add android_back component (#5)

druid/base/android_back.lua

@@ -1,11 +1,30 @@
+local data = require("druid.data")
+
 local M = {}
 
+M.interest = {
+	data.ON_INPUT
+}
+
+
+function M.init(instance, params)
+	-- TODO: first arg store as node. Find way to escape this
+	local callback = instance.node
+	instance.event = data.A_ANDR_BACK
+	instance.callback = callback
+	instance.params = params
+end
+
+
 --- input handler
 -- @param action_id - input action id
 -- @param action - input action
 function M.on_input(instance, action_id, action)
-  instance.callback(instance.parent.parent)
-  return true
+	if action[data.RELEASED] then
+		instance.callback(instance.parent.parent, instance.params)
+	end
+	return true
 end
 
+
 return M

druid/druid.lua

@@ -9,9 +9,9 @@ local STRING = "string"
 local components = {
   -- basic
   button = require("druid.base.button"),
+  android_back = require("druid.base.android_back"),
   text = require("druid.base.text"),
   timer = require("druid.base.timer"),
-  -- android_back = require("druid.base.android_back"),
 }