Refactor beatmap info wedge to not fully refresh on star difficulty change

Makes it look awkward when changing difficulty via mod settings for
example.

Now the changes should instead only affect the displayed components which consume it
directly.

osu.Game/Screens/Select/BeatmapInfoWedge.cs

@@ -21,6 +21,7 @@ using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Cursor;
 using osu.Framework.Graphics.Effects;
 using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.UserInterface;
 using osu.Framework.Localisation;
 using osu.Framework.Logging;
 using osu.Game.Configuration;
@@ -38,6 +39,8 @@ namespace osu.Game.Screens.Select
         public const float BORDER_THICKNESS = 2.5f;
         private const float shear_width = 36.75f;
 
+        private const float transition_duration = 250;
+
         private static readonly Vector2 wedged_container_shear = new Vector2(shear_width / SongSelect.WEDGE_HEIGHT, 0);
 
         [Resolved]
@@ -46,11 +49,6 @@ namespace osu.Game.Screens.Select
         [Resolved]
         private IBindable<IReadOnlyList<Mod>> mods { get; set; }
 
-        [Resolved]
-        private BeatmapDifficultyCache difficultyCache { get; set; }
-
-        private IBindable<StarDifficulty?> beatmapDifficulty;
-
         protected Container DisplayedContent { get; private set; }
 
         protected WedgeInfoText Info { get; private set; }
@@ -81,20 +79,18 @@ namespace osu.Game.Screens.Select
         {
             this.MoveToX(0, 800, Easing.OutQuint);
             this.RotateTo(0, 800, Easing.OutQuint);
-            this.FadeIn(250);
+            this.FadeIn(transition_duration);
         }
 
         protected override void PopOut()
         {
             this.MoveToX(-100, 800, Easing.In);
             this.RotateTo(10, 800, Easing.In);
-            this.FadeOut(500, Easing.In);
+            this.FadeOut(transition_duration * 2, Easing.In);
         }
 
         private WorkingBeatmap beatmap;
 
-        private CancellationTokenSource cancellationSource;
-
         public WorkingBeatmap Beatmap
         {
             get => beatmap;
@@ -103,12 +99,6 @@ namespace osu.Game.Screens.Select
                 if (beatmap == value) return;
 
                 beatmap = value;
-                cancellationSource?.Cancel();
-                cancellationSource = new CancellationTokenSource();
-
-                beatmapDifficulty?.UnbindAll();
-                beatmapDifficulty = difficultyCache.GetBindableDifficulty(beatmap.BeatmapInfo, cancellationSource.Token);
-                beatmapDifficulty.BindValueChanged(_ => updateDisplay());
 
                 updateDisplay();
             }
@@ -128,7 +118,7 @@ namespace osu.Game.Screens.Select
                 {
                     State.Value = beatmap == null ? Visibility.Hidden : Visibility.Visible;
 
-                    DisplayedContent?.FadeOut(250);
+                    DisplayedContent?.FadeOut(transition_duration);
                     DisplayedContent?.Expire();
                     DisplayedContent = null;
                 }
@@ -147,7 +137,7 @@ namespace osu.Game.Screens.Select
                     Children = new Drawable[]
                     {
                         new BeatmapInfoWedgeBackground(beatmap),
-                        Info = new WedgeInfoText(beatmap, ruleset.Value, mods.Value, beatmapDifficulty.Value ?? new StarDifficulty()),
+                        Info = new WedgeInfoText(beatmap, ruleset.Value, mods.Value),
                     }
                 }, loaded =>
                 {
@@ -160,12 +150,6 @@ namespace osu.Game.Screens.Select
             }
         }
 
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-            cancellationSource?.Cancel();
-        }
-
         public class WedgeInfoText : Container
         {
             public OsuSpriteText VersionLabel { get; private set; }
@@ -174,6 +158,9 @@ namespace osu.Game.Screens.Select
             public BeatmapSetOnlineStatusPill StatusPill { get; private set; }
             public FillFlowContainer MapperContainer { get; private set; }
 
+            private DifficultyColourBar difficultyColourBar;
+            private StarRatingDisplay starRatingDisplay;
+
             private ILocalisedBindableString titleBinding;
             private ILocalisedBindableString artistBinding;
             private FillFlowContainer infoLabelContainer;
@@ -182,20 +169,21 @@ namespace osu.Game.Screens.Select
             private readonly WorkingBeatmap beatmap;
             private readonly RulesetInfo ruleset;
             private readonly IReadOnlyList<Mod> mods;
-            private readonly StarDifficulty starDifficulty;
 
             private ModSettingChangeTracker settingChangeTracker;
 
-            public WedgeInfoText(WorkingBeatmap beatmap, RulesetInfo userRuleset, IReadOnlyList<Mod> mods, StarDifficulty difficulty)
+            public WedgeInfoText(WorkingBeatmap beatmap, RulesetInfo userRuleset, IReadOnlyList<Mod> mods)
             {
                 this.beatmap = beatmap;
                 ruleset = userRuleset ?? beatmap.BeatmapInfo.Ruleset;
                 this.mods = mods;
-                starDifficulty = difficulty;
             }
 
+            private CancellationTokenSource cancellationSource;
+            private IBindable<StarDifficulty?> starDifficulty;
+
             [BackgroundDependencyLoader]
-            private void load(LocalisationManager localisation)
+            private void load(LocalisationManager localisation, BeatmapDifficultyCache difficultyCache)
             {
                 var beatmapInfo = beatmap.BeatmapInfo;
                 var metadata = beatmapInfo.Metadata ?? beatmap.BeatmapSetInfo?.Metadata ?? new BeatmapMetadata();
@@ -207,7 +195,7 @@ namespace osu.Game.Screens.Select
 
                 Children = new Drawable[]
                 {
-                    new DifficultyColourBar(starDifficulty)
+                    difficultyColourBar = new DifficultyColourBar
                     {
                         RelativeSizeAxes = Axes.Y,
                         Width = 20,
@@ -241,14 +229,15 @@ namespace osu.Game.Screens.Select
                         Padding = new MarginPadding { Top = 14, Right = shear_width / 2 },
                         AutoSizeAxes = Axes.Both,
                         Shear = wedged_container_shear,
-                        Children = new[]
+                        Children = new Drawable[]
                         {
-                            createStarRatingDisplay(starDifficulty).With(display =>
+                            starRatingDisplay = new StarRatingDisplay(default)
                             {
-                                display.Anchor = Anchor.TopRight;
+                                Anchor = Anchor.TopRight,
-                                display.Origin = Anchor.TopRight;
+                                Origin = Anchor.TopRight,
-                                display.Shear = -wedged_container_shear;
+                                Shear = -wedged_container_shear,
-                            }),
+                                Alpha = 0f,
+                            },
                             StatusPill = new BeatmapSetOnlineStatusPill
                             {
                                 Anchor = Anchor.TopRight,
@@ -304,6 +293,15 @@ namespace osu.Game.Screens.Select
                 titleBinding.BindValueChanged(_ => setMetadata(metadata.Source));
                 artistBinding.BindValueChanged(_ => setMetadata(metadata.Source), true);
 
+                starDifficulty = difficultyCache.GetBindableDifficulty(beatmapInfo, (cancellationSource = new CancellationTokenSource()).Token);
+                starDifficulty.BindValueChanged(s =>
+                {
+                    difficultyColourBar.Current.Value = s.NewValue ?? default;
+
+                    starRatingDisplay.FadeIn(transition_duration);
+                    starRatingDisplay.Current.Value = s.NewValue ?? default;
+                });
+
                 // no difficulty means it can't have a status to show
                 if (beatmapInfo.Version == null)
                     StatusPill.Hide();
@@ -311,13 +309,6 @@ namespace osu.Game.Screens.Select
                 addInfoLabels();
             }
 
-            private static Drawable createStarRatingDisplay(StarDifficulty difficulty) => difficulty.Stars > 0
-                ? new StarRatingDisplay(difficulty)
-                {
-                    Margin = new MarginPadding { Bottom = 5 }
-                }
-                : Empty();
-
             private void setMetadata(string source)
             {
                 ArtistLabel.Text = artistBinding.Value;
@@ -429,6 +420,7 @@ namespace osu.Game.Screens.Select
             {
                 base.Dispose(isDisposing);
                 settingChangeTracker?.Dispose();
+                cancellationSource?.Cancel();
             }
 
             public class InfoLabel : Container, IHasTooltip
@@ -490,41 +482,53 @@ namespace osu.Game.Screens.Select
                 }
             }
 
-            private class DifficultyColourBar : Container
+            public class DifficultyColourBar : Container, IHasCurrentValue<StarDifficulty>
             {
-                private readonly StarDifficulty difficulty;
+                private readonly BindableWithCurrent<StarDifficulty> current = new BindableWithCurrent<StarDifficulty>();
 
-                public DifficultyColourBar(StarDifficulty difficulty)
+                public Bindable<StarDifficulty> Current
                 {
-                    this.difficulty = difficulty;
+                    get => current.Current;
+                    set => current.Current = value;
                 }
 
+                [Resolved]
+                private OsuColour colours { get; set; }
+
                 [BackgroundDependencyLoader]
-                private void load(OsuColour colours)
+                private void load()
                 {
                     const float full_opacity_ratio = 0.7f;
 
-                    var difficultyColour = colours.ForStarDifficulty(difficulty.Stars);
-
                     Children = new Drawable[]
                     {
                         new Box
                         {
                             RelativeSizeAxes = Axes.Both,
-                            Colour = difficultyColour,
                             Width = full_opacity_ratio,
                         },
                         new Box
                         {
                             RelativeSizeAxes = Axes.Both,
                             RelativePositionAxes = Axes.Both,
-                            Colour = difficultyColour,
                             Alpha = 0.5f,
                             X = full_opacity_ratio,
                             Width = 1 - full_opacity_ratio,
                         }
                     };
                 }
+
+                protected override void LoadComplete()
+                {
+                    base.LoadComplete();
+
+                    Current.BindValueChanged(c =>
+                    {
+                        this.FadeColour(colours.ForStarDifficulty(c.NewValue.Stars), transition_duration, Easing.OutQuint);
+                    }, true);
+
+                    FinishTransforms(true);
+                }
             }
         }
     }