add RadioButton Lua class

res/layouts/pages/settings.xml

@@ -1,9 +1,9 @@
 <container size='668,418' color='#0F1E2DB2' context='menu'>
     <panel pos='6' size='250' color='0' interval='1'>
-        <button id='s_aud' onclick='set_page("s_aud", "settings_audio")'>@Audio</button>
-        <button id='s_dsp' onclick='set_page("s_dsp", "settings_display")'>@Display</button>
-        <button id='s_gfx' onclick='set_page("s_gfx", "settings_graphics")'>@Graphics</button>
-        <button id='s_ctl' onclick='set_page("s_ctl", "settings_controls")'>@Controls</button>
+        <button id='s_aud' onclick='sections:set("audio")'>@Audio</button>
+        <button id='s_dsp' onclick='sections:set("display")'>@Display</button>
+        <button id='s_gfx' onclick='sections:set("graphics")'>@Graphics</button>
+        <button id='s_ctl' onclick='sections:set("controls")'>@Controls</button>
     </panel>
     <pagebox id='menu' pos='260,6' size='400'>
     </pagebox>
@@ -11,7 +11,7 @@
     <panel margin='6' gravity='bottom-left' size='250' color='0' interval='1'>
         <button onclick='menu.page="languages"' id='langs_btn'>-</button>
         <button onclick='core.open_folder("user:")'>@Open data folder</button>
-		<button id='s_rst' onclick='set_page("s_rst", "settings_reset")'>@Reset settings</button>
+		<button id='s_rst' onclick='sections:set("reset")'>@Reset settings</button>
         <button onclick='menu:back()'>@Back</button>
     </panel>
 </container>

res/layouts/pages/settings.xml.lua

@@ -3,15 +3,13 @@ function on_open()
         "%s: %s", gui.str("Language", "settings"),
         gui.get_locales_info()[core.get_setting("ui.language")].name
     )
-    set_page("s_gfx", "settings_graphics")
-end
-
-function set_page(btn, page)
-    document.s_aud.enabled = true
-    document.s_dsp.enabled = true
-    document.s_gfx.enabled = true
-    document.s_ctl.enabled = true
-    document.s_rst.enabled = true
-    document[btn].enabled = false
-    document.menu.page = page
+    sections = RadioGroup({
+        audio=document.s_aud,
+        display=document.s_dsp,
+        graphics=document.s_gfx,
+        controls=document.s_ctl,
+        reset=document.s_rst
+    }, function (page)
+        document.menu.page = "settings_"..page
+    end, "graphics")
 end

res/scripts/stdlib.lua

@@ -84,6 +84,29 @@ function Document.new(docname)
     })
 end
 
+local _RadioGroup = {}
+function _RadioGroup.set(self, key)
+    if self.current then
+        self.elements[self.current].enabled = true
+    end
+    self.elements[key].enabled = false
+    self.current = key
+    if self.callback then
+        self.callback(key)
+    end
+end
+function _RadioGroup.__call(self, elements, onset, default)
+    local group = setmetatable({
+        elements=elements, 
+        callback=onset, 
+        current=nil
+    }, {__index=_RadioGroup})
+    group:set(default)
+    return group
+end
+setmetatable(_RadioGroup, _RadioGroup)
+RadioGroup = _RadioGroup
+
 _GUI_ROOT = Document.new("core:root")
 _MENU = _GUI_ROOT.menu
 menu = _MENU