osu/osu.Game.Rulesets.Mania/UI/Components/ColumnHitObjectArea.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 osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Extensions.Color4Extensions;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Effects;
using osu.Framework.Graphics.Shapes;
using osu.Game.Graphics;
using osu.Game.Rulesets.Mania.Objects.Drawables.Pieces;
using osu.Game.Rulesets.UI;
using osu.Game.Rulesets.UI.Scrolling;
using osuTK.Graphics;

namespace osu.Game.Rulesets.Mania.UI.Components
{
    public class ColumnHitObjectArea : CompositeDrawable, IHasAccentColour
    {
        private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();

        private readonly Drawable hitTarget;

        public ColumnHitObjectArea(HitObjectContainer hitObjectContainer)
        {
            InternalChildren = new[]
            {
                hitTarget = new DefaultHitTarget
                {
                    RelativeSizeAxes = Axes.X,
                },
                hitObjectContainer
            };
        }

        [BackgroundDependencyLoader]
        private void load(IScrollingInfo scrollingInfo)
        {
            direction.BindTo(scrollingInfo.Direction);
            direction.BindValueChanged(dir =>
            {
                Anchor anchor = dir.NewValue == ScrollingDirection.Up ? Anchor.TopLeft : Anchor.BottomLeft;

                hitTarget.Anchor = hitTarget.Origin = anchor;
            }, true);
        }

        private Color4 accentColour;

        public Color4 AccentColour
        {
            get => accentColour;
            set
            {
                if (accentColour == value)
                    return;

                accentColour = value;

                if (hitTarget is IHasAccentColour colouredHitTarget)
                    colouredHitTarget.AccentColour = accentColour;
            }
        }

        private class DefaultHitTarget : CompositeDrawable, IHasAccentColour
        {
            private const float hit_target_bar_height = 2;

            private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();

            private readonly Container hitTargetLine;
            private readonly Drawable hitTargetBar;

            public DefaultHitTarget()
            {
                InternalChildren = new[]
                {
                    hitTargetBar = new Box
                    {
                        RelativeSizeAxes = Axes.X,
                        Height = NotePiece.NOTE_HEIGHT,
                        Alpha = 0.6f,
                        Colour = Color4.Black
                    },
                    hitTargetLine = new Container
                    {
                        RelativeSizeAxes = Axes.X,
                        Height = hit_target_bar_height,
                        Masking = true,
                        Child = new Box { RelativeSizeAxes = Axes.Both }
                    },
                };
            }

            [BackgroundDependencyLoader]
            private void load(IScrollingInfo scrollingInfo)
            {
                direction.BindTo(scrollingInfo.Direction);
                direction.BindValueChanged(dir =>
                {
                    Anchor anchor = dir.NewValue == ScrollingDirection.Up ? Anchor.TopLeft : Anchor.BottomLeft;

                    hitTargetBar.Anchor = hitTargetBar.Origin = anchor;
                    hitTargetLine.Anchor = hitTargetLine.Origin = anchor;
                }, true);
            }

            protected override void LoadComplete()
            {
                base.LoadComplete();
                updateColours();
            }

            private Color4 accentColour;

            public Color4 AccentColour
            {
                get => accentColour;
                set
                {
                    if (accentColour == value)
                        return;

                    accentColour = value;

                    updateColours();
                }
            }

            private void updateColours()
            {
                if (!IsLoaded)
                    return;

                hitTargetLine.EdgeEffect = new EdgeEffectParameters
                {
                    Type = EdgeEffectType.Glow,
                    Radius = 5,
                    Colour = accentColour.Opacity(0.5f),
                };
            }
        }
    }
}