Custom Inventory

--PASTE INTO LOCAL SCRIPT!
--LOCAL SCRIPT GOES INTO STARTER PLAYER SRIPTS!

--press I to open the inventory
--right click on a item to remove it from the hotbar
--left click a hotbar slot to toggle the item equip
--[[left click a item in the inventory to select it
then left click the hotbar slot you want to put it
in]]

--[[If the tool you pick up dosnt have a texture ID
the image will be set to black and yellow lines.]]

-- Removes default backpack
game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Backpack, false)

--services
local players = game:GetService("Players")
local UIS = game:GetService("UserInputService")

--var
local player = players.LocalPlayer
local character = player.Character or player.CharacterAdded:Wait()
local humanoid = character:WaitForChild("Humanoid")
local mouse = player:GetMouse()
local screenGui = Instance.new("ScreenGui", player.PlayerGui)
local backpack = {}
local debounce = false
local disable = false
local backspace = false
local selectedItem;
local hotbar = {}
local scrollingFrame = Instance.new("ScrollingFrame", screenGui)

--creates a list array to store hotbar data
local function HotbarArray()
    --[[creates nil data so that it can
    later be replaced with item data
    and maintaine its length]]
    local hotbarSize = 10
    for i = 1, hotbarSize do
        if table.getn(hotbar) == 0 then
            hotbar = {nil}
        else
            table.insert(hotbar, nil)
        end
    end
end
HotbarArray()

local function CreateInventory()
    --sets the layout type
    local gridLayout = Instance.new("UIGridLayout", scrollingFrame)
    --property's
    scrollingFrame.Size = UDim2.new(.792,0,.791,0)
    scrollingFrame.Position = UDim2.new(.89,0,.85,0)
    scrollingFrame.Visible = false
    scrollingFrame.BackgroundColor3 = Color3.new(0, 0, 1)
    scrollingFrame.BorderColor3 = Color3.new(0,0,0)
    gridLayout.CellSize = UDim2.new(0,60,0,60)
    scrollingFrame.AnchorPoint=Vector2.new(1,1)
end
CreateInventory()

local function EquipTool(item)
    --debounce and wait is added to prevent bugs
    debounce = true
    humanoid:EquipTool(item)
    wait()
    debounce = false
end

local function ToggleTool(index)
    debounce = true
    --[[checks to see if the item is already in use
    to determine rather to unequip or equip]]
    local itemInUse = false
    --searches the character for the clicked item
    for _, v in ipairs(character:GetChildren()) do
        if v.ClassName == "Tool" and v == hotbar[index] then
            humanoid:UnequipTools()
            itemInUse = true
        end
    end
    --Equips the tool
    if not itemInUse then
        humanoid:EquipTool(hotbar[index])
    end
    debounce = false
end

local function RemoveFromHotbar(slot, index)
    --clears hotbar slot
    slot.Full.Value = nil
    slot.Image = ""
    table.remove(hotbar, index)
    table.insert(hotbar, index, nil)
end

local function RemoveFromBackpack(slot, item)
    table.remove(backpack, table.find(backpack, item))
    slot:Destroy()
end

local function AddToBackpack(itemAdded)
    --adds item to list array
    if table.getn(backpack) == 0 then
        --sets list value
        backpack = {itemAdded}
    else
        --adds item to list
        table.insert(backpack, itemAdded)
    end
--[[creates a slot for that item to be
visible in the inventory]]
    local slot = Instance.new("ImageButton", scrollingFrame)
    slot.Name = "InventorySlot"
    --if the items texture id is blank a default image is set
    if itemAdded.TextureId == "" then
        slot.Image = "http://www.roblox.com/asset/?id=12249128399"
    else
        slot.Image = itemAdded.TextureId
    end
    slot.BorderSizePixel = 3
    slot.BorderColor = BrickColor.new("Black")
    slot.Size = UDim2.new(0,60,0,60)
    local val = Instance.new("ObjectValue", slot)
    val.Name = "Full"
    val.Value = itemAdded
    --selects item in that slot that was clicked
    slot.MouseButton1Click:Connect(function()
        slot.BorderColor = BrickColor.new("Really red")
        selectedItem = val.Value
    end)
    --unselects item in the slot
    local function UnselectItem(Slot)
        Slot.BorderColor = BrickColor.new("Black")
        selectedItem = nil
    end
    --triggeres unselect
    slot.MouseButton2Down:Connect(function()
        UnselectItem(slot)
    end)
    --uhselects if inventory is closed
    scrollingFrame.Changed:Connect(function()
        if scrollingFrame.Visible == false then
            UnselectItem(slot)
        end
    end)
end

local function RefreshHotbar()
    --local var
    local index = 1
    --scans through hotbar
    for _, slot in ipairs(screenGui.Hotbar:GetChildren()) do
        if slot.Name == "Slot" then
            --if there is no item for that hotbar slot it gets cleared and the for loop ends
            if hotbar[index] == "void" or hotbar[index] == nil then
                --clears hotbar slot
                slot.Full.Value = nil
                slot.Image = ""
                table.remove(hotbar, index)
                table.insert(hotbar, index, nil)
                index += 1
            else
                --if there is an item then the slot updates
                local item = hotbar[index]
                slot.Full.Value = item
                --if the items texture id is blank a default image is set
                if item.TextureId == "" then
                    slot.Image = "http://www.roblox.com/asset/?id=12249128399"
                else
                    slot.Image = item.TextureId
                end
                index += 1
            end
            if slot.Full.Value ~= nil then
                local bool, errorMessage = pcall (function()
                    if not character:FindFirstChild(slot.Full.Value.Name) and not player.Backpack:FindFirstChild(slot.Full.Value.Name) then
                        --clears hotbar slot
                        slot.Full.Value = nil
                        slot.Image = ""
                        table.remove(hotbar, index)
                        table.insert(hotbar, index, nil)
                        index += 1
                    end
                    local tool = slot.Full.Value
                    if table.getn(tool:GetChildren()) == 0 then
                        --clears hotbar slot
                        slot.Full.Value = nil
                        slot.Image = ""
                        table.remove(hotbar, index)
                        table.insert(hotbar, index, nil)
                        index += 1
                    end
                end)
            end
        end
    end
end

local function AddToHotbar(slot, item)
    local index = slot.slotIndex.Value
    hotbar[index] = item
    RefreshHotbar()
end

local function CreateHotbar()
    --creates hotbar frame
    local HotbarGui = Instance.new("Frame", screenGui)
    HotbarGui.Transparency = 1
    HotbarGui.Name = "Hotbar"
    HotbarGui.Size = UDim2.new(0.673, 0,0.098, 0)
    HotbarGui.Position = UDim2.new(.95, 0,1, 0)
    HotbarGui.AnchorPoint = Vector2.new(1,1)
    --adds grid layout for slots
    local gridLayout = Instance.new("UIGridLayout", HotbarGui)
    gridLayout.CellSize = UDim2.new(0,60,0,60)
    --creates 10 hotbar slots
    for i = 1, 10 do
        --creates slot
        local slot = Instance.new("ImageButton", HotbarGui)
        slot.Name = "Slot"
        slot.BorderSizePixel = 3
        slot.BorderColor = BrickColor.new("Black")
        --creates object value to keep track items in each slot
        local val = Instance.new("ObjectValue", slot)
        val.Name = "Full"
        --creates a frame for the textlabel
        local frame = Instance.new("Frame", slot)
        frame.Size = UDim2.new(.3, 0, .3, 0)
        frame.Position = UDim2.new(.7, 0, 0, 0)
        Instance.new("UICorner", frame)
        --text label displayes slots keybind number
        local Text = Instance.new("TextLabel", frame)
        --sets the text to i enless its the 10th slot then its set to 0
        if i < 10 then
            Text.Text = i
        elseif i == 10 then
            Text.Text = 0
        end
        --sets text properties
        Text.BackgroundTransparency = 1
        Text.TextScaled = true
        Text.Size = UDim2.new(1,0,1,0)
        --keeps track of the horbar slots index
        local slotIndex = Instance.new("IntValue", slot)
        slotIndex.Name = "slotIndex"
        slotIndex.Value = i
        slot.MouseButton1Click:Connect(function()
            --if an item is selected it will move it to the slot
            if selectedItem ~= nil then
                --if the slot it wants is full it will move the
                --item in that slot to the inventory
                if slot.Full.Value ~= nil then
                    local item = slot.Full.Value
                    AddToBackpack(item)
                end
                RemoveFromHotbar(slot, slotIndex.Value)
                --adds item and unselects it
                AddToHotbar(slot, selectedItem)
                --locates and deletes the slot
                for _, Slot in ipairs(screenGui.ScrollingFrame:GetChildren()) do
                    if Slot.Name == "InventorySlot" then
                        if Slot.Full.Value == selectedItem then
                            RemoveFromBackpack(Slot, selectedItem)
                        end
                    end
                end
                selectedItem = nil
            else
                --else it will just select the item in that slot
                ToggleTool(slotIndex.Value)
            end
        end)
        --Puts tool away in inventory
        slot.MouseButton2Click:Connect(function()
            if slot.Full.Value ~= nil then
                local item = val.Value
                humanoid:UnequipTools()
                AddToBackpack(item)
                RemoveFromHotbar(slot, slotIndex.Value)
            end
        end)
    end
end
CreateHotbar()

--Keybinds
UIS.InputBegan:Connect(function(input)
    local key = input.KeyCode

    --inventory keybind
    if key==Enum.KeyCode.I then
        local inv = screenGui.ScrollingFrame
        --toggles visibility
        if inv.Visible == true then inv.Visible = false else inv.Visible = true end
    end

    --
    if key == Enum.KeyCode.Backspace then
        backspace = true
    end

    --hotbar keybinds
    if key==Enum.KeyCode.One then
        if hotbar[1] then
            ToggleTool(1)
        end
    end
    if key==Enum.KeyCode.Two then
        if hotbar[2] then
            ToggleTool(2)
        end
    end
    if key==Enum.KeyCode.Three then
        if hotbar[3] then
            ToggleTool(3)
        end
    end
    if key==Enum.KeyCode.Four then
        if hotbar[4] then
            ToggleTool(4)
        end
    end
    if key==Enum.KeyCode.Five then
        if hotbar[5] then
            ToggleTool(5)
        end
    end
    if key==Enum.KeyCode.Six then
        if hotbar[6] then
            ToggleTool(6)
        end
    end
    if key==Enum.KeyCode.Seven then
        if hotbar[7] then
            ToggleTool(7)
        end
    end
    if key==Enum.KeyCode.Eight then
        if hotbar[8] then
            ToggleTool(8)
        end
    end
    if key==Enum.KeyCode.Nine then
        if hotbar[9] then
            ToggleTool(9)
        end
    end
    if key==Enum.KeyCode.Zero then
        if hotbar[10] then
            ToggleTool(10)
        end
    end
end)

UIS.InputEnded:Connect(function(input)
    local key = input.KeyCode

    if key == Enum.KeyCode.Backspace then
        backspace = false
        print(backspace)
    end
end)

--Attempts to add item to backpack
player.Backpack.ChildAdded:Connect(function(itemAdded)
    if table.getn(hotbar) >= 10 and debounce == false then
        if not table.find(hotbar, itemAdded) and not table.find(backpack, itemAdded) then
            AddToBackpack(itemAdded)
        end
    end
end)

--picks up an item
character.ChildAdded:Connect(function(itemAdded)
    --checks if the player dosnt already own the item
    if not table.find(backpack, itemAdded.Name) or not table.find(hotbar, itemAdded.Name) then
        --searches through the hotbar
        for _, slot in ipairs(screenGui.Hotbar:GetChildren()) do
            if slot.Name == "Slot" then
                --checks conditions to prevent an error
                if itemAdded.ClassName == "Tool"  and debounce == false then
                    --checks if hotbar is full
                    if table.getn(hotbar) < 10 and debounce == false then
                        if slot.Full.Value == nil then
                            AddToHotbar(slot, itemAdded)
                            break
                        end
                        --if hotbar is full adds to inventory
                    elseif debounce == false then
                        AddToBackpack(itemAdded)
                        break
                    end
                end
            end
        end
    end
end)

--adds starter gear
for _, v in ipairs(player.Backpack:GetChildren()) do
    --searches through the hotbar
    for _, slot in ipairs(screenGui.Hotbar:GetChildren()) do
        if slot.Name == "Slot" then
            --checks conditions to prevent an error
            if v.ClassName == "Tool"  and debounce == false then
                --checks if hotbar is full
                if table.getn(hotbar) < 10 and debounce == false then
                    if slot.Full.Value == nil then
                        AddToHotbar(slot, v)
                        break
                    end
                    --if hotbar is full adds to inventory
                elseif debounce == false then
                    AddToBackpack(v)
                    break
                end
            end
        end
    end
end

--drops item
character.ChildRemoved:Connect(function(itemRemoved)
    --makes sure item wasnt just moved to backpack
    if not table.find(backpack, itemRemoved) then
        local index = table.find(hotbar, itemRemoved)
        --searches through hotbar for  the right slot
        for _, slot in ipairs(screenGui.Hotbar:GetChildren()) do
            if  slot.Name == "Slot" then
                task.wait()
                --checks the slots index and if backspace is pressed
                if slot.slotIndex.Value == index and backspace == true then
                    RemoveFromHotbar(slot, index)
                end
            end
        end
    end
end)

while true do
    task.wait()
    RefreshHotbar()
end