Port [message] ActionWML tag from C++ to Lua

Lua API additions:
- wesnoth.skipping_replay()
- wesnoth.deselect_hex()

Note: vultraz and aetheryn deserve partial credit for the Lua implementation

data/lua/wml-tags.lua

@@ -13,14 +13,13 @@ end
 
 wesnoth.require "lua/wml/objectives.lua"
 wesnoth.require "lua/wml/items.lua"
+wesnoth.require "lua/wml/message.lua"
 
 local helper = wesnoth.require "lua/helper.lua"
 local location_set = wesnoth.require "lua/location_set.lua"
 local utils = wesnoth.require "lua/wml-utils.lua"
 local wml_actions = wesnoth.wml_actions
 
-local engine_message = wml_actions.message
-
 function wml_actions.sync_variable(cfg)
 	local names = cfg.name or helper.wml_error "[sync_variable] missing required name= attribute."
 	local result = wesnoth.synchronize_choice(
@@ -59,13 +58,6 @@ function wml_actions.sync_variable(cfg)
 	end
 end
 
-function wml_actions.message(cfg)
-	local show_if = helper.get_child(cfg, "show_if")
-	if not show_if or wesnoth.eval_conditional(show_if) then
-		engine_message(cfg)
-	end
-end
-
 function wml_actions.chat(cfg)
 	local side_list = wesnoth.get_sides(cfg)
 	local speaker = tostring(cfg.speaker or "WML")

data/lua/wml/message.lua

@@ -0,0 +1,227 @@
+
+local helper = wesnoth.require "lua/helper.lua"
+local utils = wesnoth.require "lua/wml-utils.lua"
+local location_set = wesnoth.require "lua/location_set.lua"
+local skip_messages = false
+
+local function log(msg, level)
+	wesnoth.wml_actions.wml_message({
+		message = msg,
+		logger = level,
+	})
+end
+
+local function get_image(cfg, speaker)
+	local image = cfg.image
+
+	if speaker and image == nil then
+		image = speaker.__cfg.profile
+	end
+
+	if image == "none" or image == nil then
+		return ""
+	end
+
+	return image
+end
+
+local function get_caption(cfg, speaker)
+	local caption = cfg.caption
+
+	if not caption and speaker ~= nil then
+		caption = speaker.name or speaker.type_name
+	end
+
+	return caption
+end
+
+local function get_speaker(cfg)
+	local speaker
+	local context = wesnoth.current.event_context
+
+	if cfg.speaker == "narrator" then
+		speaker = "narrator"
+	elseif cfg.speaker == "unit" then
+		speaker = wesnoth.get_unit(context.x1, context.y1)
+	elseif cfg.speaker == "second_unit" then
+		speaker = wesnoth.get_unit(context.x2, context.y2)
+	else
+		speaker = wesnoth.get_units(cfg)[1]
+	end
+
+	return speaker
+end
+
+local function message_user_choice(cfg, speaker, options, text_input)
+	local image = get_image(cfg, speaker)
+	local caption = get_caption(cfg, speaker)
+
+	local left_side = true
+	-- If this doesn't work, might need tostring()
+	if image:find("~RIGHT()") then
+		left_side = false
+		-- The percent signs escape the parentheses for a literal match
+		image = image:gsub("~RIGHT%(%)", "")
+	end
+
+	local msg_cfg = {
+		left_side = left_side,
+		title = caption,
+		message = cfg.message,
+		portrait = image,
+	}
+
+	-- Parse input text, if not available all fields are empty
+	if text_input then
+		local input_max_size = tonumber(text_input.max_length) or 256
+		if input_max_size > 1024 or input_max_size < 1 then
+			log("Invalid maximum size for input " .. input_max_size, "warning")
+			input_max_size = 256
+		end
+
+		-- This roundabout method is because text_input starts out
+		-- as an immutable userdata value
+		text_input = {
+			label = text_input.label or "",
+			text  = text_input.text	 or "",
+			max_length = input_max_size,
+		}
+	end
+
+	return function()
+		local option_chosen, ti_content = wesnoth.show_message_dialog(msg_cfg, options, text_input)
+
+		if option_chosen == -2 then -- Pressed Escape (only if no input)
+			skip_messages = true
+		end
+
+		local result_cfg = {}
+
+		if #options > 0 then
+			result_cfg.value = option_chosen
+		end
+
+		if text_input ~= nil then
+			result_cfg.text = ti_content
+		end
+
+		return result_cfg
+	end
+end
+
+function wesnoth.wml_actions.message(cfg)
+	local show_if = helper.get_child(cfg, "show_if") or {}
+	if not wesnoth.eval_conditional(show_if) then
+		log("[message] skipped because [show_if] did not pass", "debug")
+		return
+	end
+
+	-- Only the first text_input tag is considered
+	local text_input
+	for cfg in helper.child_range(cfg, "text_input") do
+		if text_input ~= nil then
+			log("Too many [text_input] tags, only one accepted", "warning")
+			break
+		end
+		text_input = cfg
+	end
+
+	local options, option_events = {}, {}
+	for option in helper.child_range(cfg, "option") do
+		local condition = helper.get_child(cfg, "show_if") or {}
+
+		if wesnoth.eval_conditional(condition) then
+			table.insert(options, option.message)
+			table.insert(option_events, {})
+
+			for cmd in helper.child_range(option, "command") do
+				table.insert(option_events[#option_events], cmd)
+			end
+		end
+	end
+
+	-- Check if there is any input to be made, if not the message may be skipped
+	local has_input = text_input ~= nil or #options > 0
+
+	if not has_input and (wesnoth.skipping_replay() or skip_messages) then
+		-- No input to get and the user is not interested either
+		log("Skipping [message] because user not interested", "debug")
+		return
+	end
+
+	local sides_for = cfg.side_for
+	if sides_for and not has_input then
+		local show_for_side = false
+
+		-- Sanity checks on side number and controller
+		for side in utils.split(sides_for) do
+			side = tonumber(side)
+			if side > 0 and side < #wesnoth.sides and wesnoth.sides[side].controller == "human" then
+				show_for_side = true
+				break
+			end
+		end
+
+		if not show_for_side then
+			-- Player isn't controlling side which should see the message
+			log("Player isn't controlling side that should see [message]", "debug")
+			return
+		end
+	end
+
+	local speaker = get_speaker(cfg)
+	if not speaker then
+		-- No matching unit found, continue onto the next message
+		log("No speaker found for [message]", "debug")
+		return
+	elseif speaker == "narrator" then
+		-- Narrator, so deselect units
+		wesnoth.deselect_hex()
+		-- The speaker is expected to be either nil or a unit later
+		speaker = nil
+	else
+		-- Check ~= false, because the default if omitted should be true
+		if cfg.scroll ~= false then
+			wesnoth.scroll_to_tile(speaker.x, speaker.y)
+		end
+
+		wesnoth.select_hex(speaker.x, speaker.y, false)
+	end
+
+	if cfg.sound then wesnoth.play_sound(cfg.sound) end
+
+	local msg_dlg = message_user_choice(cfg, speaker, options, text_input)
+
+	local option_chosen
+	if not has_input then
+		-- Always show the dialog if it has no input, whether we are replaying or not
+		msg_dlg()
+	else
+		local choice = wesnoth.synchronize_choice(msg_dlg)
+
+		option_chosen = tonumber(choice.value)
+
+		if text_input ~= nil then
+			-- Implement the consequences of the choice
+			wesnoth.set_variable(text_input.variable or "input", choice.text)
+		end
+	end
+
+	if #options > 0 then
+		if option_chosen > #options then
+			log("invalid choice (" .. option_chosen .. ") was specified, choice 1 to " ..
+				#options .. " was expected", "debug")
+			return
+		end
+
+		for i, cmd in ipairs(option_events[option_chosen]) do
+			utils.handle_event_commands(cmd)
+		end
+	end
+end
+
+local on_event = wesnoth.game_events.on_event
+function wesnoth.game_events.on_event(...)
+	if type(on_event) == "function" then on_event(...) end
+	skip_messages = false
+end