 
-                sliderVelocitySlider.Current = selectedPointBindable;
+                if (selectedPointBindable != null)
-                sliderVelocitySlider.Current.BindValueChanged(_ => beatmap?.Update(hitObject));
+                {
+                    // there may be legacy control points, which contain infinite precision for compatibility reasons (see LegacyDifficultyControlPoint).
+                    // generally that level of precision could only be set by externally editing the .osu file, so at the point
+                    // a user is looking to update this within the editor it should be safe to obliterate this additional precision.
+                    sliderVelocitySlider.Current.Value = selectedPointBindable.Value;
+                }
+
+                sliderVelocitySlider.Current.BindValueChanged(val =>
+                {
+                    if (val.NewValue == null)
+                        return;
+
+                    beatmap.BeginChange();
+
+                    foreach (var h in relevantObjects)
+                    {
+                        h.DifficultyControlPoint.SliderVelocity = val.NewValue.Value;
+                        beatmap.Update(h);
+                    }
+
+                    beatmap.EndChange();
+                });
             }
         }
     }

osu.Game/Screens/Edit/Timing/IndeterminateSliderWithTextBoxInput.cs

@@ -0,0 +1,115 @@
+// 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.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.UserInterface;
+using osu.Framework.Localisation;
+using osu.Game.Graphics.UserInterfaceV2;
+using osu.Game.Overlays.Settings;
+
+namespace osu.Game.Screens.Edit.Timing
+{
+    /// <summary>
+    /// Analogous to <see cref="SliderWithTextBoxInput{T}"/>, but supports scenarios
+    /// where multiple objects with multiple different property values are selected
+    /// by providing an "indeterminate state".
+    /// </summary>
+    public class IndeterminateSliderWithTextBoxInput<T> : CompositeDrawable, IHasCurrentValue<T?>
+        where T : struct, IEquatable<T>, IComparable<T>, IConvertible
+    {
+        /// <summary>
+        /// A custom step value for each key press which actuates a change on this control.
+        /// </summary>
+        public float KeyboardStep
+        {
+            get => slider.KeyboardStep;
+            set => slider.KeyboardStep = value;
+        }
+
+        private readonly BindableWithCurrent<T?> current = new BindableWithCurrent<T?>();
+
+        public Bindable<T?> Current
+        {
+            get => current.Current;
+            set => current.Current = value;
+        }
+
+        private readonly SettingsSlider<T> slider;
+        private readonly LabelledTextBox textbox;
+
+        /// <summary>
+        /// Creates an <see cref="IndeterminateSliderWithTextBoxInput{T}"/>.
+        /// </summary>
+        /// <param name="labelText">The label text for the slider and text box.</param>
+        /// <param name="indeterminateValue">
+        /// Bindable to use for the slider until a non-null value is set for <see cref="Current"/>.
+        /// In particular, it can be used to control min/max bounds and precision in the case of <see cref="BindableNumber{T}"/>s.
+        /// </param>
+        public IndeterminateSliderWithTextBoxInput(LocalisableString labelText, Bindable<T> indeterminateValue)
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            InternalChildren = new Drawable[]
+            {
+                new FillFlowContainer
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Direction = FillDirection.Vertical,
+                    Children = new Drawable[]
+                    {
+                        textbox = new LabelledTextBox
+                        {
+                            Label = labelText,
+                            PlaceholderText = "(multiple)"
+                        },
+                        slider = new SettingsSlider<T>
+                        {
+                            TransferValueOnCommit = true,
+                            RelativeSizeAxes = Axes.X,
+                            Current = indeterminateValue
+                        }
+                    }
+                },
+            };
+
+            textbox.OnCommit += (t, isNew) =>
+            {
+                if (!isNew) return;
+
+                try
+                {
+                    slider.Current.Parse(t.Text);
+                }
+                catch
+                {
+                    // TriggerChange below will restore the previous text value on failure.
+                }
+
+                // This is run regardless of parsing success as the parsed number may not actually trigger a change
+                // due to bindable clamping. Even in such a case we want to update the textbox to a sane visual state.
+                Current.TriggerChange();
+            };
+            slider.Current.BindValueChanged(val => Current.Value = val.NewValue);
+
+            Current.BindValueChanged(_ => updateState(), true);
+        }
+
+        private void updateState()
+        {
+            if (Current.Value is T nonNullValue)
+            {
+                slider.Current.Value = nonNullValue;
+                textbox.Text = slider.Current.ToString();
+            }
+            else
+            {
+                textbox.Text = null;
+            }
+        }
+    }
+}