Draggable Window

term.setBackgroundColor(colors.black)
term.clear()
local boxlocation = {2, 2}
local clickX, clickY = nil, nil
while true do
    term.setCursorPos(1, 1)
    term.write("click & drag")
    paintutils.drawFilledBox(boxlocation[1], boxlocation[2], boxlocation[1] + 4, boxlocation[2] + 2, colors.gray)
    local events = {os.pullEvent()}
    term.setBackgroundColor(colors.black)
    term.clear()
    if events[1] == "mouse_click" and events[2] == 1 then
        clickX, clickY = events[3], events[4]
    end
    if events[1] == "mouse_drag" and events[2] == 1 and clickX and clickY and clickX >= boxlocation[1] - 1 and clickX <= boxlocation[1] + 5 and clickY >= boxlocation[2] - 1 and clickY <= boxlocation[2] + 2 then
        clickX, clickY = events[3], events[4]
        boxlocation = {clickX, clickY}
    end
end