ichni_Official/Assets/Scripts/UI/SongSelection/SongSelectionUIPage.cs

using DG.Tweening;
using Ichni.RhythmGame;
using Ichni.UI;
using UnityEngine.Events;
using UnityEngine.UI;
using UnityEngine.UI.Extensions;

namespace Ichni.Menu
{
    public partial class SongSelectionUIPage : UIPageBase
    {
        public Button backButton;
        
        public Gradient2 backgroundFrames;
        public float framePositionOffset = -1;
        
        public SongListControllerUI songListController;
        public PlaySongUI playSongUI;
        public SongInfoUI songInfoUI;
        public DifficultySelectionContainer difficultySelectionContainer;
        //public int currentSelectedDifficultyIndex;

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

            fadeOutAction = () =>
            {
                songListController.ClearSongTabs();
                MenuInputManager.OnMoveUp -= songListController.GoToFormerTab;
                MenuInputManager.OnMoveDown -= songListController.GoToNextTab;
            };

            fadeInStartAction = () =>
            {
                songListController.InitializeList();
            };

            fadeInFinishAction = () =>
            {
                MenuInputManager.OnMoveUp += songListController.GoToFormerTab;
                MenuInputManager.OnMoveDown += songListController.GoToNextTab;
            };
            
            backButton.onClick.AddListener(() =>
            {
                FadeOut();
                MenuManager.instance.chapterSelectionUIPage.FadeIn();
                MenuAudioManager.instance.audioContainer.StopEvent("PlayPreview");
            });
            
            songInfoUI.SetUp();
        }

        private void Start()
        {
            MenuInformationRecorder.instance.GetRecordOfThisChapter().difficultyIndex = 0;
            
            Sequence framesSeq = DOTween.Sequence();
            framesSeq.Append(DOTween.To(() => framePositionOffset, x => framePositionOffset = x, 1f, 1f)
                    .SetEase(Ease.Linear)
                    .OnUpdate(() => backgroundFrames.Offset = framePositionOffset));
            framesSeq.AppendInterval(4f);
            framesSeq.SetLoops(-1, LoopType.Restart);
            framesSeq.Play();
        }
    }

    public partial class SongSelectionUIPage
    {
        public SongItemData selectedSong;
        public DifficultyData selectedDifficulty;
        public SongStatusSave selectedSave;
    }
}