Allow to adjust slider velocity on multiple objects simultaneously

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;
+            }
+        }
+    }
+}