Modified Read Function

--
--  Modified Read
--  By Gravity Score
--


local w, h = term.getSize()

local modifiedRead = function(properties)
    -- Properties:
    -- - replaceCharacter
    -- - displayLength
    -- - maxLength
    -- - onEvent
    -- - startingText

    local text = ""
    local startX, startY = term.getCursorPos()
    local pos = 0

    if not properties then
        properties = {}
    end
    if properties.displayLength then
        properties.displayLength = math.min(properties.displayLength, w - 2)
    end
    if properties.startingText then
        text = properties.startingText
        pos = text:len()
    end

    local draw = function(replaceCharacter)
        local scroll = 0
        if properties.displayLength and pos > properties.displayLength then
            scroll = pos - properties.displayLength
        end

        local repl = replaceCharacter or properties.replaceCharacter
        term.setTextColor(theme.text)
        term.setCursorPos(startX, startY)
        if repl then
            term.write(string.rep(repl:sub(1, 1), text:len() - scroll))
        else
            term.write(text:sub(scroll + 1))
        end

        term.setCursorPos(startX + pos - scroll, startY)
    end

    term.setCursorBlink(true)
    draw()
    while true do
        local event, key, x, y, param4, param5 = os.pullEvent()

        if properties.onEvent then
            -- Actions:
            -- - exit (bool)
            -- - text

            term.setCursorBlink(false)
            local action = properties.onEvent(text, event, key, x, y, param4, param5)
            if action then
                if action.text then
                    draw(" ")
                    text = action.text
                    pos = text:len()
                end if action.exit then
                    break
                end
            end
            draw()
        end

        term.setCursorBlink(true)
        if event == "char" then
            local canType = true
            if properties.maxLength and text:len() >= properties.maxLength then
                canType = false
            end

            if canType then
                text = text:sub(1, pos) .. key .. text:sub(pos + 1, -1)
                pos = pos + 1
                draw()
            end
        elseif event == "key" then
            if key == keys.enter then
                break
            elseif key == keys.left and pos > 0 then
                pos = pos - 1
                draw()
            elseif key == keys.right and pos < text:len() then
                pos = pos + 1
                draw()
            elseif key == keys.backspace and pos > 0 then
                draw(" ")
                text = text:sub(1, pos - 1) .. text:sub(pos + 1, -1)
                pos = pos - 1
                draw()
            elseif key == keys.delete and pos < text:len() then
                draw(" ")
                text = text:sub(1, pos) .. text:sub(pos + 2, -1)
                draw()
            elseif key == keys.home then
                pos = 0
                draw()
            elseif key == keys["end"] then
                pos = text:len()
                draw()
            end
        elseif event == "mouse_click" then
            local scroll = 0
            if properties.displayLength and pos > properties.displayLength then
                scroll = pos - properties.displayLength
            end

            if y == startY and x >= startX and x <= math.min(startX + text:len(), startX + (properties.displayLength or 10000)) then
                pos = x - startX + scroll
                draw()
            elseif y == startY then
                if x < startX then
                    pos = scroll
                    draw()
                elseif x > math.min(startX + text:len(), startX + (properties.displayLength or 10000)) then
                    pos = text:len()
                    draw()
                end
            end
        end
    end

    term.setCursorBlink(false)
    print("")
    return text
end