'Initiate a search by starting the GrepThread'

def search(self):

    self.edit_group.setEnabled(False)
    self.refresh_group.setEnabled(False)
    query = self.input_txt.value()
    if (len(query) < 2):
        self.result_txt.clear()
        self.preview_txt.clear()
        return
    self.worker_thread.query = query
    self.worker_thread.shell = self.shell_checkbox.isChecked()
    self.worker_thread.regexp_mode = self.regexp_mode()
    self.worker_thread.start()
