Add formspec toolkit and refactor mainmenu to use it

Fix crash on using cursor keys in client menu without selected server
Add support for non fixed size tabviews

builtin/mainmenu/common.lua

@@ -0,0 +1,193 @@
+--Minetest
+--Copyright (C) 2014 sapier
+--
+--This program is free software; you can redistribute it and/or modify
+--it under the terms of the GNU Lesser General Public License as published by
+--the Free Software Foundation; either version 2.1 of the License, or
+--(at your option) any later version.
+--
+--This program is distributed in the hope that it will be useful,
+--but WITHOUT ANY WARRANTY; without even the implied warranty of
+--MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--GNU Lesser General Public License for more details.
+--
+--You should have received a copy of the GNU Lesser General Public License along
+--with this program; if not, write to the Free Software Foundation, Inc.,
+--51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+--------------------------------------------------------------------------------
+-- Global menu data
+---------------------------------------------------------------------------------
+menudata = {}
+
+--------------------------------------------------------------------------------
+-- Menu helper functions
+--------------------------------------------------------------------------------
+
+--------------------------------------------------------------------------------
+function render_favorite(spec,render_details)
+	local text = ""
+
+	if spec.name ~= nil then
+		text = text .. core.formspec_escape(spec.name:trim())
+
+--		if spec.description ~= nil and
+--			core.formspec_escape(spec.description):trim() ~= "" then
+--			text = text .. " (" .. core.formspec_escape(spec.description) .. ")"
+--		end
+	else
+		if spec.address ~= nil then
+			text = text .. spec.address:trim()
+
+			if spec.port ~= nil then
+				text = text .. ":" .. spec.port
+			end
+		end
+	end
+
+	if not render_details then
+		return text
+	end
+
+	local details = ""
+	if spec.password == true then
+		details = details .. "*"
+	else
+		details = details .. "_"
+	end
+
+	if spec.creative then
+		details = details .. "C"
+	else
+		details = details .. "_"
+	end
+
+	if spec.damage then
+		details = details .. "D"
+	else
+		details = details .. "_"
+	end
+
+	if spec.pvp then
+		details = details .. "P"
+	else
+		details = details .. "_"
+	end
+	details = details .. " "
+
+	local playercount = ""
+
+	if spec.clients ~= nil and
+		spec.clients_max ~= nil then
+		playercount = string.format("%03d",spec.clients) .. "/" ..
+						string.format("%03d",spec.clients_max) .. " "
+	end
+
+	return playercount .. core.formspec_escape(details) ..  text
+end
+
+--------------------------------------------------------------------------------
+os.tempfolder = function()
+	if core.setting_get("TMPFolder") then
+		return core.setting_get("TMPFolder") .. DIR_DELIM .. "MT_" .. math.random(0,10000)
+	end
+
+	local filetocheck = os.tmpname()
+	os.remove(filetocheck)
+
+	local randname = "MTTempModFolder_" .. math.random(0,10000)
+	if DIR_DELIM == "\\" then
+		local tempfolder = os.getenv("TEMP")
+		return tempfolder .. filetocheck
+	else
+		local backstring = filetocheck:reverse()
+		return filetocheck:sub(0,filetocheck:len()-backstring:find(DIR_DELIM)+1) ..randname
+	end
+
+end
+
+--------------------------------------------------------------------------------
+function menu_render_worldlist()
+	local retval = ""
+
+	local current_worldlist = menudata.worldlist:get_list()
+
+	for i,v in ipairs(current_worldlist) do
+		if retval ~= "" then
+			retval = retval ..","
+		end
+
+		retval = retval .. core.formspec_escape(v.name) ..
+					" \\[" .. core.formspec_escape(v.gameid) .. "\\]"
+	end
+
+	return retval
+end
+
+--------------------------------------------------------------------------------
+function menu_handle_key_up_down(fields,textlist,settingname)
+
+	if fields["key_up"] then
+		local oldidx = core.get_textlist_index(textlist)
+
+		if oldidx ~= nil and oldidx > 1 then
+			local newidx = oldidx -1
+			core.setting_set(settingname,
+				menudata.worldlist:get_raw_index(newidx))
+		end
+		return true
+	end
+
+	if fields["key_down"] then
+		local oldidx = core.get_textlist_index(textlist)
+
+		if oldidx ~= nil and oldidx < menudata.worldlist:size() then
+			local newidx = oldidx + 1
+			core.setting_set(settingname,
+				menudata.worldlist:get_raw_index(newidx))
+		end
+		
+		return true
+	end
+	
+	return false
+end
+
+--------------------------------------------------------------------------------
+function asyncOnlineFavourites()
+
+	menudata.favorites = {}
+	core.handle_async(
+		function(param)
+			return core.get_favorites("online")
+		end,
+		nil,
+		function(result)
+			menudata.favorites = result
+			core.event_handler("Refresh")
+		end
+		)
+end
+
+--------------------------------------------------------------------------------
+function text2textlist(xpos,ypos,width,height,tl_name,textlen,text,transparency)
+	local textlines = core.splittext(text,textlen)
+	
+	local retval = "textlist[" .. xpos .. "," .. ypos .. ";"
+								.. width .. "," .. height .. ";"
+								.. tl_name .. ";"
+	
+	for i=1, #textlines, 1 do
+		textlines[i] = textlines[i]:gsub("\r","")
+		retval = retval .. core.formspec_escape(textlines[i]) .. ","
+	end
+	
+	retval = retval .. ";0;"
+	
+	if transparency then
+		retval = retval .. "true"
+	end
+	
+	retval = retval .. "]"
+
+	return retval
+end