Babushka/scripts/CSharp/Common/Inventory/InventoryUi.cs

using Godot;

namespace Babushka.scripts.CSharp.Common.Inventory;

public partial class InventoryUi : Control
{
    private GridContainer _slots;
    private InventoryInstance _playerInventory;

    private int? _slotOnMouse;

    public override void _Ready()
    {
        GD.Print("Ready inventory ui");
        _slots = GetNode<GridContainer>("Slots");
        _playerInventory = InventoryManager.Instance.playerInventory;
        PopulateSlots();
        SetSlotContent();
    }

    public override void _ExitTree()
    {
        UnsubscribeSlots();
    }

    private void SetSlotContent()
    {
        for (var i = 0; i < _playerInventory.Slots.Count; i++)
        {
            var inventorySlot = _playerInventory.Slots[i];
            var uiSlot = _slots.GetChild(i) as SlotUi;

            uiSlot!.nameLabel.Text = inventorySlot.itemInstance?.blueprint.name ?? "";
            uiSlot!.nameLabel.LabelSettings = uiSlot!.nameLabel.LabelSettings.Duplicate() as LabelSettings;
            uiSlot!.nameLabel.LabelSettings!.FontColor = inventorySlot.itemInstance?.blueprint.color ?? Colors.White;
        }
    }

    private void PopulateSlots()
    {
        var slotPackedScene = GD.Load<PackedScene>("res://prefabs/UI/Inventory/Slot.tscn");
        for (var index = 0; index < _playerInventory.Slots.Count; index++)
        {
            var slotInstance = slotPackedScene.Instantiate<SlotUi>();
            slotInstance.index = index;
            slotInstance.Clicked += SlotClicked;
            _slots.AddChild(slotInstance);
        }
    }

    private void UnsubscribeSlots()
    {
        for (var index = 0; index < _playerInventory.Slots.Count; index++)
        {
            var slotInstance = _slots.GetChild(index) as SlotUi;
            slotInstance!.Clicked -= SlotClicked;
        }
    }

    private void SlotClicked(int index)
    {
        GD.Print($"Clicked slot {index}");
        if (_slotOnMouse == null)
        {
            _slotOnMouse = index;
            GD.Print($"Slot on mouse: {_slotOnMouse}");
        }
        else
        {
            var sourceSlot = _slotOnMouse.Value;
            var destinationSlot = index;
            InventoryManager.Instance.MoveItem(_playerInventory, sourceSlot, _playerInventory, destinationSlot);
            _slotOnMouse = null;
            SetSlotContent();
        }
    }
}