Computercraft - Touchscreen Contol

-- genericCtrl

-- monSide: side of the monitor
local monSide = "back"
local term = peripheral.wrap(monSide)

--local txtScale = 1.0

-- rsSide: Redstone Bundled Output
local rsSide = "right"

-- Position in cfg arrays
local bLabel = 1
local bActive = 2

-- cfg:
local cfg = {}
cfg[1] = {"Quarry", false}
cfg[2] = {"Sugar", false}
cfg[3] = {"Melons", false}
cfg[4] = {"Oak Wood", true}
cfg[5] = {"Birch", true}
cfg[6] = {"Spruce", true}
cfg[7] = {"Rubber", false}
cfg[8] = {"Peat Bog", true}

-- columns & rows:
columns = 3
rows = 3

-- buttons: this holds the buttons definitions
local buttons = {}

-- Screen size
local screenX, screenY

-- getBundledColor: returns colors codes ( white (n=1) / black (n=16) )
function getBundledColor(n)
  return bit.blshift(1,(n-1))
end

-- fills the buttons table
function setButton(name, active, colorCode, callback, xMin, xMax, yMin, yMax)
  buttons[name] = {}
  buttons[name]["active"] = active
  buttons[name]["color"] = colorCode
  buttons[name]["func"] = callback
  buttons[name]["xMin"] = xMin
  buttons[name]["xMax"] = xMax
  buttons[name]["yMin"] = yMin
  buttons[name]["yMax"] = yMax
end

-- defineButtons: define buttons in a dynamic "centered" layout
function defineButtons()

  screenX, screenY = term.getSize()

  vertTrim = math.floor(screenY/(rows+1)) + 1
  horizTrim = math.floor(screenX/(columns+1)) + 1

  i = 1
  for row = 1, rows do

    if i > # cfg then break end

    local yMin = (row * vertTrim) - 1
    local yMax = (row * vertTrim) + 1

    for col =  1, columns do

      if i > # cfg then break end

      local labelLen = string.len(cfg[i][bLabel])
      local xMin = (col * horizTrim) - math.floor(labelLen/2) - 1
      local xMax = xMin + labelLen + 2

      setButton(cfg[i][bLabel], cfg[i][bActive], getBundledColor(i), toggleBundledOutput, xMin, xMax, yMin, yMax)
      --print(xMin..","..xMax..","..yMin..","..yMax)
      i = i + 1

    end
  end

end

-- toggleBundledOutput: toggle redstone output by button name
function toggleBundledOutput(name)
  local activeColors = rs.getBundledOutput(rsSide)
  if buttons[name]["active"] then
    rs.setBundledOutput(rsSide, (activeColors - buttons[name]["color"]))
    buttons[name]["active"] = false
  else
    rs.setBundledOutput(rsSide, (activeColors + buttons[name]["color"]))
    buttons[name]["active"] = true
  end
end


-- initBundledOutput: Init Bundled Output at reboot/restart
function initBundledOutput()
  local initColors = 0
  for name, btn in pairs(buttons) do
    if buttons[name]["active"] then
      initColors = initColors + buttons[name]["color"]
    end
  end
  rs.setBundledOutput(rsSide, initColors)
end


-- returns len whitespaces
function fillSpace(len)
  len = len or 1
  fill = ""
  for i = 1, len do
    fill = fill .. " "
  end
  return fill
end

-- as it says
function resetTermColors()
  term.setTextColor(colors.white)
  term.setBackgroundColor(colors.black)
end

-- drawScreen:
function drawScreen()

  for name, btn in pairs(buttons) do

    if buttons[name]["active"] then
      term.setTextColor(colors.white)
      term.setBackgroundColor(colors.green)
    else
      term.setTextColor(colors.black)
      term.setBackgroundColor(colors.red)
    end

    labelLen = string.len(name)

    term.setCursorPos(buttons[name]["xMin"], buttons[name]["yMin"])
    term.write(fillSpace(labelLen + 4))

    term.setCursorPos(buttons[name]["xMin"], (buttons[name]["yMin"] + 1))
    term.write("  "..name.."  ")

    term.setCursorPos(buttons[name]["xMin"], buttons[name]["yMax"])
    term.write(fillSpace(labelLen + 4))

    resetTermColors()

  end

end

-- touchEvent: process touch events
function touchEvent(x, y)
  for name, btn in pairs(buttons) do

    if (y >= buttons[name]["yMin"]) and (y <= buttons[name]["yMax"])
      and (x >= buttons[name]["xMin"]) and (x <= buttons[name]["xMax"]) then

      print("Touch on button: "..name)
      toggleBundledOutput(name)
      break

    end
  end
end

--------------------------------------------
-- MAIN --
--------------------------------------------
term.clear()
--term.setTextScale(txtScale)

defineButtons()
initBundledOutput()

while true do

  drawScreen()

  local evtp, side, x, y = os.pullEvent()

  if evtp == "monitor_touch" then

    touchEvent(x, y)

  else

    print("Ignoring event "..evtp)

  end

end