Merge branch 'master' into mania-note-input

osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmapConverter.cs

@@ -12,11 +12,17 @@ using osu.Game.Rulesets.Mania.Beatmaps.Patterns;
 using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Database;
 using osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy;
+using OpenTK;
 
 namespace osu.Game.Rulesets.Mania.Beatmaps
 {
     public class ManiaBeatmapConverter : BeatmapConverter<ManiaHitObject>
     {
+        /// <summary>
+        /// Maximum number of previous notes to consider for density calculation.
+        /// </summary>
+        private const int max_notes_for_density = 7;
+
         protected override IEnumerable<Type> ValidConversionTypes { get; } = new[] { typeof(IHasXPosition) };
 
         private Pattern lastPattern = new Pattern();
@@ -56,6 +62,26 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
                 yield return obj;
         }
 
+        private readonly List<double> prevNoteTimes = new List<double>(max_notes_for_density);
+        private double density = int.MaxValue;
+        private void computeDensity(double newNoteTime)
+        {
+            if (prevNoteTimes.Count == max_notes_for_density)
+                prevNoteTimes.RemoveAt(0);
+            prevNoteTimes.Add(newNoteTime);
+
+            density = (prevNoteTimes[prevNoteTimes.Count - 1] - prevNoteTimes[0]) / prevNoteTimes.Count;
+        }
+
+        private double lastTime;
+        private Vector2 lastPosition;
+        private PatternType lastStair;
+        private void recordNote(double time, Vector2 position)
+        {
+            lastTime = time;
+            lastPosition = position;
+        }
+
         /// <summary>
         /// Method that generates hit objects for osu!mania specific beatmaps.
         /// </summary>
@@ -92,7 +118,11 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
                 conversion = new EndTimeObjectPatternGenerator(random, original, beatmap);
             else if (positionData != null)
             {
-                // Circle
+                computeDensity(original.StartTime);
+
+                conversion = new HitObjectPatternGenerator(random, original, beatmap, lastPattern, lastTime, lastPosition, density, lastStair);
+
+                recordNote(original.StartTime, positionData.Position);
             }
 
             if (conversion == null)
@@ -101,6 +131,9 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
             Pattern newPattern = conversion.Generate();
             lastPattern = newPattern;
 
+            var stairPatternGenerator = (HitObjectPatternGenerator)conversion;
+            lastStair = stairPatternGenerator.StairType;
+
             return newPattern.HitObjects;
         }
 

osu.Game.Rulesets.Mania/Beatmaps/Patterns/Legacy/HitObjectPatternGenerator.cs

@@ -0,0 +1,407 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Linq;
+using OpenTK;
+using osu.Game.Audio;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.Timing;
+using osu.Game.Rulesets.Mania.MathUtils;
+using osu.Game.Rulesets.Mania.Objects;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+
+namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
+{
+    internal class HitObjectPatternGenerator : PatternGenerator
+    {
+        public PatternType StairType { get; private set; }
+
+        private readonly PatternType convertType;
+
+        public HitObjectPatternGenerator(FastRandom random, HitObject hitObject, Beatmap beatmap, Pattern previousPattern, double previousTime, Vector2 previousPosition, double density, PatternType lastStair)
+            : base(random, hitObject, beatmap, previousPattern)
+        {
+            StairType = lastStair;
+
+            ControlPoint overridePoint;
+            ControlPoint controlPoint = beatmap.TimingInfo.TimingPointAt(hitObject.StartTime, out overridePoint);
+
+            var positionData = hitObject as IHasPosition;
+
+            float positionSeparation = ((positionData?.Position ?? Vector2.Zero) - previousPosition).Length;
+            double timeSeparation = hitObject.StartTime - previousTime;
+
+            double beatLength = controlPoint.BeatLength;
+            bool kiai = (overridePoint ?? controlPoint).KiaiMode;
+
+            if (timeSeparation <= 125)
+            {
+                // More than 120 BPM
+                convertType |= PatternType.ForceNotStack;
+            }
+
+            if (timeSeparation <= 80)
+            {
+                // More than 187 BPM
+                convertType |= PatternType.ForceNotStack | PatternType.KeepSingle;
+            }
+            else if (timeSeparation <= 95)
+            {
+                // More than 157 BPM
+                convertType |= PatternType.ForceNotStack | PatternType.KeepSingle | lastStair;
+            }
+            else if (timeSeparation <= 105)
+            {
+                // More than 140 BPM
+                convertType |= PatternType.ForceNotStack | PatternType.LowProbability;
+            }
+            else if (timeSeparation <= 125)
+            {
+                // More than 120 BPM
+                convertType |= PatternType.ForceNotStack;
+            }
+            else if (timeSeparation <= 135 && positionSeparation < 20)
+            {
+                // More than 111 BPM stream
+                convertType |= PatternType.Cycle | PatternType.KeepSingle;
+            }
+            else if (timeSeparation <= 150 & positionSeparation < 20)
+            {
+                // More than 100 BPM stream
+                convertType |= PatternType.ForceStack | PatternType.LowProbability;
+            }
+            else if (positionSeparation < 20 && density >= beatLength / 2.5)
+            {
+                // Low density stream
+                convertType |= PatternType.Reverse | PatternType.LowProbability;
+            }
+            else if (density < beatLength / 2.5 || kiai)
+            {
+                // High density
+            }
+            else
+                convertType |= PatternType.LowProbability;
+        }
+
+        public override Pattern Generate()
+        {
+            int lastColumn = PreviousPattern.HitObjects.FirstOrDefault()?.Column ?? 0;
+
+            if ((convertType & PatternType.Reverse) > 0 && PreviousPattern.HitObjects.Any())
+            {
+                // Generate a new pattern by copying the last hit objects in reverse-column order
+                var pattern = new Pattern();
+
+                for (int i = RandomStart; i < AvailableColumns; i++)
+                    if (PreviousPattern.ColumnHasObject(i))
+                        addToPattern(pattern, RandomStart + AvailableColumns - i - 1);
+
+                return pattern;
+            }
+
+            if ((convertType & PatternType.Cycle) > 0 && PreviousPattern.HitObjects.Count() == 1
+                // If we convert to 7K + 1, let's not overload the special key
+                && (AvailableColumns != 8 || lastColumn != 0)
+                // Make sure the last column was not the centre column
+                && (AvailableColumns % 2 == 0 || lastColumn != AvailableColumns / 2))
+            {
+                // Generate a new pattern by cycling backwards (similar to Reverse but for only one hit object)
+                var pattern = new Pattern();
+
+                int column = RandomStart + AvailableColumns - lastColumn - 1;
+                addToPattern(pattern, column);
+
+                return pattern;
+            }
+
+            if ((convertType & PatternType.ForceStack) > 0 && PreviousPattern.HitObjects.Any())
+            {
+                // Generate a new pattern by placing on the already filled columns
+                var pattern = new Pattern();
+
+                for (int i = RandomStart; i < AvailableColumns; i++)
+                    if (PreviousPattern.ColumnHasObject(i))
+                        addToPattern(pattern, i);
+
+                return pattern;
+            }
+
+            if ((convertType & PatternType.Stair) > 0 && PreviousPattern.HitObjects.Count() == 1)
+            {
+                // Generate a new pattern by placing on the next column, cycling back to the start if there is no "next"
+                var pattern = new Pattern();
+
+                int targetColumn = lastColumn + 1;
+                if (targetColumn == AvailableColumns)
+                {
+                    targetColumn = RandomStart;
+                    StairType = PatternType.ReverseStair;
+                }
+
+                addToPattern(pattern, targetColumn);
+                return pattern;
+            }
+
+            if ((convertType & PatternType.ReverseStair) > 0 && PreviousPattern.HitObjects.Count() == 1)
+            {
+                // Generate a new pattern by placing on the previous column, cycling back to the end if there is no "previous"
+                var pattern = new Pattern();
+
+                int targetColumn = lastColumn - 1;
+                if (targetColumn == RandomStart - 1)
+                {
+                    targetColumn = AvailableColumns - 1;
+                    StairType = PatternType.Stair;
+                }
+
+                addToPattern(pattern, targetColumn);
+                return pattern;
+            }
+
+            if ((convertType & PatternType.KeepSingle) > 0)
+                return generateRandomNotes(1);
+
+            if ((convertType & PatternType.Mirror) > 0)
+            {
+                if (ConversionDifficulty > 6.5)
+                    return generateRandomPatternWithMirrored(0.12, 0.38, 0.12);
+                if (ConversionDifficulty > 4)
+                    return generateRandomPatternWithMirrored(0.12, 0.17, 0);
+                return generateRandomPatternWithMirrored(0.12, 0, 0);
+            }
+
+            if (ConversionDifficulty > 6.5)
+            {
+                if ((convertType & PatternType.LowProbability) > 0)
+                    return generateRandomPattern(0.78, 0.42, 0, 0);
+                return generateRandomPattern(1, 0.62, 0, 0);
+            }
+
+            if (ConversionDifficulty > 4)
+            {
+                if ((convertType & PatternType.LowProbability) > 0)
+                    return generateRandomPattern(0.35, 0.08, 0, 0);
+                return generateRandomPattern(0.52, 0.15, 0, 0);
+            }
+
+            if (ConversionDifficulty > 2)
+            {
+                if ((convertType & PatternType.LowProbability) > 0)
+                    return generateRandomPattern(0.18, 0, 0, 0);
+                return generateRandomPattern(0.45, 0, 0, 0);
+            }
+
+            return generateRandomPattern(0, 0, 0, 0);
+        }
+
+        /// <summary>
+        /// Generates random notes.
+        /// <para>
+        /// This will generate as many as it can up to <paramref name="noteCount"/>, accounting for
+        /// any stacks if <see cref="convertType"/> is forcing no stacks.
+        /// </para>
+        /// </summary>
+        /// <param name="noteCount">The amount of notes to generate.</param>
+        /// <returns>The <see cref="Pattern"/> containing the hit objects.</returns>
+        private Pattern generateRandomNotes(int noteCount)
+        {
+            var pattern = new Pattern();
+
+            bool allowStacking = (convertType & PatternType.ForceNotStack) == 0;
+
+            if (!allowStacking)
+                noteCount = Math.Min(noteCount, AvailableColumns - RandomStart - PreviousPattern.ColumnWithObjects);
+
+            int nextColumn = GetColumn((HitObject as IHasXPosition)?.X ?? 0, true);
+            for (int i = 0; i < noteCount; i++)
+            {
+                while (pattern.ColumnHasObject(nextColumn) || PreviousPattern.ColumnHasObject(nextColumn) && !allowStacking)
+                {
+                    if ((convertType & PatternType.Gathered) > 0)
+                    {
+                        nextColumn++;
+                        if (nextColumn == AvailableColumns)
+                            nextColumn = RandomStart;
+                    }
+                    else
+                        nextColumn = Random.Next(RandomStart, AvailableColumns);
+                }
+
+                addToPattern(pattern, nextColumn);
+            }
+
+            return pattern;
+        }
+
+        /// <summary>
+        /// Whether this hit object can generate a note in the special column.
+        /// </summary>
+        private bool hasSpecialColumn => HitObject.Samples.Any(s => s.Name == SampleInfo.HIT_CLAP) && HitObject.Samples.Any(s => s.Name == SampleInfo.HIT_FINISH);
+
+        /// <summary>
+        /// Generates a random pattern.
+        /// </summary>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <param name="p4">Probability for 4 notes to be generated.</param>
+        /// <param name="p5">Probability for 5 notes to be generated.</param>
+        /// <returns>The <see cref="Pattern"/> containing the hit objects.</returns>
+        private Pattern generateRandomPattern(double p2, double p3, double p4, double p5)
+        {
+            var pattern = new Pattern();
+
+            pattern.Add(generateRandomNotes(getRandomNoteCount(p2, p3, p4, p5)));
+
+            if (RandomStart > 0 && hasSpecialColumn)
+                addToPattern(pattern, 0);
+
+            return pattern;
+        }
+
+        /// <summary>
+        /// Generates a random pattern which has both normal and mirrored notes.
+        /// </summary>
+        /// <param name="centreProbability">The probability for a note to be added to the centre column.</param>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <returns>The <see cref="Pattern"/> containing the hit objects.</returns>
+        private Pattern generateRandomPatternWithMirrored(double centreProbability, double p2, double p3)
+        {
+            var pattern = new Pattern();
+
+            bool addToCentre;
+            int noteCount = getRandomNoteCountMirrored(centreProbability, p2, p3, out addToCentre);
+
+            int columnLimit = (AvailableColumns % 2 == 0 ? AvailableColumns : AvailableColumns - 1) / 2;
+            int nextColumn = Random.Next(RandomStart, columnLimit);
+            for (int i = 0; i < noteCount; i++)
+            {
+                while (pattern.ColumnHasObject(nextColumn))
+                    nextColumn = Random.Next(RandomStart, columnLimit);
+
+                // Add normal note
+                addToPattern(pattern, nextColumn);
+                // Add mirrored note
+                addToPattern(pattern, RandomStart + AvailableColumns - nextColumn - 1);
+            }
+
+            if (addToCentre)
+                addToPattern(pattern, AvailableColumns / 2);
+
+            if (RandomStart > 0 && hasSpecialColumn)
+                addToPattern(pattern, 0);
+
+            return pattern;
+        }
+
+        /// <summary>
+        /// Generates a count of notes to be generated from a list of probabilities.
+        /// </summary>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <param name="p4">Probability for 4 notes to be generated.</param>
+        /// <param name="p5">Probability for 5 notes to be generated.</param>
+        /// <returns>The amount of notes to be generated.</returns>
+        private int getRandomNoteCount(double p2, double p3, double p4, double p5)
+        {
+            switch (AvailableColumns)
+            {
+                case 2:
+                    p2 = 0;
+                    p3 = 0;
+                    p4 = 0;
+                    p5 = 0;
+                    break;
+                case 3:
+                    p2 = Math.Max(p2, 0.1);
+                    p3 = 0;
+                    p4 = 0;
+                    p5 = 0;
+                    break;
+                case 4:
+                    p2 = Math.Max(p2, 0.23);
+                    p3 = Math.Max(p3, 0.04);
+                    p4 = 0;
+                    p5 = 0;
+                    break;
+                case 5:
+                    p3 = Math.Max(p3, 0.15);
+                    p4 = Math.Max(p4, 0.03);
+                    p5 = 0;
+                    break;
+            }
+
+            if (HitObject.Samples.Any(s => s.Name == SampleInfo.HIT_CLAP))
+                p2 = 1;
+
+            return GetRandomNoteCount(p2, p3, p4, p5);
+        }
+
+        /// <summary>
+        /// Generates a count of notes to be generated from a list of probabilities.
+        /// </summary>
+        /// <param name="centreProbability">The probability for a note to be added to the centre column.</param>
+        /// <param name="p2">Probability for 2 notes to be generated.</param>
+        /// <param name="p3">Probability for 3 notes to be generated.</param>
+        /// <param name="addToCentre">Whether to add a note to the centre column.</param>
+        /// <returns>The amount of notes to be generated. The note to be added to the centre column will NOT be part of this count.</returns>
+        private int getRandomNoteCountMirrored(double centreProbability, double p2, double p3, out bool addToCentre)
+        {
+            addToCentre = false;
+
+            if ((convertType & PatternType.ForceNotStack) > 0)
+                return getRandomNoteCount(p2 / 2, p2, (p2 + p3) / 2, p3);
+
+            switch (AvailableColumns)
+            {
+                case 2:
+                    centreProbability = 0;
+                    p2 = 0;
+                    p3 = 0;
+                    break;
+                case 3:
+                    centreProbability = Math.Max(centreProbability, 0.03);
+                    p2 = Math.Max(p2, 0.1);
+                    p3 = 0;
+                    break;
+                case 4:
+                    centreProbability = 0;
+                    p2 = Math.Max(p2 * 2, 0.2);
+                    p3 = 0;
+                    break;
+                case 5:
+                    centreProbability = Math.Max(centreProbability, 0.03);
+                    p3 = 0;
+                    break;
+                case 6:
+                    centreProbability = 0;
+                    p2 = Math.Max(p2 * 2, 0.5);
+                    p3 = Math.Max(p3 * 2, 0.15);
+                    break;
+            }
+
+            double centreVal = Random.NextDouble();
+            int noteCount = GetRandomNoteCount(p2, p3);
+
+            addToCentre = AvailableColumns % 2 != 0 && noteCount != 3 && centreVal > 1 - centreProbability;
+            return noteCount;
+        }
+
+        /// <summary>
+        /// Constructs and adds a note to a pattern.
+        /// </summary>
+        /// <param name="pattern">The pattern to add to.</param>
+        /// <param name="column">The column to add the note to.</param>
+        private void addToPattern(Pattern pattern, int column)
+        {
+            pattern.Add(new Note
+            {
+                StartTime = HitObject.StartTime,
+                Samples = HitObject.Samples,
+                Column = column
+            });
+        }
+    }
+}

osu.Game.Rulesets.Mania/osu.Game.Rulesets.Mania.csproj

@@ -51,6 +51,7 @@
     <Compile Include="Beatmaps\Patterns\Legacy\DistanceObjectPatternGenerator.cs" />
     <Compile Include="Beatmaps\Patterns\Legacy\PatternGenerator.cs" />
     <Compile Include="Beatmaps\Patterns\PatternGenerator.cs" />
+    <Compile Include="Beatmaps\Patterns\Legacy\HitObjectPatternGenerator.cs" />
     <Compile Include="Beatmaps\Patterns\Legacy\PatternType.cs" />
     <Compile Include="Beatmaps\ManiaBeatmapConverter.cs" />
     <Compile Include="Beatmaps\Patterns\Pattern.cs" />

osu.Game/Graphics/Containers/BeatSyncedContainer.cs

@@ -0,0 +1,60 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Framework.Allocation;
+using osu.Framework.Configuration;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.Timing;
+
+namespace osu.Game.Graphics.Containers
+{
+    public class BeatSyncedContainer : Container
+    {
+        private readonly Bindable<WorkingBeatmap> beatmap = new Bindable<WorkingBeatmap>();
+
+        private int lastBeat;
+        private ControlPoint lastControlPoint;
+
+        protected override void Update()
+        {
+            if (beatmap.Value?.Track == null)
+                return;
+
+            double currentTrackTime = beatmap.Value.Track.CurrentTime;
+            ControlPoint overridePoint;
+            ControlPoint controlPoint = beatmap.Value.Beatmap.TimingInfo.TimingPointAt(currentTrackTime, out overridePoint);
+
+            if (controlPoint.BeatLength == 0)
+                return;
+
+            bool kiai = (overridePoint ?? controlPoint).KiaiMode;
+            int beat = (int)((currentTrackTime - controlPoint.Time) / controlPoint.BeatLength);
+
+            // The beats before the start of the first control point are off by 1, this should do the trick
+            if (currentTrackTime < controlPoint.Time)
+                beat--;
+
+            if (controlPoint == lastControlPoint && beat == lastBeat)
+                return;
+
+            double offsetFromBeat = (controlPoint.Time - currentTrackTime) % controlPoint.BeatLength;
+
+            using (BeginDelayedSequence(offsetFromBeat, true))
+                OnNewBeat(beat, controlPoint.BeatLength, controlPoint.TimeSignature, kiai);
+
+            lastBeat = beat;
+            lastControlPoint = controlPoint;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuGameBase game)
+        {
+            beatmap.BindTo(game.Beatmap);
+        }
+
+        protected virtual void OnNewBeat(int newBeat, double beatLength, TimeSignatures timeSignature, bool kiai)
+        {
+        }
+    }
+}

osu.Game/Graphics/Containers/SectionsContainer.cs

@@ -0,0 +1,171 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using osu.Framework.Configuration;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+
+namespace osu.Game.Graphics.Containers
+{
+    /// <summary>
+    /// A container that can scroll to each section inside it.
+    /// </summary>
+    public class SectionsContainer : Container
+    {
+        private Drawable expandableHeader, fixedHeader, footer;
+        public readonly ScrollContainer ScrollContainer;
+        private readonly Container<Drawable> sectionsContainer;
+
+        public Drawable ExpandableHeader
+        {
+            get { return expandableHeader; }
+            set
+            {
+                if (value == expandableHeader) return;
+
+                if (expandableHeader != null)
+                    Remove(expandableHeader);
+                expandableHeader = value;
+                if (value == null) return;
+
+                Add(expandableHeader);
+                lastKnownScroll = float.NaN;
+            }
+        }
+
+        public Drawable FixedHeader
+        {
+            get { return fixedHeader; }
+            set
+            {
+                if (value == fixedHeader) return;
+
+                if (fixedHeader != null)
+                    Remove(fixedHeader);
+                fixedHeader = value;
+                if (value == null) return;
+
+                Add(fixedHeader);
+                lastKnownScroll = float.NaN;
+            }
+        }
+
+        public Drawable Footer
+        {
+            get { return footer; }
+            set
+            {
+                if (value == footer) return;
+
+                if (footer != null)
+                    ScrollContainer.Remove(footer);
+                footer = value;
+                if (value == null) return;
+
+                footer.Anchor |= Anchor.y2;
+                footer.Origin |= Anchor.y2;
+                ScrollContainer.Add(footer);
+                lastKnownScroll = float.NaN;
+            }
+        }
+
+        public Bindable<Drawable> SelectedSection { get; } = new Bindable<Drawable>();
+
+        protected virtual Container<Drawable> CreateScrollContentContainer()
+            => new FillFlowContainer
+            {
+                Direction = FillDirection.Vertical,
+                AutoSizeAxes = Axes.Both
+            };
+
+        private List<Drawable> sections = new List<Drawable>();
+        public IEnumerable<Drawable> Sections
+        {
+            get { return sections; }
+            set
+            {
+                foreach (var section in sections)
+                    sectionsContainer.Remove(section);
+
+                sections = value.ToList();
+                if (sections.Count == 0) return;
+
+                sectionsContainer.Add(sections);
+                SelectedSection.Value = sections[0];
+                lastKnownScroll = float.NaN;
+            }
+        }
+
+        private float headerHeight, footerHeight;
+        private readonly MarginPadding originalSectionsMargin;
+        private void updateSectionsMargin()
+        {
+            if (sections.Count == 0) return;
+
+            var newMargin = originalSectionsMargin;
+            newMargin.Top += headerHeight;
+            newMargin.Bottom += footerHeight;
+
+            sectionsContainer.Margin = newMargin;
+        }
+
+        public SectionsContainer()
+        {
+            Add(ScrollContainer = new ScrollContainer()
+            {
+                RelativeSizeAxes = Axes.Both,
+                Masking = false,
+                Children = new Drawable[] { sectionsContainer = CreateScrollContentContainer() }
+            });
+            originalSectionsMargin = sectionsContainer.Margin;
+        }
+
+        private float lastKnownScroll;
+        protected override void UpdateAfterChildren()
+        {
+            base.UpdateAfterChildren();
+
+            float headerH = (ExpandableHeader?.LayoutSize.Y ?? 0) + (FixedHeader?.LayoutSize.Y ?? 0);
+            float footerH = Footer?.LayoutSize.Y ?? 0;
+            if (headerH != headerHeight || footerH != footerHeight)
+            {
+                headerHeight = headerH;
+                footerHeight = footerH;
+                updateSectionsMargin();
+            }
+
+            float currentScroll = Math.Max(0, ScrollContainer.Current);
+            if (currentScroll != lastKnownScroll)
+            {
+                lastKnownScroll = currentScroll;
+
+                if (expandableHeader != null && fixedHeader != null)
+                {
+                    float offset = Math.Min(expandableHeader.LayoutSize.Y, currentScroll);
+
+                    expandableHeader.Y = -offset;
+                    fixedHeader.Y = -offset + expandableHeader.LayoutSize.Y;
+                }
+
+                Drawable bestMatch = null;
+                float minDiff = float.MaxValue;
+
+                foreach (var section in sections)
+                {
+                    float diff = Math.Abs(ScrollContainer.GetChildPosInContent(section) - currentScroll);
+                    if (diff < minDiff)
+                    {
+                        minDiff = diff;
+                        bestMatch = section;
+                    }
+                }
+
+                if (bestMatch != null)
+                    SelectedSection.Value = bestMatch;
+            }
+        }
+    }
+}

osu.Game/Overlays/Settings/SettingsHeader.cs

@@ -1,34 +1,16 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
-using osu.Framework.Graphics.Sprites;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Sprites;
-using osu.Game.Graphics.UserInterface;
-using OpenTK.Graphics;
 
 namespace osu.Game.Overlays.Settings
 {
     public class SettingsHeader : Container
     {
-        public SearchTextBox SearchTextBox;
-
-        private Box background;
-
-        private readonly Func<float> currentScrollOffset;
-
-        public Action Exit;
-
-        /// <param name="currentScrollOffset">A reference to the current scroll position of the ScrollContainer we are contained within.</param>
-        public SettingsHeader(Func<float> currentScrollOffset)
-        {
-            this.currentScrollOffset = currentScrollOffset;
-        }
-
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
@@ -37,11 +19,6 @@ namespace osu.Game.Overlays.Settings
 
             Children = new Drawable[]
             {
-                background = new Box
-                {
-                    Colour = Color4.Black,
-                    RelativeSizeAxes = Axes.Both,
-                },
                 new FillFlowContainer
                 {
                     AutoSizeAxes = Axes.Y,
@@ -53,7 +30,8 @@ namespace osu.Game.Overlays.Settings
                         {
                             Text = "settings",
                             TextSize = 40,
-                            Margin = new MarginPadding {
+                            Margin = new MarginPadding
+                            {
                                 Left = SettingsOverlay.CONTENT_MARGINS,
                                 Top = Toolbar.Toolbar.TOOLTIP_HEIGHT
                             },
@@ -63,45 +41,15 @@ namespace osu.Game.Overlays.Settings
                             Colour = colours.Pink,
                             Text = "Change the way osu! behaves",
                             TextSize = 18,
-                            Margin = new MarginPadding {
+                            Margin = new MarginPadding
+                            {
                                 Left = SettingsOverlay.CONTENT_MARGINS,
                                 Bottom = 30
                             },
                         },
-                        SearchTextBox = new SearchTextBox
-                        {
-                            RelativeSizeAxes = Axes.X,
-                            Origin = Anchor.TopCentre,
-                            Anchor = Anchor.TopCentre,
-                            Width = 0.95f,
-                            Margin = new MarginPadding {
-                                Top = 20,
-                                Bottom = 20
-                            },
-                            Exit = () => Exit(),
-                        },
                     }
                 }
             };
         }
-
-        protected override void UpdateAfterChildren()
-        {
-            base.UpdateAfterChildren();
-
-            // the point at which we will start anchoring to the top.
-            float anchorOffset = SearchTextBox.Y;
-
-            float scrollPosition = currentScrollOffset();
-
-            // we want to anchor the search field to the top of the screen when scrolling.
-            Margin = new MarginPadding { Top = Math.Max(0, scrollPosition - anchorOffset) };
-
-            // we don't want the header to scroll when scrolling beyond the upper extent.
-            Y = Math.Min(0, scrollPosition);
-
-            // we get darker as scroll progresses
-            background.Alpha = Math.Min(1, scrollPosition / anchorOffset) * 0.5f;
-        }
     }
 }

osu.Game/Overlays/Settings/SidebarButton.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Overlays.Settings
         private readonly Box backgroundBox;
         private readonly Box selectionIndicator;
         private readonly Container text;
-        public Action Action;
+        public Action<SettingsSection> Action;
 
         private SettingsSection section;
         public SettingsSection Section
@@ -75,6 +75,7 @@ namespace osu.Game.Overlays.Settings
                 {
                     Width = Sidebar.DEFAULT_WIDTH,
                     RelativeSizeAxes = Axes.Y,
+                    Colour = OsuColour.Gray(0.6f),
                     Children = new[]
                     {
                         headerText = new OsuSpriteText
@@ -110,7 +111,7 @@ namespace osu.Game.Overlays.Settings
 
         protected override bool OnClick(InputState state)
         {
-            Action?.Invoke();
+            Action?.Invoke(section);
             backgroundBox.FlashColour(Color4.White, 400);
             return true;
         }

osu.Game/Overlays/SettingsOverlay.cs

@@ -7,10 +7,11 @@ using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Sprites;
-using osu.Game.Overlays.Settings;
-using System;
-using osu.Game.Overlays.Settings.Sections;
 using osu.Framework.Input;
+using osu.Game.Graphics.Containers;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Overlays.Settings;
+using osu.Game.Overlays.Settings.Sections;
 
 namespace osu.Game.Overlays
 {
@@ -26,18 +27,13 @@ namespace osu.Game.Overlays
 
         private const float sidebar_padding = 10;
 
-        private ScrollContainer scrollContainer;
         private Sidebar sidebar;
         private SidebarButton[] sidebarButtons;
-        private SettingsSection[] sections;
+        private SidebarButton selectedSidebarButton;
 
-        private SettingsHeader header;
+        private SettingsSectionsContainer sectionsContainer;
 
-        private SettingsFooter footer;
-
-        private SearchContainer searchContainer;
-
-        private float lastKnownScroll;
+        private SearchTextBox searchTextBox;
 
         public SettingsOverlay()
         {
@@ -48,7 +44,7 @@ namespace osu.Game.Overlays
         [BackgroundDependencyLoader(permitNulls: true)]
         private void load(OsuGame game)
         {
-            sections = new SettingsSection[]
+            var sections = new SettingsSection[]
             {
                 new GeneralSection(),
                 new GraphicsSection(),
@@ -68,27 +64,27 @@ namespace osu.Game.Overlays
                     Colour = Color4.Black,
                     Alpha = 0.6f,
                 },
-                scrollContainer = new ScrollContainer
+                sectionsContainer = new SettingsSectionsContainer
                 {
-                    ScrollDraggerVisible = false,
                     RelativeSizeAxes = Axes.Y,
                     Width = width,
                     Margin = new MarginPadding { Left = SIDEBAR_WIDTH },
-                    Children = new Drawable[]
+                    ExpandableHeader = new SettingsHeader(),
+                    FixedHeader = searchTextBox = new SearchTextBox
                     {
-                        searchContainer = new SearchContainer
+                        RelativeSizeAxes = Axes.X,
+                        Origin = Anchor.TopCentre,
+                        Anchor = Anchor.TopCentre,
+                        Width = 0.95f,
+                        Margin = new MarginPadding
                         {
-                            AutoSizeAxes = Axes.Y,
-                            RelativeSizeAxes = Axes.X,
-                            Direction = FillDirection.Vertical,
-                            Children = sections,
+                            Top = 20,
+                            Bottom = 20
                         },
-                        footer = new SettingsFooter(),
-                        header = new SettingsHeader(() => scrollContainer.Current)
-                        {
-                            Exit = Hide,
-                        },
-                    }
+                        Exit = Hide,
+                    },
+                    Sections = sections,
+                    Footer = new SettingsFooter()
                 },
                 sidebar = new Sidebar
                 {
@@ -96,84 +92,89 @@ namespace osu.Game.Overlays
                     Children = sidebarButtons = sections.Select(section =>
                         new SidebarButton
                         {
-                            Selected = sections[0] == section,
                             Section = section,
-                            Action = () => scrollContainer.ScrollIntoView(section),
+                            Action = sectionsContainer.ScrollContainer.ScrollIntoView,
                         }
                     ).ToArray()
                 }
             };
 
-            header.SearchTextBox.Current.ValueChanged += newValue => searchContainer.SearchTerm = newValue;
+            selectedSidebarButton = sidebarButtons[0];
+            selectedSidebarButton.Selected = true;
 
-            scrollContainer.Padding = new MarginPadding { Top = game?.Toolbar.DrawHeight ?? 0 };
-        }
-
-        protected override void UpdateAfterChildren()
-        {
-            base.UpdateAfterChildren();
-
-            //we need to update these manually because we can't put the SettingsHeader inside the SearchContainer (due to its anchoring).
-            searchContainer.Y = header.DrawHeight;
-            footer.Y = searchContainer.Y + searchContainer.DrawHeight;
-        }
-
-        protected override void Update()
-        {
-            base.Update();
-
-            float currentScroll = scrollContainer.Current;
-            if (currentScroll != lastKnownScroll)
+            sectionsContainer.SelectedSection.ValueChanged += section =>
             {
-                lastKnownScroll = currentScroll;
+                selectedSidebarButton.Selected = false;
+                selectedSidebarButton = sidebarButtons.Single(b => b.Section == section);
+                selectedSidebarButton.Selected = true;
+            };
 
-                SettingsSection bestCandidate = null;
-                float bestDistance = float.MaxValue;
+            searchTextBox.Current.ValueChanged += newValue => sectionsContainer.SearchContainer.SearchTerm = newValue;
 
-                foreach (SettingsSection section in sections)
-                {
-                    float distance = Math.Abs(scrollContainer.GetChildPosInContent(section) - currentScroll);
-                    if (distance < bestDistance)
-                    {
-                        bestDistance = distance;
-                        bestCandidate = section;
-                    }
-                }
-
-                var previous = sidebarButtons.SingleOrDefault(sb => sb.Selected);
-                var next = sidebarButtons.SingleOrDefault(sb => sb.Section == bestCandidate);
-                if (previous != null) previous.Selected = false;
-                if (next != null) next.Selected = true;
-            }
+            sectionsContainer.Padding = new MarginPadding { Top = game?.Toolbar.DrawHeight ?? 0 };
         }
 
         protected override void PopIn()
         {
             base.PopIn();
 
-            scrollContainer.MoveToX(0, TRANSITION_LENGTH, EasingTypes.OutQuint);
+            sectionsContainer.MoveToX(0, TRANSITION_LENGTH, EasingTypes.OutQuint);
             sidebar.MoveToX(0, TRANSITION_LENGTH, EasingTypes.OutQuint);
             FadeTo(1, TRANSITION_LENGTH / 2);
 
-            header.SearchTextBox.HoldFocus = true;
+            searchTextBox.HoldFocus = true;
         }
 
         protected override void PopOut()
         {
             base.PopOut();
 
-            scrollContainer.MoveToX(-width, TRANSITION_LENGTH, EasingTypes.OutQuint);
+            sectionsContainer.MoveToX(-width, TRANSITION_LENGTH, EasingTypes.OutQuint);
             sidebar.MoveToX(-SIDEBAR_WIDTH, TRANSITION_LENGTH, EasingTypes.OutQuint);
             FadeTo(0, TRANSITION_LENGTH / 2);
 
-            header.SearchTextBox.HoldFocus = false;
-            header.SearchTextBox.TriggerFocusLost();
+            searchTextBox.HoldFocus = false;
+            searchTextBox.TriggerFocusLost();
         }
 
         protected override bool OnFocus(InputState state)
         {
-            header.SearchTextBox.TriggerFocus(state);
+            searchTextBox.TriggerFocus(state);
             return false;
         }
+
+        private class SettingsSectionsContainer : SectionsContainer
+        {
+            public SearchContainer SearchContainer;
+            private readonly Box headerBackground;
+
+            protected override Container<Drawable> CreateScrollContentContainer()
+                => SearchContainer = new SearchContainer
+                {
+                    AutoSizeAxes = Axes.Y,
+                    RelativeSizeAxes = Axes.X,
+                    Direction = FillDirection.Vertical,
+                };
+
+            public SettingsSectionsContainer()
+            {
+                ScrollContainer.ScrollDraggerVisible = false;
+                Add(headerBackground = new Box
+                {
+                    Colour = Color4.Black,
+                    RelativeSizeAxes = Axes.X
+                });
+            }
+
+            protected override void UpdateAfterChildren()
+            {
+                base.UpdateAfterChildren();
+
+                // no null check because the usage of this class is strict
+                headerBackground.Height = ExpandableHeader.LayoutSize.Y + FixedHeader.LayoutSize.Y;
+                headerBackground.Y = ExpandableHeader.Y;
+                headerBackground.Alpha = -ExpandableHeader.Y / ExpandableHeader.LayoutSize.Y * 0.5f;
+            }
+        }
     }
 }

osu.Game/osu.Game.csproj

@@ -81,6 +81,7 @@
     <Compile Include="Overlays\Music\PlaylistItem.cs" />
     <Compile Include="Overlays\Music\PlaylistList.cs" />
     <Compile Include="Overlays\OnScreenDisplay.cs" />
+    <Compile Include="Graphics\Containers\SectionsContainer.cs" />
     <Compile Include="Overlays\Settings\SettingsHeader.cs" />
     <Compile Include="Overlays\Settings\Sections\Audio\MainMenuSettings.cs" />
     <Compile Include="Overlays\Toolbar\ToolbarChatButton.cs" />
@@ -292,6 +293,7 @@
     <Compile Include="Graphics\UserInterface\RollingCounter.cs" />
     <Compile Include="Graphics\UserInterface\Volume\VolumeControlReceptor.cs" />
     <Compile Include="Graphics\Backgrounds\Background.cs" />
+    <Compile Include="Graphics\Containers\BeatSyncedContainer.cs" />
     <Compile Include="Graphics\Containers\ParallaxContainer.cs" />
     <Compile Include="Graphics\Cursor\MenuCursor.cs" />
     <Compile Include="Graphics\Processing\RatioAdjust.cs" />