diff --git a/druid/base/back_handler.lua b/druid/base/back_handler.lua
index 7631e2e..2498665 100644
--- a/druid/base/back_handler.lua
+++ b/druid/base/back_handler.lua
@@ -60,7 +60,7 @@ end
 -- @tparam table action on_input action
 -- @local
 function BackHandler.on_input(self, action_id, action)
-	if not action[const.RELEASED] then
+	if not action.released then
 		return false
 	end
 
diff --git a/druid/base/button.lua b/druid/base/button.lua
index 4b4a18c..5bd2b51 100755
--- a/druid/base/button.lua
+++ b/druid/base/button.lua
@@ -340,10 +340,7 @@ function Button.on_input(self, action_id, action)
 	local is_pick = true
 	local is_key_trigger = (action_id == self.key_trigger)
 	if not is_key_trigger then
-		is_pick = gui.pick_node(self.node, action.x, action.y)
-		if self.click_zone then
-			is_pick = is_pick and gui.pick_node(self.click_zone, action.x, action.y)
-		end
+		is_pick = helper.pick_node(self.node, action.x, action.y, self.click_zone)
 	end
 
 	if not is_pick then
diff --git a/druid/base/drag.lua b/druid/base/drag.lua
index 52a004f..22034f6 100644
--- a/druid/base/drag.lua
+++ b/druid/base/drag.lua
@@ -185,7 +185,7 @@ function Drag.init(self, node, on_drag_callback)
 	self.is_touch = false
 	self.is_drag = false
 	self.touch_start_pos = vmath.vector3(0)
-	self._is_disabled = false
+	self._is_enabled = true
 
 	self.can_x = true
 	self.can_y = true
@@ -233,14 +233,11 @@ function Drag.on_input(self, action_id, action)
 		return false
 	end
 
-	if not gui.is_enabled(self.node, true) or self._is_disabled then
+	if not self._is_enabled or not gui.is_enabled(self.node, true) then
 		return false
 	end
 
-	local is_pick = gui.pick_node(self.node, action.x, action.y)
-	if self.click_zone then
-		is_pick = is_pick and gui.pick_node(self.click_zone, action.x, action.y)
-	end
+	local is_pick = helper.pick_node(self.node, action.x, action.y, self.click_zone)
 	if not is_pick and not self.is_drag then
 		end_touch(self)
 		return false
@@ -318,7 +315,7 @@ end
 -- @tparam Drag self @{Drag}
 -- @tparam bool is_enabled
 function Drag.set_enabled(self, is_enabled)
-	self._is_disabled = not is_enabled
+	self._is_enabled = is_enabled
 end
 
 
@@ -326,7 +323,7 @@ end
 -- @tparam Drag self @{Drag}
 -- @treturn bool
 function Drag.is_enabled(self)
-	return not self._is_disabled
+	return self._is_enabled
 end
 
 
diff --git a/druid/base/hover.lua b/druid/base/hover.lua
index 4d6e1e2..fd4fe93 100644
--- a/druid/base/hover.lua
+++ b/druid/base/hover.lua
@@ -64,11 +64,7 @@ function Hover.on_input(self, action_id, action)
 		return false
 	end
 
-	local is_pick = gui.pick_node(self.node, action.x, action.y)
-	if self.click_zone then
-		is_pick = is_pick and gui.pick_node(self.click_zone, action.x, action.y)
-	end
-
+	local is_pick = helper.pick_node(self.node, action.x, action.y, self.click_zone)
 	local hover_function = action_id and self.set_hover or self.set_mouse_hover
 
 	if not is_pick then
diff --git a/druid/component.lua b/druid/component.lua
index dd4578f..56d12e3 100644
--- a/druid/component.lua
+++ b/druid/component.lua
@@ -99,7 +99,7 @@ end
 -- @tparam string template BaseComponent template name
 -- @treturn BaseComponent @{BaseComponent}
 function BaseComponent.set_template(self, template)
-	template = template or const.EMPTY_STRING
+	template = template or ""
 
 	local parent = self:get_parent_component()
 	if parent and IS_AUTO_TEMPLATE then
@@ -183,7 +183,7 @@ end
 -- @tparam string|node node_or_name Node name or node itself
 -- @treturn node Gui node
 function BaseComponent.get_node(self, node_or_name)
-	if type(node_or_name) ~= const.STRING then
+	if type(node_or_name) ~= "string" then
 		-- Assume it's already node from gui.get_node
 		return node_or_name
 	end
diff --git a/druid/const.lua b/druid/const.lua
index 87013a1..86f674e 100755
--- a/druid/const.lua
+++ b/druid/const.lua
@@ -10,25 +10,16 @@ local M = {}
 M.ACTION_TEXT = hash(sys.get_config("druid.input_text", "text"))
 M.ACTION_TOUCH = hash(sys.get_config("druid.input_touch", "touch"))
 M.ACTION_MARKED_TEXT = hash(sys.get_config("druid.input_marked_text", "marked_text"))
-
 M.ACTION_ESC = hash(sys.get_config("druid.input_key_esc", "key_esc"))
 M.ACTION_BACK = hash(sys.get_config("druid.input_key_back", "key_back"))
 M.ACTION_ENTER = hash(sys.get_config("druid.input_key_enter", "key_enter"))
 M.ACTION_MULTITOUCH = hash(sys.get_config("druid.input_multitouch", "touch_multi"))
 M.ACTION_BACKSPACE = hash(sys.get_config("druid.input_key_backspace", "key_backspace"))
-
 M.ACTION_SCROLL_UP = hash(sys.get_config("druid.input_scroll_up", "mouse_wheel_up"))
 M.ACTION_SCROLL_DOWN = hash(sys.get_config("druid.input_scroll_down", "mouse_wheel_down"))
 
 M.IS_STENCIL_CHECK = not (sys.get_config("druid.no_stencil_check") == "1")
 
-M.RELEASED = "released"
-M.PRESSED = "pressed"
-M.STRING = "string"
-M.TABLE = "table"
-M.ZERO = "0"
-
-
 --- Component Interests
 M.ON_INPUT = "on_input"
 M.ON_UPDATE = "update"
@@ -41,12 +32,11 @@ M.ON_MESSAGE_INPUT = "on_message_input"
 M.ON_WINDOW_RESIZED = "on_window_resized"
 M.ON_LANGUAGE_CHANGE = "on_language_change"
 
-
+-- Components with higher priority value processed first
 M.PRIORITY_INPUT = 10
 M.PRIORITY_INPUT_HIGH = 20
 M.PRIORITY_INPUT_MAX = 100
 
-
 M.MESSAGE_INPUT = {
 	BUTTON_CLICK = "button_click",
 	BUTTON_LONG_CLICK = "button_long_click",
@@ -55,7 +45,6 @@ M.MESSAGE_INPUT = {
 	TEXT_SET = "text_set",
 }
 
-
 M.PIVOTS = {
 	[gui.PIVOT_CENTER] = vmath.vector3(0),
 	[gui.PIVOT_N] = vmath.vector3(0, 0.5, 0),
@@ -90,7 +79,6 @@ M.LAYOUT_MODE = {
 }
 
 M.VECTOR_ZERO = vmath.vector3(0)
-M.VECTOR_ONE = vmath.vector3(1)
 M.SYS_INFO = sys.get_sys_info()
 M.CURRENT_SYSTEM_NAME = M.SYS_INFO.system_name
 
@@ -135,6 +123,5 @@ M.ERRORS = {
 }
 
 M.EMPTY_FUNCTION = function() end
-M.EMPTY_STRING = ""
 
 return M
diff --git a/druid/extended/input.lua b/druid/extended/input.lua
index 3cb2bca..320491a 100755
--- a/druid/extended/input.lua
+++ b/druid/extended/input.lua
@@ -123,7 +123,7 @@ end
 function Input.init(self, click_node, text_node, keyboard_type)
 	self.druid = self:get_druid(self)
 
-	if type(text_node) == const.TABLE then
+	if type(text_node) == "table" then
 		self.text = text_node
 	else
 		self.text = self.druid:new_text(text_node)
diff --git a/druid/extended/swipe.lua b/druid/extended/swipe.lua
index dd09ad2..5b43112 100644
--- a/druid/extended/swipe.lua
+++ b/druid/extended/swipe.lua
@@ -120,11 +120,7 @@ function Swipe.on_input(self, action_id, action)
 		return false
 	end
 
-	local is_pick = gui.pick_node(self.node, action.x, action.y)
-	if self.click_zone then
-		is_pick = is_pick and gui.pick_node(self.click_zone, action.x, action.y)
-	end
-
+	local is_pick = helper.pick_node(self.node, action.x, action.y, self.click_zone)
 	if not is_pick then
 		reset_swipe(self, action)
 		return false
diff --git a/druid/helper.lua b/druid/helper.lua
index f091675..f61b2ad 100644
--- a/druid/helper.lua
+++ b/druid/helper.lua
@@ -271,6 +271,23 @@ function M.add_array(target, source)
 end
 
 
+--- Make a check with gui.pick_node, but with additional node_click_area check.
+-- @function helper.pick_node
+-- @tparam Node node
+-- @tparam number x
+-- @tparam number y
+-- @tparam[opt] Node node_click_area
+-- @local
+function M.pick_node(node, x, y, node_click_area)
+	local is_pick = gui.pick_node(node, x, y)
+
+	if node_click_area then
+		is_pick = is_pick and gui.pick_node(node_click_area, x, y)
+	end
+
+	return is_pick
+end
+
 --- Get node size adjusted by scale
 -- @function helper.get_scaled_size
 -- @tparam node node GUI node
@@ -356,7 +373,7 @@ end
 -- @treturn string
 function M.table_to_string(t)
 	if not t then
-		return const.EMPTY_STRING
+		return ""
 	end
 
 	local result = "{"
diff --git a/druid/styles/empty/style.lua b/druid/styles/empty/style.lua
deleted file mode 100644
index 2eec3ee..0000000
--- a/druid/styles/empty/style.lua
+++ /dev/null
@@ -1,3 +0,0 @@
--- Copyright (c) 2021 Maksim Tuprikov <insality@gmail.com>. This code is licensed under MIT license
-
-return {}
diff --git a/druid/system/druid_instance.lua b/druid/system/druid_instance.lua
index 5876a56..b125bb9 100755
--- a/druid/system/druid_instance.lua
+++ b/druid/system/druid_instance.lua
@@ -234,8 +234,8 @@ end
 
 --- Druid class constructor
 -- @tparam DruidInstance self
--- @tparam table context Druid context. Usually it is self of script
--- @tparam table style Druid style module
+-- @tparam table context Druid context. Usually it is self of gui script
+-- @tparam table style Druid style table
 -- @local
 function DruidInstance.initialize(self, context, style)
 	self._context = context