Add simplified implementation of an expandable slider

osu.Game/Overlays/ExpandableSlider.cs

@@ -0,0 +1,123 @@
+// 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.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.UserInterface;
+using osu.Framework.Localisation;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
+
+namespace osu.Game.Overlays
+{
+    /// <summary>
+    /// An <see cref="IExpandable"/> implementation for the UI slider bar control.
+    /// </summary>
+    public class ExpandableSlider<T, TSlider> : CompositeDrawable, IExpandableControl, IHasCurrentValue<T>
+        where T : struct, IEquatable<T>, IComparable<T>, IConvertible
+        where TSlider : OsuSliderBar<T>, new()
+    {
+        private readonly OsuSpriteText label;
+        private readonly TSlider slider;
+
+        private LocalisableString contractedLabelText;
+
+        /// <summary>
+        /// The label text to display when this slider is in a contracted state.
+        /// </summary>
+        public LocalisableString ContractedLabelText
+        {
+            get => contractedLabelText;
+            set
+            {
+                if (value == contractedLabelText)
+                    return;
+
+                contractedLabelText = value;
+
+                if (!Expanded.Value)
+                    label.Text = value;
+            }
+        }
+
+        private LocalisableString expandedLabelText;
+
+        /// <summary>
+        /// The label text to display when this slider is in an expanded state.
+        /// </summary>
+        public LocalisableString ExpandedLabelText
+        {
+            get => expandedLabelText;
+            set
+            {
+                if (value == expandedLabelText)
+                    return;
+
+                expandedLabelText = value;
+
+                if (Expanded.Value)
+                    label.Text = value;
+            }
+        }
+
+        public Bindable<T> Current
+        {
+            get => slider.Current;
+            set => slider.Current = value;
+        }
+
+        public BindableBool Expanded { get; } = new BindableBool();
+
+        public bool IsControlDragged => slider.IsDragged;
+
+        public override bool HandlePositionalInput => true;
+
+        public ExpandableSlider()
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            InternalChild = new FillFlowContainer
+            {
+                RelativeSizeAxes = Axes.X,
+                AutoSizeAxes = Axes.Y,
+                Children = new Drawable[]
+                {
+                    label = new OsuSpriteText(),
+                    slider = new TSlider(),
+                }
+            };
+        }
+
+        [Resolved(canBeNull: true)]
+        private IExpandingContainer expandingContainer { get; set; }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            expandingContainer?.Expanded.BindValueChanged(containerExpanded =>
+            {
+                Expanded.Value = containerExpanded.NewValue;
+            }, true);
+
+            Expanded.BindValueChanged(v =>
+            {
+                label.Text = v.NewValue ? expandedLabelText : contractedLabelText;
+                slider.FadeTo(v.NewValue ? 1f : 0f, 500, Easing.OutQuint);
+                slider.BypassAutoSizeAxes = v.NewValue ? Axes.Y : Axes.None;
+            }, true);
+        }
+    }
+
+    /// <summary>
+    /// An <see cref="IExpandable"/> implementation for the UI slider bar control.
+    /// </summary>
+    public class ExpandableSlider<T> : ExpandableSlider<T, OsuSliderBar<T>>
+        where T : struct, IEquatable<T>, IComparable<T>, IConvertible
+    {
+    }
+}

osu.Game/Overlays/IExpandableControl.cs

@@ -0,0 +1,16 @@
+// 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.
+
+namespace osu.Game.Overlays
+{
+    /// <summary>
+    /// An interface for UI controls with the ability to expand/contract.
+    /// </summary>
+    public interface IExpandableControl : IExpandable
+    {
+        /// <summary>
+        /// Returns whether the UI control is currently in a dragged state.
+        /// </summary>
+        bool IsControlDragged { get; }
+    }
+}