Computercraft buttonAPI

--[[
EyeDeck's button API
Handles drawing buttons to a screen, and mapping
raw (x,y) input coords to drawn buttons.
--]]

button_registry = {}

--monitor to write to, top left (x,y), width and height
--text color, background color, button name (optional)
function drawButton(m,x,y,w,h,txtcolor,bgcolor,text,name)
  local old_term = term.redirect(m)
  local old_bg = term.getBackgroundColor()
  local old_tx = term.getTextColor()
  local old_posx, old_posy = term.getCursorPos()

  paintutils.drawLine(x+1,   y,     x+w-2, y,     colors.lightGray)
  paintutils.drawLine(x+1,   y+h-1, x+w-2, y+h-1, colors.gray)
  paintutils.drawLine(x,     y+1,   x,     y+h-2, colors.gray)
  paintutils.drawLine(x+w-1, y+1,   x+w-1, y+h-2, colors.lightGray)
  paintutils.drawFilledBox(x+1, y+1, x+w-2, y+h-2, bgcolor)

  term.setTextColor(txtcolor)
  term.setBackgroundColor(bgcolor)
  term.setCursorPos(x+math.floor((w-string.len(text))/2),y+math.floor((h-1)/2))
  term.write(text)

  term.setCursorPos(old_posx, old_posy)
  term.setTextColor(old_tx)
  term.setBackgroundColor(old_bg)
  term.redirect(old_term)

  if name ~= nil then
    table.insert(button_registry,{x=x+1,y=y+1,x2=x+w-2,y2=y+h-2,name=name})
  end

end

function getButton(x,y)
  for _,v in pairs(button_registry) do
    if x >= v.x and x <= v.x2 and y >= v.y and y <= v.y2 then
      return v.name
    end
  end

  return false
end

function removeButton(name)
  for i,v in pairs(button_registry) do
    if v.name == name then
      table.remove(button_registry, i)
      return true
    end
  end

  return false
end