로블록스 커스텀 핫바 아키텍처: 드래그 앤 드롭 고스트, 포인터 이벤트 및 모바일 터치 UX

--!strict
local UserInputService = game:GetService("UserInputService")
local RunService = game:GetService("RunService")
local TweenService = game:GetService("TweenService")
local Players = game:GetService("Players")

local DragController = {}
DragController.__index = DragController

local player = Players.LocalPlayer
local playerGui = player:WaitForChild("PlayerGui") :: PlayerGui

export type SlotData = {
    Frame: Frame,
    SlotIndex: number,
    ItemId: string?,
    Count: number
}

local registeredSlots: { [Frame]: SlotData } = {}
local activeDrag: {
    SourceSlot: SlotData,
    Ghost: ImageLabel,
    StartPos: Vector2,
    IsDragging: boolean
}? = nil

function DragController.RegisterSlot(frame: Frame, slotIndex: number, itemId: string?, count: number)
    registeredSlots[frame] = {
        Frame = frame,
        SlotIndex = slotIndex,
        ItemId = itemId,
        Count = count
    }

    frame.InputBegan:Connect(function(input: InputObject)
        if input.UserInputType == Enum.UserInputType.MouseButton1 or input.UserInputType == Enum.UserInputType.Touch then
            DragController.StartDrag(frame, input.Position)
        end
    end)
end

function DragController.StartDrag(slotFrame: Frame, inputPos: Vector3)
    local data = registeredSlots[slotFrame]
    if not data or not data.ItemId then return end

    local icon = slotFrame:FindFirstChild("ItemIcon") :: ImageLabel?
    if not icon then return end

    local ghost = icon:Clone()
    ghost.Size = UDim2.new(0, icon.AbsoluteSize.X * 1.1, 0, icon.AbsoluteSize.Y * 1.1)
    ghost.Position = UDim2.new(0, inputPos.X, 0, inputPos.Y)
    ghost.AnchorPoint = Vector2.new(0.5, 0.5)
    ghost.ZIndex = 100
    ghost.Active = false
    ghost.Parent = playerGui:FindFirstChildOfClass("ScreenGui")

    activeDrag = {
        SourceSlot = data,
        Ghost = ghost,
        StartPos = Vector2.new(inputPos.X, inputPos.Y),
        IsDragging = true
    }
end

UserInputService.InputChanged:Connect(function(input: InputObject)
    if activeDrag and activeDrag.IsDragging then
        if input.UserInputType == Enum.UserInputType.MouseMovement or input.UserInputType == Enum.UserInputType.Touch then
            activeDrag.Ghost.Position = UDim2.new(0, input.Position.X, 0, input.Position.Y)
        end
    end
end)

UserInputService.InputEnded:Connect(function(input: InputObject)
    if not activeDrag or not activeDrag.IsDragging then return end
    if input.UserInputType == Enum.UserInputType.MouseButton1 or input.UserInputType == Enum.UserInputType.Touch then
        local dropPos = Vector2.new(input.Position.X, input.Position.Y)
        local targetSlot: SlotData? = nil

        for frame, slotData in pairs(registeredSlots) do
            local pos = frame.AbsolutePosition
            local size = frame.AbsoluteSize
            if dropPos.X >= pos.X and dropPos.X <= (pos.X + size.X) and
               dropPos.Y >= pos.Y and dropPos.Y <= (pos.Y + size.Y) then
                targetSlot = slotData
                break
            end
        end

        if targetSlot and targetSlot ~= activeDrag.SourceSlot then
            -- 서버로 슬롯 스왑 RemoteEvent 호출
            -- InventoryRemote:FireServer("SwapSlots", activeDrag.SourceSlot.SlotIndex, targetSlot.SlotIndex)
        end

        activeDrag.Ghost:Destroy()
        activeDrag = nil
    end
end)

return DragController