Allow data to be passed when showing or going back

example/game.gui

@@ -181,6 +181,69 @@ nodes {
   text_leading: 1.0
   text_tracking: 0.0
 }
+nodes {
+  position {
+    x: 320.0
+    y: 1050.0
+    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_TEXT
+  blend_mode: BLEND_MODE_ALPHA
+  text: "<text>"
+  font: "example"
+  id: "level"
+  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: "root"
+  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

example/game.gui_script

@@ -4,6 +4,9 @@ local transitions = require "monarch.transitions.gui"
 function init(self)
 	msg.post(".", "acquire_input_focus")
 	
+	local data = monarch.data(hash("game"))
+	gui.set_text(gui.get_node("level"), tostring(data.level))
+
 	self.transition = transitions.create(gui.get_node("root"))
 		.show_in(transitions.slide_in_right, gui.EASING_OUTQUAD, 0.6, 0)
 		.show_out(transitions.slide_out_left, gui.EASING_INQUAD, 0.6, 0)
@@ -14,7 +17,7 @@ end
 function on_input(self, action_id, action)
 	if action_id == hash("touch") and action.released then
 		if gui.pick_node(gui.get_node("win_button"), action.x, action.y) then
-			monarch.show(hash("menu"), { clear = true }, function()
+			monarch.show(hash("menu"), { clear = true }, nil, function()
 				print("showing menu done")
 			end)
 		end

example/menu.gui_script

@@ -14,7 +14,7 @@ end
 function on_input(self, action_id, action)
 	if action_id == hash("touch") and action.released then
 		if gui.pick_node(gui.get_node("startgame_button"), action.x, action.y) then
-			monarch.show(hash("popup"), nil, function()
+			monarch.show(hash("popup"), nil, nil, function()
 				print("showing popup done")
 			end)
 		end

example/popup.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.ok, action.x, action.y) then
 			print("ok")
-			monarch.show(hash("pregame"), nil, function()
+			monarch.show(hash("pregame"), nil, nil, function()
 				print("pregame show done")
 			end)
 		elseif gui.pick_node(self.cancel, action.x, action.y) then

example/pregame.gui_script

@@ -17,7 +17,7 @@ function on_input(self, action_id, action)
 	if action_id == hash("touch") and action.released then
 		if gui.pick_node(self.play, action.x, action.y) then
 			print("play")
-			monarch.show(hash("game"), nil, function()
+			monarch.show(hash("game"), nil, { level = 1 }, function()
 				print("showing game done")
 			end)
 		elseif gui.pick_node(self.back, action.x, action.y) then

monarch/monarch.lua

@@ -116,16 +116,27 @@ local function back_out(screen, cb)
 end
 
 
+--- Get data associated with a screen
+-- @param id Id of the screen to get data for
+-- @return Data associated with the screen
+function M.data(id)
+	assert(id, "You must provide a screen id")
+	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
+	return screens[id].data
+end
+
 --- Show a new screen
 -- @param id Id of the screen to show
 -- @param options Table with options when showing the screen (can be nil). Valid values:
 -- 		* clear - Set to true if the stack should be cleared down to an existing instance of the screen
+-- @param data Optional data to set on the screen. Can be retrieved by the data() function
 -- @ param cb Optional callback to invoke when screen is shown
-function M.show(id, options, cb)
+function M.show(id, options, data, cb)
 	assert(id, "You must provide a screen id")
 	assert(screens[id], ("There is no screen registered with id %s"):format(tostring(id)))
 
 	local screen = screens[id]
+	screen.data = data
 	
 	-- manipulate the current top
 	-- close popup if needed
@@ -163,13 +174,17 @@ end
 
 
 -- Go back to the previous screen in the stack
+-- @param data Optional data to set for the previous screen
 -- @param cb Optional callback to invoke when the previous screen is visible again
-function M.back(cb)
+function M.back(data, cb)
 	local screen = table.remove(stack)
 	if screen then
 		back_out(screen, cb)
 		local top = stack[#stack]
 		if top then
+			if data then
+				screen.data = data
+			end
 			back_in(top, screen)
 		end
 	elseif cb then