import logging


class QueueHandler(logging.Handler):
    """Class to send logging records to a queue

    It can be used from different threads
    The ConsoleUi class polls this queue to display records in a ScrolledText widget
    """
    # Example from Moshe Kaplan: https://gist.github.com/moshekaplan/c425f861de7bbf28ef06
    # (https://stackoverflow.com/questions/13318742/python-logging-to-tkinter-text-widget) is not thread safe!
    # See https://stackoverflow.com/questions/43909849/tkinter-python-crashes-on-new-thread-trying-to-log-on-main-thread

    def __init__(self, log_queue):
        super().__init__()
        self.log_queue = log_queue

    def emit(self, record):
        self.log_queue.put(record)