Defold gui button which change scale on press event

button.lua

local PRESSED_BUTTON_SCALE = vmath.vector3(1.15)
local NORMAL_BUTTON_SCALE = vmath.vector3(1)
local ANIMATION_TIME = 0.2

local Button = {}
Button.__index = Button

function Button.new(context, node_name, handler)
  local self  = setmetatable({}, Button)
  assert(handler)
  assert(node_name)
  self.node = gui.get_node(node_name)
  self.handler = handler
  self.button_pressed = false
  self.context = context
  return self
end

function Button:press()
  -- uncoment following line if you want to add sound (must be located on main collection "sound" game object and "click" sound controller
  -- msg.post("main:/sound#click", "play_sound")
  gui.animate(self.node, "scale", PRESSED_BUTTON_SCALE, gui.EASING_OUTBACK, ANIMATION_TIME)
  self.button_pressed = true
end

function Button:release()
  gui.animate(self.node, "scale", NORMAL_BUTTON_SCALE, gui.EASING_OUTBACK, ANIMATION_TIME)
  self.button_pressed = false
end

function Button:on_input(action)
  if action.pressed then
    if gui.pick_node(self.node, action.x, action.y) then
      self:press()
    end
  elseif action.released and self.button_pressed then
    self:release()
    if gui.pick_node(self.node, action.x, action.y) then
      self.handler(self.context)
    end
  end
end

return Button

usage.gui_script

local Button = require("main.gui.button") -- change path to your location 

function another_handler(self)
   -- do something here
end

function init(self)
     -- "facebook" and "another_button" is a nodes on your gui scene
     self.fb_button = Button.new(self, "facebook", function() sys.open_url("https://www.facebook.com/pipler/") end)
     self.another_button = Button.new(self, "another_button", another_handler)
end

function on_input(self, action_id, action)
  -- make sure that you use ":" colon here, each button required personal on_input call
  self.fb_button:on_input(action)
  self.another_button:on_input(action)
end

Love this implementation, I have some change that play 2 sprite in animation that not always use scale to button for implementation