Split button repeating logic from TimingAdjustButton to own component

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

@@ -0,0 +1,93 @@
+// 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.Audio;
+using osu.Framework.Audio.Sample;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Input.Events;
+using osu.Framework.Threading;
+
+namespace osu.Game.Screens.Edit.Timing
+{
+    /// <summary>
+    /// Represents a component that provides the behaviour of triggering button clicks repeatedly while holding with mouse.
+    /// </summary>
+    public class RepeatingButtonBehaviour : CompositeDrawable
+    {
+        private const double initial_delay = 300;
+        private const double minimum_delay = 80;
+
+        private readonly Drawable button;
+
+        private Sample sample;
+
+        /// <summary>
+        /// An additive modifier for the frequency of the sample played on next actuation.
+        /// This can be adjusted during the button's <see cref="Drawable.OnClick"/> event to affect the repeat sample playback of that click.
+        /// </summary>
+        public double SampleFrequencyModifier { get; set; }
+
+        public RepeatingButtonBehaviour(Drawable button)
+        {
+            this.button = button;
+
+            RelativeSizeAxes = Axes.Both;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(AudioManager audio)
+        {
+            sample = audio.Samples.Get(@"UI/notch-tick");
+        }
+
+        protected override bool OnMouseDown(MouseDownEvent e)
+        {
+            beginRepeat();
+            return true;
+        }
+
+        protected override void OnMouseUp(MouseUpEvent e)
+        {
+            adjustDelegate?.Cancel();
+            base.OnMouseUp(e);
+        }
+
+        private ScheduledDelegate adjustDelegate;
+        private double adjustDelay = initial_delay;
+
+        private void beginRepeat()
+        {
+            adjustDelegate?.Cancel();
+
+            adjustDelay = initial_delay;
+            adjustNext();
+
+            void adjustNext()
+            {
+                if (IsHovered)
+                {
+                    button.TriggerClick();
+                    adjustDelay = Math.Max(minimum_delay, adjustDelay * 0.9f);
+
+                    var channel = sample?.GetChannel();
+
+                    if (channel != null)
+                    {
+                        double repeatModifier = 0.05f * (Math.Abs(adjustDelay - initial_delay) / minimum_delay);
+                        channel.Frequency.Value = 1 + repeatModifier + SampleFrequencyModifier;
+                        channel.Play();
+                    }
+                }
+                else
+                {
+                    adjustDelay = initial_delay;
+                }
+
+                adjustDelegate = Scheduler.AddDelayed(adjustNext, adjustDelay);
+            }
+        }
+    }
+}