button

--Button api for computercraft by Siarko
--Usage:
--
-- FIRST SET MONITOR HANDLE BY 
-- button.setMonitor(handle)
--
-- new button object creation:
--  myFancyButton = button.create([label])
-- Methods:
-- setText, setPos, setSize, setColor, setBlinkColor, setActive, onClick
-- return button object so they can be chained eg:
-- myButton = button.create("My button").setSize(5,5).setColor(colors.gray).onClick(function)
-- setText(string, resize-bool) - sets button label; if resize then auto changes size to fit label
-- setSize(int, int), setPos(int, int) - quite self explainatory ;)
-- setColor(color) - sets background color, parameter color - computercraft colors api
-- setBlinkColor(color) - sets background to be drawn while button click
-- setActive(bool) - is button active and can be clicked? inactive - gray background
-- onClick(function) - function called when button is clicked
-- onClickReturn(value) - "await" function returns value instead of executing callback, 
--   returns nil if no button was clicked
-- setAlign("left" / "center" / "right") - aligns label in button accordingly;
--   if label doesn't fit, it will be cut to fit, min button width = 4

--Activate waiting for click:
-- button.await(b1, b2, b3, ...)
-- or button.await(buttonArray)
-- b1, b2, b3, - single button objects
-- buttonArray - table containing buttons eg:
-- arr = {b1, b2, b3}
-- "await" function draws supplied buttons and waits for click, if any button is clicked
-- fires callback function set in button by "onClick()" method
-- probably should be called in loop

-- If you want to do something in the background you have to run "button.await" in another thread
-- like parallel.waitForAny(background, buttonAwaitFunction)

local _locales = {
  mon = nil
}

--button class
function create(text)
  local this = {
    x = 1,
	y = 1,
	w = 0,
	h = 1,
	text = tostring(text) or "None",
	bgcol = colors.lime,
	blinkCol = colors.red,
	align = "c",
	active = true,
	callback = nil,
	ret = nil,
	textColor = colors.black,
	disabledColor = colors.gray
  }
  
  if text ~= nil then
    this.w = #tostring(text)
  end
  
  --setters, return this object
  function this.setText(text, resize)
    this.text = tostring(text)
	if resize and this.w < #this.text then
	  this.w = #this.text
	end
	return this
  end
  
  function this.setTextColor(color)
	this.textColor = color
	return this
  end
  
  function this.setDisabledColor(color)
  	this.disabledColor = color
	return this
  end
  
  function this.setAlign(align)
    if align == "center" then
	  this.align = "c"
	elseif align == "left" then
	  this.align = "l"
	elseif align == "right" then
	  this.align = "r"
	else 
	  print("Incorrect slign set! ")
	  error()
	end
    return this
  end
  
  function this.setPos(x, y)
    this.x = x
	this.y = y
	return this
  end
  
  function this.setSize(w, h)
    this.w = w
	this.h = h
    return this
  end
  
  function this.setColor(color)
    this.bgcol = color
	return this
  end
  
  function this.setBlinkColor(color)
    this.blinkCol = color
	return this
  end
  
  function this.setActive(state)
    this.active = state
    return this
  end
  
  function this.wasClicked(x,y)
    if 
	  x >= this.x and
	  x < this.x+this.w and
	  y >= this.y and
	  y < this.y+this.h and
	  this.active
	then
	  return true
	end
	return false
  end
  
  function this.onClick(callback)
    this.callback = callback
	return this
  end
  
  function this.onClickReturn(value)
    this.ret = value
	return this
  end
  
  function this.fireEvent()
    if this.callback ~= nil then
	  this.callback()
	end
  end
  
  function this.drawWrapper(bgcol)
    if _locales.mon == nil then
	  print("Monitor not set!")
	  error()
	end
	local xpos = this.x+(this.w/2-#this.text/2)
	local t = this.text
    local bg = _locales.mon.getBackgroundColor()
	local tc = _locales.mon.getTextColor()
	if this.align == "l" then
	  xpos = this.x
	end
	if this.align == "r" then
	  xpos = this.x+this.w-#this.text
	end
	if #this.text > this.w then
		xpos = this.x
		t = string.sub(t,1,this.w-3)..".."..string.sub(t,-1)
	end
	_locales.mon.setTextColor(this.textColor)
	local f = string.rep(" ", this.w)
	if this.active then
	  _locales.mon.setBackgroundColor(bgcol)
	else
	  _locales.mon.setBackgroundColor(this.disabledColor)
	end
	for i = 1, this.h do
	  _locales.mon.setCursorPos(this.x, this.y+(i-1))
	  _locales.mon.write(f)
	end
	_locales.mon.setCursorPos(xpos,this.y+this.h/2)
	_locales.mon.write(t)
	_locales.mon.setBackgroundColor(bg)
	_locales.mon.setTextColor(tc)
  end
  
  function this.draw()
    this.drawWrapper(this.bgcol)
  end
  
  function this.blink()
    this.drawWrapper(this.blinkCol)
	sleep(0.2)
	this.draw()
  end
	
  return this
end

--set Monitor handle to draw on
function setMonitor(mon)
  _locales.mon = mon
  --MON = mon
end

function clearMon()
  _locales.mon.clear()
end

local function isTable(element)
  return type(element) == "table"
end

local function isButton(element)
  if isTable(element) and element.text ~= nil then
    return true
  end
  return false
end

local function mergeTables(tab1, tab2)
  for i in pairs(tab2) do
    tab1[#tab1+1] = tab2[i]
  end
end

--manage button checks
function await(...)
  array = {}
  for i in pairs(arg) do
    if i ~= "n" then
	  if isTable(arg[i]) and not isButton(arg[i]) then --table of buttons
	    mergeTables(array, arg[i])
	  else --single button
	    array[#array+1] = arg[i]
	  end
	end
  end
  
  for i in pairs(array) do
    array[i].draw()
  end
  e, s, x, y = os.pullEvent("monitor_touch")
  for i in pairs(array) do
    if array[i].wasClicked(x,y) then
	  array[i].blink()
	  if array[i].ret ~= nil then
	    return array[i].ret
	  end
	  array[i].fireEvent()
	end
  end
end