Prevent show/back operations while busy

Fixes #22

CHANGELOG.md

@@ -0,0 +1,56 @@
+## 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]
+
+

README.md

@@ -245,6 +245,10 @@ The options table can contain the following fields:
 * ```clear``` (boolean) - If the clear flag is set Monarch will search the stack for the screen that is to be shown. If the screen already exists in the stack and the clear flag is set Monarch will remove all screens between the current top and the screen in question.
 * ```reload``` (boolean) - If the reload flag is set Monarch will reload the collection proxy if it's already loaded (this can happen if the previous screen was a popup).
 
+**RETURN**
+* ```success``` (boolean) - True if the process of showing the screen was started successfully. False if already busy showing/hiding a screen.
+
+
 ### monarch.back([data], [callback])
 Go back to a previous Monarch screen
 
@@ -252,6 +256,9 @@ Go back to a previous Monarch screen
 * ```data``` (table) - Optional data to associate with the screen you are going back to.  Retrieve using ```monarch.data()```.
 * ```callback``` (function) - Optional function to call when the previous screen is visible.
 
+**RETURN**
+* ```success``` (boolean) - True if the process of going back to a previous screen was started successfully. False if already busy showing/hiding a screen.
+
 
 ### monarch.preload(screen_id, [callback])
 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.

monarch/monarch.lua

@@ -1,9 +1,5 @@
 local M = {}
 
-local screens = {}
-
-local stack = {}
-
 local CONTEXT = hash("monarch_context")
 local PROXY_LOADED = hash("proxy_loaded")
 local PROXY_UNLOADED = hash("proxy_unloaded")
@@ -25,6 +21,15 @@ M.FOCUS = {}
 M.FOCUS.GAINED = hash("monarch_focus_gained")
 M.FOCUS.LOST = hash("monarch_focus_lost")
 
+-- all registered screens
+local screens = {}
+
+-- the current stack of screens
+local stack = {}
+
+-- true while busy showing/hiding something
+local busy = false
+
 
 local function log(...) end
 
@@ -225,6 +230,7 @@ local function show_out(screen, next_screen, cb)
 	log("show_out()", screen.id)
 	local co
 	co = coroutine.create(function()
+		busy = true
 		screen.co = co
 		change_context(screen)
 		release_input(screen)
@@ -238,6 +244,7 @@ local function show_out(screen, next_screen, cb)
 			unload(screen)
 		end
 		screen.co = nil
+		busy = false
 		if cb then cb() end
 	end)
 	coroutine.resume(co)
@@ -247,6 +254,7 @@ local function show_in(screen, previous_screen, reload, cb)
 	log("show_in()", screen.id)
 	local co
 	co = coroutine.create(function()
+		busy = true
 		screen.co = co
 		change_context(screen)
 		if reload and screen.loaded then
@@ -271,6 +279,7 @@ local function show_in(screen, previous_screen, reload, cb)
 		acquire_input(screen)
 		focus_gained(screen, previous_screen)
 		screen.co = nil
+		busy = false
 		if cb then cb() end
 	end)
 	coroutine.resume(co)
@@ -280,6 +289,7 @@ local function back_in(screen, previous_screen, cb)
 	log("back_in()", screen.id)
 	local co
 	co = coroutine.create(function()
+		busy = true
 		screen.co = co
 		change_context(screen)
 		if screen.preloaded then
@@ -297,6 +307,7 @@ local function back_in(screen, previous_screen, cb)
 		acquire_input(screen)
 		focus_gained(screen, previous_screen)
 		screen.co = nil
+		busy = false
 		if cb then cb() end
 	end)
 	coroutine.resume(co)
@@ -306,6 +317,7 @@ local function back_out(screen, next_screen, cb)
 	log("back_out()", screen.id)
 	local co
 	co = coroutine.create(function()
+		busy = true
 		screen.co = co
 		change_context(screen)
 		release_input(screen)
@@ -313,6 +325,7 @@ local function back_out(screen, next_screen, cb)
 		transition(screen, M.TRANSITION.BACK_OUT, { next_screen = next_screen and next_screen.id })
 		unload(screen)
 		screen.co = nil
+		busy = false
 		if cb then cb() end
 	end)
 	coroutine.resume(co)
@@ -346,8 +359,13 @@ end
 --				   This would be the case if doing a show() from a popup on the screen just below the popup.
 -- @param data (*) - Optional data to set on the screen. Can be retrieved by the data() function
 -- @param cb (function) - Optional callback to invoke when screen is shown
+-- @return success True if screen is successfully shown, false if busy performing another operation
 function M.show(id, options, data, cb)
 	assert(id, "You must provide a screen id")
+	if busy then
+		return false
+	end
+	
 	id = tohash(id)
 	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
 
@@ -392,13 +410,20 @@ function M.show(id, options, data, cb)
 
 	-- show screen
 	show_in(screen, top, options and options.reload, cb)
+
+	return true
 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
+-- @return true if successfully going back, false if busy performing another operation
 function M.back(data, cb)
+	if busy then
+		return false
+	end
+
 	local screen = table.remove(stack)
 	if screen then
 		log("back()", screen.id)
@@ -424,6 +449,7 @@ function M.back(data, cb)
 	elseif cb then
 		cb()
 	end
+	return true
 end
 
 --- Preload a screen. This will load but not enable and show a screen. Useful for "heavier" screens

monarch/transitions/gui.lua

@@ -110,22 +110,28 @@ function M.create(node)
 			delay = delay,
 			in_progress = false,
 			urls = {},
+			id = nil
 		}
 	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)
+			msg.post(url, monarch.TRANSITION.DONE, message)
+		end
+	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())
-			current_transition = transition
 			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()
-				transition.in_progress = false
-				local message = { transition = transition_id }
-				while #transition.urls > 0 do
-					local url = table.remove(transition.urls)
-					msg.post(url, monarch.TRANSITION.DONE, message)
-				end
+				finish_transition(transition)
 			end)
 		end
 	end
@@ -139,6 +145,9 @@ function M.create(node)
 			-- 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)
+				end
 			end
 		else
 			local transition = transitions[message_id]

test/test_monarch.lua

@@ -148,6 +148,23 @@ return function()
 		end)
 
 		
+		it("should prevent further operations while hiding/showing a screen", function()
+			assert(monarch.show(SCREEN1) == true)
+			assert(monarch.show(SCREEN2) == false)
+			assert(wait_until_shown(SCREEN1), "Screen1 was never shown")
+			assert_stack({ SCREEN1 })
+
+			assert(monarch.show(SCREEN2) == true)
+			assert(wait_until_shown(SCREEN2), "Screen1 was never shown")
+			assert_stack({ SCREEN1, SCREEN2 })
+
+			assert(monarch.back() == true)
+			assert(monarch.back() == false)
+			assert(wait_until_shown(SCREEN1), "Screen1 was never shown")
+			assert_stack({ SCREEN1 })
+		end)
+		
+		
 		it("should close any open popups when showing a popup without the Popup On Popup flag", function()
 			monarch.show(SCREEN1)
 			assert(wait_until_shown(SCREEN1), "Screen1 was never shown")