Add color=value to [message] (#651)

Add support for the pango attributes as keys in [message]
This is equivalent to surrounding the entire string in a span with the specified attribtues.

changelog

@@ -26,6 +26,7 @@ Version 1.13.4+dev:
    * Improved the dialog for choosing what to do when a player leaves in
      multiplayer.
  * WML engine:
+   * Add color= attribute to [message].
    * Fix some issues with [foreach]
    * Fix some issues with backstab-like weapon specials
    * Support [effect]times=<integer>

data/core/about.cfg

@@ -1320,6 +1320,9 @@
         name = "Paŭlo Ebermann (Pauxlo)"
         wikiuser = "Pauxlo"
     [/entry]
+    [entry]
+    	name = "Pentarctagon"
+    [/entry]
     [entry]
         name = "Peter Elmers"
     [/entry]

data/lua/wml/message.lua

@@ -52,6 +52,131 @@ local function get_caption(cfg, speaker)
 	return caption
 end
 
+local function get_pango_color(color)
+	local pango_color = "#"
+
+	-- if a hex color was passed in
+	-- or if a color string was passed in - contains no non-letter characters
+	-- just use that
+	if string.sub(color, 1, 1) == "#" or not string.match(color, "%A+") then
+		pango_color = color
+	-- decimal color was passed in, convert to hex color for pango
+	else
+		for s in string.gmatch(color, "%d+") do
+			pango_color = pango_color .. tonumber(s, 16)
+		end
+	end
+
+	return pango_color
+end
+
+-- add formatting
+local function add_formatting(cfg, text)
+	-- span tag
+	local formatting = "<span"  
+
+	-- if message text, add formatting
+	if text and cfg then
+		-- add font
+		if cfg.font and cfg.font ~= '' then
+			formatting = formatting .. " font='" .. cfg.font .. "'"
+		end
+
+		-- add font_family
+		if cfg.font_family and cfg.font_family ~= '' then
+			formatting = formatting .. " font_family='" .. cfg.font_family .. "'"
+		end
+
+		-- add font_size
+		if cfg.font_size and cfg.font_size ~= '' then
+			formatting = formatting .. " font_size='" .. cfg.font_size .. "'"
+		end
+
+		-- font_style
+		if cfg.font_style and cfg.font_style ~= '' then
+			formatting = formatting .. " font_style='" .. cfg.font_style .. "'"
+		end
+
+		-- font_weight
+		if cfg.font_weight and cfg.font_weight ~= '' then
+			formatting = formatting .. " font_weight='" .. cfg.font_weight .. "'"
+		end
+
+		-- font_variant
+		if cfg.font_variant and cfg.font_variant ~= '' then
+			formatting = formatting .. " font_variant='" .. cfg.font_variant .. "'"
+		end
+
+		-- font_stretch
+		if cfg.font_stretch and cfg.font_stretch ~= '' then
+			formatting = formatting .. " font_stretch='" .. cfg.font_stretch .. "'"
+		end
+
+		-- add color
+		if cfg.color and cfg.color ~= '' then
+			formatting = formatting .. " color='" .. get_pango_color(cfg.color) .. "'"
+		end
+
+		-- bgcolor
+		if cfg.bgcolor and cfg.bgcolor ~= '' then
+			formatting = formatting .. " bgcolor='" .. get_pango_color(cfg.bgcolor) .. "'"
+		end
+
+		-- underline
+		if cfg.underline and cfg.underline ~= '' then
+			formatting = formatting .. " underline='" .. cfg.underline .. "'"
+		end
+
+		-- underline_color
+		if cfg.underline_color and cfg.underline_color ~= '' then
+			formatting = formatting .. " underline_color='" .. get_pango_color(cfg.underline_color) .. "'"
+		end
+
+		-- rise
+		if cfg.rise and cfg.rise ~= '' then
+			formatting = formatting .. " rise='" .. cfg.rise .. "'"
+		end
+
+		-- strikethrough
+		if cfg.strikethrough and tostring(cfg.strikethrough) ~= '' then
+			formatting = formatting .. " strikethrough='" .. tostring(cfg.strikethrough) .. "'"
+		end
+
+		-- strikethrough_color
+		if cfg.strikethrough_color and cfg.strikethrough_color ~= '' then
+			formatting = formatting .. " strikethrough_color='" .. get_pango_color(cfg.strikethrough_color) .. "'"
+		end
+
+		-- fallback
+		if cfg.fallback and tostring(cfg.fallback) ~= '' then
+			formatting = formatting .. " fallback='" .. tostring(cfg.fallback) .. "'"
+		end
+
+		-- letter_spacing
+		if cfg.letter_spacing and cfg.letter_spacing ~= '' then
+			formatting = formatting .. " letter_spacing='" .. cfg.letter_spacing .. "'"
+		end
+
+		-- gravity
+		if cfg.gravity and cfg.gravity ~= '' then
+			formatting = formatting .. " gravity='" .. cfg.gravity .. "'"
+		end
+
+		-- gravity_hint
+		if cfg.gravity_hint and cfg.gravity_hint ~= '' then
+			formatting = formatting .. " gravity_hint='" .. cfg.gravity_hint .. "'"
+		end
+
+		-- wrap in span tags and return if a color was added
+		if formatting ~= "<span" then
+			return formatting .. ">" .. text .. "</span>"
+		end
+ 	end
+
+	-- or return unmodified message
+	return text
+end
+
 local function get_speaker(cfg)
 	local speaker
 	local context = wesnoth.current.event_context
@@ -87,7 +212,10 @@ local function message_user_choice(cfg, speaker, options, text_input)
 			msg_cfg.message = cfg.female_message
 		end
 	end
-
+
+	-- add formatting
+	msg_cfg.message = add_formatting(cfg, cfg.message)
+
 	-- 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