Add recommended difficulty numerical value near filter in beatmap listing

Author: Joehuu

osu.Game/Beatmaps/DifficultyRecommender.cs

@@ -20,6 +20,8 @@ namespace osu.Game.Beatmaps
     /// </summary>
     public partial class DifficultyRecommender : Component
     {
+        public event Action? StarRatingUpdated;
+
         private readonly LocalUserStatisticsProvider statisticsProvider;
 
         [Resolved]
@@ -77,8 +79,12 @@ private void updateMapping(RulesetInfo ruleset, UserStatistics statistics)
         {
             // algorithm taken from https://github.com/ppy/osu-web/blob/e6e2825516449e3d0f3f5e1852c6bdd3428c3437/app/Models/User.php#L1505
             recommendedDifficultyMapping[ruleset.ShortName] = Math.Pow((double)(statistics.PP ?? 0), 0.4) * 0.195;
+
+            StarRatingUpdated?.Invoke();
         }
 
+        public double GetRecommendedStarRatingFor(RulesetInfo ruleset) => recommendedDifficultyMapping[ruleset.ShortName];
+
         /// <summary>
         /// Find the recommended difficulty from a selection of available difficulties for the current local user.
         /// </summary>

osu.Game/Overlays/BeatmapListing/BeatmapListingSearchControl.cs

@@ -65,7 +65,7 @@ public APIBeatmapSet? BeatmapSet
         }
 
         private readonly BeatmapSearchTextBox textBox;
-        private readonly BeatmapSearchMultipleSelectionFilterRow<SearchGeneral> generalFilter;
+        private readonly BeatmapSearchGeneralFilterRow generalFilter;
         private readonly BeatmapSearchRulesetFilterRow modeFilter;
         private readonly BeatmapSearchFilterRow<SearchCategory> categoryFilter;
         private readonly BeatmapSearchFilterRow<SearchGenre> genreFilter;
@@ -163,6 +163,13 @@ private void load(OverlayColourProvider colourProvider, OsuConfigManager config)
             }, true);
         }
 
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            generalFilter.Ruleset.BindTo(Ruleset);
+        }
+
         public void TakeFocus() => textBox.TakeFocus();
 
         private partial class BeatmapSearchTextBox : BasicSearchTextBox

osu.Game/Overlays/BeatmapListing/BeatmapSearchGeneralFilterRow.cs

@@ -4,35 +4,95 @@
 using System;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Input.Events;
+using osu.Framework.Localisation;
+using osu.Game.Beatmaps;
 using osu.Game.Configuration;
+using osu.Game.Extensions;
 using osu.Game.Graphics;
 using osu.Game.Localisation;
+using osu.Game.Online.API;
 using osu.Game.Overlays.Dialog;
 using osu.Game.Resources.Localisation.Web;
+using osu.Game.Rulesets;
+using osu.Game.Utils;
 using osuTK.Graphics;
 using CommonStrings = osu.Game.Resources.Localisation.Web.CommonStrings;
 
 namespace osu.Game.Overlays.BeatmapListing
 {
     public partial class BeatmapSearchGeneralFilterRow : BeatmapSearchMultipleSelectionFilterRow<SearchGeneral>
     {
+        public readonly IBindable<RulesetInfo> Ruleset = new Bindable<RulesetInfo>();
+
         public BeatmapSearchGeneralFilterRow()
             : base(BeatmapsStrings.ListingSearchFiltersGeneral)
         {
         }
 
-        protected override MultipleSelectionFilter CreateMultipleSelectionFilter() => new GeneralFilter();
+        protected override MultipleSelectionFilter CreateMultipleSelectionFilter() => new GeneralFilter
+        {
+            Ruleset = { BindTarget = Ruleset }
+        };
 
         private partial class GeneralFilter : MultipleSelectionFilter
         {
+            public readonly IBindable<RulesetInfo> Ruleset = new Bindable<RulesetInfo>();
+
             protected override MultipleSelectionFilterTabItem CreateTabItem(SearchGeneral value)
             {
-                if (value == SearchGeneral.FeaturedArtists)
-                    return new FeaturedArtistsTabItem();
+                switch (value)
+                {
+                    case SearchGeneral.Recommended:
+                        return new RecommendedDifficultyTabItem
+                        {
+                            Ruleset = { BindTarget = Ruleset }
+                        };
+
+                    case SearchGeneral.FeaturedArtists:
+                        return new FeaturedArtistsTabItem();
+
+                    default:
+                        return new MultipleSelectionFilterTabItem(value);
+                }
+            }
+        }
+
+        private partial class RecommendedDifficultyTabItem : MultipleSelectionFilterTabItem
+        {
+            public readonly IBindable<RulesetInfo> Ruleset = new Bindable<RulesetInfo>();
+
+            [Resolved]
+            private DifficultyRecommender? recommender { get; set; }
+
+            [Resolved]
+            private IAPIProvider api { get; set; } = null!;
+
+            [Resolved]
+            private RulesetStore rulesets { get; set; } = null!;
+
+            public RecommendedDifficultyTabItem()
+                : base(SearchGeneral.Recommended)
+            {
+            }
+
+            protected override void LoadComplete()
+            {
+                base.LoadComplete();
+
+                if (recommender != null) recommender.StarRatingUpdated += updateText;
 
-                return new MultipleSelectionFilterTabItem(value);
+                Ruleset.BindValueChanged(_ => updateText(), true);
+            }
+
+            private void updateText()
+            {
+                // fallback to profile default game mode if beatmap listing mode filter is set to Any
+                // TODO: find a way to update `PlayMode` when the profile default game mode has changed
+                var ruleset = Ruleset.Value.IsLegacyRuleset() ? Ruleset.Value : rulesets.GetRuleset(api.LocalUser.Value.PlayMode)!;
+                Text.Text = LocalisableString.Interpolate($"{Value.GetLocalisableDescription()} ({recommender?.GetRecommendedStarRatingFor(ruleset).FormatStarRating()})");
             }
         }