Merge pull request #10077 from peppy/editor-bpm-usability

Improve usability of BPM modifying in timing setup view

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

@@ -1,30 +1,30 @@
 // 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.Game.Beatmaps.ControlPoints;
 using osu.Game.Beatmaps.Timing;
+using osu.Game.Graphics.UserInterfaceV2;
 using osu.Game.Overlays.Settings;
 
 namespace osu.Game.Screens.Edit.Timing
 {
     internal class TimingSection : Section<TimingControlPoint>
     {
-        private SettingsSlider<double> bpm;
+        private SettingsSlider<double> bpmSlider;
         private SettingsEnumDropdown<TimeSignatures> timeSignature;
+        private BPMTextBox bpmTextEntry;
 
         [BackgroundDependencyLoader]
         private void load()
         {
             Flow.AddRange(new Drawable[]
             {
-                bpm = new BPMSlider
+                bpmTextEntry = new BPMTextBox(),
-                {
+                bpmSlider = new BPMSlider(),
-                    Bindable = new TimingControlPoint().BeatLengthBindable,
-                    LabelText = "BPM",
-                },
                 timeSignature = new SettingsEnumDropdown<TimeSignatures>
                 {
                     LabelText = "Time Signature"
@@ -36,7 +36,8 @@ namespace osu.Game.Screens.Edit.Timing
         {
             if (point.NewValue != null)
             {
-                bpm.Bindable = point.NewValue.BeatLengthBindable;
+                bpmSlider.Bindable = point.NewValue.BeatLengthBindable;
+                bpmTextEntry.Bindable = point.NewValue.BeatLengthBindable;
                 timeSignature.Bindable = point.NewValue.TimeSignatureBindable;
             }
         }
@@ -52,34 +53,88 @@ namespace osu.Game.Screens.Edit.Timing
             };
         }
 
+        private class BPMTextBox : LabelledTextBox
+        {
+            private readonly BindableNumber<double> beatLengthBindable = new TimingControlPoint().BeatLengthBindable;
+
+            public BPMTextBox()
+            {
+                Label = "BPM";
+
+                OnCommit += (val, isNew) =>
+                {
+                    if (!isNew) return;
+
+                    if (double.TryParse(Current.Value, out double doubleVal))
+                    {
+                        try
+                        {
+                            beatLengthBindable.Value = beatLengthToBpm(doubleVal);
+                        }
+                        catch
+                        {
+                            // will restore the previous text value on failure.
+                            beatLengthBindable.TriggerChange();
+                        }
+                    }
+                };
+
+                beatLengthBindable.BindValueChanged(val =>
+                {
+                    Current.Value = beatLengthToBpm(val.NewValue).ToString("N2");
+                }, true);
+            }
+
+            public Bindable<double> Bindable
+            {
+                get => beatLengthBindable;
+                set
+                {
+                    // incoming will be beat length, not bpm
+                    beatLengthBindable.UnbindBindings();
+                    beatLengthBindable.BindTo(value);
+                }
+            }
+        }
+
         private class BPMSlider : SettingsSlider<double>
         {
-            private readonly BindableDouble beatLengthBindable = new BindableDouble();
+            private const double sane_minimum = 60;
+            private const double sane_maximum = 240;
 
-            private BindableDouble bpmBindable;
+            private readonly BindableNumber<double> beatLengthBindable = new TimingControlPoint().BeatLengthBindable;
+            private readonly BindableDouble bpmBindable = new BindableDouble();
+
+            public BPMSlider()
+            {
+                beatLengthBindable.BindValueChanged(beatLength => updateCurrent(beatLengthToBpm(beatLength.NewValue)), true);
+                bpmBindable.BindValueChanged(bpm => bpmBindable.Default = beatLengthBindable.Value = beatLengthToBpm(bpm.NewValue));
+
+                base.Bindable = bpmBindable;
+            }
 
             public override Bindable<double> Bindable
             {
                 get => base.Bindable;
                 set
                 {
-                    // incoming will be beatlength
+                    // incoming will be beat length, not bpm
-
                     beatLengthBindable.UnbindBindings();
                     beatLengthBindable.BindTo(value);
-
-                    base.Bindable = bpmBindable = new BindableDouble(beatLengthToBpm(beatLengthBindable.Value))
-                    {
-                        MinValue = beatLengthToBpm(beatLengthBindable.MaxValue),
-                        MaxValue = beatLengthToBpm(beatLengthBindable.MinValue),
-                        Default = beatLengthToBpm(beatLengthBindable.Default),
-                    };
-
-                    bpmBindable.BindValueChanged(bpm => beatLengthBindable.Value = beatLengthToBpm(bpm.NewValue));
                 }
             }
 
-            private double beatLengthToBpm(double beatLength) => 60000 / beatLength;
+            private void updateCurrent(double newValue)
+            {
+                // we use a more sane range for the slider display unless overridden by the user.
+                // if a value comes in outside our range, we should expand temporarily.
+                bpmBindable.MinValue = Math.Min(newValue, sane_minimum);
+                bpmBindable.MaxValue = Math.Max(newValue, sane_maximum);
+
+                bpmBindable.Value = newValue;
+            }
         }
+
+        private static double beatLengthToBpm(double beatLength) => 60000 / beatLength;
     }
 }