osu-lazer/osu.Game/Overlays/Settings/SettingsItem.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 System.Collections.Generic;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Cursor;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Graphics.UserInterface;
using osu.Framework.Localisation;
using osu.Game.Graphics;
using osu.Game.Graphics.Sprites;
using osu.Game.Graphics.Containers;
using osuTK;

namespace osu.Game.Overlays.Settings
{
    public abstract class SettingsItem<T> : Container, IFilterable, ISettingsItem, IHasCurrentValue<T>, IHasTooltip
    {
        protected abstract Drawable CreateControl();

        protected Drawable Control { get; }

        private IHasCurrentValue<T> controlWithCurrent => Control as IHasCurrentValue<T>;

        protected override Container<Drawable> Content => FlowContent;

        protected readonly FillFlowContainer FlowContent;

        private SpriteText label;

        private OsuTextFlowContainer warningText;

        public bool ShowsDefaultIndicator = true;
        private readonly Container defaultValueIndicatorContainer;

        public LocalisableString TooltipText { get; set; }

        [Resolved]
        private OsuColour colours { get; set; }

        private LocalisableString labelText;

        public virtual LocalisableString LabelText
        {
            get => labelText;
            set
            {
                ensureLabelCreated();

                labelText = value;
                updateLabelText();
            }
        }

        private LocalisableString? contractedLabelText;

        /// <summary>
        /// Text to be displayed in place of <see cref="LabelText"/> when this <see cref="SettingsItem{T}"/> is in a contracted state.
        /// </summary>
        public LocalisableString? ContractedLabelText
        {
            get => contractedLabelText;
            set
            {
                ensureLabelCreated();

                contractedLabelText = value;
                updateLabelText();
            }
        }

        /// <summary>
        /// Text to be displayed at the bottom of this <see cref="SettingsItem{T}"/>.
        /// Generally used to recommend the user change their setting as the current one is considered sub-optimal.
        /// </summary>
        public LocalisableString? WarningText
        {
            set
            {
                bool hasValue = value != default;

                if (warningText == null)
                {
                    if (!hasValue)
                        return;

                    // construct lazily for cases where the label is not needed (may be provided by the Control).
                    FlowContent.Add(warningText = new SettingsNoticeText(colours) { Margin = new MarginPadding { Bottom = 5 } });
                }

                warningText.Alpha = hasValue ? 1 : 0;
                warningText.Text = value ?? default;
            }
        }

        public virtual Bindable<T> Current
        {
            get => controlWithCurrent.Current;
            set => controlWithCurrent.Current = value;
        }

        public BindableBool Expanded { get; } = new BindableBool(true);

        public bool IsControlDragged => Control.IsDragged;

        public event Action SettingChanged;

        public virtual IEnumerable<string> FilterTerms => Keywords == null ? new[] { LabelText.ToString() } : new List<string>(Keywords) { LabelText.ToString() }.ToArray();

        public IEnumerable<string> Keywords { get; set; }

        public bool MatchingFilter
        {
            set => Alpha = value ? 1 : 0;
        }

        public bool FilteringActive { get; set; }

        protected SettingsItem()
        {
            RelativeSizeAxes = Axes.X;
            AutoSizeAxes = Axes.Y;
            Padding = new MarginPadding { Right = SettingsPanel.CONTENT_MARGINS };

            InternalChildren = new Drawable[]
            {
                defaultValueIndicatorContainer = new Container
                {
                    Width = SettingsPanel.CONTENT_MARGINS,
                },
                new Container
                {
                    RelativeSizeAxes = Axes.X,
                    AutoSizeAxes = Axes.Y,
                    Padding = new MarginPadding { Left = SettingsPanel.CONTENT_MARGINS },
                    Child = FlowContent = new FillFlowContainer
                    {
                        RelativeSizeAxes = Axes.X,
                        AutoSizeAxes = Axes.Y,
                        Spacing = new Vector2(0, 10),
                        Child = Control = CreateControl(),
                    }
                }
            };

            // IMPORTANT: all bindable logic is in constructor intentionally to support "CreateSettingsControls" being used in a context it is
            // never loaded, but requires bindable storage.
            if (controlWithCurrent == null)
                throw new ArgumentException(@$"Control created via {nameof(CreateControl)} must implement {nameof(IHasCurrentValue<T>)}");

            controlWithCurrent.Current.ValueChanged += _ => SettingChanged?.Invoke();
            controlWithCurrent.Current.DisabledChanged += _ => updateDisabled();
        }

        [BackgroundDependencyLoader]
        private void load()
        {
            // intentionally done before LoadComplete to avoid overhead.
            if (ShowsDefaultIndicator)
            {
                defaultValueIndicatorContainer.Add(new RestoreDefaultValueButton<T>
                {
                    Current = controlWithCurrent.Current,
                    Anchor = Anchor.Centre,
                    Origin = Anchor.Centre
                });
            }
        }

        [Resolved(canBeNull: true)]
        private IExpandingContainer expandingContainer { get; set; }

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

            expandingContainer?.Expanded.BindValueChanged(containerExpanded => Expanded.Value = containerExpanded.NewValue, true);

            Expanded.BindValueChanged(v =>
            {
                updateLabelText();

                Control.FadeTo(v.NewValue ? 1 : 0, 500, Easing.OutQuint);
                Control.BypassAutoSizeAxes = v.NewValue ? Axes.None : Axes.Both;
            }, true);

            FinishTransforms(true);
        }

        private void ensureLabelCreated()
        {
            if (label != null)
                return;

            // construct lazily for cases where the label is not needed (may be provided by the Control).
            FlowContent.Insert(-1, label = new OsuSpriteText());

            updateDisabled();
        }

        private void updateLabelText()
        {
            if (label != null)
            {
                if (contractedLabelText is LocalisableString contractedText)
                    label.Text = Expanded.Value ? labelText : contractedText;
                else
                    label.Text = labelText;
            }

            // if the settings item is providing a non-empty label, the default value indicator should be centred vertically to the left of the label.
            // otherwise, it should be centred vertically to the left of the main control of the settings item.
            defaultValueIndicatorContainer.Height = !string.IsNullOrEmpty(label?.Text.ToString()) ? label.DrawHeight : Control.DrawHeight;
        }

        private void updateDisabled()
        {
            if (label != null)
                label.Alpha = controlWithCurrent.Current.Disabled ? 0.3f : 1;
        }
    }
}