Added additional tests and increased test framework version

README.md

@@ -334,8 +334,26 @@ Preload a Monarch screen. This will load but not enable the screen. This is usef
 * ```callback``` (function) - Optional function to call when the screen is preloaded.
 
 
+### monarch.is_preloading(screen_id)
+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
+
+**RETURN**
+* ```preloading``` (boolean) - True if the screen is preloading.
+
+
+### monarch.when_preloaded(screen_id, callback)
+Invoke a callback when a screen has been preloaded.
+
+**PARAMETERS**
+* ```screen_id``` (hash) - Id of the screen to check
+* ```callback``` (function) - Function to call when the screen has been preloaded.
+
+
 ### monarch.unload(screen_id, [callback])
-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.
+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.

game.project

@@ -1,7 +1,7 @@
 [project]
 title = Monarch
 version = 0.9
-dependencies = https://github.com/britzl/deftest/archive/2.4.3.zip
+dependencies = https://github.com/britzl/deftest/archive/2.7.0.zip
 
 [bootstrap]
 main_collection = /test/test.collectionc

monarch/monarch.lua

@@ -39,8 +39,8 @@ local screens = {}
 -- the current stack of screens
 local stack = {}
 
--- navigation listeners
-local listeners = {}
+-- transition listeners
+local transition_listeners = {}
 
 -- the number of active transitions
 -- monarch is considered busy while there are active transitions
@@ -61,9 +61,15 @@ local function tohash(s)
 	return hash_lookup[s]
 end
 
-local function notify_listeners(message_id, message)
-	log("notify_listeners()", message_id)
-	for _,url in pairs(listeners) do
+local function pcallfn(fn, ...)
+	if fn then
+		local ok, err = pcall(fn, ...)
+		if not ok then print(err) end
+	end
+end
+local function notify_transition_listeners(message_id, message)
+	log("notify_transition_listeners()", message_id)
+	for _,url in pairs(transition_listeners) do
 		msg.post(url, message_id, message or {})
 	end
 end
@@ -134,6 +140,7 @@ local function register(id, settings)
 		popup = settings and settings.popup,
 		popup_on_popup = settings and settings.popup_on_popup,
 		timestep_below_popup = settings and settings.timestep_below_popup or 1,
+		preload_listeners = {},
 	}
 	return screens[id]
 end
@@ -376,11 +383,20 @@ local function reset_timestep(screen)
 	end
 end
 
-local function disable(screen, next_screen)
-	log("disable()", screen.id)
+local function run_coroutine(screen, cb, fn)
 	local co
 	co = coroutine.create(function()
 		screen.co = co
+		fn()
+		screen.co = nil
+		pcallfn(cb)
+	end)
+	assert(coroutine.resume(co))
+end
+
+local function disable(screen, next_screen)
+	log("disable()", screen.id)
+	run_coroutine(screen, nil, function()
 		change_context(screen)
 		release_input(screen)
 		focus_lost(screen, next_screen)
@@ -389,34 +405,24 @@ local function disable(screen, next_screen)
 		else
 			reset_timestep(screen)
 		end
-		screen.co = nil
-		if cb then cb() end
 	end)
-	assert(coroutine.resume(co))
 end
 
 local function enable(screen, previous_screen)
 	log("enable()", screen.id)
-	local co
-	co = coroutine.create(function()
-		screen.co = co
+	run_coroutine(screen, nil, function()
 		change_context(screen)
 		acquire_input(screen)
 		focus_gained(screen, previous_screen)
 		reset_timestep(screen)
-		screen.co = nil
-		if cb then cb() end
 	end)
-	assert(coroutine.resume(co))
 end
 
 local function show_out(screen, next_screen, cb)
 	log("show_out()", screen.id)
-	local co
-	co = coroutine.create(function()
+	run_coroutine(screen, cb, function()
 		active_transition_count = active_transition_count + 1
-		notify_listeners(M.SCREEN_TRANSITION_OUT_STARTED, { screen = screen.id, next_screen = next_screen.id })
-		screen.co = co
+		notify_transition_listeners(M.SCREEN_TRANSITION_OUT_STARTED, { screen = screen.id, next_screen = next_screen.id })
 		change_context(screen)
 		release_input(screen)
 		focus_lost(screen, next_screen)
@@ -431,21 +437,16 @@ local function show_out(screen, next_screen, cb)
 		elseif next_is_popup then
 			change_timestep(screen)
 		end
-		screen.co = nil
 		active_transition_count = active_transition_count - 1
-		if cb then cb() end
-		notify_listeners(M.SCREEN_TRANSITION_OUT_FINISHED, { screen = screen.id, next_screen = next_screen.id })
+		notify_transition_listeners(M.SCREEN_TRANSITION_OUT_FINISHED, { screen = screen.id, next_screen = next_screen.id })
 	end)
-	coroutine.resume(co)
 end
 
 local function show_in(screen, previous_screen, reload, add_to_stack, cb)
 	log("show_in()", screen.id)
-	local co
-	co = coroutine.create(function()
+	run_coroutine(screen, cb, function()
 		active_transition_count = active_transition_count + 1
-		notify_listeners(M.SCREEN_TRANSITION_IN_STARTED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
-		screen.co = co
+		notify_transition_listeners(M.SCREEN_TRANSITION_IN_STARTED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
 		change_context(screen)
 		if reload and screen.loaded then
 			log("show_in() reloading", screen.id)
@@ -459,21 +460,16 @@ local function show_in(screen, previous_screen, reload, add_to_stack, cb)
 		transition(screen, M.TRANSITION.SHOW_IN, { previous_screen = previous_screen and previous_screen.id })
 		acquire_input(screen)
 		focus_gained(screen, previous_screen)
-		screen.co = nil
 		active_transition_count = active_transition_count - 1
-		if cb then cb() end
-		notify_listeners(M.SCREEN_TRANSITION_IN_FINISHED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
+		notify_transition_listeners(M.SCREEN_TRANSITION_IN_FINISHED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
 	end)
-	coroutine.resume(co)
 end
 
 local function back_in(screen, previous_screen, cb)
 	log("back_in()", screen.id)
-	local co
-	co = coroutine.create(function()
+	run_coroutine(screen, cb, function()
 		active_transition_count = active_transition_count + 1
-		notify_listeners(M.SCREEN_TRANSITION_IN_STARTED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
-		screen.co = co
+		notify_transition_listeners(M.SCREEN_TRANSITION_IN_STARTED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
 		change_context(screen)
 		load(screen)
 		reset_timestep(screen)
@@ -482,21 +478,16 @@ local function back_in(screen, previous_screen, cb)
 		end
 		acquire_input(screen)
 		focus_gained(screen, previous_screen)
-		screen.co = nil
 		active_transition_count = active_transition_count - 1
-		if cb then cb() end
-		notify_listeners(M.SCREEN_TRANSITION_IN_FINISHED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
+		notify_transition_listeners(M.SCREEN_TRANSITION_IN_FINISHED, { screen = screen.id, previous_screen = previous_screen and previous_screen.id })
 	end)
-	coroutine.resume(co)
 end
 
 local function back_out(screen, next_screen, cb)
 	log("back_out()", screen.id)
-	local co
-	co = coroutine.create(function()
-		notify_listeners(M.SCREEN_TRANSITION_OUT_STARTED, { screen = screen.id, next_screen = next_screen and next_screen.id })
+	run_coroutine(screen, cb, function()
+		notify_transition_listeners(M.SCREEN_TRANSITION_OUT_STARTED, { screen = screen.id, next_screen = next_screen and next_screen.id })
 		active_transition_count = active_transition_count + 1
-		screen.co = co
 		change_context(screen)
 		release_input(screen)
 		focus_lost(screen, next_screen)
@@ -505,12 +496,9 @@ local function back_out(screen, next_screen, cb)
 		end
 		transition(screen, M.TRANSITION.BACK_OUT, { next_screen = next_screen and next_screen.id })
 		unload(screen)
-		screen.co = nil
 		active_transition_count = active_transition_count - 1
-		if cb then cb() end
-		notify_listeners(M.SCREEN_TRANSITION_OUT_FINISHED, { screen = screen.id, next_screen = next_screen and next_screen.id })
+		notify_transition_listeners(M.SCREEN_TRANSITION_OUT_FINISHED, { screen = screen.id, next_screen = next_screen and next_screen.id })
 	end)
-	coroutine.resume(co)
 end
 
 
@@ -611,7 +599,15 @@ function M.show(id, options, data, cb)
 			end
 		end
 
-		-- show screen
+		-- show screen, wait until preloaded if it is already preloading
+		-- this can typpically happen if you do a show() on app start for a
+		-- screen that has Preload set to true
+		if M.is_preloading(id) then
+			M.when_preloaded(id, function()
+				coroutine.resume(co)
+			end)
+			coroutine.yield()
+		end
 		show_in(screen, top, options and options.reload, add_to_stack, callbacks.track())
 
 		if cb then callbacks.when_done(cb) end
@@ -637,6 +633,7 @@ function M.hide(id, cb)
 	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
 
 	local screen = screens[id]
+	log("hide()", screen.id)
 	if M.in_stack(id) then
 		if not M.is_top(id) then
 			log("hide() you can only hide the screen at the top of the stack", id)
@@ -646,8 +643,8 @@ function M.hide(id, cb)
 	else
 		if M.is_visible(id) then
 			back_out(screen, nil, cb)
-		elseif cb then
-			cb()
+		else
+			pcallfn(cb)
 		end
 	end
 	return true
@@ -696,6 +693,36 @@ function M.back(data, cb)
 end
 
 
+--- Check if a screen is preloading via monarch.preload() or automatically
+-- via the Preload screen option
+-- @param id Screen id
+-- @return true if preloading
+function M.is_preloading(id)
+	assert(id, "You must provide a screen id")
+	id = tohash(id)
+	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
+	local screen = screens[id]
+	return screen.preloading
+end
+
+
+--- Invoke a callback when a specific screen has been preloaded
+-- This is mainly useful on app start when wanting to show a screen that
+-- has the Preload flag set (since it will immediately start to load which
+-- would prevent a call to monarch.show from having any effect).
+function M.when_preloaded(id, cb)
+	assert(id, "You must provide a screen id")
+	id = tohash(id)
+	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
+	local screen = screens[id]
+	if screen.preloaded or screen.loaded then
+		pcallfn(cb, id)
+	else
+		screen.preload_listeners[#screen.preload_listeners + 1] = cb
+	end
+end
+
+
 --- Preload a screen. This will load but not enable and show a screen. Useful for "heavier" screens
 -- that you wish to show without any delay.
 -- @param id (string|hash) - Id of the screen to preload
@@ -713,22 +740,31 @@ function M.preload(id, cb)
 	local screen = screens[id]
 	log("preload()", screen.id)
 	if screen.preloaded or screen.loaded then
-		if cb then cb() end
+		pcallfn(cb)
 		return true
 	end
-	local co
-	co = coroutine.create(function()
-		screen.co = co
+	
+	local function when_preloaded()
+		-- invoke any listeners added using monarch.when_preloaded()
+		while #screen.preload_listeners > 0 do
+			pcallfn(table.remove(screen.preload_listeners), id)
+		end
+		-- invoke the normal callback
+		pcallfn(cb)
+	end
+	run_coroutine(screen, when_preloaded, function()
+		screen.preloading = true
 		change_context(screen)
 		preload(screen)
-		log("preload() done", screen.id)
-		if cb then cb() end
+		screen.preloading = false
 	end)
-	assert(coroutine.resume(co))
 	return true
 end
 
 
+--- Unload a preloaded monarch screen
+-- @param id (string|hash) - Id of the screen to unload
+-- @param cb (function) - Optional callback to invoke when screen is unloaded
 function M.unload(id, cb)
 	if M.is_busy() then
 		log("unload() monarch is busy, ignoring request")
@@ -744,19 +780,16 @@ function M.unload(id, cb)
 	end
 
 	local screen = screens[id]
+	log("unload()", screen.id)
 	if not screen.preloaded and not screen.loaded then
 		log("unload() screen is not loaded", tostring(id))
-		if cb then cb() end
+		pcallfn(cb)
 		return true
 	end
-	local co
-	co = coroutine.create(function()
-		screen.co = co
+	run_coroutine(screen, cb, function()
 		change_context(screen)
 		unload(screen)
-		if cb then cb() end
 	end)
-	assert(coroutine.resume(co))
 	return true
 end
 
@@ -828,7 +861,7 @@ end
 -- @param url The url to notify, nil for current url
 function M.add_listener(url)
 	url = url or msg.url()
-	listeners[url_to_key(url)] = url
+	transition_listeners[url_to_key(url)] = url
 end
 
 
@@ -836,7 +869,7 @@ end
 -- @param url The url to remove, nil for current url
 function M.remove_listener(url)
 	url = url or msg.url()
-	listeners[url_to_key(url)] = nil
+	transition_listeners[url_to_key(url)] = nil
 end
 
 

monarch/utils/callback_tracker.lua

@@ -7,15 +7,20 @@ function M.create()
 	local callback = nil
 	local callback_count = 0
 
+	local function invoke_if_done()
+		if callback_count == 0 and callback then
+			local ok, err = pcall(callback)
+			if not ok then print(err) end
+		end
+	end
+
 	--- Create a callback function and track when it is done
 	-- @return Callback function
 	function instance.track()
 		callback_count = callback_count + 1
 		return function()
 			callback_count = callback_count - 1
-			if callback_count == 0 and callback then
-				callback()
-			end
+			invoke_if_done()
 		end
 	end
 
@@ -23,9 +28,7 @@ function M.create()
 	-- @param cb Function to call when all 
 	function instance.when_done(cb)
 		callback = cb
-		if callback_count == 0 then
-			callback()
-		end
+		invoke_if_done()
 	end
 
 	return instance

test/test.script

@@ -5,5 +5,8 @@ local test_monarch = require "test.test_monarch"
 
 function init(self)
 	deftest.add(test_monarch)
-	deftest.run({ coverage = { enabled = true }})
+	deftest.run({ 
+		coverage = { enabled = true },
+		--pattern = "preload",
+	})
 end

test/test_monarch.lua

@@ -34,6 +34,14 @@ return function()
 		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)
+	end
 	local function wait_until_visible(screen_id)
 		return wait_timeout(is_visible, screen_id)
 	end
@@ -302,6 +310,16 @@ return function()
 			assert(wait_until_not_busy())
 		end)
 
+		it("should be able to preload a screen and wait for it", function()
+			assert(not monarch.is_preloading(TRANSITION1))
+			monarch.preload(TRANSITION1)
+			assert(monarch.is_preloading(TRANSITION1))
+			wait_until_done(function(done)
+				monarch.when_preloaded(TRANSITION1, done)
+			end)
+			assert(not monarch.is_preloading(TRANSITION1))
+		end)
+		
 		it("should ignore any preload calls while busy", function()
 			monarch.show(TRANSITION1)
 			-- previously a call to preload() while also showing a screen would
@@ -357,7 +375,12 @@ return function()
 			assert(mock_msg.messages(URL1)[10].message.screen == SCREEN1)
 		end)
 
-
+		it("should be able to show a screen even while it is preloading", function()
+			assert(monarch.is_preloading(SCREEN_PRELOAD))
+			monarch.show(SCREEN_PRELOAD, nil, { count = 1 })
+			assert(wait_until_shown(SCREEN_PRELOAD), "Screen_preload was never shown")
+		end)
+		
 		it("should be able to preload a screen and always keep it loaded", function()
 			monarch.show(SCREEN_PRELOAD, nil, { count = 1 })
 			assert(wait_until_shown(SCREEN_PRELOAD), "Screen_preload was never shown")