diff --git a/example/slidingwindow/slidingwindow.collection b/example/slidingwindow/slidingwindow.collection
index fcd88ef..bdca53d 100644
--- a/example/slidingwindow/slidingwindow.collection
+++ b/example/slidingwindow/slidingwindow.collection
@@ -58,11 +58,6 @@ embedded_instances {
   "    value: \"window1\"\n"
   "    type: PROPERTY_TYPE_HASH\n"
   "  }\n"
-  "  properties {\n"
-  "    id: \"transition_url\"\n"
-  "    value: \"window1:/go\"\n"
-  "    type: PROPERTY_TYPE_URL\n"
-  "  }\n"
   "  property_decls {\n"
   "  }\n"
   "}\n"
@@ -123,11 +118,6 @@ embedded_instances {
   "    value: \"window2\"\n"
   "    type: PROPERTY_TYPE_HASH\n"
   "  }\n"
-  "  properties {\n"
-  "    id: \"transition_url\"\n"
-  "    value: \"window2:/go\"\n"
-  "    type: PROPERTY_TYPE_URL\n"
-  "  }\n"
   "  property_decls {\n"
   "  }\n"
   "}\n"
diff --git a/example/slidingwindow/window1.gui b/example/slidingwindow/window1.gui
index dcbd241..770393c 100644
--- a/example/slidingwindow/window1.gui
+++ b/example/slidingwindow/window1.gui
@@ -47,7 +47,7 @@ nodes {
   xanchor: XANCHOR_NONE
   yanchor: YANCHOR_NONE
   pivot: PIVOT_CENTER
-  adjust_mode: ADJUST_MODE_FIT
+  adjust_mode: ADJUST_MODE_STRETCH
   layer: ""
   inherit_alpha: true
   slice9 {
diff --git a/example/slidingwindow/window1.gui_script b/example/slidingwindow/window1.gui_script
index 5aefe8e..73c12b0 100644
--- a/example/slidingwindow/window1.gui_script
+++ b/example/slidingwindow/window1.gui_script
@@ -2,12 +2,16 @@ local monarch = require "monarch.monarch"
 local transitions = require "monarch.transitions.gui"
 
 function init(self)
-	print("window2", msg.url())
-	self.transition = transitions.create(gui.get_node("bg"))
-	.show_in(transitions.slide_in_right, gui.EASING_LINEAR, 0.3, 0)
-	.show_out(transitions.slide_out_left, gui.EASING_LINEAR, 0.3, 0)
-	.back_in(transitions.slide_in_left, gui.EASING_LINEAR, 0.3, 0)
-	.back_out(transitions.slide_out_right, gui.EASING_LINEAR, 0.3, 0)
+	print("window1", msg.url())
+
+	local DURATION = 1
+	local transition = transitions.create(gui.get_node("bg"))
+	.show_in(transitions.slide_in_right, gui.EASING_LINEAR, DURATION, 0)
+	.show_out(transitions.slide_out_left, gui.EASING_LINEAR, DURATION, 0)
+	.back_in(transitions.slide_in_left, gui.EASING_LINEAR, DURATION, 0)
+	.back_out(transitions.slide_out_right, gui.EASING_LINEAR, DURATION, 0)
+
+	monarch.on_transition("window1", transition)
 
 	msg.post(".", "acquire_input_focus")
 end
@@ -21,5 +25,5 @@ function on_input(self, action_id, action)
 end
 
 function on_message(self, message_id, message, sender)
-	self.transition.handle(message_id, message, sender)
+	monarch.on_message(message_id, message, sender)
 end
\ No newline at end of file
diff --git a/example/slidingwindow/window2.gui b/example/slidingwindow/window2.gui
index a2468b3..2d600a3 100644
--- a/example/slidingwindow/window2.gui
+++ b/example/slidingwindow/window2.gui
@@ -47,7 +47,7 @@ nodes {
   xanchor: XANCHOR_NONE
   yanchor: YANCHOR_NONE
   pivot: PIVOT_CENTER
-  adjust_mode: ADJUST_MODE_FIT
+  adjust_mode: ADJUST_MODE_STRETCH
   layer: ""
   inherit_alpha: true
   slice9 {
diff --git a/example/slidingwindow/window2.gui_script b/example/slidingwindow/window2.gui_script
index 59bb108..f81fbb2 100644
--- a/example/slidingwindow/window2.gui_script
+++ b/example/slidingwindow/window2.gui_script
@@ -3,11 +3,15 @@ local transitions = require "monarch.transitions.gui"
 
 function init(self)
 	print("window2", msg.url())
-	self.transition = transitions.create(gui.get_node("bg"))
-	.show_in(transitions.slide_in_right, gui.EASING_LINEAR, 0.3, 0)
-	.show_out(transitions.slide_out_left, gui.EASING_LINEAR, 0.3, 0)
-	.back_in(transitions.slide_in_left, gui.EASING_LINEAR, 0.3, 0)
-	.back_out(transitions.slide_out_right, gui.EASING_LINEAR, 0.3, 0)
+
+	local DURATION = 1
+	local transition = transitions.create(gui.get_node("bg"))
+	.show_in(transitions.slide_in_right, gui.EASING_LINEAR, DURATION, 0)
+	.show_out(transitions.slide_out_left, gui.EASING_LINEAR, DURATION, 0)
+	.back_in(transitions.slide_in_left, gui.EASING_LINEAR, DURATION, 0)
+	.back_out(transitions.slide_out_right, gui.EASING_LINEAR, DURATION, 0)
+
+	monarch.on_transition("window2", transition)
 
 	msg.post(".", "acquire_input_focus")
 end
@@ -21,5 +25,5 @@ function on_input(self, action_id, action)
 end
 
 function on_message(self, message_id, message, sender)
-	self.transition.handle(message_id, message, sender)
+	monarch.on_message(message_id, message, sender)
 end
\ No newline at end of file
diff --git a/monarch/monarch.lua b/monarch/monarch.lua
index 38c1077..ff5aac8 100644
--- a/monarch/monarch.lua
+++ b/monarch/monarch.lua
@@ -6,6 +6,7 @@ local M = {}
 local CONTEXT = hash("monarch_context")
 local PROXY_LOADED = hash("proxy_loaded")
 local PROXY_UNLOADED = hash("proxy_unloaded")
+local LAYOUT_CHANGED = hash("layout_changed")
 
 local RELEASE_INPUT_FOCUS = hash("release_input_focus")
 local ACQUIRE_INPUT_FOCUS = hash("acquire_input_focus")
@@ -134,18 +135,22 @@ local function notify_transition_listeners(message_id, message)
 	end
 end
 
-local function screen_from_proxy(proxy)
+local function find_screen(url)
+	local current_url = msg.url()
 	for _,screen in pairs(screens) do
-		if screen.proxy == proxy then
+		if screen.transition_url == current_url
+		or screen.script == current_url
+		or screen.proxy == current_url
+		then
 			return screen
 		end
 	end
-end
 
-local function screen_from_script()
-	local url = msg.url()
 	for _,screen in pairs(screens) do
-		if screen.script == url then
+		if screen.transition_url == url
+		or screen.script == url
+		or screen.proxy == url
+		then
 			return screen
 		end
 	end
@@ -612,6 +617,7 @@ local function show_in(screen, previous_screen, reload, add_to_stack, wait_for_t
 			notify_transition_listeners(M.SCREEN_TRANSITION_FAILED, { screen = screen.id })
 			return
 		end
+		cowait(0)
 		reset_timestep(screen)
 		transition(screen, M.TRANSITION.SHOW_IN, { previous_screen = previous_screen and previous_screen.id }, wait_for_transition)
 		screen.visible = true
@@ -1128,29 +1134,44 @@ end
 
 function M.on_message(message_id, message, sender)
 	if message_id == PROXY_LOADED then
-		local screen = screen_from_proxy(sender)
+		local screen = find_screen(sender)
 		assert(screen, "Unable to find screen for loaded proxy")
 		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)
+		local screen = find_screen(sender)
 		assert(screen, "Unable to find screen for unloaded proxy")
 		if screen.wait_for == PROXY_UNLOADED then
 			assert(coroutine.resume(screen.co))
 		end
 	elseif message_id == CONTEXT then
-		local screen = screen_from_script()
+		local screen = find_screen(sender)
 		assert(screen, "Unable to find screen for current script url")
 		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")
+		local screen = find_screen(sender)
+		assert(screen, "Unable to find screen for transition")
 		if screen.wait_for == M.TRANSITION.DONE then
 			assert(coroutine.resume(screen.co))
 		end
+	elseif message_id == M.TRANSITION.SHOW_IN
+	or message_id == M.TRANSITION.SHOW_OUT
+	or message_id == M.TRANSITION.BACK_IN
+	or message_id == M.TRANSITION.BACK_OUT
+	then
+		local screen = find_screen(sender)
+		assert(screen, "Unable to find screen for transition")
+		if screen.transition_fn then
+			screen.transition_fn(message_id, message, sender)
+		end
+	elseif message_id == LAYOUT_CHANGED then
+		local screen = find_screen(sender)
+		if screen and screen.transition_fn then
+			screen.transition_fn(message_id, message, sender)
+		end
 	end
 end
 
@@ -1197,6 +1218,17 @@ function M.set_timestep_below_popup(id, timestep)
 end
 
 
+function M.on_transition(id, fn)
+	assert(id, "You must provide a screen id")
+	assert(fn, "You must provide a transition function")
+	id = tohash(id)
+	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
+	local screen = screens[id]
+	screen.transition_url = msg.url()
+	screen.transition_fn = fn
+end
+
+
 local function url_to_key(url)
 	return (url.socket or hash("")) .. (url.path or hash("")) .. (url.fragment or hash(""))
 end
diff --git a/monarch/transitions/gui.lua b/monarch/transitions/gui.lua
index e7eb3a6..0f67527 100644
--- a/monarch/transitions/gui.lua
+++ b/monarch/transitions/gui.lua
@@ -20,10 +20,10 @@ local LAYOUT_CHANGED = hash("layout_changed")
 function M.window_resized(width, height)
 	WIDTH = width
 	HEIGHT = height
-	LEFT = vmath.vector3(-WIDTH * 2, 0, 0)
-	RIGHT = vmath.vector3(WIDTH * 2, 0, 0)
-	TOP = vmath.vector3(0, HEIGHT * 2, 0)
-	BOTTOM = vmath.vector3(0, - HEIGHT * 2, 0)
+	LEFT = vmath.vector3(-WIDTH, 0, 0)
+	RIGHT = vmath.vector3(WIDTH, 0, 0)
+	TOP = vmath.vector3(0, HEIGHT, 0)
+	BOTTOM = vmath.vector3(0, - HEIGHT, 0)
 end
 
 M.window_resized(tonumber(sys.get_config("display.width")), tonumber(sys.get_config("display.height")))
@@ -176,7 +176,6 @@ local function create()
 		local t = transitions[transition_id]
 		table.insert(t.urls, url)
 		if t.in_progress_count == 0 then
-			table.insert(t.urls, msg.url())
 			current_transition = t
 			current_transition.id = transition_id
 			if #t.transitions > 0 then
@@ -254,7 +253,11 @@ local function create()
 		return instance
 	end
 
-	return instance
+	return setmetatable(instance, {
+		__call = function(t, ...)
+			return instance.handle(...)
+		end
+	})
 end
 
 function M.create(node)