// 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.Collections.Generic;
using System.Collections.Specialized;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using osu.Framework.Allocation;
using osu.Framework.Audio;
using osu.Framework.Audio.Sample;
using osu.Framework.Bindables;
using osu.Framework.Caching;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Pooling;
using osu.Framework.Input.Bindings;
using osu.Framework.Input.Events;
using osu.Framework.Layout;
using osu.Framework.Threading;
using osu.Framework.Utils;
using osu.Game.Beatmaps;
using osu.Game.Configuration;
using osu.Game.Database;
using osu.Game.Extensions;
using osu.Game.Graphics.Containers;
using osu.Game.Input.Bindings;
using osu.Game.Screens.Select.Carousel;
using osuTK;
using osuTK.Input;
using Realms;
namespace osu.Game.Screens.Select
{
public partial class BeatmapCarousel : CompositeDrawable, IKeyBindingHandler<GlobalAction>
{
/// <summary>
/// Height of the area above the carousel that should be treated as visible due to transparency of elements in front of it.
/// </summary>
public float BleedTop { get; set; }
/// <summary>
/// Height of the area below the carousel that should be treated as visible due to transparency of elements in front of it.
/// </summary>
public float BleedBottom { get; set; }
/// <summary>
/// Triggered when <see cref="BeatmapSets"/> finish loading, or are subsequently changed.
/// </summary>
public Action? BeatmapSetsChanged;
/// <summary>
/// Triggered after filter conditions have finished being applied to the model hierarchy.
/// </summary>
public Action? FilterApplied;
/// <summary>
/// The currently selected beatmap.
/// </summary>
public BeatmapInfo? SelectedBeatmapInfo => selectedBeatmap?.BeatmapInfo;
private CarouselBeatmap? selectedBeatmap => selectedBeatmapSet?.Beatmaps.FirstOrDefault(s => s.State.Value == CarouselItemState.Selected);
/// <summary>
/// The total count of non-filtered beatmaps displayed.
/// </summary>
public int CountDisplayed => beatmapSets.Where(s => !s.Filtered.Value).Sum(s => s.TotalItemsNotFiltered);
/// <summary>
/// The currently selected beatmap set.
/// </summary>
public BeatmapSetInfo? SelectedBeatmapSet => selectedBeatmapSet?.BeatmapSet;
/// <summary>
/// A function to optionally decide on a recommended difficulty from a beatmap set.
/// </summary>
public Func<IEnumerable<BeatmapInfo>, BeatmapInfo?>? GetRecommendedBeatmap;
private CarouselBeatmapSet? selectedBeatmapSet;
/// <summary>
/// Raised when the <see cref="SelectedBeatmapInfo"/> is changed.
/// </summary>
public Action<BeatmapInfo?>? SelectionChanged;
public override bool HandleNonPositionalInput => AllowSelection;
public override bool HandlePositionalInput => AllowSelection;
public override bool PropagatePositionalInputSubTree => AllowSelection;
public override bool PropagateNonPositionalInputSubTree => AllowSelection;
private (int first, int last) displayedRange;
/// <summary>
/// Extend the range to retain already loaded pooled drawables.
/// </summary>
private const float distance_offscreen_before_unload = 2048;
/// <summary>
/// Extend the range to update positions / retrieve pooled drawables outside of visible range.
/// </summary>
private const float distance_offscreen_to_preload = 768;
/// <summary>
/// Whether carousel items have completed asynchronously loaded.
/// </summary>
public bool BeatmapSetsLoaded { get; private set; }
[Cached]
protected readonly CarouselScrollContainer Scroll;
[Resolved]
private RealmAccess realm { get; set; } = null!;
[Resolved]
private DetachedBeatmapStore? detachedBeatmapStore { get; set; }
private IBindableList<BeatmapSetInfo>? detachedBeatmapSets;
private readonly NoResultsPlaceholder noResultsPlaceholder;
private IEnumerable<CarouselBeatmapSet> beatmapSets => root.Items.OfType<CarouselBeatmapSet>();
internal IEnumerable<BeatmapSetInfo> BeatmapSets
{
get => beatmapSets.Select(g => g.BeatmapSet);
set
{
if (LoadState != LoadState.NotLoaded)
throw new InvalidOperationException("If not using a realm source, beatmap sets must be set before load.");
detachedBeatmapSets = new BindableList<BeatmapSetInfo>(value);
Schedule(loadNewRoot);
}
}
private void loadNewRoot()
{
beatmapsSplitOut = activeCriteria.SplitOutDifficulties;
// Ensure no changes are made to the list while we are initialising items.
// We'll catch up on changes via subscriptions anyway.
BeatmapSetInfo[] loadableSets = detachedBeatmapSets!.ToArray();
if (selectedBeatmapSet != null && !loadableSets.Contains(selectedBeatmapSet.BeatmapSet, EqualityComparer<BeatmapSetInfo>.Default))
selectedBeatmapSet = null;
var selectedBeatmapBefore = selectedBeatmap?.BeatmapInfo;
CarouselRoot newRoot = new CarouselRoot(this);
if (beatmapsSplitOut)
{
var carouselBeatmapSets = loadableSets.SelectMany(s => s.Beatmaps).Select(b =>
{
return createCarouselSet(new BeatmapSetInfo(new[] { b })
{
ID = b.BeatmapSet!.ID,
OnlineID = b.BeatmapSet!.OnlineID,
Status = b.BeatmapSet!.Status,
});
}).OfType<CarouselBeatmapSet>();
newRoot.AddItems(carouselBeatmapSets);
}
else
{
var carouselBeatmapSets = loadableSets.Select(createCarouselSet).OfType<CarouselBeatmapSet>();
newRoot.AddItems(carouselBeatmapSets);
}
root = newRoot;
root.Filter(activeCriteria);
Scroll.Clear(false);
itemsCache.Invalidate();
ScrollToSelected();
// Restore selection
if (selectedBeatmapBefore != null && newRoot.BeatmapSetsByID.TryGetValue(selectedBeatmapBefore.BeatmapSet!.ID, out var newSelectionCandidates))
{
CarouselBeatmap? found = newSelectionCandidates.SelectMany(s => s.Beatmaps).SingleOrDefault(b => b.BeatmapInfo.ID == selectedBeatmapBefore.ID);
if (found != null)
found.State.Value = CarouselItemState.Selected;
}
Schedule(() =>
{
invalidateAfterChange();
BeatmapSetsLoaded = true;
});
}
private readonly List<CarouselItem> visibleItems = new List<CarouselItem>();
private readonly Cached itemsCache = new Cached();
private PendingScrollOperation pendingScrollOperation = PendingScrollOperation.None;
public Bindable<bool> RightClickScrollingEnabled = new Bindable<bool>();
public Bindable<RandomSelectAlgorithm> RandomAlgorithm = new Bindable<RandomSelectAlgorithm>();
private readonly List<CarouselBeatmapSet> previouslyVisitedRandomSets = new List<CarouselBeatmapSet>();
private readonly List<CarouselBeatmap> randomSelectedBeatmaps = new List<CarouselBeatmap>();
private CarouselRoot root;
private IDisposable? subscriptionBeatmaps;
private readonly DrawablePool<DrawableCarouselBeatmapSet> setPool = new DrawablePool<DrawableCarouselBeatmapSet>(100);
private Sample? spinSample;
private Sample? randomSelectSample;
private int visibleSetsCount;
public BeatmapCarousel(FilterCriteria initialCriteria)
{
root = new CarouselRoot(this);
InternalChild = new Container
{
RelativeSizeAxes = Axes.Both,
Children = new Drawable[]
{
setPool,
Scroll = new CarouselScrollContainer
{
RelativeSizeAxes = Axes.Both,
},
noResultsPlaceholder = new NoResultsPlaceholder()
}
};
activeCriteria = initialCriteria;
}
[BackgroundDependencyLoader]
private void load(OsuConfigManager config, AudioManager audio, CancellationToken? cancellationToken)
{
spinSample = audio.Samples.Get("SongSelect/random-spin");
randomSelectSample = audio.Samples.Get(@"SongSelect/select-random");
config.BindWith(OsuSetting.RandomSelectAlgorithm, RandomAlgorithm);
config.BindWith(OsuSetting.SongSelectRightMouseScroll, RightClickScrollingEnabled);
RightClickScrollingEnabled.BindValueChanged(enabled => Scroll.RightMouseScrollbar = enabled.NewValue, true);
if (detachedBeatmapStore != null && detachedBeatmapSets == null)
{
// This is performing an unnecessary second lookup on realm (in addition to the subscription), but for performance reasons
// we require it to be separate: the subscription's initial callback (with `ChangeSet` of `null`) will run on the update
// thread. If we attempt to detach beatmaps in this callback the game will fall over (it takes time).
detachedBeatmapSets = detachedBeatmapStore.GetDetachedBeatmaps(cancellationToken);
detachedBeatmapSets.BindCollectionChanged(beatmapSetsChanged);
loadNewRoot();
}
}
protected override void LoadComplete()
{
base.LoadComplete();
subscriptionBeatmaps = realm.RegisterForNotifications(r => r.All<BeatmapInfo>().Where(b => !b.Hidden), beatmapsChanged);
}
private readonly HashSet<BeatmapSetInfo> setsRequiringUpdate = new HashSet<BeatmapSetInfo>();
private readonly HashSet<BeatmapSetInfo> setsRequiringRemoval = new HashSet<BeatmapSetInfo>();
private void beatmapSetsChanged(object? beatmaps, NotifyCollectionChangedEventArgs changed)
{
IEnumerable<BeatmapSetInfo>? newBeatmapSets = changed.NewItems?.Cast<BeatmapSetInfo>();
switch (changed.Action)
{
case NotifyCollectionChangedAction.Add:
HashSet<Guid> newBeatmapSetIDs = newBeatmapSets!.Select(s => s.ID).ToHashSet();
setsRequiringRemoval.RemoveWhere(s => newBeatmapSetIDs.Contains(s.ID));
setsRequiringUpdate.AddRange(newBeatmapSets!);
break;
case NotifyCollectionChangedAction.Remove:
IEnumerable<BeatmapSetInfo> oldBeatmapSets = changed.OldItems!.Cast<BeatmapSetInfo>();
HashSet<Guid> oldBeatmapSetIDs = oldBeatmapSets.Select(s => s.ID).ToHashSet();
setsRequiringUpdate.RemoveWhere(s => oldBeatmapSetIDs.Contains(s.ID));
setsRequiringRemoval.AddRange(oldBeatmapSets);
break;
case NotifyCollectionChangedAction.Replace:
setsRequiringUpdate.AddRange(newBeatmapSets!);
break;
case NotifyCollectionChangedAction.Move:
setsRequiringUpdate.AddRange(newBeatmapSets!);
break;
case NotifyCollectionChangedAction.Reset:
setsRequiringRemoval.Clear();
setsRequiringUpdate.Clear();
loadNewRoot();
break;
}
Scheduler.AddOnce(processBeatmapChanges);
}
// All local operations must be scheduled.
//
// If we don't schedule, beatmaps getting changed while song select is suspended (ie. last played being updated)
// will cause unexpected sounds and operations to occur in the background.
private void processBeatmapChanges()
{
try
{
// To handle the beatmap update flow, attempt to track selection changes across delete-insert transactions.
// When an update occurs, the previous beatmap set is either soft or hard deleted.
// Check if the current selection was potentially deleted by re-querying its validity.
bool selectedSetMarkedDeleted = SelectedBeatmapSet != null && fetchFromID(SelectedBeatmapSet.ID)?.DeletePending != false;
foreach (var set in setsRequiringRemoval) removeBeatmapSet(set.ID);
foreach (var set in setsRequiringUpdate) updateBeatmapSet(set);
if (setsRequiringRemoval.Count > 0 && SelectedBeatmapInfo != null)
{
// If SelectedBeatmapInfo is non-null, the set should also be non-null.
Debug.Assert(SelectedBeatmapSet != null);
if (selectedSetMarkedDeleted && setsRequiringUpdate.Any())
{
// If it is no longer valid, make the bold assumption that an updated version will be available in the modified/inserted indices.
// This relies on the full update operation being in a single transaction, so please don't change that.
foreach (var set in setsRequiringUpdate)
{
foreach (var beatmapInfo in set.Beatmaps)
{
if (!((IBeatmapMetadataInfo)beatmapInfo.Metadata).Equals(SelectedBeatmapInfo.Metadata)) continue;
// Best effort matching. We can't use ID because in the update flow a new version will get its own GUID.
if (beatmapInfo.DifficultyName == SelectedBeatmapInfo.DifficultyName)
{
SelectBeatmap(beatmapInfo);
return;
}
}
}
// If a direct selection couldn't be made, it's feasible that the difficulty name (or beatmap metadata) changed.
// Let's attempt to follow set-level selection anyway.
SelectBeatmap(setsRequiringUpdate.First().Beatmaps.First());
}
}
}
finally
{
BeatmapSetsLoaded = true;
invalidateAfterChange();
}
setsRequiringRemoval.Clear();
setsRequiringUpdate.Clear();
BeatmapSetInfo? fetchFromID(Guid id) => realm.Realm.Find<BeatmapSetInfo>(id);
}
private void beatmapsChanged(IRealmCollection<BeatmapInfo> sender, ChangeSet? changes)
{
// we only care about actual changes in hidden status.
if (changes == null)
return;
bool changed = false;
foreach (int i in changes.InsertedIndices)
{
var beatmapInfo = sender[i];
var beatmapSet = beatmapInfo.BeatmapSet;
Debug.Assert(beatmapSet != null);
// Only require to action here if the beatmap is missing.
// This avoids processing these events unnecessarily when new beatmaps are imported, for example.
if (root.BeatmapSetsByID.TryGetValue(beatmapSet.ID, out var existingSets)
&& existingSets.SelectMany(s => s.Beatmaps).All(b => b.BeatmapInfo.ID != beatmapInfo.ID))
{
updateBeatmapSet(beatmapSet.Detach());
changed = true;
}
}
if (changed)
invalidateAfterChange();
}
public void RemoveBeatmapSet(BeatmapSetInfo beatmapSet) => Schedule(() =>
{
removeBeatmapSet(beatmapSet.ID);
invalidateAfterChange();
});
private void removeBeatmapSet(Guid beatmapSetID)
{
if (!root.BeatmapSetsByID.TryGetValue(beatmapSetID, out var existingSets))
return;
foreach (var set in existingSets)
{
foreach (var beatmap in set.Beatmaps)
randomSelectedBeatmaps.Remove(beatmap);
previouslyVisitedRandomSets.Remove(set);
root.RemoveItem(set);
}
}
public void UpdateBeatmapSet(BeatmapSetInfo beatmapSet) => Schedule(() =>
{
updateBeatmapSet(beatmapSet);
invalidateAfterChange();
});
private void updateBeatmapSet(BeatmapSetInfo beatmapSet)
{
var newSets = new List<CarouselBeatmapSet>();
if (beatmapsSplitOut)
{
foreach (var beatmap in beatmapSet.Beatmaps)
{
var newSet = createCarouselSet(new BeatmapSetInfo(new[] { beatmap })
{
ID = beatmapSet.ID,
OnlineID = beatmapSet.OnlineID,
Status = beatmapSet.Status,
});
if (newSet != null)
newSets.Add(newSet);
}
}
else
{
var newSet = createCarouselSet(beatmapSet);
if (newSet != null)
newSets.Add(newSet);
}
var removedSets = root.ReplaceItem(beatmapSet, newSets);
// If we don't remove these here, it may remain in a hidden state until scrolled off screen.
// Doesn't really affect anything during actual user interaction, but makes testing annoying.
foreach (var removedSet in removedSets)
{
var removedDrawable = Scroll.FirstOrDefault(c => c.Item == removedSet);
if (removedDrawable != null)
expirePanelImmediately(removedDrawable);
}
}
/// <summary>
/// Selects a given beatmap on the carousel.
/// </summary>
/// <param name="beatmapInfo">The beatmap to select.</param>
/// <param name="bypassFilters">Whether to select the beatmap even if it is filtered (i.e., not visible on carousel).</param>
/// <returns>True if a selection was made, False if it wasn't.</returns>
public bool SelectBeatmap(BeatmapInfo? beatmapInfo, bool bypassFilters = true)
{
// ensure that any pending events from BeatmapManager have been run before attempting a selection.
Scheduler.Update();
if (beatmapInfo?.Hidden != false)
return false;
foreach (CarouselBeatmapSet set in beatmapSets)
{
if (!bypassFilters && set.Filtered.Value)
continue;
var item = set.Beatmaps.FirstOrDefault(p => p.BeatmapInfo.Equals(beatmapInfo));
if (item == null)
// The beatmap that needs to be selected doesn't exist in this set
continue;
if (!bypassFilters && item.Filtered.Value)
return false;
select(item);
// if we got here and the set is filtered, it means we were bypassing filters.
// in this case, reapplying the filter is necessary to ensure the panel is in the correct place
// (since it is forcefully being included in the carousel).
if (set.Filtered.Value)
{
Debug.Assert(bypassFilters);
applyActiveCriteria(false);
}
return true;
}
return false;
}
/// <summary>
/// Increment selection in the carousel in a chosen direction.
/// </summary>
/// <param name="direction">The direction to increment. Negative is backwards.</param>
/// <param name="skipDifficulties">Whether to skip individual difficulties and only increment over full groups.</param>
public void SelectNext(int direction = 1, bool skipDifficulties = true)
{
if (beatmapSets.All(s => s.Filtered.Value))
return;
if (skipDifficulties)
selectNextSet(direction, true);
else
selectNextDifficulty(direction);
}
private void selectNextSet(int direction, bool skipDifficulties)
{
if (selectedBeatmap == null || selectedBeatmapSet == null)
return;
var unfilteredSets = beatmapSets.Where(s => !s.Filtered.Value).ToList();
var nextSet = unfilteredSets[(unfilteredSets.IndexOf(selectedBeatmapSet) + direction + unfilteredSets.Count) % unfilteredSets.Count];
if (skipDifficulties)
select(nextSet);
else
select(direction > 0 ? nextSet.Beatmaps.First(b => !b.Filtered.Value) : nextSet.Beatmaps.Last(b => !b.Filtered.Value));
}
private void selectNextDifficulty(int direction)
{
if (selectedBeatmap == null || selectedBeatmapSet == null)
return;
var unfilteredDifficulties = selectedBeatmapSet.Items.Where(s => !s.Filtered.Value).ToList();
int index = unfilteredDifficulties.IndexOf(selectedBeatmap);
if (index + direction < 0 || index + direction >= unfilteredDifficulties.Count)
selectNextSet(direction, false);
else
select(unfilteredDifficulties[index + direction]);
}
/// <summary>
/// Select the next beatmap in the random sequence.
/// </summary>
/// <returns>True if a selection could be made, else False.</returns>
public bool SelectNextRandom()
{
if (!AllowSelection)
return false;
var visibleSets = beatmapSets.Where(s => !s.Filtered.Value).ToList();
visibleSetsCount = visibleSets.Count;
if (!visibleSets.Any())
return false;
if (selectedBeatmap != null && selectedBeatmapSet != null)
{
randomSelectedBeatmaps.Add(selectedBeatmap);
// when performing a random, we want to add the current set to the previously visited list
// else the user may be "randomised" to the existing selection.
if (previouslyVisitedRandomSets.LastOrDefault() != selectedBeatmapSet)
previouslyVisitedRandomSets.Add(selectedBeatmapSet);
}
CarouselBeatmapSet set;
if (RandomAlgorithm.Value == RandomSelectAlgorithm.RandomPermutation)
{
var notYetVisitedSets = visibleSets.Except(previouslyVisitedRandomSets).ToList();
if (!notYetVisitedSets.Any())
{
previouslyVisitedRandomSets.RemoveAll(s => visibleSets.Contains(s));
notYetVisitedSets = visibleSets;
}
set = notYetVisitedSets.ElementAt(RNG.Next(notYetVisitedSets.Count));
previouslyVisitedRandomSets.Add(set);
}
else
set = visibleSets.ElementAt(RNG.Next(visibleSets.Count));
if (selectedBeatmapSet != null)
playSpinSample(distanceBetween(set, selectedBeatmapSet));
select(set);
return true;
}
public void SelectPreviousRandom()
{
while (randomSelectedBeatmaps.Any())
{
var beatmap = randomSelectedBeatmaps[^1];
randomSelectedBeatmaps.RemoveAt(randomSelectedBeatmaps.Count - 1);
if (!beatmap.Filtered.Value && beatmap.BeatmapInfo.BeatmapSet?.DeletePending != true)
{
if (selectedBeatmapSet != null)
{
if (RandomAlgorithm.Value == RandomSelectAlgorithm.RandomPermutation)
previouslyVisitedRandomSets.Remove(selectedBeatmapSet);
playSpinSample(distanceBetween(beatmap, selectedBeatmapSet));
}
select(beatmap);
break;
}
}
}
private double distanceBetween(CarouselItem item1, CarouselItem item2) => Math.Ceiling(Math.Abs(item1.CarouselYPosition - item2.CarouselYPosition) / DrawableCarouselItem.MAX_HEIGHT);
private void playSpinSample(double distance)
{
var chan = spinSample?.GetChannel();
if (chan != null)
{
chan.Frequency.Value = 1f + Math.Min(1f, distance / visibleSetsCount);
chan.Play();
}
randomSelectSample?.Play();
}
private void select(CarouselItem? item)
{
if (!AllowSelection)
return;
if (item == null) return;
item.State.Value = CarouselItemState.Selected;
}
private FilterCriteria activeCriteria;
protected ScheduledDelegate? PendingFilter;
public bool AllowSelection = true;
/// <summary>
/// Half the height of the visible content.
/// <remarks>
/// This is different from the height of <see cref="ScrollContainer{T}"/>.displayableContent, since
/// the beatmap carousel bleeds into the <see cref="FilterControl"/> and the <see cref="Footer"/>
/// </remarks>
/// </summary>
private float visibleHalfHeight => (DrawHeight + BleedBottom + BleedTop) / 2;
/// <summary>
/// The position of the lower visible bound with respect to the current scroll position.
/// </summary>
private float visibleBottomBound => Scroll.Current + DrawHeight + BleedBottom;
/// <summary>
/// The position of the upper visible bound with respect to the current scroll position.
/// </summary>
private float visibleUpperBound => Scroll.Current - BleedTop;
public void FlushPendingFilterOperations()
{
if (!IsLoaded)
return;
if (PendingFilter?.Completed == false)
{
applyActiveCriteria(false);
Update();
}
}
public void Filter(FilterCriteria? newCriteria)
{
if (newCriteria != null)
activeCriteria = newCriteria;
applyActiveCriteria(true);
}
private bool beatmapsSplitOut;
private void applyActiveCriteria(bool debounce)
{
PendingFilter?.Cancel();
PendingFilter = null;
if (debounce)
PendingFilter = Scheduler.AddDelayed(perform, 250);
else
{
// if initial load is not yet finished, this will be run inline in loadBeatmapSets to ensure correct order of operation.
if (!BeatmapSetsLoaded)
PendingFilter = Schedule(perform);
else
perform();
}
void perform()
{
PendingFilter = null;
if (activeCriteria.SplitOutDifficulties != beatmapsSplitOut)
{
loadNewRoot();
return;
}
root.Filter(activeCriteria);
itemsCache.Invalidate();
ScrollToSelected(true);
FilterApplied?.Invoke();
}
}
private void invalidateAfterChange()
{
itemsCache.Invalidate();
if (!Scroll.UserScrolling)
ScrollToSelected(true);
BeatmapSetsChanged?.Invoke();
}
private float? scrollTarget;
/// <summary>
/// Scroll to the current <see cref="SelectedBeatmapInfo"/>.
/// </summary>
/// <param name="immediate">
/// Whether the scroll position should immediately be shifted to the target, delegating animation to visible panels.
/// This should be true for operations like filtering - where panels are changing visibility state - to avoid large jumps in animation.
/// </param>
public void ScrollToSelected(bool immediate = false) =>
pendingScrollOperation = immediate ? PendingScrollOperation.Immediate : PendingScrollOperation.Standard;
#region Button selection logic
public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
{
switch (e.Action)
{
case GlobalAction.SelectNext:
case GlobalAction.SelectNextGroup:
SelectNext(1, e.Action == GlobalAction.SelectNextGroup);
return true;
case GlobalAction.SelectPrevious:
case GlobalAction.SelectPreviousGroup:
SelectNext(-1, e.Action == GlobalAction.SelectPreviousGroup);
return true;
}
return false;
}
public void OnReleased(KeyBindingReleaseEvent<GlobalAction> e)
{
}
#endregion
protected override bool OnInvalidate(Invalidation invalidation, InvalidationSource source)
{
// handles the vertical size of the carousel changing (ie. on window resize when aspect ratio has changed).
if (invalidation.HasFlag(Invalidation.DrawSize))
itemsCache.Invalidate();
return base.OnInvalidate(invalidation, source);
}
protected override void Update()
{
base.Update();
bool revalidateItems = !itemsCache.IsValid;
// 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)
updateScrollPosition();
// This data is consumed to find the currently displayable range.
// This is the range we want to keep drawables for, and should exceed the visible range slightly to avoid drawable churn.
var newDisplayRange = getDisplayRange();
// If the filtered items or visible range has changed, pooling requirements need to be checked.
// This involves fetching new items from the pool, returning no-longer required items.
if (revalidateItems || newDisplayRange != displayedRange)
{
displayedRange = newDisplayRange;
if (visibleItems.Count > 0)
{
var toDisplay = visibleItems.GetRange(displayedRange.first, displayedRange.last - displayedRange.first + 1);
foreach (var panel in Scroll)
{
Debug.Assert(panel.Item != null);
if (toDisplay.Remove(panel.Item))
{
// panel already displayed.
continue;
}
// panel loaded as drawable but not required by visible range.
// remove but only if too far off-screen
if (panel.Y + panel.DrawHeight < visibleUpperBound - distance_offscreen_before_unload || panel.Y > visibleBottomBound + distance_offscreen_before_unload)
expirePanelImmediately(panel);
}
// Add those items within the previously found index range that should be displayed.
foreach (var item in toDisplay)
{
var panel = setPool.Get();
panel.Item = item;
panel.Y = item.CarouselYPosition;
Scroll.Add(panel);
}
}
}
// Update externally controlled state of currently visible items (e.g. x-offset and opacity).
// This is a per-frame update on all drawable panels.
foreach (DrawableCarouselItem item in Scroll)
{
updateItem(item);
Debug.Assert(item.Item != null);
if (item.Item.Visible)
{
bool isSelected = item.Item.State.Value == CarouselItemState.Selected;
bool hasPassedSelection = item.Item.CarouselYPosition < selectedBeatmapSet?.CarouselYPosition;
// Cheap way of doing animations when entering / exiting song select.
const double half_time = 50;
const float panel_x_offset_when_inactive = 200;
if (isSelected || AllowSelection)
{
item.Alpha = (float)Interpolation.DampContinuously(item.Alpha, 1, half_time, Clock.ElapsedFrameTime);
item.X = (float)Interpolation.DampContinuously(item.X, 0, half_time, Clock.ElapsedFrameTime);
}
else
{
item.Alpha = (float)Interpolation.DampContinuously(item.Alpha, 0, half_time, Clock.ElapsedFrameTime);
item.X = (float)Interpolation.DampContinuously(item.X, panel_x_offset_when_inactive, half_time, Clock.ElapsedFrameTime);
}
Scroll.ChangeChildDepth(item, hasPassedSelection ? -item.Item.CarouselYPosition : item.Item.CarouselYPosition);
}
if (item is DrawableCarouselBeatmapSet set)
{
for (int i = 0; i < set.DrawableBeatmaps.Count; i++)
updateItem(set.DrawableBeatmaps[i], item);
}
}
}
private static void expirePanelImmediately(DrawableCarouselItem panel)
{
// may want a fade effect here (could be seen if a huge change happens, like a set with 20 difficulties becomes selected).
panel.ClearTransforms();
panel.Expire();
}
private readonly CarouselBoundsItem carouselBoundsItem = new CarouselBoundsItem();
private (int firstIndex, int lastIndex) getDisplayRange()
{
// Find index range of all items that should be on-screen
carouselBoundsItem.CarouselYPosition = visibleUpperBound - distance_offscreen_to_preload;
int firstIndex = visibleItems.BinarySearch(carouselBoundsItem);
if (firstIndex < 0) firstIndex = ~firstIndex;
carouselBoundsItem.CarouselYPosition = visibleBottomBound + distance_offscreen_to_preload;
int lastIndex = visibleItems.BinarySearch(carouselBoundsItem);
if (lastIndex < 0) lastIndex = ~lastIndex;
// as we can't be 100% sure on the size of individual carousel drawables,
// always play it safe and extend bounds by one.
firstIndex = Math.Max(0, firstIndex - 1);
lastIndex = Math.Clamp(lastIndex + 1, firstIndex, Math.Max(0, visibleItems.Count - 1));
return (firstIndex, lastIndex);
}
private CarouselBeatmapSet? createCarouselSet(BeatmapSetInfo beatmapSet)
{
// This can be moved to the realm query if required using:
// .Filter("DeletePending == false && Protected == false && ANY Beatmaps.Hidden == false")
//
// As long as we are detaching though, it makes more sense to do it here as adding to the realm query has an overhead
// as seen at https://github.com/realm/realm-dotnet/discussions/2773#discussioncomment-2004275.
if (beatmapSet.Beatmaps.All(b => b.Hidden))
return null;
var set = new CarouselBeatmapSet(beatmapSet)
{
GetRecommendedBeatmap = beatmaps => GetRecommendedBeatmap?.Invoke(beatmaps)
};
foreach (var c in set.Beatmaps)
{
c.State.ValueChanged += state =>
{
if (state.NewValue == CarouselItemState.Selected)
{
selectedBeatmapSet = set;
SelectionChanged?.Invoke(c.BeatmapInfo);
itemsCache.Invalidate();
ScrollToSelected();
}
};
}
return set;
}
/// <summary>
/// Computes the target Y positions for every item in the carousel.
/// </summary>
/// <returns>The Y position of the currently selected item.</returns>
private void updateYPositions()
{
visibleItems.Clear();
float currentY = visibleHalfHeight;
scrollTarget = null;
foreach (CarouselItem item in root.Items)
{
if (item.Filtered.Value)
continue;
switch (item)
{
case CarouselBeatmapSet set:
{
bool isSelected = item.State.Value == CarouselItemState.Selected;
float padding = isSelected ? 5 : -5;
if (isSelected)
// double padding because we want to cancel the negative padding from the last item.
currentY += padding * 2;
visibleItems.Add(set);
set.CarouselYPosition = currentY;
if (isSelected)
{
// scroll position at currentY makes the set panel appear at the very top of the carousel's screen space
// move down by half of visible height (height of the carousel's visible extent, including semi-transparent areas)
// then reapply the top semi-transparent area (because carousel's screen space starts below it)
scrollTarget = currentY + DrawableCarouselBeatmapSet.HEIGHT - visibleHalfHeight + BleedTop;
foreach (var b in set.Beatmaps)
{
if (!b.Visible)
continue;
if (b.State.Value == CarouselItemState.Selected)
{
scrollTarget += b.TotalHeight / 2;
break;
}
scrollTarget += b.TotalHeight;
}
}
currentY += set.TotalHeight + padding;
break;
}
}
}
currentY += visibleHalfHeight;
Scroll.ScrollContent.Height = currentY;
itemsCache.Validate();
// update and let external consumers know about selection loss.
if (BeatmapSetsLoaded && AllowSelection)
{
bool selectionLost = selectedBeatmapSet != null && selectedBeatmapSet.State.Value != CarouselItemState.Selected;
if (selectionLost)
{
selectedBeatmapSet = null;
SelectionChanged?.Invoke(null);
}
}
}
private bool firstScroll = true;
private void updateScrollPosition()
{
if (scrollTarget != null)
{
if (firstScroll)
{
// reduce movement when first displaying the carousel.
Scroll.ScrollTo(scrollTarget.Value - 200, false);
firstScroll = false;
}
switch (pendingScrollOperation)
{
case PendingScrollOperation.Standard:
Scroll.ScrollTo(scrollTarget.Value);
break;
case PendingScrollOperation.Immediate:
// in order to simplify animation logic, rather than using the animated version of ScrollTo,
// we take the difference in scroll height and apply to all visible panels.
// this avoids edge cases like when the visible panels is reduced suddenly, causing ScrollContainer
// to enter clamp-special-case mode where it animates completely differently to normal.
float scrollChange = scrollTarget.Value - Scroll.Current;
Scroll.ScrollTo(scrollTarget.Value, false);
foreach (var i in Scroll)
i.Y += scrollChange;
break;
}
pendingScrollOperation = PendingScrollOperation.None;
}
}
/// <summary>
/// Computes the x-offset of currently visible items. Makes the carousel appear round.
/// </summary>
/// <param name="dist">
/// Vertical distance from the center of the carousel container
/// ranging from -1 to 1.
/// </param>
/// <param name="halfHeight">Half the height of the carousel container.</param>
private static float offsetX(float dist, float halfHeight)
{
// The radius of the circle the carousel moves on.
const float circle_radius = 3;
float discriminant = MathF.Max(0, circle_radius * circle_radius - dist * dist);
float x = (circle_radius - MathF.Sqrt(discriminant)) * halfHeight;
return 125 + x;
}
/// <summary>
/// Update an item's x position and multiplicative alpha based on its y position and
/// the current scroll position.
/// </summary>
/// <param name="item">The item to be updated.</param>
/// <param name="parent">For nested items, the parent of the item to be updated.</param>
private void updateItem(DrawableCarouselItem item, DrawableCarouselItem? parent = null)
{
Vector2 posInScroll = Scroll.ScrollContent.ToLocalSpace(item.Header.ScreenSpaceDrawQuad.Centre);
float itemDrawY = posInScroll.Y - visibleUpperBound;
float dist = Math.Abs(1f - itemDrawY / visibleHalfHeight);
// adjusting the item's overall X position can cause it to become masked away when
// child items (difficulties) are still visible.
item.Header.X = offsetX(dist, visibleHalfHeight) - (parent?.X ?? 0);
}
private enum PendingScrollOperation
{
None,
Standard,
Immediate,
}
/// <summary>
/// A carousel item strictly used for binary search purposes.
/// </summary>
private class CarouselBoundsItem : CarouselItem
{
public override DrawableCarouselItem CreateDrawableRepresentation() => throw new NotImplementedException();
}
private class CarouselRoot : CarouselGroupEagerSelect
{
// May only be null during construction (State.Value set causes PerformSelection to be triggered).
private readonly BeatmapCarousel? carousel;
public readonly Dictionary<Guid, List<CarouselBeatmapSet>> BeatmapSetsByID = new Dictionary<Guid, List<CarouselBeatmapSet>>();
public CarouselRoot(BeatmapCarousel carousel)
{
// root should always remain selected. if not, PerformSelection will not be called.
State.Value = CarouselItemState.Selected;
State.ValueChanged += _ => State.Value = CarouselItemState.Selected;
this.carousel = carousel;
}
public override void AddItem(CarouselItem i)
{
CarouselBeatmapSet set = (CarouselBeatmapSet)i;
if (BeatmapSetsByID.TryGetValue(set.BeatmapSet.ID, out var sets))
sets.Add(set);
else
BeatmapSetsByID.Add(set.BeatmapSet.ID, new List<CarouselBeatmapSet> { set });
base.AddItem(i);
}
/// <summary>
/// A special method to handle replace operations (general for updating a beatmap).
/// Avoids event-driven selection flip-flopping during the remove/add process.
/// </summary>
/// <param name="oldItem">The beatmap set to be replaced.</param>
/// <param name="newItems">All new items to replace the removed beatmap set.</param>
/// <returns>All removed items, for any further processing.</returns>
public IEnumerable<CarouselBeatmapSet> ReplaceItem(BeatmapSetInfo oldItem, List<CarouselBeatmapSet> newItems)
{
var previousSelection = (LastSelected as CarouselBeatmapSet)?.Beatmaps
.FirstOrDefault(s => s.State.Value == CarouselItemState.Selected)
?.BeatmapInfo;
bool wasSelected = previousSelection?.BeatmapSet?.ID == oldItem.ID;
// Without doing this, the removal of the old beatmap will cause carousel's eager selection
// logic to invoke, causing one unnecessary selection.
DisableSelection = true;
var removedSets = RemoveItemsByID(oldItem.ID);
DisableSelection = false;
foreach (var set in newItems)
AddItem(set);
// Check if we can/need to maintain our current selection.
if (wasSelected)
{
CarouselBeatmap? matchingBeatmap = newItems.SelectMany(s => s.Beatmaps)
.FirstOrDefault(b => b.BeatmapInfo.ID == previousSelection?.ID);
if (matchingBeatmap != null)
matchingBeatmap.State.Value = CarouselItemState.Selected;
}
return removedSets;
}
public IEnumerable<CarouselBeatmapSet> RemoveItemsByID(Guid beatmapSetID)
{
if (BeatmapSetsByID.TryGetValue(beatmapSetID, out var carouselBeatmapSets))
{
foreach (var set in carouselBeatmapSets)
RemoveItem(set);
return carouselBeatmapSets;
}
return Enumerable.Empty<CarouselBeatmapSet>();
}
public override void RemoveItem(CarouselItem i)
{
CarouselBeatmapSet set = (CarouselBeatmapSet)i;
BeatmapSetsByID.Remove(set.BeatmapSet.ID);
base.RemoveItem(i);
}
protected override void PerformSelection()
{
if (LastSelected == null)
carousel?.SelectNextRandom();
else
base.PerformSelection();
}
}
public partial class CarouselScrollContainer : UserTrackingScrollContainer<DrawableCarouselItem>
{
private bool rightMouseScrollBlocked;
public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => true;
public CarouselScrollContainer()
{
// size is determined by the carousel itself, due to not all content necessarily being loaded.
ScrollContent.AutoSizeAxes = Axes.None;
// the scroll container may get pushed off-screen by global screen changes, but we still want panels to display outside of the bounds.
Masking = false;
}
protected override bool OnMouseDown(MouseDownEvent e)
{
if (e.Button == MouseButton.Right)
{
// we need to block right click absolute scrolling when hovering a carousel item so context menus can display.
// this can be reconsidered when we have an alternative to right click scrolling.
if (GetContainingInputManager()!.HoveredDrawables.OfType<DrawableCarouselItem>().Any())
{
rightMouseScrollBlocked = true;
return false;
}
}
rightMouseScrollBlocked = false;
return base.OnMouseDown(e);
}
protected override bool OnDragStart(DragStartEvent e)
{
if (rightMouseScrollBlocked)
return false;
return base.OnDragStart(e);
}
protected override ScrollbarContainer CreateScrollbar(Direction direction)
{
return new PaddedScrollbar();
}
protected partial class PaddedScrollbar : OsuScrollbar
{
public PaddedScrollbar()
: base(Direction.Vertical)
{
}
}
private const float top_padding = 10;
private const float bottom_padding = 70;
protected override float ToScrollbarPosition(float scrollPosition)
{
if (Precision.AlmostEquals(0, ScrollableExtent))
return 0;
return top_padding + (ScrollbarMovementExtent - (top_padding + bottom_padding)) * (scrollPosition / ScrollableExtent);
}
protected override float FromScrollbarPosition(float scrollbarPosition)
{
if (Precision.AlmostEquals(0, ScrollbarMovementExtent))
return 0;
return ScrollableExtent * ((scrollbarPosition - top_padding) / (ScrollbarMovementExtent - (top_padding + bottom_padding)));
}
}
protected override void Dispose(bool isDisposing)
{
base.Dispose(isDisposing);
subscriptionBeatmaps?.Dispose();
}
}
}