Don't create a transition for a node if one already exists

Fixes #50

.travis.yml

@@ -17,11 +17,12 @@ language: java
 jdk:
   - oraclejdk8
 
-#DEFOLD_AUTH=auth token
+dist: trusty
+
 env:
   global:
-    - secure: "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"
-    - DEFOLD_USER=bjorn.ritzl@king.com
+    - DEFOLD_AUTH=foobar
+    - DEFOLD_USER=bjorn.ritzl@gmail.com
     - DEFOLD_BOOSTRAP_COLLECTION=/test/test.collectionc
 
 script:

README.md

@@ -31,8 +31,9 @@ For proxies the recommended setup is to create one game object per screen and pe
 * **Popup (boolean)** - Check this if the screen should be treated as a [popup](#popups).
 * **Popup on Popup (boolean)** - Check this if the screen is a [popup](#popups) and it can be shown on top of other popups.
 * **Timestep below Popup (number)** - Timestep to set on screen proxy when it is below a popup. This is useful when pausing animations and gameplay while a popup is open.
-* **Transition Url (url)** - Optional URL to call when the screen is about to be shown/hidden. Use this to trigger a transition (see the section on [transitions](#transitions)).
-* **Focus Url (url)** - Optional URL to call when the screen gains or loses focus (see the section on [screen focus](#screen-focus-gainloss)).
+* **Transition Url (url)** - Optional URL to post messages to when the screen is about to be shown/hidden. Use this to trigger a transition (see the section on [transitions](#transitions)).
+* **Focus Url (url)** - Optional URL to post messages to when the screen gains or loses focus (see the section on [screen focus](#screen-focus-gainloss)).
+* **Receiver Url (url)** - Optional URL to post messages to using `monarch.post()`.
 * **Preload (boolean)** - Check this if the screen should be preloaded and kept loaded at all times. For a collection proxy it means that it will be async loaded but not enabled at all times while not visible. This can also temporarily be achieved through the `monarch.preload()` function.
 
 ![](docs/setup_proxy.png)
@@ -44,8 +45,8 @@ For factories the recommended setup is to create one game object per screen and
 * **Screen Id (hash)** - A unique id that can be used to reference the screen when navigating your app.
 * **Popup (boolean)** - Check this if the screen should be treated as a [popup](#popups).
 * **Popup on Popup (boolean)** - Check this if the screen is a [popup](#popups) and it can be shown on top of other popups.
-* **Transition Id (url)** - Optional id of the game object to send a message to when the screen is about to be shown/hidden. Use this to trigger a transition (see the section on [transitions](#transitions)).
-* **Focus Id (url)** - Optional id of the game object to send a message to when the screen gains or loses focus (see the section on [screen focus](#screen-focus-gainloss)).
+* **Transition Id (hash)** - Optional id of the game object to send a message to when the screen is about to be shown/hidden. Use this to trigger a transition (see the section on [transitions](#transitions)).
+* **Focus Id (hash)** - Optional id of the game object to send a message to when the screen gains or loses focus (see the section on [screen focus](#screen-focus-gainloss)).
 * **Preload (boolean)** - Check this if the screen should be preloaded and kept loaded at all times. For a collection factory this means that its resources will be dynamically loaded at all times. This can also temporarily be achieved through the `monarch.preload()` function.
 
 ![](docs/setup_factory.png)
@@ -147,7 +148,7 @@ If a screen is shown on top of one or more popups they will all be removed from
 
 
 ## 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:
+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` (proxy) or `Transition Id` (collectionfactory) property described above should be the URL/Id to a script with an ```on_message``` handlers for the following messages:
 
 * ```transition_show_in``` (constant defined as ```monarch.TRANSITION.SHOW_IN```)
 * ```transition_show_out``` (constant defined as ```monarch.TRANSITION.SHOW_OUT```)
@@ -266,7 +267,7 @@ This information can be used to create dynamic transitions where the direction o
 
 
 ## 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:
+Monarch will send focus gain and focus loss messages if a `Focus Url` (proxy) or `Focus Id` (collectionfactory) 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"
 
@@ -289,7 +290,7 @@ Both the ```monarch.show()``` and ```monarch.back()``` functions take an optiona
 Show a Monarch screen. Note that the screen must be registered before it can be shown. The ```init()``` function of the ```screen.script``` takes care of registration.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to show.
+* ```screen_id``` (string|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) - Optional function to call when the new screen is visible.
@@ -308,7 +309,7 @@ The options table can contain the following fields:
 Hide a screen that has been shown using the `no_stack` option. If used on a screen that was shown without the `no_stack` option it will only hide it if the screen is on top of the stack and the behavior will be exactly like if `monarch.back()` had been called.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to hide.
+* ```screen_id``` (string|hash) - Id of the screen to hide.
 * ```callback``` (function) - Optional function to call when the screen has been hidden.
 
 **RETURN**
@@ -330,7 +331,7 @@ Go back to a previous Monarch screen
 Preload a Monarch screen. This will load but not enable the screen. This is useful for content heavy screens that you wish to be able to show without having to wait for it load.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to preload.
+* ```screen_id``` (string|hash) - Id of the screen to preload.
 * ```callback``` (function) - Optional function to call when the screen is preloaded.
 
 
@@ -338,7 +339,7 @@ Preload a Monarch screen. This will load but not enable the screen. This is usef
 Check if a Monarch screen is preloading (via monarch.preload() or the Preload screen setting).
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to check
+* ```screen_id``` (string|hash) - Id of the screen to check
 
 **RETURN**
 * ```preloading``` (boolean) - True if the screen is preloading.
@@ -348,7 +349,7 @@ Check if a Monarch screen is preloading (via monarch.preload() or the Preload sc
 Invoke a callback when a screen has been preloaded.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to check
+* ```screen_id``` (string|hash) - Id of the screen to check
 * ```callback``` (function) - Function to call when the screen has been preloaded.
 
 
@@ -356,7 +357,7 @@ Invoke a callback when a screen has been preloaded.
 Unload a preloaded Monarch screen. A preloaded screen will automatically get unloaded when hidden, but this function can be useful if a screen has been preloaded and it needs to be unloaded again without actually hiding it.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to unload.
+* ```screen_id``` (string|hash) - Id of the screen to unload.
 * ```callback``` (function) - Optional function to call when the screen is unloaded.
 
 
@@ -367,7 +368,7 @@ Get the id of the screen at the top of the stack.
 * ```offset``` (number) - Optional offset from the top of the stack, ie -1 to get the previous screen
 
 **RETURN**
-* ```screen_id``` (hash) - Id of the requested screen
+* ```screen_id``` (string|hash) - Id of the requested screen
 
 
 ### monarch.bottom([offset])
@@ -377,14 +378,14 @@ Get the id of the screen at the bottom of the stack.
 * ```offset``` (number) - Optional offset from the bottom of the stack
 
 **RETURN**
-* ```screen_id``` (hash) - Id of the requested screen
+* ```screen_id``` (string|hash) - Id of the requested screen
 
 
 ### monarch.data(screen_id)
 Get the data associated with a screen (from a call to ```monarch.show()``` or ```monarch.back()```).
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to get data for
+* ```screen_id``` (string|hash) - Id of the screen to get data for
 
 **RETURN**
 * ```data``` (table) - Data associated with the screen.
@@ -394,7 +395,7 @@ Get the data associated with a screen (from a call to ```monarch.show()``` or ``
 Check if a Monarch screen exists.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to get data for
+* ```screen_id``` (string|hash) - Id of the screen to get data for
 
 **RETURN**
 * ```exists``` (boolean) - True if the screen exists.
@@ -407,21 +408,21 @@ Check if Monarch is busy showing and/or hiding a screen.
 * ```busy``` (boolean) - True if busy hiding and/or showing a screen.
 
 
-### monarch.is_top(id)
+### monarch.is_top(screen_id)
 Check if a Monarch screen is at the top of the view stack.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to check
+* ```screen_id``` (string|hash) - Id of the screen to check
 
 **RETURN**
 * ```exists``` (boolean) - True if the screen is at the top of the stack.
 
 
-### monarch.is_visible(id)
+### monarch.is_visible(screen_id)
 Check if a Monarch screen is visible.
 
 **PARAMETERS**
-* ```screen_id``` (hash) - Id of the screen to check
+* ```screen_id``` (string|hash) - Id of the screen to check
 
 **RETURN**
 * ```exists``` (boolean) - True if the screen is visible.
@@ -441,12 +442,25 @@ Remove a previously added listener.
 * ```url``` (url) - URL to remove. Will use current URL if omitted.
 
 
+### monarch.post(screen_id, message_id, [message])
+Post a message to a visible screen. If the screen is created through a collection proxy it must have specified a receiver url. If the screen is created through a collection factory the function will post the message to all game objects within the collection.
+
+**PARAMETERS**
+* ```screen_id``` (string|hash) - Id of the screen to post message to
+* ```message_id``` (string|hash) - Id of the message to send
+* ```message``` (table|nil) - Optional message data to send
+
+**RETURN**
+* ```result``` (boolean) - True if the message was sent
+* ```error``` (string|nil) - Error message if unable to send message
+
+
 ### monarch.debug()
 Enable verbose logging of the internals of Monarch.
 
 
 ### monarch.SCREEN_TRANSITION_IN_STARTED
-Message sent to listeners when a screen has started to transition in.
+Message sent to listeners added using `monarch.add_listener()` when a screen has started to transition in.
 
 **PARAMETERS**
 * ```screen``` (hash) - Id of the screen
@@ -454,7 +468,7 @@ Message sent to listeners when a screen has started to transition in.
 
 
 ### monarch.SCREEN_TRANSITION_IN_FINISHED
-Message sent to listeners when a screen has finished to transition in.
+Message sent to listeners added using `monarch.add_listener()` when a screen has finished to transition in.
 
 **PARAMETERS**
 * ```screen``` (hash) - Id of the screen
@@ -462,7 +476,7 @@ Message sent to listeners when a screen has finished to transition in.
 
 
 ### monarch.SCREEN_TRANSITION_OUT_STARTED
-Message sent to listeners when a screen has started to transition out.
+Message sent to listeners added using `monarch.add_listener()` when a screen has started to transition out.
 
 **PARAMETERS**
 * ```screen``` (hash) - Id of the screen
@@ -470,7 +484,7 @@ Message sent to listeners when a screen has started to transition out.
 
 
 ### monarch.SCREEN_TRANSITION_OUT_FINISHED
-Message sent to listeners when a screen has finished to transition out.
+Message sent to listeners added using `monarch.add_listener()` when a screen has finished to transition out.
 
 **PARAMETERS**
 * ```screen``` (hash) - Id of the screen

example/confirm.gui_script

@@ -18,7 +18,7 @@ function on_input(self, action_id, action)
 	if action_id == hash("touch") and action.released then
 		if gui.pick_node(self.yes, action.x, action.y) then
 			print("yes")
-			monarch.show(monarch.data(hash("confirm")).next, nil, nil, function()
+			monarch.show(monarch.data("confirm").next, nil, nil, function()
 				print("next screen show done")
 			end)
 		elseif gui.pick_node(self.no, action.x, action.y) then

monarch/monarch.lua

@@ -70,7 +70,7 @@ end
 
 local function cowait(delay)
 	local co = coroutine.running()
-	assert(co, "You must run this form within a coroutine")
+	assert(co, "You must run this from within a coroutine")
 	timer.delay(delay, false, function()
 		assert(coroutine.resume(co))
 	end)
@@ -170,6 +170,8 @@ end
 --		  screen transitions
 -- 		* focus_url - URL to a script that is to be notified of focus
 --		  lost/gained events
+--		* receiver_url - URL to a script that is to receive messages sent
+--		  using monarch.send()
 --		* timestep_below_popup - Timestep to set on proxy when below a popup
 --		* auto_preload - true if the screen should be automatically preloaded
 function M.register_proxy(id, proxy, settings)
@@ -178,6 +180,7 @@ function M.register_proxy(id, proxy, settings)
 	screen.proxy = proxy
 	screen.transition_url = settings and settings.transition_url
 	screen.focus_url = settings and settings.focus_url
+	screen.receiver_url = settings and settings.receiver_url
 	screen.auto_preload = settings and settings.auto_preload
 	if screen.auto_preload then
 		M.preload(id)
@@ -225,7 +228,7 @@ function M.unregister(id)
 end
 
 local function acquire_input(screen)
-	log("change_context()", screen.id)
+	log("acquire_input()", screen.id)
 	if not screen.input then
 		if screen.proxy then
 			msg.post(screen.script, ACQUIRE_INPUT_FOCUS)
@@ -239,7 +242,7 @@ local function acquire_input(screen)
 end
 
 local function release_input(screen)
-	log("change_context()", screen.id)
+	log("release_input()", screen.id)
 	if screen.input then
 		if screen.proxy then
 			msg.post(screen.script, RELEASE_INPUT_FOCUS)
@@ -814,6 +817,43 @@ function M.unload(id, cb)
 end
 
 
+--- Post a message to a screen (using msg.post)
+-- @param id (string|hash) Id of the screen to send message to
+-- @param message_id (string|hash) Id of the message to send
+-- @param message (table|nil) Optional message data to send
+-- @return result (boolean) true if successful
+-- @return error (string|nil) Error message if unable to send message
+function M.post(id, message_id, message)
+	assert(id, "You must provide a screen id")
+	if not M.is_visible(id) then
+		return false, "Unable to post message to screen if it isn't visible"
+	end
+
+	assert(message_id, "You must provide a message_id")
+	id = tohash(id)
+	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
+	local screen = screens[id]
+
+	if screen.proxy then
+		if screen.receiver_url then
+			log("post() sending message to", screen.receiver_url)
+			msg.post(screen.receiver_url, message_id, message)
+		else
+			return false, "Unable to post message since screen has no receiver url specified"
+		end
+	else
+		run_coroutine(screen, nil, function()
+			change_context(screen)
+			log("post() sending message to", screen.receiver_url)
+			for id,instance in pairs(screen.factory_ids) do
+				msg.post(instance, message_id, message)
+			end
+		end)
+	end
+	return true
+end
+
+
 function M.on_message(message_id, message, sender)
 	if message_id == PROXY_LOADED then
 		local screen = screen_from_proxy(sender)

monarch/screen_proxy.script

@@ -7,6 +7,7 @@ go.property("popup_on_popup", false)
 go.property("timestep_below_popup", 1)
 go.property("transition_url", msg.url())
 go.property("focus_url", msg.url())
+go.property("receiver_url", msg.url())
 go.property("preload", false)
 
 
@@ -22,6 +23,7 @@ function init(self)
 		popup_on_popup = self.popup_on_popup,
 		transition_url = self.transition_url ~= url and self.transition_url or nil,
 		focus_url = self.focus_url ~= url and self.focus_url or nil,
+		receiver_url = self.receiver_url ~= url and self.receiver_url or nil,
 		timestep_below_popup = self.timestep_below_popup,
 		auto_preload = self.preload,
 	}

monarch/transitions/gui.lua

@@ -104,73 +104,116 @@ function M.fade_in(node, from, easing, duration, delay, cb)
 	gui.animate(node, gui.PROP_COLOR, to, easing, duration, delay, cb)
 end
 
---- Create a transition for a node
--- @return Transition instance
-function M.create(node)
-	assert(node, "You must provide a node")
 
+
+--- Create a transition
+-- @return Transition instance
+local function create()
 	local instance = {}
 
-	local transitions = {}
+	local transitions = {
+		[monarch.TRANSITION.SHOW_IN] = { urls = {}, transitions = {}, in_progress_count = 0, },
+		[monarch.TRANSITION.SHOW_OUT] = { urls = {}, transitions = {}, in_progress_count = 0, },
+		[monarch.TRANSITION.BACK_IN] = { urls = {}, transitions = {}, in_progress_count = 0, },
+		[monarch.TRANSITION.BACK_OUT] = { urls = {}, transitions = {}, in_progress_count = 0, },
+	}
 
 	local current_transition = nil
 
-	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 {
+	local function create_transition(transition_id, node, fn, easing, duration, delay)
+		local t = transitions[transition_id]
+		-- find if there's already a transition for the node in
+		-- question and if so update it instead of creating a new
+		-- transition
+		for _,transition in ipairs(t) do
+			if transition.node == node then
+				transition.fn = fn
+				transition.easing = easing
+				transition.duration = duration
+				transitions.delay = delay
+				return
+			end
+		end
+		-- create new transition
+		t.transitions[#t.transitions + 1] = {
+			node = node,
+			node_data = {
+				pos = gui.get_position(node),
+				scale = gui.get_scale(node),
+			},
 			fn = fn,
 			easing = easing,
 			duration = duration,
 			delay = delay,
-			in_progress = false,
-			urls = {},
-			id = nil
+			id = transition_id
 		}
 	end
 
-	local function finish_transition(transition)
-		transition.in_progress = false
-		local message = { transition = transition.id }
-		while #transition.urls > 0 do
-			local url = table.remove(transition.urls)
+	local function finish_transition(transition_id)
+		local t = transitions[transition_id]
+		if #t.urls > 0 then
+			local message = { transition = transition_id }
+			while #t.urls > 0 do
+				local url = table.remove(t.urls)
 				msg.post(url, monarch.TRANSITION.DONE, message)
 			end
 		end
+		current_transition = nil
+	end
 
-	local function start_transition(transition, transition_id, url)
-		table.insert(transition.urls, url)
-		if not transition.in_progress then
-			table.insert(transition.urls, msg.url())
-			transition.in_progress = true
-			transition.id = transition_id
-			current_transition = transition
-			transition.fn(node, initial_data, transition.easing, transition.duration, transition.delay or 0, function()
-				finish_transition(transition)
+	local function check_and_finish_transition(transition_id)
+		local t = transitions[transition_id]
+		if t.in_progress_count == 0 then
+			finish_transition(transition_id)
+		end
+	end
+
+	local function start_transition(transition_id, url)
+		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
+			if #t.transitions > 0 then
+				for i=1,#t.transitions do
+					local transition = t.transitions[i]
+					t.in_progress_count = t.in_progress_count + 1
+					transition.fn(transition.node, transition.node_data, transition.easing, transition.duration, transition.delay or 0, function()
+						t.in_progress_count = t.in_progress_count - 1
+						check_and_finish_transition(transition_id)
 					end)
 				end
+			else
+				check_and_finish_transition(transition_id)
+			end
+		end
 	end
 
 	-- Forward on_message calls here
 	function instance.handle(message_id, message, sender)
 		if message_id == LAYOUT_CHANGED then
-			initial_data.pos = gui.get_position(node)
+			for _,t in pairs(transitions) do
+				for _,transitions in pairs(t.transitions) do
+					transitions.node_data.pos = gui.get_position(transitions.node)
+				end
+			end
 			-- replay the current transition if the layout changes
 			-- this will ensure that things are still hidden if they
 			-- were transitioned out
 			if current_transition then
-				current_transition.fn(node, initial_data, current_transition.easing, 0, 0)
-				if current_transition.in_progress then
-					finish_transition(current_transition)
+				for _,transition in pairs(current_transition.transitions) do
+					local node = transition.node
+					transition.fn(transition.node, transition.node_data, transition.easing, 0, 0)
+				end
+				if current_transition.in_progress_count > 0 then
+					finish_transition(message_id)
 				end
 			end
-		else
-			local transition = transitions[message_id]
-			if transition then
-				start_transition(transition, message_id, sender)
-			end
+		elseif message_id == monarch.TRANSITION.SHOW_IN
+		or message_id == monarch.TRANSITION.SHOW_OUT
+		or message_id == monarch.TRANSITION.BACK_IN
+		or message_id == monarch.TRANSITION.BACK_OUT then
+			start_transition(message_id, sender)
 		end
 	end
 
@@ -180,38 +223,57 @@ function M.create(node)
 	-- @param easing Easing function to use
 	-- @param duration Transition duration
 	-- @param delay Transition delay
-	function instance.show_in(fn, easing, duration, delay)
-		transitions[monarch.TRANSITION.SHOW_IN] = create_transition(fn, easing, duration, delay)
+	function instance.show_in(node, fn, easing, duration, delay)
+		create_transition(monarch.TRANSITION.SHOW_IN, node, 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] = create_transition(fn, easing, duration, delay)
+	function instance.show_out(node, fn, easing, duration, delay)
+		create_transition(monarch.TRANSITION.SHOW_OUT, node, 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] = create_transition(fn, easing, duration, delay)
+	function instance.back_in(node, fn, easing, duration, delay)
+		create_transition(monarch.TRANSITION.BACK_IN, node, 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] = create_transition(fn, easing, duration, delay)
+	function instance.back_out(node, fn, easing, duration, delay)
+		create_transition(monarch.TRANSITION.BACK_OUT, node, 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
 
+function M.create(node)
+	local instance = create()
+	-- backward compatibility with the old version of create
+	-- where a single node was used
+	if node then
+		local show_in = instance.show_in
+		local show_out = instance.show_out
+		local back_in = instance.back_in
+		local back_out = instance.back_out
+		instance.show_in = function(fn, easing, duration, delay)
+			return show_in(node, fn, easing, duration, delay)
+		end
+		instance.show_out = function(fn, easing, duration, delay)
+			return show_out(node, fn, easing, duration, delay)
+		end
+		instance.back_in = function(fn, easing, duration, delay)
+			return back_in(node, fn, easing, duration, delay)
+		end
+		instance.back_out = function(fn, easing, duration, delay)
+			return back_out(node, fn, easing, duration, delay)
+		end
+	end
 	return instance
 end
 

monarch/utils/callback_tracker.lua

@@ -18,9 +18,15 @@ function M.create()
 	-- @return Callback function
 	function instance.track()
 		callback_count = callback_count + 1
+		local done = false
 		return function()
+			if done then
+				return false, "The callback has already been invoked once"
+			end
+			done = true
 			callback_count = callback_count - 1
 			invoke_if_done()
+			return true
 		end
 	end
 

test/cowait.lua

@@ -1,38 +1,25 @@
 local M = {}
 
-
-local instances = {}
-
-local function create(fn)
-	local instance = {
-		co = coroutine.running(),
-		fn = fn,
-	}
-	table.insert(instances, instance)
-	coroutine.yield(instance.co)
-end
-
-	
-
 function M.seconds(amount)
-	local time = socket.gettime() + amount
-	create(function()
-		return socket.gettime() >= time
+	local co = coroutine.running()
+	assert(co, "You must run this from within a coroutine")
+	timer.delay(amount, false, function()
+		coroutine.resume(co)
 	end)
+	coroutine.yield()
 end
 
-
-function M.eval(fn)
-	create(fn)
-end
-
-function M.update()
-	for k,instance in pairs(instances) do
-		if instance.fn() then
-			instances[k] = nil
-			coroutine.resume(instance.co)
-		end
+function M.eval(fn, timeout)
+	local co = coroutine.running()
+	assert(co, "You must run this from within a coroutine")
+	local start = socket.gettime()
+	timer.delay(0.01, true, function(self, handle, time_elapsed)
+		if fn() or (timeout and socket.gettime() > (start + timeout)) then
+			timer.cancel(handle)
+			coroutine.resume(co)
 		end
+	end)
+	coroutine.yield()
 end
 
 return setmetatable(M, {

test/cowait.script

@@ -1,5 +0,0 @@
-local cowait = require "test.cowait"
-
-function update(self, dt)
-	cowait.update()
-end

test/data/screen1.gui_script

@@ -7,6 +7,7 @@ function final(self)
 end
 
 function on_message(self, message_id, message, sender)
-	-- Add message-handling code here
-	-- Remove this function if not needed
+	if message_id == hash("foobar") then
+		_G.screen1_foobar = message or true
+	end
 end

test/data/screen2.gui_script

@@ -7,6 +7,7 @@ function final(self)
 end
 
 function on_message(self, message_id, message, sender)
-	-- Add message-handling code here
-	-- Remove this function if not needed
+	if message_id == hash("foobar") then
+		_G.screen2_foobar = message or true
+	end
 end

test/data/screens.collection

@@ -21,6 +21,11 @@ embedded_instances {
   "    value: \"screen1\"\n"
   "    type: PROPERTY_TYPE_HASH\n"
   "  }\n"
+  "  properties {\n"
+  "    id: \"receiver_url\"\n"
+  "    value: \"screen1:/go\"\n"
+  "    type: PROPERTY_TYPE_URL\n"
+  "  }\n"
   "}\n"
   "embedded_components {\n"
   "  id: \"collectionproxy\"\n"

test/test.collection

@@ -17,21 +17,6 @@ embedded_instances {
   "    w: 1.0\n"
   "  }\n"
   "}\n"
-  "components {\n"
-  "  id: \"cowait\"\n"
-  "  component: \"/test/cowait.script\"\n"
-  "  position {\n"
-  "    x: 0.0\n"
-  "    y: 0.0\n"
-  "    z: 0.0\n"
-  "  }\n"
-  "  rotation {\n"
-  "    x: 0.0\n"
-  "    y: 0.0\n"
-  "    z: 0.0\n"
-  "    w: 1.0\n"
-  "  }\n"
-  "}\n"
   "embedded_components {\n"
   "  id: \"screensfactory\"\n"
   "  type: \"collectionfactory\"\n"

test/test.script

@@ -1,12 +1,14 @@
 local deftest = require "deftest.deftest"
 
 local test_monarch = require "test.test_monarch"
+local test_callback_tracker = require "test.test_callback_tracker"
 
 
 function init(self)
 	deftest.add(test_monarch)
+	deftest.add(test_callback_tracker)
 	deftest.run({ 
 		coverage = { enabled = true },
-		--pattern = "preload",
+		pattern = "",
 	})
 end

test/test_callback_tracker.lua

@@ -0,0 +1,69 @@
+local unload = require "deftest.util.unload"
+local cowat = require "test.cowait"
+local callback_tracker = require "monarch.utils.callback_tracker"
+
+return function()
+
+	describe("callback tracker", function()
+		before(function()
+			callback_tracker = require "monarch.utils.callback_tracker"
+		end)
+
+		after(function()
+			unload.unload("monarch%..*")
+		end)
+
+
+		it("should be able to tell when all callbacks are done", function()
+			local tracker = callback_tracker.create()
+			local t1 = tracker.track()
+			local t2 = tracker.track()
+
+			local done = false
+			tracker.when_done(function() done = true end)
+			
+			assert(not done, "It should not be done yet - No callback has completed")
+			t1()
+			assert(not done, "It should not be done yet - Only one callback has completed")
+			t2()
+			assert(done, "It should be done now - All callbacks have completed")
+		end)
+
+		it("should indicate if a tracked callback has been invoked more than once", function()
+			local tracker = callback_tracker.create()
+			local t = tracker.track()
+			local ok, err = t()
+			assert(ok == true and err == nil, "It should return true when successful")
+			ok, err = t()
+			assert(ok == false and err, "It should return false and a message when invoked multiple times")
+		end)
+
+		it("should not be possible to track the same callback more than one time", function()
+			local tracker = callback_tracker.create()
+			local t1 = tracker.track()
+			local t2 = tracker.track()
+
+			local done = false
+			tracker.when_done(function() done = true end)
+
+			assert(not done, "It should not be done yet - No callback has completed")
+			t1()
+			t1()
+			assert(not done, "It should not be done yet - Even if one callback has been invoked twice")
+			t2()
+			assert(done, "It should be done now - All callbacks have completed")
+		end)
+
+		it("should handle when callbacks are done before calling when_done()", function()
+			local tracker = callback_tracker.create()
+			local t1 = tracker.track()
+			local t2 = tracker.track()
+			t1()
+			t2()
+
+			local done = false
+			tracker.when_done(function() done = true end)
+			assert(done, "It should be done now - All callbacks have completed")
+		end)
+	end)
+end

test/test_monarch.lua

@@ -28,20 +28,14 @@ return function()
 
 	local function wait_timeout(fn, ...)
 		local args = { ... }
-		local time = socket.gettime()
-		cowait(function()
-			return fn(unpack(args)) or socket.gettime() > time + 5	
-		end)
+		cowait(function() return fn(unpack(args)) end, 5)
 		return fn(...)
 	end
 
 	local function wait_until_done(fn)
-		local is_done = false
-		local function done()
-			is_done = true
-		end
-		fn(done)
-		wait_timeout(function() return is_done end)
+		local done = false
+		fn(function() done = true end)
+		wait_timeout(function() return done end)
 	end
 	local function wait_until_visible(screen_id)
 		return wait_timeout(is_visible, screen_id)
@@ -422,5 +416,69 @@ return function()
 			assert(wait_until_hidden(FOCUS1), "Focus1 was never hidden")
 			assert(_G.focus1_lost)
 		end)
+
+
+		it("should be able to post messages without message data to visible screens", function()
+			_G.screen1_foobar = nil
+			_G.screen2_foobar = nil
+
+			-- proxy screen
+			monarch.show(SCREEN1)
+			wait_until_shown(SCREEN1)
+			assert(monarch.post(SCREEN1, "foobar"), "Expected monarch.post() to return true")
+			cowait(0.1)
+			assert(_G.screen1_foobar, "Screen1 never received a message")
+
+			-- factory screen
+			monarch.show(SCREEN2)
+			wait_until_shown(SCREEN2)
+			assert(monarch.post(SCREEN2, "foobar"), "Expected monarch.post() to return true")
+			cowait(0.1)
+			assert(_G.screen2_foobar, "Screen2 never received a message")
+		end)
+
+
+		it("should be able to post messages with message data to visible screens", function()
+			_G.screen1_foobar = nil
+			_G.screen2_foobar = nil
+
+			-- proxy screen
+			monarch.show(SCREEN1)
+			wait_until_shown(SCREEN1)
+			assert(monarch.post(SCREEN1, "foobar", { foo = "bar" }), "Expected monarch.post() to return true")
+			cowait(0.1)
+			assert(_G.screen1_foobar, "Screen1 never received a message")
+			assert(_G.screen1_foobar.foo == "bar", "Screen1 never received message data")
+			
+			-- factory screen
+			monarch.show(SCREEN2)
+			wait_until_shown(SCREEN2)
+			assert(monarch.post(SCREEN2, "foobar", { foo = "bar" }), "Expected monarch.post() to return true")
+			cowait(0.1)
+			assert(_G.screen2_foobar, "Screen2 never received a message")
+			assert(_G.screen2_foobar.foo == "bar", "Screen2 never received message data")
+		end)
+
+
+		it("should not be able to post messages to hidden screens", function()
+			_G.screen1_foobar = nil
+
+			monarch.show(SCREEN1)
+			wait_until_shown(SCREEN1)
+			monarch.show(SCREEN2)
+			wait_until_shown(SCREEN2)
+			local ok, err = monarch.post(SCREEN1, "foobar")
+			assert(not ok and err, "Expected monarch.post() to return false plus an error message")
+			cowait(0.1)
+			assert(not _G.screen1_foobar, "Screen1 should not have received a message")
+		end)
+
+
+		it("should not be able to post messages to proxy screens without a receiver url", function()
+			monarch.show(POPUP1)
+			wait_until_shown(POPUP1)
+			local ok, err = monarch.post(POPUP1, "foobar")
+			assert(not ok and err, "Expected monarch.post() to return false plus an error message")
+		end)
 	end)
 end