Add a retry button for when scores request fails.

osu.Game/Screens/Select/Leaderboards/Leaderboard.cs

@@ -20,6 +20,8 @@ using osu.Game.Online.API.Requests;
 using System.Linq;
 using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics;
+using osu.Framework.Logging;
+using System.Net;
 
 namespace osu.Game.Screens.Select.Leaderboards
 {
@@ -29,7 +31,8 @@ namespace osu.Game.Screens.Select.Leaderboards
 
         private readonly ScrollContainer scrollContainer;
         private FillFlowContainer<LeaderboardScore> scrollFlow;
-        private Container placeholderContainer;
+        private Container noResultsPlaceholder;
+        private Container retryPlaceholder;
 
         public Action<Score> ScoreSelected;
 
@@ -44,19 +47,20 @@ namespace osu.Game.Screens.Select.Leaderboards
             {
                 scores = value;
                 getScoresRequest?.Cancel();
+                getScoresRequest = null;
 
-                placeholderContainer.FadeOut(fade_duration);
+                noResultsPlaceholder.FadeOut(fade_duration);
                 scrollFlow?.FadeOut(fade_duration).Expire();
                 scrollFlow = null;
 
+                loading.Hide();
+
                 if (scores == null)
                     return;
 
-                loading.Hide();
-
                 if (scores.Count() == 0)
                 {
-                    placeholderContainer.FadeIn(fade_duration);
+                    noResultsPlaceholder.FadeIn(fade_duration);
                     return;
                 }
 
@@ -110,7 +114,7 @@ namespace osu.Game.Screens.Select.Leaderboards
                     ScrollbarVisible = false,
                 },
                 loading = new LoadingAnimation(),
-                placeholderContainer = new Container
+                noResultsPlaceholder = new Container
                 {
                     Alpha = 0,
                     RelativeSizeAxes = Axes.Both,
@@ -139,6 +143,35 @@ namespace osu.Game.Screens.Select.Leaderboards
                         },
                     },
                 },
+                retryPlaceholder = new Container
+                {
+                    Alpha = 0,
+                    RelativeSizeAxes = Axes.Both,
+                    Children = new Drawable[]
+                    {
+                        new FillFlowContainer
+                        {
+                            Direction = FillDirection.Horizontal,
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            AutoSizeAxes = Axes.Both,
+                            Children = new Drawable[]
+                            {
+                                new RetryButton
+                                {
+                                    Action = updateScores,
+                                    Margin = new MarginPadding { Right = 10 },
+                                },
+                                new OsuSpriteText
+                                {
+                                    Anchor = Anchor.TopLeft,
+                                    Text = @"An error occurred!",
+                                    TextSize = 22,
+                                },
+                            }
+                        },
+                    },
+                },
             };
         }
 
@@ -180,6 +213,8 @@ namespace osu.Game.Screens.Select.Leaderboards
         {
             if (!IsLoaded) return;
 
+            retryPlaceholder.FadeOut(fade_duration);
+
             Scores = null;
 
             if (api == null || Beatmap?.OnlineBeatmapID == null) return;
@@ -198,6 +233,17 @@ namespace osu.Game.Screens.Select.Leaderboards
             {
                 Scores = r.Scores;
             };
+            getScoresRequest.Failure += e =>
+            {
+                // TODO: check why failure is repeatedly invoked even on successful requests
+                if (e is WebException)
+                {
+                    Scores = null;
+                    retryPlaceholder.FadeIn(fade_duration);
+                    Logger.Error(e, @"Couldn't fetch beatmap scores!");
+                }
+            };
+
             api.Queue(getScoresRequest);
         }
 
@@ -229,6 +275,51 @@ namespace osu.Game.Screens.Select.Leaderboards
                 }
             }
         }
+
+        private class RetryButton : ClickableContainer
+        {
+            private SpriteIcon icon;
+
+            public RetryButton()
+            {
+                Height = 26;
+                Width = 26;
+                Children = new Drawable[]
+                {
+                    icon = new SpriteIcon
+                    {
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        Icon = FontAwesome.fa_refresh,
+                        Size = new Vector2(26),
+                    }
+                };
+            }
+
+            protected override bool OnHover(Framework.Input.InputState state)
+            {
+                icon.ScaleTo(1.4f, 400, Easing.OutQuint);
+                return base.OnHover(state);
+            }
+
+            protected override void OnHoverLost(Framework.Input.InputState state)
+            {
+                icon.ScaleTo(1f, 400, Easing.OutQuint);
+                base.OnHoverLost(state);
+            }
+
+            protected override bool OnMouseDown(Framework.Input.InputState state, Framework.Input.MouseDownEventArgs args)
+            {
+                icon.ScaleTo(0.8f, 200, Easing.InElastic);
+                return base.OnMouseDown(state, args);
+            }
+
+            protected override bool OnMouseUp(Framework.Input.InputState state, Framework.Input.MouseUpEventArgs args)
+            {
+                icon.ScaleTo(1.2f, 400, Easing.OutElastic).Then().ScaleTo(1f, 400, Easing.OutElastic);
+                return base.OnMouseUp(state, args);
+            }
+        }
     }
 
     public enum LeaderboardScope