Export PDF event handler

def OnExportPDF(self, event):
        """Export PDF event handler"""

        wildcards = get_filetypes2wildcards(["pdf"]).values()

        if not wildcards:
            return

        wildcard = "|".join(wildcards)

        # Get filepath from user
        message = _("Choose file path for PDF export.")

        style = wx.SAVE
        filepath, filterindex = \
            self.interfaces.get_filepath_findex_from_user(wildcard, message,
                                                          style)

        if filepath is None:
            return

        self.main_window.actions.export_cairo(filepath, "pdf")

        event.Skip()