Add initial implementation of beatmap carousel no-results-placeholder

osu.Game.Tests/Visual/SongSelect/TestScenePlaySongSelect.cs

@@ -18,6 +18,7 @@ using osu.Game.Database;
 using osu.Game.Extensions;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Online.Chat;
 using osu.Game.Overlays;
 using osu.Game.Overlays.Mods;
 using osu.Game.Rulesets;
@@ -80,6 +81,37 @@ namespace osu.Game.Tests.Visual.SongSelect
             AddStep("delete all beatmaps", () => manager?.Delete());
         }
 
+        [Test]
+        public void TestPlaceholderBeatmapPresence()
+        {
+            createSongSelect();
+
+            AddUntilStep("wait for placeholder visible", () => getPlaceholder()?.State.Value == Visibility.Visible);
+
+            addRulesetImportStep(0);
+            AddUntilStep("wait for placeholder hidden", () => getPlaceholder()?.State.Value == Visibility.Hidden);
+
+            AddStep("delete all beatmaps", () => manager?.Delete());
+            AddUntilStep("wait for placeholder visible", () => getPlaceholder()?.State.Value == Visibility.Visible);
+        }
+
+        [Test]
+        public void TestPlaceholderConvertSetting()
+        {
+            changeRuleset(2);
+            addRulesetImportStep(0);
+            AddStep("change convert setting", () => config.SetValue(OsuSetting.ShowConvertedBeatmaps, false));
+
+            createSongSelect();
+
+            AddUntilStep("wait for placeholder visible", () => getPlaceholder()?.State.Value == Visibility.Visible);
+
+            AddStep("click link in placeholder", () => getPlaceholder().ChildrenOfType<DrawableLinkCompiler>().First().TriggerClick());
+
+            AddUntilStep("convert setting changed", () => config.Get<bool>(OsuSetting.ShowConvertedBeatmaps));
+            AddUntilStep("wait for placeholder visible", () => getPlaceholder()?.State.Value == Visibility.Hidden);
+        }
+
         [Test]
         public void TestSingleFilterOnEnter()
         {
@@ -941,6 +973,8 @@ namespace osu.Game.Tests.Visual.SongSelect
 
         private int getBeatmapIndex(BeatmapSetInfo set, BeatmapInfo info) => set.Beatmaps.IndexOf(info);
 
+        private NoResultsPlaceholder getPlaceholder() => songSelect.ChildrenOfType<NoResultsPlaceholder>().FirstOrDefault();
+
         private int getCurrentBeatmapIndex() => getBeatmapIndex(songSelect.Carousel.SelectedBeatmapSet, songSelect.Carousel.SelectedBeatmapInfo);
 
         private int getDifficultyIconIndex(DrawableCarouselBeatmapSet set, FilterableDifficultyIcon icon)

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -97,6 +97,8 @@ namespace osu.Game.Screens.Select
 
         protected readonly CarouselScrollContainer Scroll;
 
+        private readonly NoResultsPlaceholder noResultsPlaceholder;
+
         private IEnumerable<CarouselBeatmapSet> beatmapSets => root.Children.OfType<CarouselBeatmapSet>();
 
         // todo: only used for testing, maybe remove.
@@ -170,7 +172,8 @@ namespace osu.Game.Screens.Select
                     Scroll = new CarouselScrollContainer
                     {
                         RelativeSizeAxes = Axes.Both,
-                    }
+                    },
+                    noResultsPlaceholder = new NoResultsPlaceholder()
                 }
             };
         }
@@ -648,8 +651,18 @@ namespace osu.Game.Screens.Select
             // First we iterate over all non-filtered carousel items and populate their
             // vertical position data.
             if (revalidateItems)
+            {
                 updateYPositions();
 
+                if (visibleItems.Count == 0)
+                {
+                    noResultsPlaceholder.Filter = activeCriteria;
+                    noResultsPlaceholder.Show();
+                }
+                else
+                    noResultsPlaceholder.Hide();
+            }
+
             // if there is a pending scroll action we apply it without animation and transfer the difference in position to the panels.
             // this is intentionally applied before updating the visible range below, to avoid animating new items (sourced from pool) from locations off-screen, as it looks bad.
             if (pendingScrollOperation != PendingScrollOperation.None)

osu.Game/Screens/Select/NoResultsPlaceholder.cs

@@ -0,0 +1,122 @@
+// 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.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Beatmaps;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Containers;
+using osu.Game.Online.Chat;
+using osu.Game.Overlays;
+using osuTK;
+
+namespace osu.Game.Screens.Select
+{
+    public class NoResultsPlaceholder : CompositeDrawable
+    {
+        private FilterCriteria filter;
+
+        private LinkFlowContainer textFlow;
+
+        [Resolved]
+        private BeatmapManager beatmaps { get; set; }
+
+        [Resolved(CanBeNull = true)]
+        private FirstRunSetupOverlay firstRunSetupOverlay { get; set; }
+
+        public FilterCriteria Filter
+        {
+            get => filter;
+            set
+            {
+                filter = value;
+                Scheduler.AddOnce(updateText);
+            }
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            Masking = true;
+            CornerRadius = 10;
+
+            Width = 300;
+            AutoSizeAxes = Axes.Y;
+
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+
+            InternalChildren = new Drawable[]
+            {
+                new Box
+                {
+                    Colour = colours.Gray2,
+                    RelativeSizeAxes = Axes.Both,
+                },
+                new SpriteIcon
+                {
+                    Icon = FontAwesome.Regular.QuestionCircle,
+                    Anchor = Anchor.TopCentre,
+                    Origin = Anchor.TopCentre,
+                    Margin = new MarginPadding(10),
+                    Size = new Vector2(50),
+                },
+                textFlow = new LinkFlowContainer
+                {
+                    Y = 70,
+                    Padding = new MarginPadding(10),
+                    TextAnchor = Anchor.TopCentre,
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                }
+            };
+        }
+
+        public override void Show()
+        {
+            this.FadeIn(600, Easing.OutQuint);
+
+            this.ScaleTo(0.8f)
+                .ScaleTo(1f, 1000, Easing.OutElastic);
+
+            Scheduler.AddOnce(updateText);
+        }
+
+        public override void Hide()
+        {
+            this.FadeOut(200, Easing.OutQuint);
+        }
+
+        private void updateText()
+        {
+            textFlow.Clear();
+
+            if (beatmaps.QueryBeatmapSet(s => !s.Protected && !s.DeletePending) == null)
+            {
+                textFlow.AddParagraph("No beatmaps found!");
+                textFlow.AddParagraph(string.Empty);
+
+                textFlow.AddParagraph("Consider running the ");
+                textFlow.AddLink("first run setup", () => firstRunSetupOverlay?.Show());
+                textFlow.AddText(" to load or import some beatmaps!");
+            }
+            else
+            {
+                textFlow.AddParagraph("No beatmaps match your filter criteria!");
+                textFlow.AddParagraph(string.Empty);
+
+                // TODO: hint when beatmaps are available in another ruleset
+                // TODO: hint when beatmaps are available by toggling "show converted".
+                if (!string.IsNullOrEmpty(filter?.SearchText))
+                {
+                    textFlow.AddParagraph("You can try ");
+                    textFlow.AddLink("searching online", LinkAction.SearchBeatmapSet, filter.SearchText);
+                    textFlow.AddText(" for this query.");
+                }
+            }
+        }
+    }
+}