allow nested wxMenu added wxTreebook added flag, border, option and minsize props to "button" first tries to fetch a bitmap via wxArtProvider, using the 2 attributes; if that fails, loads the bitmap file pointed to by the URL in the element's text contents either 0 or 1 0 1 the value must be one out of a fixed list #RRGGBB format or symbolic color name comma separated values a distance, can be like tInteger with optional 'd' suffix (dialog units instead of pixels) floating point value, can only contain digits, one dot and optional '-' prefix property elements, defining a font normal italic slant normal bold light roman script decorative swiss modern teletype contains the HTML code as a string, with escaped angle brackets (&lt; &gt;) eg. wxART_FILE_OPEN, wxART_MENU can only contain digits and an optional '-' prefix. Or, of course, a constant like wxSL_DEFAULT_MIN one or more <item> elements (each with an optional 'checked' attribute) two integers, separated by a comma; optional 'd' suffix (dialog units instead of pixels) any string combination of wx style flags, separated with '|' unsigned integer, can only contain digits pointer to a file horizontal vertical abstract class, must be subclassed wxHORIZONTAL wxVERTICAL wxHORIZONTAL wxVERTICAL wxHORIZONTAL wxVERTICAL wxBOTH wxHORIZONTAL wxVERTICAL wxBOTH wxHORIZONTAL wxVERTICAL wxSB_NORMAL wxSB_FLAT wxSB_RAISED