rewrite editor script to use editor.transact api (#115)

Fixes #

.github/workflows/ci-workflow.yml

@@ -7,13 +7,13 @@ jobs:
         name: Build and run
         runs-on: ubuntu-latest
         steps:
-          - uses: actions/checkout@v1
+          - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
-          - uses: actions/setup-java@v1
+          - uses: actions/setup-java@99b8673ff64fbf99d8d325f52d9a5bdedb8483e9
             with:
-                java-version: '17'
+                java-version: '21.0.5+11.0.LTS'
+                distribution: 'temurin'
           - name: Run.sh
             env:
                 DEFOLD_USER: bjorn.ritzl@gmail.com
                 DEFOLD_AUTH: foobar
-                DEFOLD_BOOSTRAP_COLLECTION: /test/test.collectionc
             run: ./.test/run.sh

.gitignore

@@ -9,3 +9,6 @@ build
 builtins
 .internal
 luacov.report.out
+/.editor_settings
+manifest.private.der
+manifest.public.der

.test/run.sh

@@ -5,7 +5,6 @@ else
 	PLATFORM="$1"
 fi
 
-
 echo "${PLATFORM}"
 
 # {"version": "1.2.89", "sha1": "5ca3dd134cc960c35ecefe12f6dc81a48f212d40"}
@@ -16,26 +15,28 @@ echo "Using Defold dmengine_headless version ${SHA1}"
 # Create dmengine_headless and bob.jar URLs
 DMENGINE_URL="http://d.defold.com/archive/${SHA1}/engine/${PLATFORM}/dmengine_headless"
 BOB_URL="http://d.defold.com/archive/${SHA1}/bob/bob.jar"
+DMENGINE_FILE=dmengine_headless_${SHA1}
+BOB_FILE=bob_${SHA1}.jar
 
 # Download dmengine_headless
-echo "Downloading ${DMENGINE_URL}"
+if ! [ -f ${DMENGINE_FILE} ]; then
-curl -L -o dmengine_headless ${DMENGINE_URL}
+	echo "Downloading ${DMENGINE_URL} to ${DMENGINE_FILE}"
-chmod +x dmengine_headless
+	curl -L -o ${DMENGINE_FILE} ${DMENGINE_URL}
+	chmod +x ${DMENGINE_FILE}
+fi
 
 # Download bob.jar
-echo "Downloading ${BOB_URL}"
+if ! [ -f ${BOB_FILE} ]; then
-curl -L -o bob.jar ${BOB_URL}
+	echo "Downloading ${BOB_URL} to ${BOB_FILE}"
+	curl -L -o ${BOB_FILE} ${BOB_URL}
+fi
 
 # Fetch libraries
-echo "Running bob.jar - resolving dependencies"
+echo "Running ${BOB_FILE} - resolving dependencies"
-java -jar bob.jar --auth "foobar" --email "john@doe.com" resolve
+java -jar ${BOB_FILE} --auth "foobar" --email "john@doe.com" resolve
 
-echo "Running bob.jar - building"
+echo "Running ${BOB_FILE} - building"
-java -jar bob.jar --debug build --keep-unused
+java -jar ${BOB_FILE} --debug build --settings=test.settings
 
-echo "Starting dmengine_headless"
+echo "Starting ${DMENGINE_FILE}"
-if [ -n "${DEFOLD_BOOSTRAP_COLLECTION}" ]; then
+./${DMENGINE_FILE}
-	./dmengine_headless --config=bootstrap.main_collection=${DEFOLD_BOOSTRAP_COLLECTION}
-else
-	./dmengine_headless
-fi

README.md

@@ -20,10 +20,15 @@ Or point to the ZIP file of a [specific release](https://github.com/britzl/monar
 Using Monarch requires that screens are created in a certain way. Once you have one or more screens created you can start navigating between the screens.
 
 ## Editor Script
-Right click in on a`.gui` file in the outline and selected the menu item, it creates a `.collection` and a `.gui_script` with the same name as the `.gui` file. It adds the file with some basic setup done to them, adding the selected gui script to the created gui scene and in turns adds the gui scene to the newly created collection.
+Right click in on a`.gui`, `.gui_script` or `.collection` file in the outline and selected the menu item, it creates the other two file types with the same name as the selected file. It adds the file with some basic setup done to them, adding the selected gui script to the created gui scene and in turns adds the gui scene to the newly created collection.
+
+You can also right click on directory to get the option to create a monarch scene from it, the directory should be empty (or only contain other monarch scene files).Use the option and it will create all three files inside of the directory.
 
 <img src="/docs/editor_script.gif" width="200px">
 
+You can use Monarchs editor script with your own custom templates. Create the template files you want, these are normal defold files. Then inside of your game.project file add a path to the files you created.
+
+
 ## Creating screens
 Monarch screens are created in individual collections and either loaded through collection proxies or created through collection factories.
 

README_API.md

@@ -212,12 +212,21 @@ IMPORTANT! You must call `monarch.on_message(message_id, message, sender)` from
 * `fn` (function) - The function to call screen focus changes
 
 
-## monarch.on_post(screen_id, fn)
+## monarch.on_post(screen_id, fn_or_url)
-Set a function to be called when `msg.post()` is called on a specific screen. IMPORTANT! You must call `monarch.on_message(message_id, message, sender)` from the same script as this function was called.
+Set either a function to be called when `msg.post()` is called on a specific screen or a URL where the message is sent.
+
+IMPORTANT! If you provide a function you must also make sure to call `monarch.on_message(message_id, message, sender)` from the same script as this function was called.
 
 **PARAMETERS**
 * `screen_id` (string|hash) - Id of the screen
-* `fn` (function) - The function to call when the screen receives a message using `msg.post`
+* `fn_or_url` (function) - The function to call or URL to send message to
+
+
+## monarch.has_missing_resources(screen_id)
+Check if a screen has any missing resources. If the screen is loaded by a collection proxy with Load Dynamically this will use `collectionproxy.missing_resources()`. For other cases this function will always return false.
+
+**RETURN**
+* `result` (boolean) - true if the screen has missing resources
 
 
 ## monarch.debug()

README_TRANSITIONS.md

@@ -114,7 +114,7 @@ end
 
 function on_message(self, message_id, message, sender)
 	if message_id == hash("my_resize_message") then
-		self.transition.window_resized(message.width, message.height)
+		transition.window_resized(message.width, message.height)
 	end
 end
 ```

example/advanced/confirm.gui_script

@@ -29,7 +29,7 @@ function on_input(self, action_id, action)
 			end
 		elseif gui.pick_node(self.no, action.x, action.y) then
 			print("no")
-			monarch.back(function()
+			monarch.back(nil, nil, function()
 				print("back from popup done")
 			end)
 		end

example/advanced/popup.gui_script

@@ -27,7 +27,7 @@ function on_input(self, action_id, action)
 			end)
 		elseif gui.pick_node(self.cancel, action.x, action.y) then
 			print("cancel")
-			monarch.back(function()
+			monarch.back(nil, nil, function()
 				print("back from popup done")
 			end)
 		elseif gui.pick_node(self.about, action.x, action.y) then

example/advanced/pregame.gui_script

@@ -19,7 +19,7 @@ function on_input(self, action_id, action)
 			end)
 		elseif gui.pick_node(self.back, action.x, action.y) then
 			print("back")
-			monarch.back(function()
+			monarch.back(nil, nil, function()
 				print("back from pregame done")
 			end)
 		end

game.project

@@ -2,7 +2,6 @@
 title = Monarch
 version = 0.9
 dependencies#0 = https://github.com/britzl/deftest/archive/2.7.0.zip
-dependencies#1 = https://github.com/defold/lua-language-server/releases/download/v0.0.3/release.zip
 
 [bootstrap]
 main_collection = /example/advanced/advanced.collectionc
@@ -20,10 +19,10 @@ display_profiles = /example/example.display_profilesc
 shared_state = 1
 
 [ios]
-bundle_identifier = com.example.todo
+bundle_identifier = com.defold.monarch
 
 [osx]
-bundle_identifier = com.example.todo
+bundle_identifier = com.defold.monarch
 
 [library]
 include_dirs = monarch

monarch/editor-script/make_monarch.editor_script

@@ -1,8 +1,13 @@
 local M = {}
 
 local collection_template
-local gui_script_content
+local gui_script_template
-local gui_file_content
+local gui_template
+
+local function _log(msg)
+    io.stdout:write("ERROR:MONARCH: " .. msg .. "\n")
+    io.stdout:flush()
+end
 
 local function ends_with(str, ending)
     return ending == "" or str:sub(-#ending) == ending
@@ -18,43 +23,138 @@ local function get_filename(path)
     return main, filename
 end
 
-local function create_files(file_path)
+local function get_template(game_project_path)
-    -- Construct paths
+    -- The input file can be the "compiled" file. If they are they end with "c".
-    local path = editor.get(file_path, "path")
+    -- If they end with "c" remove the last charater.
-    local main, filename = get_filename(path)
+    local path = editor.get("/game.project", game_project_path)
-    local basename = filename:match("(.+)%..+")
+    if path == nil then
-    local target_collection_path = "." .. main .. basename .. ".collection"
+        return
-    local target_gui_script_path = "." .. main .. basename .. ".gui_script"
+    end
-    local target_gui_path = "." .. main .. basename .. ".gui"
+    if ends_with(path, "c") then
+        return path:sub(1, -2)
+    end
+    return path
+end
 
-    -- Create the files if they don't exists
+local function get_template_content(type_string)
-    if not file_exists(target_collection_path) then
+    local default_template = {
-        local collection_content = collection_template(path, basename)
+        collection = collection_template,
-        local collection = io.open(target_collection_path, "w")
+        gui_script = gui_script_template,
-        collection:write(collection_content)
+        gui = gui_template,
+    }
+    local custom_template = {
+        collection = get_template("monarch.collection_template"),
+        gui_script = get_template("monarch.gui_script_template"),
+        gui = get_template("monarch.gui_template"),
+    }
+    local template = custom_template[type_string]
+    if template ~= nil then
+        local file = io.open("." .. template, "rb")
+        if file == nil then
+            _log("Could not read " .. type_string .. " template '" .. template .. "'")
+            return
+        end
+        local content = file:read("*a")
+        file:close()
+        return content
+    end
+    return default_template[type_string]
+end
+
+local function add_monarch_go(collection_file, gui_file, name)
+    return editor.tx.add(collection_file, "children", {
+        type = "go",
+        id = "monarch",
+        components = {
+            {
+                type = "component-reference",
+                id = name,
+                path = gui_file,
+            }
+        }
+    })
+end
+
+local function create_collection(collection_file, gui_file, name)
+    local _collection_content = get_template_content("collection")
+    if _collection_content == nil then
+        _log("Could not create colletion file at " .. gui)
+        return
+    end
+    local collection = io.open("." .. collection_file, "w")
+    if collection == nil then
+        _log("Could not create colletion file at " .. collection_file)
+        return
+    end
+    collection:write(_collection_content)
     collection:close()
+    return add_monarch_go(collection_file, gui_file, name)
+end
+
+local function create_gui(gui_file, gui_script_file)
+    local gui_content = get_template_content("gui")
+    if gui_content == nil then
+        _log("Could not create gui file at " .. gui)
+        return
     end
-    if not file_exists(target_gui_script_path) then
+    local gui = io.open("." .. gui_file, "w")
-        local gui_script = io.open(target_gui_script_path, "w")
+    if gui == nil then
-        gui_script:write(gui_script_content)
+        _log("Could not create gui file at " .. gui)
-        gui_script:close()
+        return
-
-        -- Put the gui_script path into the gui file
-        local gui_file = io.open("." .. path, "rb")
-        local gui_text = gui_file:read("*a")
-        gui_file:close()
-
-        gui_text = string.gsub(gui_text, 'script: "%.*"', [[script: "]] .. main .. basename .. ".gui_script" .. [["]])
-
-        gui_file = io.open("." .. path, "w")
-        gui_file:write(gui_text)
-        gui_file:close()
     end
-    if not file_exists(target_gui_path) then
-        local gui_content = gui_template(path)
-        local gui = io.open(target_gui_path, "w")
     gui:write(gui_content)
     gui:close()
+
+    return editor.tx.set(gui_file, "script", gui_script_file)
+end
+
+local function create_files(directory, name)
+    -- Construct paths
+    local target_collection_path = directory .. name .. ".collection"
+    local target_gui_script_path = directory .. name .. ".gui_script"
+    local target_gui_path = directory .. name .. ".gui"
+
+    if not file_exists("." .. target_gui_script_path) then
+        local gui_script_template_content = get_template_content("gui_script")
+        if gui_script_template_content == nil then
+            return
+        end
+        local gui_script = io.open("." .. target_gui_script_path, "w")
+        gui_script:write(gui_script_template_content)
+        gui_script:close()
+    end
+    local transactions = {}
+
+    if file_exists("." .. target_gui_path) then
+        -- If the gui file exists change the script.
+        table.insert(transactions, editor.tx.set(target_gui_path, "script", target_gui_script_path)
+    )
+    else
+        -- If the gui file doesn't exist create a new one.
+        local transaction = create_gui(target_gui_path, target_gui_script_path)
+        if transaction == nil then
+            return
+        end
+        table.insert(transactions, transaction)
+    end
+    if file_exists("." .. target_collection_path) then
+        --- If the collection already exists we will add the monarch go to it.
+        local transaction = add_monarch_go(target_collection_path, target_gui_path, name)
+        if transaction == nil then
+            return
+        end
+        table.insert(transactions, transaction)
+    else
+        -- If the collection doesn't exists we create a new one.
+        local transaction = create_collection(target_collection_path, target_gui_path, name)
+        if transaction == nil then
+            return
+        end
+        table.insert(transactions, transaction)
+    end
+    if #transactions > 1 then
+        editor.transact(transactions)
+        editor.save()
     end
 end
 
@@ -68,30 +168,54 @@ function M.get_commands()
             },
             active = function(opts)
                 local path = editor.get(opts.selection, "path")
-                return ends_with(path, ".gui")
+                return ends_with(path, ".gui") or ends_with(path, ".gui_script") or ends_with(path, ".collection")
             end,
             run = function(opts)
-                create_files(opts.selection)
+                local path = editor.get(opts.selection, "path")
+                local directory, filename = get_filename(path)
+
+                local basename = filename:match("(.+)%..+")
+                create_files(directory, basename)
+            end
+        },
+        {
+            label="Create Monarch Scene From Directory",
+            locations = {"Assets"},
+            query = {
+                selection = {type = "resource", cardinality = "one"}
+            },
+            active = function(opts)
+                local _is_directory = editor.resource_attributes(editor.get(opts.selection, "path")).is_directory
+                if not _is_directory then
+                    return false
+                end
+                local _children = editor.get(opts.selection, "children")
+                if #_children >= 3 then
+                    return false
+                end
+                for i = 1, #_children do
+                    local _path = editor.get(_children[i], "path")
+                    if not (ends_with(_path, ".gui") or ends_with(_path, ".collection") or ends_with(_path, ".gui_script")) then
+                        return false
+                    end
+                end
+                return true
+            end,
+            run = function(opts)
+                local path = editor.get(opts.selection, "path")
+                local _, filename = get_filename(path)
+                create_files(path .. "/", filename)
             end
         }
     }
 end
 
-gui_template = function(gui_script)
+gui_template = [[
-    return [[script: "]].. gui_script .. [["
-background_color {
-    x: 0.0
-    y: 0.0
-    z: 0.0
-    w: 0.0
-}
 material: "/builtins/materials/gui.material"
 adjust_reference: ADJUST_REFERENCE_PARENT
-max_nodes: 512
 ]]
-end
 
-gui_script_content = [[local monarch = require "monarch.monarch"
+gui_script_template = [[local monarch = require "monarch.monarch"
 
 function init(self)
     msg.post(".", "acquire_input_focus")
@@ -113,49 +237,10 @@ function on_reload(self)
 end
 ]]
 
-
+collection_template = [[
-collection_template = function(gui_script, name)
+name: "m"
-    return [[name: "]].. name .. [["
 scale_along_z: 0
-embedded_instances {
-  id: "go"
-  data: "components {\n"
-  "  id: \"monarch\"\n"
-  "  component: \"]].. gui_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"
-  ""
-  position {
-      x: 0.0
-      y: 0.0
-      z: 0.0
-  }
-  rotation {
-      x: 0.0
-      y: 0.0
-      z: 0.0
-      w: 1.0
-  }
-  scale3 {
-      x: 1.0
-      y: 1.0
-      z: 1.0
-  }
-}
 ]]
 
-end
-
-
 
 return M

monarch/ext.properties

@@ -0,0 +1,10 @@
+[monarch]
+
+collection_template.type = resource
+collection_template.filter = collection
+
+gui_script_template.type = resource
+gui_script_template.filter = gui_script
+
+gui_template.type = resource
+gui_template.filter = gui

monarch/monarch.lua

@@ -228,6 +228,17 @@ function M.is_visible(id)
 end
 
 
+--- Check if a screen is loaded
+-- @param id (string|hash)
+-- @return true if the screen is loaded
+function M.is_loaded(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)))
+	return screens[id].loaded
+end
+
+
 --- Check if a screen is a popup
 -- @param id Screen id
 -- @return true if the screen is a popup
@@ -419,8 +430,10 @@ local function unload(screen, force)
 	elseif screen.factory then
 		log("unload() factory", screen.id)
 		for id, instance in pairs(screen.factory_ids) do
+			if go.exists(instance) then
 				go.delete(instance)
 			end
+		end
 		screen.factory_ids = nil
 		if screen.auto_preload and not force then
 			screen.loaded = false
@@ -451,8 +464,7 @@ local function preload(screen)
 	screen.preloading = true
 	if screen.proxy then
 		log("preload() proxy")
-		local missing_resources = collectionproxy.missing_resources(screen.proxy)
+		if M.has_missing_resources(screen.id) then
-		if #missing_resources > 0 then
 			local error_message = ("preload() collection proxy %s is missing resources"):format(tostring(screen.id))
 			log(error_message)
 			screen.preloading = false
@@ -509,9 +521,13 @@ local function load(screen)
 		msg.post(screen.proxy, MSG_ENABLE)
 	elseif screen.factory then
 		screen.factory_ids = collectionfactory.create(screen.factory)
+		if screen.transition_id then
 			screen.transition_url = screen.factory_ids[screen.transition_id]
+		end
+		if screen.focus_id then
 			screen.focus_url = screen.factory_ids[screen.focus_id]
 		end
+	end
 	screen.loaded = true
 	screen.preloaded = false
 	return true
@@ -909,7 +925,7 @@ function M.hide(id, cb)
 			log("hide() you can only hide the screen at the top of the stack", id)
 			return false
 		end
-		return M.back(id, cb)
+		return M.back(nil, nil, cb)
 	else
 		log("hide() queuing action", id)
 		queue_action(function(action_done, action_error)
@@ -971,29 +987,18 @@ end
 -- @param cb (function) - Optional callback to invoke when the previous screen is visible again
 function M.back(options, data, cb)
 	log("back() queuing action")
-	-- backwards compatibility with old version M.back(data, cb)
-	-- case when back(data, cb)
-	if type(data) == "function" then
-		cb = data
-		data = options
-		options = nil
-	-- case when back(data, nil)
-	elseif options ~= nil and data == nil and cb == nil then
-		data = options
-		options = nil
-	end
 
 	queue_action(function(action_done)
 		local callbacks = callback_tracker()
 		local screen = table.remove(stack)
 		if screen then
 			log("back()", screen.id)
-			local back_cb = callbacks.track()
 			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
 			local same_screen = top and top.id == screen.id
 			if same_screen or (options and options.sequential) then
+				local back_cb = callbacks.track()
 				back_out(screen, top, WAIT_FOR_TRANSITION, function()
 					if data then
 						top.data = data
@@ -1127,6 +1132,20 @@ function M.preload(id, options, cb)
 	return true -- return true for legacy reasons (before queue existed)
 end
 
+--- Check if a screen has missing resources, always returns false for factory
+-- @param id (string|hash) - Id of the screen to preload
+function M.has_missing_resources(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]
+	if screen.proxy then
+		local missing_resources = collectionproxy.missing_resources(screen.proxy)
+		return #missing_resources > 0
+	end
+	return false
+end
 
 --- Unload a preloaded monarch screen
 -- @param id (string|hash) - Id of the screen to unload
@@ -1178,8 +1197,8 @@ end
 -- @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
+	if not M.is_loaded(id) then
-		return false, "Unable to post message to screen if it isn't visible"
+		return false, "Unable to post message to screen if it isn't loaded"
 	end
 
 	assert(message_id, "You must provide a message_id")
@@ -1331,24 +1350,36 @@ function M.on_focus_changed(id, fn)
 end
 
 ---
--- Set a function to call when a screen is sent a message using monarch.post()
+-- Set either a function to be called when msg.post() is called on a specific
--- The function will receive (message_id, message, sender)
+-- screen or a URL where the message is sent.
--- IMPORTANT! You must call monarch.on_message() from the same script as
+-- IMPORTANT! If you provide a function you must also make sure to call
--- this function was called
+-- monarch.on_message(message_id, message, sender) from the same script as
+-- this function was called.
 -- @param id Screen id to associate the message listener function with
--- @param fn Message listener function
+-- @param fn_or_url The function to call or URL to send message to
-function M.on_post(id, fn)
+function M.on_post(id, fn_or_url)
 	assert(id, "You must provide a screen id")
-	assert(fn, "You must provide a post receiver function")
 	id = tohash(id)
 	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
 	local screen = screens[id]
+
+	local t = type(fn_or_url)
+	if t == "function" then
+		screen.receiver_fn = fn_or_url
 		screen.receiver_url = msg.url()
-	screen.receiver_fn = fn
+	elseif t == "userdata" or t == "string" then
+		screen.receiver_fn = nil
+		screen.receiver_url = fn_or_url
+	else
+		screen.receiver_fn = nil
+		screen.receiver_url = msg.url()
+	end
 end
 
+local empty_hash = hash("")
+
 local function url_to_key(url)
-	return (url.socket or hash("")) .. (url.path or hash("")) .. (url.fragment or hash(""))
+	return (url.socket or empty_hash) .. (url.path or empty_hash) .. (url.fragment or empty_hash)
 end
 
 

test.settings

@@ -0,0 +1,2 @@
+[bootstrap]
+main_collection = /test/test.collectionc

test/msg.lua

@@ -64,5 +64,17 @@ function M.last(url)
 	return messages[#messages]
 end
 
+function M.filter(url, fn)
+	local t = {}
+	local messages = M.messages(url)
+	for i=1,#messages do
+		local message = messages[i]
+		if fn(message) then
+			t[#t + 1] = message
+		end
+	end
+	return t
+end
+
 
 return M

test/test_monarch.lua

@@ -155,6 +155,17 @@ return function()
 			assert(wait_until_visible(POPUP1))
 		end)
 
+		it("should be able to tell if a screen is loaded or not", function()
+			assert(not monarch.is_loaded(SCREEN1))
+			monarch.show(SCREEN1)
+			assert(wait_until_visible(SCREEN1))
+			assert(monarch.is_loaded(SCREEN1))
+			
+			monarch.hide(SCREEN1)
+			assert(wait_until_hidden(SCREEN1))
+			assert(not monarch.is_loaded(SCREEN1))
+		end)
+		
 		it("should be able to show a screen without adding it to the stack", function()
 			monarch.show(BACKGROUND, { no_stack = true })
 			assert(wait_until_visible(BACKGROUND), "Background was never shown")
@@ -407,43 +418,37 @@ return function()
 
 			monarch.show(SCREEN1)
 			assert(wait_until_not_busy())
-			assert(mock_msg.messages(URL1)[1].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
-			assert(mock_msg.messages(URL1)[1].message.screen == SCREEN1)
-			assert(mock_msg.messages(URL2)[1].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
-			assert(mock_msg.messages(URL2)[1].message.screen == SCREEN1)
-			assert(mock_msg.messages(URL1)[2].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
-			assert(mock_msg.messages(URL1)[2].message.screen == SCREEN1)
-			assert(mock_msg.messages(URL2)[2].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
-			assert(mock_msg.messages(URL2)[2].message.screen == SCREEN1)
 
 			monarch.remove_listener(URL2)
 			monarch.show(SCREEN2)
 			assert(wait_until_not_busy())
 
-			assert(#mock_msg.messages(URL1) == 6)
-			assert(#mock_msg.messages(URL2) == 2)
-			assert(mock_msg.messages(URL1)[3].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
-			assert(mock_msg.messages(URL1)[3].message.screen == SCREEN2)
-			assert(mock_msg.messages(URL1)[4].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
-			assert(mock_msg.messages(URL1)[4].message.screen == SCREEN2)
-			assert(mock_msg.messages(URL1)[5].message_id == monarch.SCREEN_TRANSITION_OUT_STARTED)
-			assert(mock_msg.messages(URL1)[5].message.screen == SCREEN1)
-			assert(mock_msg.messages(URL1)[6].message_id == monarch.SCREEN_TRANSITION_OUT_FINISHED)
-			assert(mock_msg.messages(URL1)[6].message.screen == SCREEN1)
-
 			monarch.back()
 			assert(wait_until_not_busy())
 
-			assert(#mock_msg.messages(URL1) == 10)
+			local messages = mock_msg.filter(URL1, function(m)
-			assert(#mock_msg.messages(URL2) == 2)
+				return m.message.screen == SCREEN1
-			assert(mock_msg.messages(URL1)[7].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
+			end)
-			assert(mock_msg.messages(URL1)[7].message.screen == SCREEN1)
+			assert(messages[1].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
-			assert(mock_msg.messages(URL1)[8].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
+			assert(messages[2].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
-			assert(mock_msg.messages(URL1)[8].message.screen == SCREEN1)
+			assert(messages[3].message_id == monarch.SCREEN_TRANSITION_OUT_STARTED)
-			assert(mock_msg.messages(URL1)[9].message_id == monarch.SCREEN_TRANSITION_OUT_STARTED)
+			assert(messages[4].message_id == monarch.SCREEN_TRANSITION_OUT_FINISHED)
-			assert(mock_msg.messages(URL1)[9].message.screen == SCREEN2)
+			assert(messages[5].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
-			assert(mock_msg.messages(URL1)[10].message_id == monarch.SCREEN_TRANSITION_OUT_FINISHED)
+			assert(messages[6].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
-			assert(mock_msg.messages(URL1)[10].message.screen == SCREEN2)
+
+			messages = mock_msg.filter(URL2, function(m)
+				return m.message.screen == SCREEN1
+			end)
+			assert(messages[1].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
+			assert(messages[2].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
+			
+			messages = mock_msg.filter(URL1, function(m)
+				return m.message.screen == SCREEN2
+			end)
+			assert(messages[1].message_id == monarch.SCREEN_TRANSITION_IN_STARTED)
+			assert(messages[2].message_id == monarch.SCREEN_TRANSITION_IN_FINISHED)
+			assert(messages[3].message_id == monarch.SCREEN_TRANSITION_OUT_STARTED)
+			assert(messages[4].message_id == monarch.SCREEN_TRANSITION_OUT_FINISHED)
 		end)
 		
 		it("should be able to show a screen even while it is preloading", function()