local function onKeyDown(char, code)
  if code == keyboard.keys.back and not readonly then
    if left() then
      delete()
    end
  elseif code == keyboard.keys.delete and not readonly then
    delete()
  elseif code == keyboard.keys.left then
    left()
  elseif code == keyboard.keys.right then
    right()
  elseif code == keyboard.keys.home then
    home()
  elseif code == keyboard.keys["end"] then
    ende()
  elseif code == keyboard.keys.up then
    up()
  elseif code == keyboard.keys.down then
    down()
  elseif code == keyboard.keys.pageUp then
    local w, h = getSize()
    up(h - 1)
  elseif code == keyboard.keys.pageDown then
    local w, h = getSize()
    down(h - 1)
  elseif code == keyboard.keys.enter and not readonly then
    enter()
  elseif readonly and code == keyboard.keys.q then
    running = false
  elseif not keyboard.isControl(char) and not readonly then
    insert(unicode.char(char))
  end
end


while running do
  local event, address, arg1, arg2, arg3 = event.pull()             -- arg1 equates to char, arg2 is code in the onKeyDown() function
  if type(address) == "string" and component.isPrimary(address) then
    local blink = true
    if event == "key_down" then
      onKeyDown(arg1, arg2)
    else
      blink = false
    end
    if blink then
      term.setCursorBlink(true)
      term.setCursorBlink(true) -- force toggle to caret
    end
  end
end