Merge branch 'unload-carousel-panels' into update-framework-with-everyrthing

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -486,6 +486,15 @@ namespace osu.Game.Screens.Select
                 updateItem(p, halfHeight);
         }
 
+        protected override void Dispose(bool isDisposing)
+        {
+            base.Dispose(isDisposing);
+
+            // aggressively dispose "off-screen" items to reduce GC pressure.
+            foreach (var i in Items)
+                i.Dispose();
+        }
+
         private CarouselBeatmapSet createCarouselSet(BeatmapSetInfo beatmapSet)
         {
             if (beatmapSet.Beatmaps.All(b => b.Hidden))

osu.Game/Screens/Select/Carousel/DrawableCarouselBeatmapSet.cs

@@ -50,12 +50,12 @@ namespace osu.Game.Screens.Select.Carousel
 
             Children = new Drawable[]
             {
-                new DelayedLoadWrapper(
+                new DelayedLoadUnloadWrapper(() =>
                     new PanelBackground(manager.GetWorkingBeatmap(beatmapSet.Beatmaps.FirstOrDefault()))
                     {
                         RelativeSizeAxes = Axes.Both,
                         OnLoadComplete = d => d.FadeInFromZero(1000, Easing.OutQuint),
-                    }, 300
+                    }, 300, 5000
                 ),
                 new FillFlowContainer
                 {