location to store the retrieved string. The string retrieved must be freed with glib.global.gfree.
location to store the retrieved attribute list. When you are done with this list, you must unreference it with pango.attr_list.AttrList.unref.
location to store position of cursor (in characters) within the preedit string.
Retrieve the current preedit string for the input context, and a list of attributes to apply to the string.
This string should be displayed inserted at the insertion point.