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834 lines
32 KiB
C#
834 lines
32 KiB
C#
// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
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// See the LICENCE file in the repository root for full licence text.
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using System;
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using System.Collections.Generic;
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using System.Diagnostics;
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using System.Linq;
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using System.Threading;
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using System.Threading.Tasks;
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using osu.Framework.Bindables;
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using osu.Framework.Caching;
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using osu.Framework.Extensions.TypeExtensions;
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using osu.Framework.Graphics;
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using osu.Framework.Graphics.Containers;
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using osu.Framework.Graphics.Cursor;
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using osu.Framework.Graphics.Pooling;
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using osu.Framework.Input.Bindings;
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using osu.Framework.Input.Events;
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using osu.Framework.Logging;
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using osu.Framework.Utils;
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using osu.Game.Graphics.Containers;
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using osu.Game.Input.Bindings;
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using osuTK;
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using osuTK.Input;
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namespace osu.Game.Screens.SelectV2
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{
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/// <summary>
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/// A highly efficient vertical list display that is used primarily for the song select screen,
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/// but flexible enough to be used for other use cases.
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/// </summary>
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public abstract partial class Carousel<T> : CompositeDrawable, IKeyBindingHandler<GlobalAction>
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where T : notnull
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{
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#region Properties and methods for external usage
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/// <summary>
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/// Height of the area above the carousel that should be treated as visible due to transparency of elements in front of it.
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/// </summary>
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public float BleedTop { get; set; } = 0;
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/// <summary>
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/// Height of the area below the carousel that should be treated as visible due to transparency of elements in front of it.
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/// </summary>
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public float BleedBottom { get; set; } = 0;
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/// <summary>
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/// The number of pixels outside the carousel's vertical bounds to manifest drawables.
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/// This allows preloading content before it scrolls into view.
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/// </summary>
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public float DistanceOffscreenToPreload { get; set; }
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/// <summary>
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/// Vertical space between panel layout. Negative value can be used to create an overlapping effect.
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/// </summary>
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protected float SpacingBetweenPanels { get; set; } = -5;
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/// <summary>
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/// When a new request arrives to change filtering, the number of milliseconds to wait before performing the filter.
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/// Regardless of any external debouncing, this is a safety measure to avoid triggering too many threaded operations.
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/// </summary>
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public int DebounceDelay { get; set; }
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/// <summary>
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/// Whether an asynchronous filter / group operation is currently underway.
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/// </summary>
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public bool IsFiltering => !filterTask.IsCompleted;
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/// <summary>
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/// The number of displayable items currently being tracked (before filtering).
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/// </summary>
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public int ItemsTracked => Items.Count;
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/// <summary>
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/// The number of carousel items currently in rotation for display.
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/// </summary>
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public int DisplayableItems => carouselItems?.Count ?? 0;
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/// <summary>
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/// The number of items currently actualised into drawables.
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/// </summary>
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public int VisibleItems => scroll.Panels.Count;
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/// <summary>
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/// The currently selected model. Generally of type T.
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/// </summary>
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/// <remarks>
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/// A carousel may create panels for non-T types.
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/// To keep things simple, we therefore avoid generic constraints on the current selection.
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///
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/// The selection is never reset due to not existing. It can be set to anything.
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/// If no matching carousel item exists, there will be no visually selected item while waiting for potential new item which matches.
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/// </remarks>
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public object? CurrentSelection
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{
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get => currentSelection.Model;
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set => setSelection(value);
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}
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/// <summary>
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/// Activate the current selection, if a selection exists and matches keyboard selection.
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/// If keyboard selection does not match selection, this will transfer the selection on first invocation.
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/// </summary>
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public void TryActivateSelection()
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{
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if (currentSelection.CarouselItem != currentKeyboardSelection.CarouselItem)
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{
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CurrentSelection = currentKeyboardSelection.Model;
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return;
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}
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if (currentSelection.CarouselItem != null)
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{
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(GetMaterialisedDrawableForItem(currentSelection.CarouselItem) as ICarouselPanel)?.Activated();
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HandleItemActivated(currentSelection.CarouselItem);
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}
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}
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#endregion
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#region Properties and methods concerning implementations
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/// <summary>
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/// A collection of filters which should be run each time a <see cref="FilterAsync"/> is executed.
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/// </summary>
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/// <remarks>
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/// Implementations should add all required filters as part of their initialisation.
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///
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/// Importantly, each filter is sequentially run in the order provided.
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/// Each filter receives the output of the previous filter.
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///
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/// A filter may add, mutate or remove items.
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/// </remarks>
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public IEnumerable<ICarouselFilter> Filters { get; init; } = Enumerable.Empty<ICarouselFilter>();
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/// <summary>
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/// All items which are to be considered for display in this carousel.
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/// Mutating this list will automatically queue a <see cref="FilterAsync"/>.
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/// </summary>
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/// <remarks>
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/// Note that an <see cref="ICarouselFilter"/> may add new items which are displayed but not tracked in this list.
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/// </remarks>
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protected readonly BindableList<T> Items = new BindableList<T>();
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/// <summary>
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/// Queue an asynchronous filter operation.
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/// </summary>
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protected virtual Task FilterAsync() => filterTask = performFilter();
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/// <summary>
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/// Create a drawable for the given carousel item so it can be displayed.
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/// </summary>
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/// <remarks>
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/// For efficiency, it is recommended the drawables are retrieved from a <see cref="DrawablePool{T}"/>.
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/// </remarks>
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/// <param name="item">The item which should be represented by the returned drawable.</param>
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/// <returns>The manifested drawable.</returns>
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protected abstract Drawable GetDrawableForDisplay(CarouselItem item);
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/// <summary>
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/// Given a <see cref="CarouselItem"/>, find a drawable representation if it is currently displayed in the carousel.
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/// </summary>
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/// <remarks>
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/// This will only return a drawable if it is "on-screen".
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/// </remarks>
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/// <param name="item">The item to find a related drawable representation.</param>
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/// <returns>The drawable representation if it exists.</returns>
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protected Drawable? GetMaterialisedDrawableForItem(CarouselItem item) =>
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scroll.Panels.SingleOrDefault(p => ((ICarouselPanel)p).Item == item);
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/// <summary>
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/// When a user is traversing the carousel via group selection keys, assert whether the item provided is a valid target.
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/// </summary>
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/// <param name="item">The candidate item.</param>
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/// <returns>Whether the provided item is a valid group target. If <c>false</c>, more panels will be checked in the user's requested direction until a valid target is found.</returns>
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protected virtual bool CheckValidForGroupSelection(CarouselItem item) => true;
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/// <summary>
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/// Called when an item is "selected".
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/// </summary>
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/// <returns>Whether the item should be selected.</returns>
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protected virtual bool HandleItemSelected(object? model) => true;
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/// <summary>
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/// Called when an item is "deselected".
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/// </summary>
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protected virtual void HandleItemDeselected(object? model)
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{
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}
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/// <summary>
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/// Called when an item is "activated".
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/// </summary>
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/// <remarks>
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/// An activated item should for instance:
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/// - Open or close a folder
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/// - Start gameplay on a beatmap difficulty.
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/// </remarks>
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/// <param name="item">The carousel item which was activated.</param>
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protected virtual void HandleItemActivated(CarouselItem item)
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{
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}
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#endregion
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#region Initialisation
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private readonly CarouselScrollContainer scroll;
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protected Carousel()
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{
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InternalChild = scroll = new CarouselScrollContainer
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{
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RelativeSizeAxes = Axes.Both,
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};
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Items.BindCollectionChanged((_, _) => FilterAsync());
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}
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#endregion
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#region Filtering and display preparation
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private List<CarouselItem>? carouselItems;
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private Task filterTask = Task.CompletedTask;
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private CancellationTokenSource cancellationSource = new CancellationTokenSource();
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private async Task performFilter()
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{
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Debug.Assert(SynchronizationContext.Current != null);
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Stopwatch stopwatch = Stopwatch.StartNew();
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var cts = new CancellationTokenSource();
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lock (this)
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{
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cancellationSource.Cancel();
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cancellationSource = cts;
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}
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if (DebounceDelay > 0)
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{
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log($"Filter operation queued, waiting for {DebounceDelay} ms debounce");
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await Task.Delay(DebounceDelay, cts.Token).ConfigureAwait(true);
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}
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// Copy must be performed on update thread for now (see ConfigureAwait above).
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// Could potentially be optimised in the future if it becomes an issue.
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IEnumerable<CarouselItem> items = new List<CarouselItem>(Items.Select(m => new CarouselItem(m)));
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await Task.Run(async () =>
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{
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try
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{
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foreach (var filter in Filters)
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{
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log($"Performing {filter.GetType().ReadableName()}");
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items = await filter.Run(items, cts.Token).ConfigureAwait(false);
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}
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log("Updating Y positions");
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updateYPositions(items, visibleHalfHeight, SpacingBetweenPanels);
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}
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catch (OperationCanceledException)
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{
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log("Cancelled due to newer request arriving");
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}
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}, cts.Token).ConfigureAwait(true);
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if (cts.Token.IsCancellationRequested)
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return;
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log("Items ready for display");
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carouselItems = items.ToList();
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displayedRange = null;
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// Need to call this to ensure correct post-selection logic is handled on the new items list.
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HandleItemSelected(currentSelection.Model);
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refreshAfterSelection();
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void log(string text) => Logger.Log($"Carousel[op {cts.GetHashCode().ToString()}] {stopwatch.ElapsedMilliseconds} ms: {text}");
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}
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private static void updateYPositions(IEnumerable<CarouselItem> carouselItems, float offset, float spacing)
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{
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foreach (var item in carouselItems)
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updateItemYPosition(item, ref offset, spacing);
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}
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private static void updateItemYPosition(CarouselItem item, ref float offset, float spacing)
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{
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item.CarouselYPosition = offset;
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if (item.IsVisible)
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offset += item.DrawHeight + spacing;
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}
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#endregion
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#region Input handling
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public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
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{
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switch (e.Action)
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{
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case GlobalAction.Select:
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TryActivateSelection();
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return true;
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case GlobalAction.SelectNext:
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traverseKeyboardSelection(1);
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return true;
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case GlobalAction.SelectPrevious:
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traverseKeyboardSelection(-1);
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return true;
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case GlobalAction.SelectNextGroup:
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traverseGroupSelection(1);
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return true;
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case GlobalAction.SelectPreviousGroup:
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traverseGroupSelection(-1);
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return true;
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}
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return false;
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}
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public void OnReleased(KeyBindingReleaseEvent<GlobalAction> e)
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{
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}
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private void traverseKeyboardSelection(int direction)
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{
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if (carouselItems == null || carouselItems.Count == 0) return;
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int originalIndex;
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if (currentKeyboardSelection.Index != null)
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originalIndex = currentKeyboardSelection.Index.Value;
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else if (direction > 0)
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originalIndex = carouselItems.Count - 1;
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else
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originalIndex = 0;
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int newIndex = originalIndex;
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// Iterate over every item back to the current selection, finding the first valid item.
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// The fail condition is when we reach the selection after a cyclic loop over every item.
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do
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{
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newIndex = (newIndex + direction + carouselItems.Count) % carouselItems.Count;
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var newItem = carouselItems[newIndex];
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if (newItem.IsVisible)
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{
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setKeyboardSelection(newItem.Model);
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return;
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}
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} while (newIndex != originalIndex);
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}
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/// <summary>
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/// Select the next valid selection relative to a current selection.
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/// This is generally for keyboard based traversal.
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/// </summary>
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/// <param name="direction">Positive for downwards, negative for upwards.</param>
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/// <returns>Whether selection was possible.</returns>
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private void traverseGroupSelection(int direction)
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{
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if (carouselItems == null || carouselItems.Count == 0) return;
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// If the user has a different keyboard selection and requests
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// group selection, first transfer the keyboard selection to actual selection.
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if (currentSelection.CarouselItem != currentKeyboardSelection.CarouselItem)
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{
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TryActivateSelection();
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// There's a chance this couldn't resolve, at which point continue with standard traversal.
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if (currentSelection.CarouselItem == currentKeyboardSelection.CarouselItem)
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return;
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}
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int originalIndex;
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int newIndex;
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if (currentSelection.Index == null)
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{
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// If there's no current selection, start from either end of the full list.
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newIndex = originalIndex = direction > 0 ? carouselItems.Count - 1 : 0;
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}
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else
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{
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newIndex = originalIndex = currentSelection.Index.Value;
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// As a second special case, if we're group selecting backwards and the current selection isn't a group,
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// make sure to go back to the group header this item belongs to, so that the block below doesn't find it and stop too early.
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if (direction < 0)
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{
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while (!CheckValidForGroupSelection(carouselItems[newIndex]))
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newIndex--;
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}
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}
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// Iterate over every item back to the current selection, finding the first valid item.
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// The fail condition is when we reach the selection after a cyclic loop over every item.
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do
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{
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newIndex = (newIndex + direction + carouselItems.Count) % carouselItems.Count;
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var newItem = carouselItems[newIndex];
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if (CheckValidForGroupSelection(newItem))
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{
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setSelection(newItem.Model);
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return;
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}
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} while (newIndex != originalIndex);
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}
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#endregion
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#region Selection handling
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private readonly Cached selectionValid = new Cached();
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private Selection currentKeyboardSelection = new Selection();
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private Selection currentSelection = new Selection();
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private void setSelection(object? model)
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{
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if (currentSelection.Model == model)
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return;
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if (HandleItemSelected(model))
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{
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if (currentSelection.Model != null)
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HandleItemDeselected(currentSelection.Model);
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currentKeyboardSelection = new Selection(model);
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currentSelection = currentKeyboardSelection;
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}
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selectionValid.Invalidate();
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}
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private void setKeyboardSelection(object? model)
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{
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currentKeyboardSelection = new Selection(model);
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selectionValid.Invalidate();
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}
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/// <summary>
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/// Call after a selection of items change to re-attach <see cref="CarouselItem"/>s to current <see cref="Selection"/>s.
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/// </summary>
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private void refreshAfterSelection()
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{
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float yPos = visibleHalfHeight;
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// Invalidate display range as panel positions and visible status may have changed.
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// Position transfer won't happen unless we invalidate this.
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displayedRange = null;
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// The case where no items are available for display yet.
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if (carouselItems == null)
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{
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currentKeyboardSelection = new Selection();
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currentSelection = new Selection();
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return;
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}
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float spacing = SpacingBetweenPanels;
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int count = carouselItems.Count;
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Selection prevKeyboard = currentKeyboardSelection;
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// We are performing two important operations here:
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// - Update all Y positions. After a selection occurs, panels may have changed visibility state and therefore Y positions.
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// - Link selected models to CarouselItems. If a selection changed, this is where we find the relevant CarouselItems for further use.
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for (int i = 0; i < count; i++)
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{
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var item = carouselItems[i];
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updateItemYPosition(item, ref yPos, spacing);
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if (ReferenceEquals(item.Model, currentKeyboardSelection.Model))
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currentKeyboardSelection = new Selection(item.Model, item, item.CarouselYPosition, i);
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if (ReferenceEquals(item.Model, currentSelection.Model))
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currentSelection = new Selection(item.Model, item, item.CarouselYPosition, i);
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}
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// If a keyboard selection is currently made, we want to keep the view stable around the selection.
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// That means that we should offset the immediate scroll position by any change in Y position for the selection.
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if (prevKeyboard.YPosition != null && currentKeyboardSelection.YPosition != prevKeyboard.YPosition)
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scroll.OffsetScrollPosition((float)(currentKeyboardSelection.YPosition!.Value - prevKeyboard.YPosition.Value));
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}
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private void scrollToSelection()
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{
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if (currentKeyboardSelection.CarouselItem != null)
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scroll.ScrollTo(currentKeyboardSelection.CarouselItem.CarouselYPosition - visibleHalfHeight);
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}
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#endregion
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#region Display handling
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private DisplayRange? displayedRange;
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private readonly CarouselItem carouselBoundsItem = new CarouselItem(new object());
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/// <summary>
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/// The position of the lower visible bound with respect to the current scroll position.
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/// </summary>
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private float visibleBottomBound => (float)(scroll.Current + DrawHeight + BleedBottom);
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/// <summary>
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/// The position of the upper visible bound with respect to the current scroll position.
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/// </summary>
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private float visibleUpperBound => (float)(scroll.Current - BleedTop);
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/// <summary>
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/// Half the height of the visible content.
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/// </summary>
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private float visibleHalfHeight => (DrawHeight + BleedBottom + BleedTop) / 2;
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protected override void Update()
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{
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base.Update();
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if (carouselItems == null)
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return;
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if (!selectionValid.IsValid)
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{
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refreshAfterSelection();
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scrollToSelection();
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selectionValid.Validate();
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}
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var range = getDisplayRange();
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if (range != displayedRange)
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{
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Logger.Log($"Updating displayed range of carousel from {displayedRange} to {range}");
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displayedRange = range;
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updateDisplayedRange(range);
|
|
}
|
|
|
|
foreach (var panel in scroll.Panels)
|
|
{
|
|
var c = (ICarouselPanel)panel;
|
|
|
|
// panel in the process of expiring, ignore it.
|
|
if (c.Item == null)
|
|
continue;
|
|
|
|
if (panel.Depth != c.DrawYPosition)
|
|
scroll.Panels.ChangeChildDepth(panel, (float)c.DrawYPosition);
|
|
|
|
if (c.DrawYPosition != c.Item.CarouselYPosition)
|
|
c.DrawYPosition = Interpolation.DampContinuously(c.DrawYPosition, c.Item.CarouselYPosition, 50, Time.Elapsed);
|
|
|
|
Vector2 posInScroll = scroll.ToLocalSpace(panel.ScreenSpaceDrawQuad.Centre);
|
|
float dist = Math.Abs(1f - posInScroll.Y / visibleHalfHeight);
|
|
|
|
panel.X = offsetX(dist, visibleHalfHeight);
|
|
|
|
c.Selected.Value = c.Item == currentSelection?.CarouselItem;
|
|
c.KeyboardSelected.Value = c.Item == currentKeyboardSelection?.CarouselItem;
|
|
}
|
|
}
|
|
|
|
/// <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);
|
|
return (circle_radius - MathF.Sqrt(discriminant)) * halfHeight;
|
|
}
|
|
|
|
private DisplayRange getDisplayRange()
|
|
{
|
|
Debug.Assert(carouselItems != null);
|
|
|
|
// Find index range of all items that should be on-screen
|
|
carouselBoundsItem.CarouselYPosition = visibleUpperBound - DistanceOffscreenToPreload;
|
|
int firstIndex = carouselItems.BinarySearch(carouselBoundsItem);
|
|
if (firstIndex < 0) firstIndex = ~firstIndex;
|
|
|
|
carouselBoundsItem.CarouselYPosition = visibleBottomBound + DistanceOffscreenToPreload;
|
|
int lastIndex = carouselItems.BinarySearch(carouselBoundsItem);
|
|
if (lastIndex < 0) lastIndex = ~lastIndex;
|
|
|
|
firstIndex = Math.Max(0, firstIndex - 1);
|
|
lastIndex = Math.Max(0, lastIndex - 1);
|
|
|
|
return new DisplayRange(firstIndex, lastIndex);
|
|
}
|
|
|
|
private void updateDisplayedRange(DisplayRange range)
|
|
{
|
|
Debug.Assert(carouselItems != null);
|
|
|
|
List<CarouselItem> toDisplay = range.Last - range.First == 0
|
|
? new List<CarouselItem>()
|
|
: carouselItems.GetRange(range.First, range.Last - range.First + 1);
|
|
|
|
toDisplay.RemoveAll(i => !i.IsVisible);
|
|
|
|
// Iterate over all panels which are already displayed and figure which need to be displayed / removed.
|
|
foreach (var panel in scroll.Panels)
|
|
{
|
|
var carouselPanel = (ICarouselPanel)panel;
|
|
|
|
// The case where we're intending to display this panel, but it's already displayed.
|
|
// Note that we **must compare the model here** as the CarouselItems may be fresh instances due to a filter operation.
|
|
var existing = toDisplay.FirstOrDefault(i => i.Model == carouselPanel.Item!.Model);
|
|
|
|
if (existing != null)
|
|
{
|
|
carouselPanel.Item = existing;
|
|
toDisplay.Remove(existing);
|
|
continue;
|
|
}
|
|
|
|
// If the new display range doesn't contain the panel, it's no longer required for display.
|
|
expirePanelImmediately(panel);
|
|
}
|
|
|
|
// Add any new items which need to be displayed and haven't yet.
|
|
foreach (var item in toDisplay)
|
|
{
|
|
var drawable = GetDrawableForDisplay(item);
|
|
|
|
if (drawable is not ICarouselPanel carouselPanel)
|
|
throw new InvalidOperationException($"Carousel panel drawables must implement {typeof(ICarouselPanel)}");
|
|
|
|
carouselPanel.DrawYPosition = item.CarouselYPosition;
|
|
carouselPanel.Item = item;
|
|
|
|
scroll.Add(drawable);
|
|
}
|
|
|
|
// Update the total height of all items (to make the scroll container scrollable through the full height even though
|
|
// most items are not displayed / loaded).
|
|
if (carouselItems.Count > 0)
|
|
{
|
|
var lastItem = carouselItems[^1];
|
|
scroll.SetLayoutHeight((float)(lastItem.CarouselYPosition + lastItem.DrawHeight + visibleHalfHeight));
|
|
}
|
|
else
|
|
scroll.SetLayoutHeight(0);
|
|
}
|
|
|
|
private static void expirePanelImmediately(Drawable panel)
|
|
{
|
|
panel.FinishTransforms();
|
|
panel.Expire();
|
|
|
|
var carouselPanel = (ICarouselPanel)panel;
|
|
|
|
carouselPanel.Item = null;
|
|
carouselPanel.Selected.Value = false;
|
|
carouselPanel.KeyboardSelected.Value = false;
|
|
}
|
|
|
|
#endregion
|
|
|
|
#region Internal helper classes
|
|
|
|
/// <summary>
|
|
/// Bookkeeping for a current selection.
|
|
/// </summary>
|
|
/// <param name="Model">The selected model. If <c>null</c>, there's no selection.</param>
|
|
/// <param name="CarouselItem">A related carousel item representation for the model. May be null if selection is not present as an item, or if <see cref="Carousel{T}.refreshAfterSelection"/> has not been run yet.</param>
|
|
/// <param name="YPosition">The Y position of the selection as of the last run of <see cref="Carousel{T}.refreshAfterSelection"/>. May be null if selection is not present as an item, or if <see cref="Carousel{T}.refreshAfterSelection"/> has not been run yet.</param>
|
|
/// <param name="Index">The index of the selection as of the last run of <see cref="Carousel{T}.refreshAfterSelection"/>. May be null if selection is not present as an item, or if <see cref="Carousel{T}.refreshAfterSelection"/> has not been run yet.</param>
|
|
private record Selection(object? Model = null, CarouselItem? CarouselItem = null, double? YPosition = null, int? Index = null);
|
|
|
|
private record DisplayRange(int First, int Last);
|
|
|
|
/// <summary>
|
|
/// Implementation of scroll container which handles very large vertical lists by internally using <c>double</c> precision
|
|
/// for pre-display Y values.
|
|
/// </summary>
|
|
private partial class CarouselScrollContainer : UserTrackingScrollContainer, IKeyBindingHandler<GlobalAction>
|
|
{
|
|
public readonly Container Panels;
|
|
|
|
public void SetLayoutHeight(float height) => Panels.Height = height;
|
|
|
|
public CarouselScrollContainer()
|
|
{
|
|
// Managing our own custom layout within ScrollContent causes feedback with public ScrollContainer calculations,
|
|
// so we must maintain one level of separation from ScrollContent.
|
|
base.Add(Panels = new Container
|
|
{
|
|
Name = "Layout content",
|
|
RelativeSizeAxes = Axes.X,
|
|
});
|
|
}
|
|
|
|
public override void OffsetScrollPosition(double offset)
|
|
{
|
|
base.OffsetScrollPosition(offset);
|
|
|
|
foreach (var panel in Panels)
|
|
{
|
|
var c = (ICarouselPanel)panel;
|
|
Debug.Assert(c.Item != null);
|
|
|
|
c.DrawYPosition += offset;
|
|
}
|
|
}
|
|
|
|
public override void Clear(bool disposeChildren)
|
|
{
|
|
Panels.Height = 0;
|
|
Panels.Clear(disposeChildren);
|
|
}
|
|
|
|
public override void Add(Drawable drawable)
|
|
{
|
|
if (drawable is not ICarouselPanel)
|
|
throw new InvalidOperationException($"Carousel panel drawables must implement {typeof(ICarouselPanel)}");
|
|
|
|
Panels.Add(drawable);
|
|
}
|
|
|
|
public override double GetChildPosInContent(Drawable d, Vector2 offset)
|
|
{
|
|
if (d is not ICarouselPanel panel)
|
|
return base.GetChildPosInContent(d, offset);
|
|
|
|
return panel.DrawYPosition + offset.X;
|
|
}
|
|
|
|
protected override void ApplyCurrentToContent()
|
|
{
|
|
Debug.Assert(ScrollDirection == Direction.Vertical);
|
|
|
|
double scrollableExtent = -Current + ScrollableExtent * ScrollContent.RelativeAnchorPosition.Y;
|
|
|
|
foreach (var d in Panels)
|
|
d.Y = (float)(((ICarouselPanel)d).DrawYPosition + scrollableExtent);
|
|
}
|
|
|
|
#region Absolute scrolling
|
|
|
|
private bool absoluteScrolling;
|
|
|
|
protected override bool IsDragging => base.IsDragging || absoluteScrolling;
|
|
|
|
public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
|
|
{
|
|
switch (e.Action)
|
|
{
|
|
case GlobalAction.AbsoluteScrollSongList:
|
|
beginAbsoluteScrolling(e);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
public void OnReleased(KeyBindingReleaseEvent<GlobalAction> e)
|
|
{
|
|
switch (e.Action)
|
|
{
|
|
case GlobalAction.AbsoluteScrollSongList:
|
|
endAbsoluteScrolling();
|
|
break;
|
|
}
|
|
}
|
|
|
|
protected override bool OnMouseDown(MouseDownEvent e)
|
|
{
|
|
if (e.Button == MouseButton.Right)
|
|
{
|
|
// To avoid conflicts with context menus, disallow absolute scroll if it looks like things will fall over.
|
|
if (GetContainingInputManager()!.HoveredDrawables.OfType<IHasContextMenu>().Any())
|
|
return false;
|
|
|
|
beginAbsoluteScrolling(e);
|
|
}
|
|
|
|
return base.OnMouseDown(e);
|
|
}
|
|
|
|
protected override void OnMouseUp(MouseUpEvent e)
|
|
{
|
|
if (e.Button == MouseButton.Right)
|
|
endAbsoluteScrolling();
|
|
base.OnMouseUp(e);
|
|
}
|
|
|
|
protected override bool OnMouseMove(MouseMoveEvent e)
|
|
{
|
|
if (absoluteScrolling)
|
|
{
|
|
ScrollToAbsolutePosition(e.CurrentState.Mouse.Position);
|
|
return true;
|
|
}
|
|
|
|
return base.OnMouseMove(e);
|
|
}
|
|
|
|
private void beginAbsoluteScrolling(UIEvent e)
|
|
{
|
|
ScrollToAbsolutePosition(e.CurrentState.Mouse.Position);
|
|
absoluteScrolling = true;
|
|
}
|
|
|
|
private void endAbsoluteScrolling() => absoluteScrolling = false;
|
|
|
|
#endregion
|
|
}
|
|
|
|
#endregion
|
|
}
|
|
}
|