TextInput.lua

local TextService = game:GetService("TextService")

local root = script.Parent.Parent.Parent

local gui = root.Gui
local colors = require(gui.Colors)

local core = require(gui.Core)
local event = core.Event
local instanceEvent = core.InstanceEvent
local forceMousePosition = core.ForceMousePosition
local forceInputChange = core.ForceInputChange

local functions = root.Functions
local setupTooltip = require(functions.Tooltip).Setup
local sanitizeRichText = require(functions.SanitizeRichText)
local color3Difference = require(functions.Color3Difference)

local function getTextWidth(text)
    return TextService:GetTextSize(text, 14, Enum.Font.SourceSans, Vector2.new(math.huge, math.huge)).X
end

type Module = (name: string, parent: ScrollingFrame, default: string?, tooltip: string?) -> Frame
return function(name, parent, default, tooltip)
    if typeof(parent) ~= "Instance" or parent.ClassName ~= "ScrollingFrame" then error("Invalid parent.") end

    local container = Instance.new("Frame")
    container.Size = UDim2.new(1, -2, 0, 20)
    container.BackgroundTransparency = 1
    container.BorderSizePixel = 0
    container.Name = name
    container.Parent = parent

    local left = Instance.new("Frame")
    left.Position = UDim2.new(0, 1, 0, 0)
    left.Size = UDim2.new(0.5, -1, 1, 0)
    left.BackgroundColor3 = colors.Background
    left.Name = "Left"
    left.Parent = container
    do
        local stroke = Instance.new("UIStroke")
        stroke.Color = colors.Border.Secondary
        stroke.ApplyStrokeMode = Enum.ApplyStrokeMode.Border
        stroke.LineJoinMode = Enum.LineJoinMode.Miter
        stroke.Parent = left
    end
    if type(tooltip) == "string" then
        setupTooltip(left, tooltip)
    end

    local right = Instance.new("Frame")
    right.Position = UDim2.new(0.5, 1, 0, 0)
    right.Size = UDim2.fromScale(0.5, 1)
    right.BackgroundColor3 = colors.Background
    right.ClipsDescendants = true
    right.Name = "Right"
    right.Parent = container
    do
        local stroke = Instance.new("UIStroke")
        stroke.Color = colors.Border.Secondary
        stroke.ApplyStrokeMode = Enum.ApplyStrokeMode.Border
        stroke.LineJoinMode = Enum.LineJoinMode.Miter
        stroke.Parent = right
    end
    local rightBottomBorderCover = Instance.new("Frame")
    rightBottomBorderCover.Position = UDim2.new(0.5, 1, 1, 0)
    rightBottomBorderCover.Size = UDim2.new(0.5, 0, 0, 1)
    rightBottomBorderCover.BackgroundColor3 = colors.TextField
    rightBottomBorderCover.BorderSizePixel = 0
    rightBottomBorderCover.ZIndex = 2147483647 -- int-32 limit.
    rightBottomBorderCover.Visible = false
    rightBottomBorderCover.Name = "RightBottomBorderCover"
    rightBottomBorderCover.Parent = container

    container:SetAttribute("Selected", false)
    instanceEvent.MouseEnter(container, function()
        if not container:GetAttribute("Selected") then
            left.BackgroundColor3 = colors.Highlighted
            right.BackgroundColor3 = colors.Highlighted
        end
    end)
    instanceEvent.MouseLeave(container, function()
        if not container:GetAttribute("Selected") then
            left.BackgroundColor3 = colors.Background
            right.BackgroundColor3 = colors.Background
        end
    end)

    local label = Instance.new("TextLabel")
    label.Position = UDim2.fromOffset(24, 2)
    label.Size = UDim2.new(1, -28, 1, 0)
    label.BackgroundTransparency = 1
    label.Font = Enum.Font.SourceSans
    label.TextSize = 14
    label.TextColor3 = colors.Text.Primary
    label.TextXAlignment = Enum.TextXAlignment.Left
    label.TextYAlignment = Enum.TextYAlignment.Top
    label.TextTruncate = Enum.TextTruncate.SplitWord
    label.Text = name
    label.Name = "Label"
    label.Parent = left

    local textBox = Instance.new("TextBox")
    textBox.Size = UDim2.fromScale(1, 1)
    textBox.BackgroundTransparency = 1
    textBox.TextTransparency = 1
    textBox.Font = Enum.Font.SourceSans
    textBox.TextSize = 14
    textBox.TextXAlignment = Enum.TextXAlignment.Left
    textBox.TextYAlignment = Enum.TextYAlignment.Top
    textBox.ClearTextOnFocus = false
    textBox.Active = false
    textBox.Parent = right
    do
        local padding = Instance.new("UIPadding")
        padding.PaddingTop = UDim.new(0, 2)
        padding.PaddingLeft = UDim.new(0, 2)
        padding.PaddingRight = UDim.new(0, 2)
        padding.Parent = textBox
    end
    local textLabel = Instance.new("TextLabel")
    textLabel.Position = UDim2.fromOffset(4, 2)
    textLabel.Size = UDim2.new(1, -8, 1, -12)
    textLabel.BackgroundTransparency = 1
    textLabel.BorderSizePixel = 0
    textLabel.Font = Enum.Font.SourceSans
    textLabel.TextSize = 14
    textLabel.TextColor3 = colors.Text.Primary
    textLabel.TextXAlignment = Enum.TextXAlignment.Left
    textLabel.TextYAlignment = Enum.TextYAlignment.Top
    textLabel.TextTruncate = Enum.TextTruncate.SplitWord
    textLabel.Parent = right

    if type(default) == "string" then
        container:SetAttribute("Text", default)
        textBox.Text = default
        textLabel.Text = sanitizeRichText(default)
    else
        container:SetAttribute("Text", "")
        textBox.Text = ""
        textLabel.Text = ""
    end

    local cursor = Instance.new("Frame")
    cursor.Position = UDim2.fromOffset(0, 1)
    cursor.Size = UDim2.fromOffset(1, 15)
    cursor.BackgroundColor3 = colors.Cursor -- rbg(255, 255, 255) with "difference" blending mode for identical to Studio - not supported in Roblox unfortunately.
    cursor.BorderSizePixel = 0
    cursor.ZIndex = 2
    cursor.Visible = false
    cursor.Parent = textBox

    local selectionBackground = Instance.new("Frame")
    selectionBackground.Position = UDim2.fromOffset(0, 1)
    selectionBackground.Size = UDim2.fromOffset(0, 15)
    selectionBackground.BackgroundColor3 = colors.Primary
    selectionBackground.BorderSizePixel = 0
    selectionBackground.Visible = false
    selectionBackground.Parent = textBox

    local cursorThread = nil
    local hoverConnection = nil
    local inputConnection = nil

    local lastAbsoluteCursorPosition = 0
    local lastCursorPosition = -1
    local lastSelectionStart = -1
    local lastText = textBox.Text

    local justDefocused = false

    local differentSelectionColor = color3Difference(colors.Text.Edit, colors.Text.Highlighted) > 0.000004 -- We detect 0.01 difference; a difference that is visually unpresent, yet the code can detect.
    event.ThemeChanged:Connect(function()
        if color3Difference(colors.Text.Edit, colors.Text.Highlighted) < 0.000004 then
            textLabel.Text = lastText
            textLabel.RichText = false
            differentSelectionColor = false
        elseif not differentSelectionColor then
            textLabel.Text = sanitizeRichText(lastText)
            textLabel.RichText = true
            differentSelectionColor = true
        end
    end)

    local function cursorLoop()
        while true do
            task.wait(0.533)
            cursor.Visible = false
            task.wait(0.533)
            cursor.Visible = true
        end
    end

    local function updateSelection()
        -- lastText will be current text.
        -- lastSelectionStart will be current selection start.
        -- lastCursorPosition will be current cursor position.
        -- lastAbsoluteCursorPosition will be current absolute cursor position.

        if lastSelectionStart == -1 then
            selectionBackground.Visible = false

            textLabel.Text = lastText
            textLabel.RichText = false
        else
            if lastSelectionStart > lastCursorPosition then
                local selectedText = lastText:sub(lastCursorPosition, lastSelectionStart - 1)
                selectionBackground.Size = UDim2.fromOffset(getTextWidth(selectedText), 15)
                selectionBackground.Position = UDim2.fromOffset(textLabel.Position.X.Offset - 2 + lastAbsoluteCursorPosition, 1)

                if differentSelectionColor then
                    textLabel.Text = sanitizeRichText(lastText:sub(1, lastCursorPosition - 1))..'<font color="#'..colors.Text.Highlighted:ToHex()..'">'..sanitizeRichText(selectedText).."</font>"..sanitizeRichText(lastText:sub(lastSelectionStart, -1))
                    textLabel.RichText = true
                end
            else
                local selectedText = lastText:sub(lastSelectionStart, lastCursorPosition - 1)
                local leftOfSelectionText = lastText:sub(1, lastSelectionStart - 1)
                selectionBackground.Size = UDim2.fromOffset(getTextWidth(selectedText), 15)
                selectionBackground.Position = UDim2.fromOffset(textLabel.Position.X.Offset - 2 + getTextWidth(leftOfSelectionText), 1)

                if differentSelectionColor then
                    textLabel.Text = sanitizeRichText(leftOfSelectionText)..'<font color="#'..colors.Text.Highlighted:ToHex()..'">'..sanitizeRichText(selectedText).."</font>"..sanitizeRichText(lastText:sub(lastCursorPosition, -1))
                    textLabel.RichText = true
                end
            end

            selectionBackground.Visible = true
        end
    end
    local function updatePosition()
        -- lastText will be current text.

        coroutine.close(cursorThread)
        cursor.Visible = true
        cursorThread = coroutine.create(cursorLoop)
        coroutine.resume(cursorThread)

        local absoluteCursorPosition = getTextWidth(lastText:sub(1, textBox.CursorPosition - 1))
        local move = absoluteCursorPosition - lastAbsoluteCursorPosition
        if move > 0 then
            lastAbsoluteCursorPosition = absoluteCursorPosition

            local newCursorPosition = cursor.Position.X.Offset + move
            local difference = newCursorPosition - (textBox.AbsoluteSize.X - 4)
            if difference > 0 then
                textLabel.Position = UDim2.fromOffset(textLabel.Position.X.Offset - difference, 2)
                textLabel.Size = UDim2.new(1, textLabel.Size.X.Offset + difference, 1, -12)
                cursor.Position = UDim2.fromOffset(textBox.AbsoluteSize.X - 4, 1)
            else
                cursor.Position = UDim2.fromOffset(newCursorPosition, 1)
            end
        elseif move < 0 then
            lastAbsoluteCursorPosition = absoluteCursorPosition

            local newCursorPosition = cursor.Position.X.Offset + move
            if newCursorPosition < 0 then
                textLabel.Position = UDim2.fromOffset(textLabel.Position.X.Offset - newCursorPosition, 2)
                textLabel.Size = UDim2.new(1, textLabel.Size.X.Offset + newCursorPosition, 1, -12)

                cursor.Position = UDim2.fromOffset(0, 1)
            else
                cursor.Position = UDim2.fromOffset(newCursorPosition, 1)
            end
        end

        if textLabel.Position.X.Offset < 2 then
            local difference = textLabel.Position.X.Offset + getTextWidth(lastText) - (textBox.AbsoluteSize.X - 2)
            if difference < 0 then
                local position = textLabel.Position.X.Offset - difference
                if position > 2 then
                    textLabel.Position = UDim2.fromOffset(2, 2)
                    textLabel.Size = UDim2.new(1, textLabel.Size.X.Offset + difference + position - 2, 1, -12)
                    cursor.Position = UDim2.fromOffset(cursor.Position.X.Offset - difference - position + 2, 1)
                else
                    textLabel.Position = UDim2.fromOffset(position, 2)
                    textLabel.Size = UDim2.new(1, textLabel.Size.X.Offset + difference, 1, -12)
                    cursor.Position = UDim2.fromOffset(cursor.Position.X.Offset - difference, 1)
                end
            end
        end
    end
    textBox.Changed:Connect(function()
        if cursorThread == nil then return end

        local newCursorPosition = false

        if textBox.Text ~= lastText then
            lastText = textBox.Text -- lastText is now current text.
            if differentSelectionColor then
                textLabel.Text = sanitizeRichText(lastText)
            else
                textLabel.Text = lastText
            end

            updatePosition()

            container:SetAttribute("Text", lastText)
        elseif textBox.CursorPosition ~= lastCursorPosition then
            newCursorPosition = true
            lastCursorPosition = textBox.CursorPosition

            updatePosition()
            updateSelection()
        end

        if newCursorPosition then
            updateSelection()
        elseif lastSelectionStart ~= textBox.SelectionStart then
            lastSelectionStart = textBox.SelectionStart -- lastSelectionStart is now current selection start.

            updateSelection()
        end
    end)
    instanceEvent.MouseButton1Down(container, function()
        local focused = false

        if cursorThread == nil and not justDefocused then
            focused = true

            textBox:CaptureFocus()
            textBox.ZIndex = 2147483647 -- int-32 limit.
            textBox.SelectionStart = 1

            hoverConnection = textBox.MouseEnter:Connect(function()
                forceMousePosition(Vector2.new(textBox.AbsolutePosition.X, textBox.AbsolutePosition.Y))
            end)
            inputConnection = textBox.InputChanged:Connect(forceInputChange)

            textLabel.Position = UDim2.fromOffset(2, 2)
            textLabel.Size = UDim2.new(1, -4, 1, -12)
            textLabel.TextColor3 = colors.Text.Edit
            right.BackgroundColor3 = colors.TextField
            textLabel.TextTruncate = Enum.TextTruncate.None
            cursor.Visible = true
            rightBottomBorderCover.Visible = true

            cursorThread = coroutine.create(cursorLoop)
            coroutine.resume(cursorThread)
        end

        if not container:GetAttribute("Selected") then
            container:SetAttribute("Selected", true)
            left.BackgroundColor3 = colors.Primary
            if cursorThread == nil then
                right.BackgroundColor3 = colors.Primary
            end
            label.TextColor3 = colors.Text.Highlighted
            if not differentSelectionColor or not focused then
                textLabel.TextColor3 = colors.Text.Highlighted
            else
                textLabel.TextColor3 = colors.Text.Edit
            end

            for _, instance in ipairs(parent:GetChildren()) do
                if instance.ClassName ~= "Frame" then continue end
                if instance == container then continue end

                instance:SetAttribute("Selected", false)
            end
        end
    end)
    textBox.FocusLost:Connect(function()
        justDefocused = true

        coroutine.close(cursorThread)
        cursorThread = nil
        hoverConnection:Disconnect()
        hoverConnection = nil
        inputConnection:Disconnect()
        inputConnection = nil

        textBox.ZIndex = 1

        lastCursorPosition = -1
        lastAbsoluteCursorPosition = 0

        cursor.Position = UDim2.fromOffset(0, 1)
        textLabel.Position = UDim2.fromOffset(4, 2)
        textLabel.Size = UDim2.new(1, -8, 1, -12)
        if container:GetAttribute("Selected") then
            textLabel.TextColor3 = colors.Text.Highlighted
        else
            textLabel.TextColor3 = colors.Text.Primary
        end
        right.BackgroundColor3 = colors.Primary
        textLabel.TextTruncate = Enum.TextTruncate.SplitWord
        cursor.Visible = false
        rightBottomBorderCover.Visible = false

        task.wait()
        justDefocused = false
    end)

    container:GetAttributeChangedSignal("Selected"):Connect(function()
        if not container:GetAttribute("Selected") then
            left.BackgroundColor3 = colors.Background
            right.BackgroundColor3 = colors.Background
            label.TextColor3 = colors.Text.Primary
            textLabel.TextColor3 = colors.Text.Primary
        end
    end)

    return container
end :: Module