Add simple implementation of in-game leaderboard

osu.Game/Screens/Play/InGameLeaderboard.cs

@@ -0,0 +1,42 @@
+// 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 osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Users;
+
+namespace osu.Game.Screens.Play
+{
+    public class InGameLeaderboard : CompositeDrawable
+    {
+        protected readonly InGameScoreContainer ScoresContainer;
+
+        public readonly BindableDouble PlayerCurrentScore = new BindableDouble();
+
+        private bool playerItemCreated;
+        private User playerUser;
+
+        public User PlayerUser
+        {
+            get => playerUser;
+            set
+            {
+                playerUser = value;
+
+                if (playerItemCreated)
+                    return;
+
+                ScoresContainer.AddRealTimePlayer(PlayerCurrentScore, playerUser);
+                playerItemCreated = true;
+            }
+        }
+
+        public InGameLeaderboard()
+        {
+            AutoSizeAxes = Axes.Y;
+
+            InternalChild = ScoresContainer = new InGameScoreContainer();
+        }
+    }
+}

osu.Game/Screens/Play/InGameScoreContainer.cs

@@ -0,0 +1,206 @@
+// 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 System.Linq;
+using Humanizer;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Scoring;
+using osu.Game.Users;
+using osuTK;
+
+namespace osu.Game.Screens.Play
+{
+    public class InGameScoreContainer : FillFlowContainer<InGameScoreItem>
+    {
+        /// <summary>
+        /// Whether to declare a new position for un-positioned players.
+        /// Must be disabled for online leaderboards with top 50 scores only.
+        /// </summary>
+        public bool DeclareNewPosition = true;
+
+        public InGameScoreContainer()
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+            Direction = FillDirection.Vertical;
+            Spacing = new Vector2(2.5f);
+            LayoutDuration = 500;
+            LayoutEasing = Easing.OutQuint;
+        }
+
+        public void AddRealTimePlayer(BindableDouble currentScore, User user = null)
+        {
+            if (currentScore == null)
+                return;
+
+            var scoreItem = addScore(currentScore.Value, user);
+            currentScore.ValueChanged += s => scoreItem.TotalScore = s.NewValue;
+        }
+
+        public void AddScore(ScoreInfo score, int? position = null)
+        {
+            if (score != null)
+                addScore(score.TotalScore, score.User, position);
+        }
+
+        private int maxPosition => this.Where(i => i.ScorePosition.HasValue).Max(i => i.ScorePosition) ?? 0;
+
+        private InGameScoreItem addScore(double totalScore, User user = null, int? position = null)
+        {
+            var scoreItem = new InGameScoreItem
+            {
+                User = user,
+                TotalScore = totalScore,
+                ScorePosition = position,
+                OnScoreChange = updateScores,
+            };
+
+            Add(scoreItem);
+            SetLayoutPosition(scoreItem, position ?? maxPosition + 1);
+
+            updateScores();
+
+            return scoreItem;
+        }
+
+        private void updateScores()
+        {
+            var orderedByScore = this.OrderByDescending(i => i.TotalScore).ToList();
+            var orderedPositions = this.OrderByDescending(i => i.ScorePosition.HasValue).ThenBy(i => i.ScorePosition).Select(i => i.ScorePosition).ToList();
+
+            for (int i = 0; i < Count; i++)
+            {
+                int newPosition = orderedPositions[i] ?? maxPosition + 1;
+
+                SetLayoutPosition(orderedByScore[i], newPosition);
+                orderedByScore[i].ScorePosition = DeclareNewPosition ? newPosition : orderedPositions[i];
+            }
+        }
+    }
+
+    public class InGameScoreItem : CompositeDrawable
+    {
+        private readonly OsuSpriteText positionText, positionSymbol, userString;
+        private readonly GlowingSpriteText scoreText;
+
+        public Action OnScoreChange;
+
+        private int? scorePosition;
+
+        public int? ScorePosition
+        {
+            get => scorePosition;
+            set
+            {
+                scorePosition = value;
+
+                if (scorePosition.HasValue)
+                    positionText.Text = $"#{scorePosition.Value.ToMetric(decimals: scorePosition < 100000 ? 1 : 0)}";
+
+                positionText.FadeTo(scorePosition.HasValue ? 1 : 0, 100);
+                positionSymbol.FadeTo(scorePosition.HasValue ? 1 : 0, 100);
+            }
+        }
+
+        private double totalScore;
+
+        public double TotalScore
+        {
+            get => totalScore;
+            set
+            {
+                totalScore = value;
+                scoreText.Text = totalScore.ToString("N0");
+
+                OnScoreChange?.Invoke();
+            }
+        }
+
+        private User user;
+
+        public User User
+        {
+            get => user;
+            set
+            {
+                user = value;
+                userString.Text = user?.Username;
+            }
+        }
+
+        public InGameScoreItem()
+        {
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            InternalChild = new Container
+            {
+                Masking = true,
+                Anchor = Anchor.TopCentre,
+                Origin = Anchor.TopCentre,
+                AutoSizeAxes = Axes.Both,
+                Children = new Drawable[]
+                {
+                    new FillFlowContainer
+                    {
+                        Anchor = Anchor.TopCentre,
+                        Origin = Anchor.TopRight,
+                        AutoSizeAxes = Axes.Both,
+                        Direction = FillDirection.Horizontal,
+                        Margin = new MarginPadding { Right = 2.5f },
+                        Spacing = new Vector2(2.5f),
+                        Children = new[]
+                        {
+                            positionText = new OsuSpriteText
+                            {
+                                Alpha = 0,
+                                Font = OsuFont.GetFont(size: 14, weight: FontWeight.Bold),
+                            },
+                            positionSymbol = new OsuSpriteText
+                            {
+                                Alpha = 0,
+                                Font = OsuFont.GetFont(size: 14, weight: FontWeight.SemiBold),
+                                Text = ">",
+                            },
+                        }
+                    },
+                    new FillFlowContainer
+                    {
+                        Anchor = Anchor.TopCentre,
+                        Origin = Anchor.TopLeft,
+                        AutoSizeAxes = Axes.Both,
+                        Direction = FillDirection.Horizontal,
+                        Margin = new MarginPadding { Left = 2.5f },
+                        Spacing = new Vector2(2.5f),
+                        Children = new Drawable[]
+                        {
+                            userString = new OsuSpriteText
+                            {
+                                Size = new Vector2(80, 16),
+                                Font = OsuFont.GetFont(size: 14, weight: FontWeight.Bold, italics: true),
+                            },
+                            scoreText = new GlowingSpriteText
+                            {
+                                GlowColour = OsuColour.FromHex(@"83ccfa"),
+                                Font = OsuFont.Numeric.With(size: 14),
+                            }
+                        }
+                    },
+                },
+            };
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            positionText.Colour = colours.YellowLight;
+            positionSymbol.Colour = colours.Yellow;
+        }
+    }
+}