Gtk.Entry.prototype.layout_index_to_text_index

function layout_index_to_text_index(layout_index:Number):Number {
    // Gjs wrapper for gtk_entry_layout_index_to_text_index()
}

Converts from a position in the entry contents (returned by Gtk.Entry.prototype.get_text) to a position in the entry's Pango.Layout (returned by Gtk.Entry.prototype.get_layout, with text retrieved via Pango.get_text).