monarch.back_to() test

2025-11-26 19:00:53 +01:00 · 2021-06-28 01:04:23 +02:00
13 changed files with 633 additions and 185 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -0,0 +1,60 @@
+## Monarch 2.8.0 [britzl released 2018-06-10]
+NEW: Prevent show/hide operations while busy showing/hiding another screen  
+FIX: Make sure to properly finish active transitions when layout changes
+
+## Monarch 2.7.0 [britzl released 2018-06-04]
+NEW: Added monarch.top([offset]) and monarch.bottom([offset]) to get screen id of top and bottom screens (w. optional offset)  
+NEW: Transition messages now contain `next_screen` or `previous_screen`
+
+## Monarch 2.6.1 [britzl released 2018-06-04]
+FIX: Check if screen has already been preloaded before trying to preload it again (the callback will still be invoked).
+
+## Monarch 2.6.0 [britzl released 2018-06-03]
+NEW: monarch.preload() to load but not show a screen. Useful for content heavy screens that you wish to show without delay.
+
+## Monarch 2.5.0 [britzl released 2018-06-01]
+NEW: Transitions will send a `transition_done` message to the creator of the transition to notify that the transition has finished. The `message` will contain which transition that was finished.
+
+## Monarch 2.4.0 [britzl released 2018-05-26]
+NEW: Screen transitions are remembered so that they can be replayed when the screen layout changes.
+
+## Monarch 2.3.0 [britzl released 2018-03-24]
+CHANGE: The functions in monarch.lua that previously only accepted a hash as screen id now also accepts strings (and does the conversion internally)
+
+## Monarch 2.2.0 [britzl released 2018-03-19]
+NEW: Transitions now handle layout changes (via `layout_changed` message)  
+NEW: Transitions can now be notified of changes in window size using transition.window_resize(width, height)
+
+## Monarch 2.1 [britzl released 2017-12-27]
+NEW: Added Popup on Popup flag that allows a popup to be shown on top of another popup
+
+## Monarch 2.0 [britzl released 2017-12-08]
+BREAKING CHANGE: If you are using custom screen transitions (ie your own transition functions) you need to make a change to the function. The previous function signature was ```(node, to, easing, duration, delay, url)``` where ```url``` was the URL  to where the ```transition_done``` message was supposed to be posted. The new function signature for a transition function is: ```(node, to, easing, duration, delay, cb)``` where ```cb``` is a function that should be invoked when the transition is completed.  
+  
+FIX: Fixed issues related to screen transitions.  
+FIX: Code cleanup to reduce code duplication.  
+FIX: Improved documentation regarding transitions.
+
+## Monarch 1.4 [britzl released 2017-12-06]
+FIX: Several bugfixes for specific corner cases.
+
+## Monarch 1.3 [britzl released 2017-12-01]
+FIX: monarch.back(data, cb) set the data on the previous screen not the new current screen.  
+NEW: monarch.is_top(id)  
+NEW: monarch.get_stack()  
+NEW: monarch.in_stack(id)
+
+## Monarch 1.2 [britzl released 2017-11-28]
+NEW: Message id constants exposed from the Monarch module  
+NEW: Focus lost/gained contains id of next/previous screen
+
+## Monarch 1.1 [britzl released 2017-11-22]
+FIX: Bugfixes for transitions and state under certain circumstances  
+NEW: Added 'reload' option to show() command.
+
+## Monarch 1.0 [britzl released 2017-09-28]
+First public stable release
+
+## Monarch 0.9 [britzl released 2017-09-17]
+
+
--- a/README_API.md
+++ b/README_API.md
@@ -33,13 +33,6 @@ Hide a screen that has been shown using the `no_stack` option. If used on a scre
 * `success` (boolean) - True if the process of hiding the screen was started successfully.


-## monarch.clear([callback])
-Clear the stack of screens completely. Any visible screen will be hidden by navigating back out from them. This operation will be added to the queue if Monarch is busy.
-
-**PARAMETERS**
-* `callback` (function) - Optional function to call when the stack has been cleared.
-
-
 ## monarch.back([data], [callback])
 Go back to a previous Monarch screen. This operation will be added to the queue if Monarch is busy.

@@ -149,14 +142,6 @@ Check if a Monarch screen is visible.
 * `exists` (boolean) - True if the screen is visible.


-## monarch.set_timestep_below_popup(screen_id, timestep)
-Set the timestep to apply for a screen when below a popup.
-
-**PARAMETERS**
-* `screen_id` (string|hash) - Id of the screen to change timestep setting for
-* `timestep` (number) - Timestep to apply
-
-
 ## monarch.add_listener([url])
 Add a URL that will be notified of navigation events.

--- a/example/basic/basic.collection
+++ b/example/basic/basic.collection
@@ -151,3 +151,61 @@ embedded_instances {
    z: 1.0
  }
 }
+embedded_instances {
+  id: "screen3"
+  data: "components {\n"
+  "  id: \"screen_proxy\"\n"
+  "  component: \"/monarch/screen_proxy.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"
+  "  properties {\n"
+  "    id: \"screen_id\"\n"
+  "    value: \"screen3\"\n"
+  "    type: PROPERTY_TYPE_HASH\n"
+  "  }\n"
+  "}\n"
+  "embedded_components {\n"
+  "  id: \"collectionproxy\"\n"
+  "  type: \"collectionproxy\"\n"
+  "  data: \"collection: \\\"/example/basic/screen3.collection\\\"\\n"
+  "exclude: false\\n"
+  "\"\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
+  }
+}
--- a/example/basic/screen2.gui
+++ b/example/basic/screen2.gui
@@ -11,7 +11,124 @@ background_color {
 }
 nodes {
  position {
-    x: 320.0
+    x: 519.0
+    y: 568.0
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 200.0
+    y: 100.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  type: TYPE_BOX
+  blend_mode: BLEND_MODE_ALPHA
+  texture: ""
+  id: "showscreen3"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  adjust_mode: ADJUST_MODE_FIT
+  layer: ""
+  inherit_alpha: true
+  slice9 {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 0.0
+  }
+  clipping_mode: CLIPPING_MODE_NONE
+  clipping_visible: true
+  clipping_inverted: false
+  alpha: 1.0
+  template_node_child: false
+  size_mode: SIZE_MODE_AUTO
+}
+nodes {
+  position {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 200.0
+    y: 100.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  type: TYPE_TEXT
+  blend_mode: BLEND_MODE_ALPHA
+  text: "SHOW 3"
+  font: "example"
+  id: "text"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  outline {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  shadow {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  adjust_mode: ADJUST_MODE_FIT
+  line_break: false
+  parent: "showscreen3"
+  layer: ""
+  inherit_alpha: true
+  alpha: 1.0
+  outline_alpha: 1.0
+  shadow_alpha: 1.0
+  template_node_child: false
+  text_leading: 1.0
+  text_tracking: 0.0
+}
+nodes {
+  position {
+    x: 132.0
    y: 568.0
    z: 0.0
    w: 1.0
@@ -98,7 +215,7 @@ nodes {
  blend_mode: BLEND_MODE_ALPHA
  text: "BACK"
  font: "example"
-  id: "text"
+  id: "text1"
  xanchor: XANCHOR_NONE
  yanchor: YANCHOR_NONE
  pivot: PIVOT_CENTER
--- a/example/basic/screen2.gui_script
+++ b/example/basic/screen2.gui_script
@@ -6,7 +6,9 @@ end

 function on_input(self, action_id, action)
 	if action_id == hash("touch") and action.pressed then
-		if gui.pick_node(gui.get_node("backbutton"), action.x, action.y) then
+		if gui.pick_node(gui.get_node("showscreen3"), action.x, action.y) then
+			monarch.show(hash("screen3"))
+		elseif gui.pick_node(gui.get_node("backbutton"), action.x, action.y) then
 			monarch.back()
 		end
 	end
--- a/example/basic/screen3.collection
+++ b/example/basic/screen3.collection
@@ -0,0 +1,37 @@
+name: "screen3"
+scale_along_z: 0
+embedded_instances {
+  id: "go"
+  data: "components {\n"
+  "  id: \"screen3\"\n"
+  "  component: \"/example/basic/screen3.gui\"\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
+  }
+}
--- a/example/basic/screen3.gui
+++ b/example/basic/screen3.gui
@@ -0,0 +1,248 @@
+script: "/example/basic/screen3.gui_script"
+fonts {
+  name: "example"
+  font: "/assets/example.font"
+}
+background_color {
+  x: 0.0
+  y: 0.0
+  z: 0.0
+  w: 0.0
+}
+nodes {
+  position {
+    x: 137.0
+    y: 568.0
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 200.0
+    y: 100.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  type: TYPE_BOX
+  blend_mode: BLEND_MODE_ALPHA
+  texture: ""
+  id: "backbutton"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  adjust_mode: ADJUST_MODE_FIT
+  layer: ""
+  inherit_alpha: true
+  slice9 {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 0.0
+  }
+  clipping_mode: CLIPPING_MODE_NONE
+  clipping_visible: true
+  clipping_inverted: false
+  alpha: 1.0
+  template_node_child: false
+  size_mode: SIZE_MODE_AUTO
+}
+nodes {
+  position {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 200.0
+    y: 100.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  type: TYPE_TEXT
+  blend_mode: BLEND_MODE_ALPHA
+  text: "BACK"
+  font: "example"
+  id: "text"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  outline {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  shadow {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  adjust_mode: ADJUST_MODE_FIT
+  line_break: false
+  parent: "backbutton"
+  layer: ""
+  inherit_alpha: true
+  alpha: 1.0
+  outline_alpha: 1.0
+  shadow_alpha: 1.0
+  template_node_child: false
+  text_leading: 1.0
+  text_tracking: 0.0
+}
+nodes {
+  position {
+    x: 525.0
+    y: 568.0
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 200.0
+    y: 100.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  type: TYPE_BOX
+  blend_mode: BLEND_MODE_ALPHA
+  texture: ""
+  id: "tostart"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  adjust_mode: ADJUST_MODE_FIT
+  layer: ""
+  inherit_alpha: true
+  slice9 {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 0.0
+  }
+  clipping_mode: CLIPPING_MODE_NONE
+  clipping_visible: true
+  clipping_inverted: false
+  alpha: 1.0
+  template_node_child: false
+  size_mode: SIZE_MODE_AUTO
+}
+nodes {
+  position {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 200.0
+    y: 100.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  type: TYPE_TEXT
+  blend_mode: BLEND_MODE_ALPHA
+  text: "TOSTART"
+  font: "example"
+  id: "text1"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  outline {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  shadow {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  adjust_mode: ADJUST_MODE_FIT
+  line_break: false
+  parent: "tostart"
+  layer: ""
+  inherit_alpha: true
+  alpha: 1.0
+  outline_alpha: 1.0
+  shadow_alpha: 1.0
+  template_node_child: false
+  text_leading: 1.0
+  text_tracking: 0.0
+}
+material: "/builtins/materials/gui.material"
+adjust_reference: ADJUST_REFERENCE_PARENT
+max_nodes: 512
--- a/example/basic/screen3.gui_script
+++ b/example/basic/screen3.gui_script
@@ -0,0 +1,15 @@
+local monarch = require "monarch.monarch"
+
+function init(self)
+	msg.post(".", "acquire_input_focus")
+end
+
+function on_input(self, action_id, action)
+	if action_id == hash("touch") and action.pressed then
+		if gui.pick_node(gui.get_node("backbutton"), action.x, action.y) then
+			monarch.back()
+		elseif gui.pick_node(gui.get_node("tostart"), action.x, action.y) then
+			monarch.back_to(hash("screen1"))
+		end
+	end
+end
--- a/monarch/monarch.lua
+++ b/monarch/monarch.lua
@@ -1,5 +1,4 @@
 local callback_tracker = require "monarch.utils.callback_tracker"
-local async = require "monarch.utils.async"

 local M = {}

@@ -50,7 +49,7 @@ local transition_listeners = {}
 -- monarch is considered busy while there are active transitions
 local active_transition_count = 0

-local function log(...) end
+local function log(...) end 

 function M.debug()
 	log = print
@@ -605,6 +604,9 @@ 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
+		-- wait until screen has had a chance to render
+		cowait(0)
+		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
@@ -629,6 +631,9 @@ local function back_in(screen, previous_screen, wait_for_transition, cb)
 			notify_transition_listeners(M.SCREEN_TRANSITION_FAILED, { screen = screen.id })
 			return
 		end
+		-- wait until screen has had a chance to render
+		cowait(0)
+		cowait(0)
 		reset_timestep(screen)
 		if previous_screen and not previous_screen.popup then
 			transition(screen, M.TRANSITION.BACK_IN, { previous_screen = previous_screen.id }, wait_for_transition)
@@ -745,9 +750,8 @@ function M.show(id, options, data, cb)
 						pop = pop - 1
 					end
 					stack[#stack] = nil
-					async(function(await, resume)
-						await(show_out, top, screen, WAIT_FOR_TRANSITION, resume)
-					end)
+					show_out(top, screen, WAIT_FOR_TRANSITION, callbacks.track())
+					callbacks.yield_until_done()
 					top = stack[#stack]
 				end

@@ -786,16 +790,15 @@ function M.show(id, options, data, cb)
 			local same_screen = top and top.id == screen.id
 			if same_screen or (options and options.sequential) then
 				if top then
-					async(function(await, resume)
-						await(show_out, top, screen, WAIT_FOR_TRANSITION, resume)
-					end)
+					show_out(top, screen, WAIT_FOR_TRANSITION, callbacks.track())
+					callbacks.yield_until_done()
 				end
 				show_in(screen, top, options and options.reload, add_to_stack, WAIT_FOR_TRANSITION, callbacks.track())
 			else
 				-- show screen
 				local cb = callbacks.track()
 				show_in(screen, top, options and options.reload, add_to_stack, DO_NOT_WAIT_FOR_TRANSITION, function()
-					if add_to_stack and top and not top.popup then
+					if top and not top.popup then
 						show_out(top, screen, WAIT_FOR_TRANSITION, callbacks.track())
 					end
 					cb()
@@ -829,7 +832,7 @@ end

 -- Hide a screen. The screen must either be at the top of the stack or
 -- visible but not added to the stack (through the no_stack option)
-- @param id (string|hash) - Id of the screen to .hide
+-- @param id (string|hash) - Id of the screen to show
 -- @param cb (function) - Optional callback to invoke when the screen is hidden
 -- @return true if successfully hiding, false if busy or for some other reason unable to hide the screen
 function M.hide(id, cb)
@@ -866,80 +869,86 @@ function M.hide(id, cb)
 end


+local function internal_back(to, data, cb)
+	if #stack == 0 then
+		cb()
+		return
+	end

+	if not to then
+		if #stack > 1 then
+			to = stack[#stack - 1]
+		end
+	end

-- Clear stack completely. Any visible screens will be hidden by navigating back out
-- from them.
-- @param cb (function) - Optional callback to invoke when the stack has been cleared
-function M.clear(cb)
-	log("clear() queuing action")
+	queue_action(function(action_done)
+		local co
+		co = coroutine.create(function()
+			local callbacks = callback_tracker()
+			if not to then
+				back_out(table.remove(stack), nil, WAIT_FOR_TRANSITION, callbacks.track())
+			else
+				if data then
+					to.data = data
+				end

-	queue_action(function(action_done, action_error)
-		async(function(await, resume)
-			local top = stack[#stack]
-			while top and top.visible do
-				stack[#stack] = nil
-				await(back_out, top, stack[#stack - 1], WAIT_FOR_TRANSITION, resume)
-				top = stack[#stack]
+				-- close visible screens until target screen is below top screen
+				while to ~= stack[#stack - 1] do
+					local top = table.remove(stack)
+					local below = stack[#stack]
+					if top.visible then
+						back_out(top, below, WAIT_FOR_TRANSITION, callbacks.track())
+						callbacks.yield_until_done()
+					end
+				end
+				
+				local top = table.remove(stack)
+				if to == top then
+					-- 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
+					back_out(to, to, WAIT_FOR_TRANSITION, function()
+						back_in(to, to, WAIT_FOR_TRANSITION, callbacks.track())
+					end)
+				else
+					back_in(to, top, DO_NOT_WAIT_FOR_TRANSITION, function()
+						if top.visible then
+							back_out(top, to, WAIT_FOR_TRANSITION, callbacks.track())
+						end
+					end)
+				end
 			end
-
-			while stack[#stack] do
-				table.remove(stack)
-			end
-
-			pcallfn(cb)
-			pcallfn(action_done)
+			
+			callbacks.when_done(function()
+				pcallfn(cb)
+				pcallfn(action_done)
+			end)
 		end)
+		assert(coroutine.resume(co))
 	end)
 end

-
 -- Go back to the previous screen in the stack.
 -- @param data (*) - Optional data to set for the previous screen
 -- @param cb (function) - Optional callback to invoke when the previous screen is visible again
 function M.back(data, cb)
 	log("back() queuing action")
-
-	queue_action(function(action_done)
-		local callbacks = callback_tracker()
-		local back_cb = callbacks.track()
-		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
-			if top and screen.id == top.id then
-				back_out(screen, top, WAIT_FOR_TRANSITION, function()
-					if data then
-						top.data = data
-					end
-					back_in(top, screen, WAIT_FOR_TRANSITION, back_cb)
-				end)
-			else
-				if top then
-					if data then
-						top.data = data
-					end
-					back_in(top, screen, DO_NOT_WAIT_FOR_TRANSITION, function()
-						back_out(screen, top, WAIT_FOR_TRANSITION, back_cb)
-					end)
-				else
-					back_out(screen, top, WAIT_FOR_TRANSITION, back_cb)
-				end
-			end
-		end
-
-		callbacks.when_done(function()
-			pcallfn(cb)
-			pcallfn(action_done)
-		end)
-	end)
-
-	return true -- return true for legacy reasons (before queue existed)
+	internal_back(nil, data, cb)
 end


+-- Go back to the previous screen in the stack.
+-- @param data (*) - Optional data to set for the previous screen
+-- @param cb (function) - Optional callback to invoke when the previous screen is visible again
+function M.back_to(id, data, cb)
+	log("back_to() queuing action")
+	id = tohash(id)
+	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
+	local screen = screens[id]
+	internal_back(screen, data, cb)
+end
+
+
+
 --- Check if a screen is preloading via monarch.preload() or automatically
 -- via the Preload screen option
 -- @param id Screen id
@@ -1155,19 +1164,6 @@ function M.bottom(offset)
 	return screen and screen.id
 end

-
--- Set the timestep to apply for a screen when below a popup
-- @param id (string|hash) Id of the screen to change timestep setting for
-- @param timestep (number) Timestep to apply
-function M.set_timestep_below_popup(id, timestep)
-	assert(id, "You must provide a screen id")
-	assert(timestep, "You must provide a timestep")
-	id = tohash(id)
-	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
-	screens[id].timestep_below_popup = timestep
-end
-
-
 local function url_to_key(url)
 	return (url.socket or hash("")) .. (url.path or hash("")) .. (url.fragment or hash(""))
 end
--- a/monarch/transitions/gui.lua
+++ b/monarch/transitions/gui.lua
@@ -121,15 +121,11 @@ local function create()
 	local current_transition = nil

 	local function create_transition(transition_id, node, fn, easing, duration, delay)
-		assert(transition_id, "You must provide a valid transition id")
-		assert(node, "You must provide a node")
-		assert(fn, "You must provide a transition function")
-
 		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.transitions) do
+		for _,transition in ipairs(t) do
 			if transition.node == node then
 				transition.fn = fn
 				transition.easing = easing
--- a/monarch/utils/async.lua
+++ b/monarch/utils/async.lua
@@ -1,47 +0,0 @@
-local M = {}
-
-local NOT_STARTED = "not_started"
-local YIELDED = "yielded"
-local RESUMED = "resumed"
-local RUNNING = "running"
-
-function M.async(fn)
-	local co = coroutine.running()
-	
-	local state = NOT_STARTED
-
-	local function await(fn, ...)
-		state = RUNNING
-		fn(...)
-		if state ~= RUNNING then
-			return
-		end
-		state = YIELDED
-		local r = { coroutine.yield() }
-		return unpack(r)
-	end
-
-	local function resume(...)
-		if state ~= RUNNING then
-			state = RUNNING
-			local ok, err = coroutine.resume(co, ...)
-			if not ok then
-				print(err)
-				print(debug.traceback())
-			end
-		end
-	end
-
-	if co then
-		return fn(await, resume)
-	else
-		co = coroutine.create(fn)
-		return resume(await, resume)
-	end
-end
-
-return setmetatable(M, {
-	__call = function(t, ...)
-		return M.async(...)
-	end
-})
--- a/monarch/utils/callback_tracker.lua
+++ b/monarch/utils/callback_tracker.lua
@@ -6,18 +6,13 @@ function M.create()

 	local callback = nil
 	local callback_count = 0
-	local all_callbacks_done = false

 	local function is_done()
 		return callback_count == 0
 	end

 	local function invoke_if_done()
-		if all_callbacks_done then
-			print("Warning: The same callback will be invoked twice from the callback tracker!")
-		end
 		if callback_count == 0 and callback then
-			all_callbacks_done = true
 			local ok, err = pcall(callback)
 			if not ok then print(err) end
 		end
@@ -46,12 +41,26 @@ function M.create()
 		invoke_if_done()
 	end

+	function instance.yield_until_done()
+		local co = coroutine.running()
+		callback = function()
+			local ok, err = coroutine.resume(co)
+			if not ok then
+				print(err)
+			end
+		end
+		invoke_if_done()
+		if not is_done() then
+			coroutine.yield()
+		end
+	end
+
 	return instance
 end


 return setmetatable(M, {
 	__call = function(_, ...)
-		return M.create()
+		return M.create(...)
 	end
 })
--- a/test/test_transitions.lua
+++ b/test/test_transitions.lua
@@ -8,12 +8,6 @@ local easing = require "monarch.transitions.easings"

 return function()

-local function wait_timeout(fn, ...)
-	local args = { ... }
-	cowait(function() return fn(unpack(args)) end, 5)
-	return fn(...)
-end
-
 describe("transitions", function()
 	before(function()
 		mock_msg.mock()
@@ -28,28 +22,6 @@ describe("transitions", function()
 	end)


-	it("should replace an existing transition with a new one", function()
-		local one = false
-		function dummy_transition1(node, to, easing, duration, delay, cb)
-			one = true
-		end
-		local two = false
-		function dummy_transition2(node, to, easing, duration, delay, cb)
-			two = true
-		end
-		
-		local node = gui.new_box_node(vmath.vector3(), vmath.vector3(100, 100, 0))
-		local duration = 2
-		local t = transitions.create(node)
-		t.show_in(dummy_transition1, easing.OUT, duration, delay or 0)
-		t.show_in(dummy_transition2, easing.OUT, duration, delay or 0)
-		t.handle(monarch.TRANSITION.SHOW_IN)
-		
-		wait_timeout(function() return one or two end)
-		assert(two)
-		assert(not one)
-	end)
-
 	it("should replay and immediately finish on layout change", function()
 		function dummy_transition(node, to, easing, duration, delay, cb)
 			print("dummy transition")