53288877

main.py

import sys
import time
import logging
import multiprocessing
import threading
from PySide2 import QtCore, QtWidgets

def long_task():
    logging.info('Starting long task')
    time.sleep(3) # this would be replaced with a real task
    logging.info('Long task complete')

class LogEmitter(QtCore.QObject):
    sigLog = QtCore.Signal(str)

class LogHandler(logging.Handler):
    def __init__(self):
        super().__init__()
        self.r, self.w = multiprocessing.Pipe()
        self.emitter = LogEmitter()
        threading.Thread(target=self.listen, daemon=True).start()

    def emit(self, record):
        msg = self.format(record)
        self.w.send(msg)

    def listen(self):
        while True:
            try:
                msg = self.r.recv()
                self.emitter.sigLog.emit(msg)
            except EOFError:
                break

class LogDialog(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super().__init__(parent)
        log_txt = QtWidgets.QPlainTextEdit(self)
        log_txt.setReadOnly(True)
        layout = QtWidgets.QHBoxLayout(self)
        layout.addWidget(log_txt)
        self.setWindowTitle('Event Log')
        handler = LogHandler()
        handler.emitter.sigLog.connect(log_txt.appendPlainText)
        logger = logging.getLogger()
        logger.addHandler(handler)
        logger.setLevel(logging.INFO)


class MainWindow(QtWidgets.QMainWindow):

    def __init__(self):
        super().__init__()
        widget = QtWidgets.QWidget()
        layout = QtWidgets.QHBoxLayout(widget)
        start_btn = QtWidgets.QPushButton('Start')
        start_btn.clicked.connect(self.start)
        layout.addWidget(start_btn)
        self.setCentralWidget(widget)

        self.log_dialog = LogDialog()
        self.pool = multiprocessing.Pool()
        self.running = False

    def start(self):
        if not self.running:
            self.log_dialog.show()
            logging.info('Run Starting')
            self.pool.apply_async(long_task, callback=self.handle_result)

    def handle_result(self, result=None):
        logging.info('Result received')
        self.running = False


if __name__ == '__main__':
    app = QtWidgets.QApplication()
    win = MainWindow()
    win.show()
    sys.exit(app.exec_())