Merge branch 'dev/agulev'

The transition module will now properly handle if the same transition is started more than once before completed. In such a case only one animation will be played but all senders will be notified when completed.

.travis.yml

@@ -22,6 +22,7 @@ env:
   global:
     - secure: "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"
     - DEFOLD_USER=bjorn.ritzl@king.com
+    - DEFOLD_BOOSTRAP_COLLECTION=/test/test.collectionc
 
 script:
-  - "./.test/run.sh"
+  - "./.travis/run.sh"

.travis/run.sh

@@ -5,30 +5,39 @@ else
 	PLATFORM="$1"
 fi
 
+
 echo "${PLATFORM}"
 
 # {"version": "1.2.89", "sha1": "5ca3dd134cc960c35ecefe12f6dc81a48f212d40"}
+# Get SHA1 of the current Defold stable release
 SHA1=$(curl -s http://d.defold.com/stable/info.json | sed 's/.*sha1": "\(.*\)".*/\1/')
 echo "Using Defold dmengine_headless version ${SHA1}"
 
-#DMENGINE_URL="http://d.defold.com/archive/${SHA1}/engine/linux/dmengine_headless"
+# Create dmengine_headless and bob.jar URLs
 DMENGINE_URL="http://d.defold.com/archive/${SHA1}/engine/${PLATFORM}/dmengine_headless"
 BOB_URL="http://d.defold.com/archive/${SHA1}/bob/bob.jar"
 
+# Download dmengine_headless
 echo "Downloading ${DMENGINE_URL}"
 curl -o dmengine_headless ${DMENGINE_URL}
 chmod +x dmengine_headless
 
+# Download bob.jar
 echo "Downloading ${BOB_URL}"
 curl -o bob.jar ${BOB_URL}
 
+# Fetch libraries if DEFOLD_AUTH and DEFOLD_USER are set
 if [ -n "${DEFOLD_AUTH}" ] && [ -n "${DEFOLD_USER}" ]; then
 	echo "Running bob.jar - resolving dependencies"
 	java -jar bob.jar --auth "${DEFOLD_AUTH}" --email "${DEFOLD_USER}" resolve
 fi
 
 echo "Running bob.jar - building"
-java -jar bob.jar --debug build
+java -jar bob.jar --debug build --keep-unused
 
 echo "Starting dmengine_headless"
-./dmengine_headless
+if [ -n "${DEFOLD_BOOSTRAP_COLLECTION}" ]; then
+	./dmengine_headless --config=bootstrap.main_collection=${DEFOLD_BOOSTRAP_COLLECTION}
+else
+	./dmengine_headless
+fi

README.md

@@ -1,3 +1,5 @@
+[![Build Status](https://travis-ci.org/britzl/monarch.svg?branch=master)](https://travis-ci.org/britzl/monarch)
+
 # Monarch
 Monarch is a screen manager for the [Defold](https://www.defold.com) game engine.
 
@@ -64,7 +66,7 @@ You navigate back in the screen hierarchy in one of two ways:
 Monarch will acquire and release input focus on the game objects containing the proxies to the screens and ensure that only the top-most screen will ever have input focus.
 
 ## Popups
-A screen that is flagged as a popup (see list of screen properties above) will be treated slightly differently when it comes to navigation. If a popup is at the top of the stack (ie currently shown) and another screen or popup is shown then the current popup will be removed from the stack. This means that it is not possible to have a popup anywhere in the stack but the top. This also means that you cannot navigate back to a popup since popups can only exist on the top of the stack. Another important difference between normal screens and popups is that when a popup is shown on top of a non-popup the current top screen will not be unloaded and instead remain visible in the background.
+A screen that is flagged as a popup (see [list of screen properties](#creating-screens) above) will be treated slightly differently when it comes to navigation. If a popup is at the top of the stack (ie currently shown) and another screen or popup is shown then the current popup will be removed from the stack. This means that it is not possible to have a popup anywhere in the stack but the top. This also means that you cannot navigate back to a popup since popups can only exist on the top of the stack. Another important difference between normal screens and popups is that when a popup is shown on top of a non-popup the current top screen will not be unloaded and instead remain visible in the background.
 
 * Stack is ```[A, B]```
 * A call to ```monarch.show(C)``` is made and C is a popup
@@ -75,12 +77,14 @@ A screen that is flagged as a popup (see list of screen properties above) will b
 ## Transitions
 You can add optional transitions when navigating between screens. The default behavior is that screen navigation is instant but if you have defined a transition for a screen Monarch will wait until the transition is completed before proceeding. The Transition Url property described above should be the URL to a script with an ```on_message``` handlers for the following messages:
 
-* ```transition_show_in```
-* ```transition_show_out```
-* ```transition_back_in```
-* ```transition_back_out```
+* ```transition_show_in``` (constant defined as ```monarch.TRANSITION.SHOW_IN```)
+* ```transition_show_out``` (constant defined as ```monarch.TRANSITION.SHOW_OUT```)
+* ```transition_back_in``` (constant defined as ```monarch.TRANSITION.BACK_IN```)
+* ```transition_back_out``` (constant defined as ```monarch.TRANSITION.BACK_OUT```)
 
-When a transition is completed it is up to the developer to send a ```transition_done``` message back to the sender to indicate that the transition is completed and that Monarch can continue the navigation sequence. Monarch comes with a system for setting up transitions easily in a gui_script. Example:
+When a transition is completed it is up to the developer to send a ```transition_done``` (constant ```monarch.TRANSITION.DONE```) message back to the sender to indicate that the transition is completed and that Monarch can continue the navigation sequence. Monarch comes with a system for setting up transitions easily in a gui_script. Example:
+
+Monarch comes with a system for setting up transitions easily in a gui_script using the ```monarch.transitions.gui``` module. Example:
 
 	local transitions = require "monarch.transitions.gui"
 
@@ -99,15 +103,43 @@ When a transition is completed it is up to the developer to send a ```transition
 		self.transition.handle(message_id, message, sender)
 	end
 
+### Predefined transitions
+The predefined transitions provided by ```monarch.transitions.gui``` are:
+
+* ```slide_in_right```
+* ```slide_in_left```
+* ```slide_in_top```
+* ```slide_in_bottom```
+* ```slide_out_right```
+* ```slide_out_left```
+* ```slide_out_top```
+* ```slide_out_bottom```
+* ```scale_in```
+* ```scale_out```
+
+### Custom transitions
+You can create and use your own transition as long as the provided transition function has the following function signature:
+
+	custom_transition(node, to, easing, duration, delay, cb)
+
+**PARAMETERS**
+* ```node``` (node) - Gui node to animate.
+* ```to``` (vector3) - Target position.
+* ```easing``` (number) - One of gui.EASING_* constants.
+* ```duration``` (number) - Transition duration in seconds.
+* ```delay``` (number) - Transition delay in seconds.
+* ```cb``` (function) - This function must be called when the transition is completed.
+
+
 ## Screen focus gain/loss
 Monarch will send focus gain and focus loss messages if a Focus Url was provided when the screen was created. The focus gained message will contain the id of the previous screen and the focus loss message will contain the id of the next screen. Example:
 
 	local monarch = require "monarch.monarch"
 
 	function on_message(self, message_id, message, sender)
-		if message_id == monarch.FOCUS_GAINED then
+		if message_id == monarch.FOCUS.GAINED then
 			print("Focus gained, previous screen: ", message.id)
-		elseif message_id == monarch.FOCUS_LOST then
+		elseif message_id == monarch.FOCUS.LOST then
 			print("Focus lost, next screen: ", message.id)
 		end
 	end
@@ -124,7 +156,7 @@ Show a Monarch screen
 * ```screen_id``` (hash) - Id of the screen to show.
 * ```options``` (table) - Options when showing the new screen (see below).
 * ```data``` (table) - Optional data to associate with the screen.  Retrieve using ```monarch.data()```.
-* ```callback``` (function) - Function to call when the new screen is visible.
+* ```callback``` (function) - Optional function to call when the new screen is visible.
 
 The options table can contain the following fields:
 
@@ -136,7 +168,7 @@ Go back to a previous Monarch screen
 
 **PARAMETERS**
 * ```data``` (table) - Optional data to associate with the screen you are going back to.  Retrieve using ```monarch.data()```.
-* ```callback``` (function) - Function to call when the previous screen is visible.
+* ```callback``` (function) - Optional function to call when the previous screen is visible.
 
 
 ### monarch.data(screen_id)

example/main.script

@@ -1,14 +1,13 @@
 local monarch = require "monarch.monarch"
 
 function init(self)
-	self.wait = true
+	monarch.debug()
 	msg.post("@render:/", "clear_color", { color = vmath.vector4(0.4, 0.6, 0.8,1.0) })
+	msg.post("#", "init_monarch") -- wait until init() has been called for all screen.script instances
 end
 
-function update(self)
-	-- Ensure that the initial screen has had enough time to register
-	if self.wait == true and monarch.screen_exists(hash("menu")) then
-		self.wait = false
+function on_message(self, message_id, message, sender)
+	if message_id == hash("init_monarch") then
 		monarch.show(hash("menu"))
 	end
 end

monarch/monarch.lua

@@ -26,6 +26,12 @@ M.FOCUS.GAINED = hash("monarch_focus_gained")
 M.FOCUS.LOST = hash("monarch_focus_lost")
 
 
+local function log(...) end
+
+function M.debug()
+	log = print
+end
+
 local function screen_from_proxy(proxy)
 	for _, screen in pairs(screens) do
 		if screen.proxy == proxy then
@@ -101,29 +107,86 @@ function M.unregister(id)
 	screens[id] = nil
 end
 
+local function acquire_input(screen)
+	log("change_context()", screen.id)
+	if not screen.input then
+		msg.post(screen.script, ACQUIRE_INPUT_FOCUS)
+		screen.input = true
+	end
+end
+
+local function release_input(screen)
+	log("change_context()", screen.id)
+	if screen.input then
+		msg.post(screen.script, RELEASE_INPUT_FOCUS)
+		screen.input = false
+	end
+end
+
+local function change_context(screen)
+	log("change_context()", screen.id)
+	screen.wait_for = CONTEXT
+	msg.post(screen.script, CONTEXT)
+	coroutine.yield()
+	screen.wait_for = nil
+end
+
+local function unload(screen)
+	log("unload()", screen.id)
+	screen.wait_for = PROXY_UNLOADED
+	msg.post(screen.proxy, UNLOAD)
+	coroutine.yield()
+	screen.loaded = false
+	screen.wait_for = nil
+end
+
+local function async_load(screen)
+	log("async_load()", screen.id)
+	screen.wait_for = PROXY_LOADED
+	msg.post(screen.proxy, ASYNC_LOAD)
+	coroutine.yield()
+	msg.post(screen.proxy, ENABLE)
+	screen.loaded = true
+	screen.wait_for = nil
+end
+
+local function transition(screen, message_id)
+	log("transition()", screen.id)
+	screen.wait_for = M.TRANSITION.DONE
+	msg.post(screen.transition_url, message_id)
+	coroutine.yield()
+	screen.wait_for = nil
+end
+
+local function focus_gained(screen, previous_screen)
+	log("focus_gained()", screen.id)
+	if screen.focus_url then
+		msg.post(screen.focus_url, M.FOCUS.GAINED, {id = previous_screen and previous_screen.id})
+	end
+end
+
+local function focus_lost(screen, next_screen)
+	log("focus_lost()", screen.id)
+	if screen.focus_url then
+		msg.post(screen.focus_url, M.FOCUS.LOST, {id = next_screen and next_screen.id})
+	end
+end
+
 local function show_out(screen, next_screen, cb)
+	log("show_out()", screen.id)
 	local co
 	co = coroutine.create(function()
 		screen.co = co
-		msg.post(screen.script, RELEASE_INPUT_FOCUS)
-		screen.input = false
-
-		if screen.focus_url then
-			msg.post(screen.focus_url, M.FOCUS.LOST, {id = next_screen.id})
-		end
-				
-		msg.post(screen.script, CONTEXT)
-		coroutine.yield()
+		change_context(screen)
+		release_input(screen)
+		focus_lost(screen, next_screen)
 		-- if the next screen is a popup we want the current screen to stay visible below the popup
 		-- if the next screen isn't a popup the current one should be unloaded and transitioned out
 		local next_is_popup = next_screen and not next_screen.popup
 		local current_is_popup = screen.popup
 		if (next_is_popup and not current_is_popup) or (current_is_popup) then
-			msg.post(screen.transition_url, M.TRANSITION.SHOW_OUT)
-			coroutine.yield()
-			msg.post(screen.proxy, UNLOAD)
-			coroutine.yield()
-			screen.loaded = false
+			transition(screen, M.TRANSITION.SHOW_OUT)
+			unload(screen)
 		end
 		screen.co = nil
 		if cb then cb() end
@@ -132,39 +195,25 @@ local function show_out(screen, next_screen, cb)
 end
 
 local function show_in(screen, previous_screen, reload, cb)
+	log("show_in()", screen.id)
 	local co
 	co = coroutine.create(function()
 		screen.co = co
-		msg.post(screen.script, CONTEXT)
-		coroutine.yield()
-
+		change_context(screen)
 		if reload and screen.loaded then
-			msg.post(screen.proxy, UNLOAD)
-			coroutine.yield()
-			screen.loaded = false
+			log("show_in() reloading", screen.id)
+			unload(screen)
 		end
-	
 		-- the screen could be loaded if the previous screen was a popup
 		-- and the popup asked to show this screen again
 		-- in that case we shouldn't attempt to load it again
 		if not screen.loaded then
-			msg.post(screen.proxy, ASYNC_LOAD)
-			coroutine.yield()
-			msg.post(screen.proxy, ENABLE)
-			screen.loaded = true
+			async_load(screen)
 		end
 		stack[#stack + 1] = screen
-		msg.post(screen.transition_url, M.TRANSITION.SHOW_IN)
-		coroutine.yield()
-
-		if not screen.input then
-			msg.post(screen.script, ACQUIRE_INPUT_FOCUS)
-			screen.input = true
-		end
-		
-		if screen.focus_url then
-			msg.post(screen.focus_url, M.FOCUS.GAINED, {id = previous_screen and previous_screen.id})
-		end
+		transition(screen, M.TRANSITION.SHOW_IN)
+		acquire_input(screen)
+		focus_gained(screen, previous_screen)
 		screen.co = nil
 		if cb then cb() end
 	end)
@@ -172,30 +221,19 @@ local function show_in(screen, previous_screen, reload, cb)
 end
 
 local function back_in(screen, previous_screen, cb)
+	log("back_in()", screen.id)
 	local co
 	co = coroutine.create(function()
 		screen.co = co
-		msg.post(screen.script, CONTEXT)
-		coroutine.yield()
+		change_context(screen)
 		if not screen.loaded then
-			msg.post(screen.proxy, ASYNC_LOAD)
-			coroutine.yield()
-			msg.post(screen.proxy, ENABLE)
-			screen.loaded = true
+			async_load(screen)
 		end
 		if previous_screen and not previous_screen.popup then
-			msg.post(screen.transition_url, M.TRANSITION.BACK_IN)
-			coroutine.yield()
-		end
-
-		if not screen.input then
-			msg.post(screen.script, ACQUIRE_INPUT_FOCUS)
-			screen.input = true
-		end
-
-		if screen.focus_url then
-			msg.post(screen.focus_url, M.FOCUS.GAINED, {id = previous_screen.id})
+			transition(screen, M.TRANSITION.BACK_IN)
 		end
+		acquire_input(screen)
+		focus_gained(screen, previous_screen)
 		screen.co = nil
 		if cb then cb() end
 	end)
@@ -203,21 +241,15 @@ local function back_in(screen, previous_screen, cb)
 end
 
 local function back_out(screen, next_screen, cb)
+	log("back_out()", screen.id)
 	local co
 	co = coroutine.create(function()
 		screen.co = co
-		msg.post(screen.script, RELEASE_INPUT_FOCUS)
-		screen.input = false
-		if screen.focus_url then
-			msg.post(screen.focus_url, M.FOCUS.LOST, {id = next_screen and next_screen.id})
-		end
-		msg.post(screen.script, CONTEXT)
-		coroutine.yield()
-		msg.post(screen.transition_url, M.TRANSITION.BACK_OUT)
-		coroutine.yield()
-		msg.post(screen.proxy, UNLOAD)
-		coroutine.yield()
-		screen.loaded = false
+		change_context(screen)
+		release_input(screen)
+		focus_lost(screen, next_screen)
+		transition(screen, M.TRANSITION.BACK_OUT)
+		unload(screen)
 		screen.co = nil
 		if cb then cb() end
 	end)
@@ -256,6 +288,8 @@ function M.show(id, options, data, cb)
 	local screen = screens[id]
 	screen.data = data
 
+	log("show()", screen.id)
+
 	-- manipulate the current top
 	-- close popup if needed
 	-- transition out
@@ -279,6 +313,7 @@ function M.show(id, options, data, cb)
 	-- to remove every screen on the stack up until and
 	-- including the screen itself
 	if options and options.clear then
+		log("show() clearing")
 		while M.in_stack(id) do
 			table.remove(stack)
 		end
@@ -295,6 +330,7 @@ end
 function M.back(data, cb)
 	local screen = table.remove(stack)
 	if screen then
+		log("back()", screen.id)
 		local top = stack[#stack]
 		-- if we go back to the same screen we need to first hide it
 		-- and wait until it is hidden before we show it again
@@ -324,19 +360,27 @@ function M.on_message(message_id, message, sender)
 	if message_id == PROXY_LOADED then
 		local screen = screen_from_proxy(sender)
 		assert(screen, "Unable to find screen for loaded proxy")
-		assert(coroutine.resume(screen.co))
+		if screen.wait_for == PROXY_LOADED then
+			assert(coroutine.resume(screen.co))
+		end
 	elseif message_id == PROXY_UNLOADED then
 		local screen = screen_from_proxy(sender)
 		assert(screen, "Unable to find screen for unloaded proxy")
-		assert(coroutine.resume(screen.co))
+		if screen.wait_for == PROXY_UNLOADED then
+			assert(coroutine.resume(screen.co))
+		end
 	elseif message_id == CONTEXT then
 		local screen = screen_from_script()
 		assert(screen, "Unable to find screen for current script url")
-		assert(coroutine.resume(screen.co))
+		if screen.wait_for == CONTEXT then
+			assert(coroutine.resume(screen.co))
+		end
 	elseif message_id == M.TRANSITION.DONE then
 		local screen = screen_from_script()
 		assert(screen, "Unable to find screen for current script url")
-		assert(coroutine.resume(screen.co))
+		if screen.wait_for == M.TRANSITION.DONE then
+			assert(coroutine.resume(screen.co))
+		end
 	end
 end
 

monarch/transitions/gui.lua

@@ -12,71 +12,63 @@ local BOTTOM = vmath.vector3(0, - HEIGHT * 2, 0)
 
 local ZERO_SCALE = vmath.vector3(0, 0, 1)
 
-function M.instant(node, to, easing, duration, delay, url)
-	msg.post(url, monarch.TRANSITION.DONE)
+function M.instant(node, to, easing, duration, delay, cb)
+	cb()
 end
 
-local function slide_in(direction, node, to, easing, duration, delay, url)
+local function slide_in(direction, node, to, easing, duration, delay, cb)
 	local from = to + direction
 	gui.set_position(node, from)
-	gui.animate(node, gui.PROP_POSITION, to, easing, duration, delay, function()
-		msg.post(url, monarch.TRANSITION.DONE)
-	end)
+	gui.animate(node, gui.PROP_POSITION, to, easing, duration, delay, cb)
 end
 
-function M.slide_in_left(node, to, easing, duration, delay, url)
-	return slide_in(LEFT, node, to.pos, easing, duration, delay, url)
+function M.slide_in_left(node, to, easing, duration, delay, cb)
+	return slide_in(LEFT, node, to.pos, easing, duration, delay, cb)
 end
 
-function M.slide_in_right(node, to, easing, duration, delay, url)
-	slide_in(RIGHT, node, to.pos, easing, duration, delay, url)
+function M.slide_in_right(node, to, easing, duration, delay, cb)
+	slide_in(RIGHT, node, to.pos, easing, duration, delay, cb)
 end
 
-function M.slide_in_top(node, to, easing, duration, delay, url)
-	slide_in(TOP, node, to.pos, easing, duration, delay, url)
+function M.slide_in_top(node, to, easing, duration, delay, cb)
+	slide_in(TOP, node, to.pos, easing, duration, delay, cb)
 end
 
-function M.slide_in_bottom(node, to, easing, duration, delay, url)
-	slide_in(BOTTOM, node, to.pos, easing, duration, delay, url)
+function M.slide_in_bottom(node, to, easing, duration, delay, cb)
+	slide_in(BOTTOM, node, to.pos, easing, duration, delay, cb)
 end
 
 
-local function slide_out(direction, node, from, easing, duration, delay, url)
+local function slide_out(direction, node, from, easing, duration, delay, cb)
 	local to = from + direction
 	gui.set_position(node, from)
-	gui.animate(node, gui.PROP_POSITION, to, easing, duration, delay, function()
-		msg.post(url, monarch.TRANSITION.DONE)
-	end)
+	gui.animate(node, gui.PROP_POSITION, to, easing, duration, delay, cb)
 end
 
-function M.slide_out_left(node, from, easing, duration, delay, url)
-	slide_out(LEFT, node, from.pos, easing, duration, delay, url)
+function M.slide_out_left(node, from, easing, duration, delay, cb)
+	slide_out(LEFT, node, from.pos, easing, duration, delay, cb)
 end
 
-function M.slide_out_right(node, from, easing, duration, delay, url)
-	slide_out(RIGHT, node, from.pos, easing, duration, delay, url)
+function M.slide_out_right(node, from, easing, duration, delay, cb)
+	slide_out(RIGHT, node, from.pos, easing, duration, delay, cb)
 end
 
-function M.slide_out_top(node, from, easing, duration, delay, url)
-	slide_out(TOP, node, from.pos, easing, duration, delay, url)
+function M.slide_out_top(node, from, easing, duration, delay, cb)
+	slide_out(TOP, node, from.pos, easing, duration, delay, cb)
 end
 
-function M.slide_out_bottom(node, from, easing, duration, delay, url)
-	slide_out(BOTTOM, node, from.pos, easing, duration, delay, url)
+function M.slide_out_bottom(node, from, easing, duration, delay, cb)
+	slide_out(BOTTOM, node, from.pos, easing, duration, delay, cb)
 end
 
-function M.scale_in(node, to, easing, duration, delay, url)
+function M.scale_in(node, to, easing, duration, delay, cb)
 	gui.set_scale(node, ZERO_SCALE)
-	gui.animate(node, gui.PROP_SCALE, to.scale, easing, duration, delay, function()
-		msg.post(url, monarch.TRANSITION.DONE)
-	end)
+	gui.animate(node, gui.PROP_SCALE, to.scale, easing, duration, delay, cb)
 end
 
-function M.scale_out(node, from, easing, duration, delay, url)
+function M.scale_out(node, from, easing, duration, delay, cb)
 	gui.set_scale(node, from.scale)
-	gui.animate(node, gui.PROP_SCALE, ZERO_SCALE, easing, duration, delay, function()
-		msg.post(url, monarch.TRANSITION.DONE)
-	end)
+	gui.animate(node, gui.PROP_SCALE, ZERO_SCALE, easing, duration, delay, cb)
 end
 
 --- Create a transition for a node
@@ -86,21 +78,42 @@ function M.create(node)
 
 	local instance = {}
 
-	local transitions = {
-		[monarch.TRANSITION.SHOW_IN] = M.instant,
-		[monarch.TRANSITION.SHOW_OUT] = M.instant,
-		[monarch.TRANSITION.BACK_IN] = M.instant,
-		[monarch.TRANSITION.BACK_OUT] = M.instant,
-	}
+	local transitions = {}
 
 	local initial_data = {}
 	initial_data.pos = gui.get_position(node)
 	initial_data.scale = gui.get_scale(node)
 
+	local function create_transition(fn, easing, duration, delay)
+		return {
+			fn = fn,
+			easing = easing,
+			duration = duration,
+			delay = delay,
+			in_progress = false,
+			urls = {},
+		}
+	end
+
+	local function start_transition(transition, url)
+		table.insert(transition.urls, url)
+		if not transition.in_progress then
+			transition.in_progress = true
+			transition.fn(node, initial_data, transition.easing, transition.duration, transition.delay or 0, function()
+				transition.in_progress = false
+				while #transition.urls > 0 do
+					local url = table.remove(transition.urls)
+					msg.post(url, monarch.TRANSITION.DONE)
+				end
+			end)
+		end
+	end
+
 	-- Forward on_message calls here
 	function instance.handle(message_id, message, sender)
-		if transitions[message_id] then
-			transitions[message_id](sender)
+		local transition = transitions[message_id]
+		if transition then
+			start_transition(transition, sender)
 		end
 	end
 	
@@ -111,39 +124,37 @@ function M.create(node)
 	-- @param duration Transition duration
 	-- @param delay Transition delay
 	function instance.show_in(fn, easing, duration, delay)
-		transitions[monarch.TRANSITION.SHOW_IN] = function(url)
-			fn(node, initial_data, easing, duration, delay or 0, url)
-		end
+		transitions[monarch.TRANSITION.SHOW_IN] = create_transition(fn, easing, duration, delay)
 		return instance
 	end
 
 	-- Specify the transition function when this node is transitioned
 	-- from when showing another screen
 	function instance.show_out(fn, easing, duration, delay)
-		transitions[monarch.TRANSITION.SHOW_OUT] = function(url)
-			fn(node, initial_data, easing, duration, delay or 0, url)
-		end
+		transitions[monarch.TRANSITION.SHOW_OUT] = create_transition(fn, easing, duration, delay)
 		return instance
 	end
 
 	--- Specify the transition function when this node is transitioned
 	-- to when navigating back in the screen stack
 	function instance.back_in(fn, easing, duration, delay)
-		transitions[monarch.TRANSITION.BACK_IN] = function(url)
-			fn(node, initial_data, easing, duration, delay or 0, url)
-		end
+		transitions[monarch.TRANSITION.BACK_IN] = create_transition(fn, easing, duration, delay)
 		return instance
 	end
 
 	--- Specify the transition function when this node is transitioned
 	-- from when navigating back in the screen stack
 	function instance.back_out(fn, easing, duration, delay)
-		transitions[monarch.TRANSITION.BACK_OUT] = function(url)
-			fn(node, initial_data, easing, duration, delay or 0, url)
-		end
+		transitions[monarch.TRANSITION.BACK_OUT] = create_transition(fn, easing, duration, delay)
 		return instance
 	end
 
+	-- set default transitions (instant)
+	instance.show_in(M.instant)
+	instance.show_out(M.instant)
+	instance.back_in(M.instant)
+	instance.back_out(M.instant)
+	
 	return instance
 end