osu-lazer/osu.Game/Screens/OsuScreen.cs

// 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 Microsoft.EntityFrameworkCore.Internal;
using osu.Framework.Allocation;
using osu.Framework.Audio;
using osu.Framework.Audio.Sample;
using osu.Framework.Configuration;
using osu.Framework.Graphics;
using osu.Framework.Input.Bindings;
using osu.Framework.Screens;
using osu.Game.Beatmaps;
using osu.Game.Input.Bindings;
using osu.Game.Rulesets;
using osu.Game.Screens.Menu;
using osu.Game.Overlays;

namespace osu.Game.Screens
{
    public abstract class OsuScreen : Screen, IOsuScreen, IKeyBindingHandler<GlobalAction>, IHasDescription
    {
        /// <summary>
        /// The amount of negative padding that should be applied to game background content which touches both the left and right sides of the screen.
        /// This allows for the game content to be pushed byt he options/notification overlays without causing black areas to appear.
        /// </summary>
        public const float HORIZONTAL_OVERFLOW_PADDING = 50;

        /// <summary>
        /// A user-facing title for this screen.
        /// </summary>
        public virtual string Title => GetType().ShortDisplayName();

        public string Description => Title;

        protected virtual bool AllowBackButton => true;

        public virtual bool AllowExternalScreenChange => false;

        /// <summary>
        /// Whether all overlays should be hidden when this screen is entered or resumed.
        /// </summary>
        public virtual bool HideOverlaysOnEnter => false;

        /// <summary>
        /// Whether overlays should be able to be opened once this screen is entered or resumed.
        /// </summary>
        public virtual OverlayActivation InitialOverlayActivationMode => OverlayActivation.All;

        public virtual bool CursorVisible => true;

        protected new OsuGameBase Game => base.Game as OsuGameBase;


        /// <summary>
        /// Disallow changes to game-wise Beatmap/Ruleset bindables for this screen (and all children).
        /// </summary>
        public virtual bool DisallowExternalBeatmapRulesetChanges => false;

        private SampleChannel sampleExit;

        public virtual float BackgroundParallaxAmount => 1;

        public Bindable<WorkingBeatmap> Beatmap => screenDependencies.Beatmap;

        public Bindable<RulesetInfo> Ruleset => screenDependencies.Ruleset;

        private OsuScreenDependencies screenDependencies;

        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent) => screenDependencies = new OsuScreenDependencies(DisallowExternalBeatmapRulesetChanges, base.CreateChildDependencies(parent));

        protected BackgroundScreen Background => backgroundStack?.CurrentScreen as BackgroundScreen;

        private BackgroundScreen localBackground;

        [Resolved(canBeNull: true)]
        private BackgroundScreenStack backgroundStack { get; set; }

        [Resolved(canBeNull: true)]
        private OsuLogo logo { get; set; }

        protected OsuScreen()
        {
            Anchor = Anchor.Centre;
            Origin = Anchor.Centre;
        }

        [BackgroundDependencyLoader(true)]
        private void load(OsuGame osu, AudioManager audio)
        {
            sampleExit = audio.Sample.Get(@"UI/screen-back");
        }

        public virtual bool OnPressed(GlobalAction action)
        {
            if (!this.IsCurrentScreen()) return false;

            if (action == GlobalAction.Back && AllowBackButton)
            {
                this.Exit();
                return true;
            }

            return false;
        }

        public bool OnReleased(GlobalAction action) => action == GlobalAction.Back && AllowBackButton;

        public override void OnResuming(IScreen last)
        {
            sampleExit?.Play();
            applyArrivingDefaults(true);

            base.OnResuming(last);
        }

        public override void OnSuspending(IScreen next)
        {
            base.OnSuspending(next);
            onSuspendingLogo();
        }

        public override void OnEntering(IScreen last)
        {
            applyArrivingDefaults(false);

            backgroundStack?.Push(localBackground = CreateBackground());

            base.OnEntering(last);
        }

        public override bool OnExiting(IScreen next)
        {
            if (ValidForResume && logo != null)
                onExitingLogo();

            if (base.OnExiting(next))
                return true;

            if (localBackground != null && backgroundStack?.CurrentScreen == localBackground)
                backgroundStack?.Exit();

            screenDependencies.Dispose();

            return false;
        }

        /// <summary>
        /// Fired when this screen was entered or resumed and the logo state is required to be adjusted.
        /// </summary>
        protected virtual void LogoArriving(OsuLogo logo, bool resuming)
        {
            ApplyLogoArrivingDefaults(logo);
        }

        private void applyArrivingDefaults(bool isResuming)
        {
            logo?.AppendAnimatingAction(() =>
            {
                if (this.IsCurrentScreen()) LogoArriving(logo, isResuming);
            }, true);
        }

        /// <summary>
        /// Applies default animations to an arriving logo.
        /// Todo: This should not exist.
        /// </summary>
        /// <param name="logo">The logo to apply animations to.</param>
        public static void ApplyLogoArrivingDefaults(OsuLogo logo)
        {
            logo.Action = null;
            logo.FadeOut(300, Easing.OutQuint);
            logo.Anchor = Anchor.TopLeft;
            logo.Origin = Anchor.Centre;
            logo.RelativePositionAxes = Axes.None;
            logo.BeatMatching = true;
            logo.Triangles = true;
            logo.Ripple = true;
        }

        private void onExitingLogo()
        {
            logo?.AppendAnimatingAction(() => LogoExiting(logo), false);
        }

        /// <summary>
        /// Fired when this screen was exited to add any outwards transition to the logo.
        /// </summary>
        protected virtual void LogoExiting(OsuLogo logo)
        {
        }

        private void onSuspendingLogo()
        {
            logo?.AppendAnimatingAction(() => LogoSuspending(logo), false);
        }

        /// <summary>
        /// Fired when this screen was suspended to add any outwards transition to the logo.
        /// </summary>
        protected virtual void LogoSuspending(OsuLogo logo)
        {
        }

        /// <summary>
        /// Override to create a BackgroundMode for the current screen.
        /// Note that the instance created may not be the used instance if it matches the BackgroundMode equality clause.
        /// </summary>
        protected virtual BackgroundScreen CreateBackground() => null;
    }

    public class OsuScreenDependencies : DependencyContainer, IDisposable
    {
        private readonly bool leaseOwner;

        public Bindable<WorkingBeatmap> Beatmap { get; private set; }

        public Bindable<RulesetInfo> Ruleset { get; private set; }

        public OsuScreenDependencies(bool requireLease, IReadOnlyDependencyContainer parent)
            : base(parent)
        {
            if (requireLease)
            {
                Beatmap = parent.Get<LeasedBindable<WorkingBeatmap>>()?.GetBoundCopy();
                if (Beatmap == null)
                {
                    leaseOwner = true;
                    Cache(Beatmap = parent.Get<Bindable<WorkingBeatmap>>().BeginLease(true));
                }

                Ruleset = parent.Get<LeasedBindable<RulesetInfo>>()?.GetBoundCopy();
                if (Ruleset == null)
                {
                    leaseOwner = true;
                    Cache(Ruleset = parent.Get<Bindable<RulesetInfo>>().BeginLease(true));
                }
            }
            else
            {
                Beatmap = (parent.Get<LeasedBindable<WorkingBeatmap>>() ?? parent.Get<Bindable<WorkingBeatmap>>()).GetBoundCopy();
                Ruleset = (parent.Get<LeasedBindable<RulesetInfo>>() ?? parent.Get<Bindable<RulesetInfo>>()).GetBoundCopy();
            }
        }

        public void Dispose()
        {
            if (leaseOwner)
            {
                ((LeasedBindable<WorkingBeatmap>)Beatmap).Return();
                ((LeasedBindable<RulesetInfo>)Ruleset).Return();
            }
            else
            {
                Beatmap.UnbindAll();
                Ruleset.UnbindAll();
            }
        }
    }
}