import sys, traceback
from PyQt5.QtCore import QRunnable, QObject, pyqtSignal, pyqtSlot

class WorkerSignals(QObject):
    '''
    Defines the signals available from a running worker thread.

    Supported signals are:

    finished
        No data

    error
        `tuple` (exctype, value, traceback.format_exc() )

    result
        `object` data returned from processing, anything

    progress
        `int` indicating % progress

    # 信号必须定义为类属性，不能放在__init__方法里
    '''
    finished = pyqtSignal()
    error = pyqtSignal(tuple)
    result = pyqtSignal(object)
    progress = pyqtSignal(int)  # 可以用作进度条

    serial = pyqtSignal(object)  # 2record_system_v26的此信号移动到类SerialPort中了

    image_signal = pyqtSignal(dict)  # 只用在2record_system_v25中
    spectral_signal = pyqtSignal(dict)  # 只用在2record_system_v25中

    openinfo = pyqtSignal(int)  # 只用在2record_system_v25中
    plotsignal = pyqtSignal()  # 2record_system_v26的此信号移动到类ImageWindowPhone中了

# https://www.learnpyqt.com/courses/concurrent-execution/multithreading-pyqt-applications-qthreadpool/
# 用于qt多线程：运行long-time task
class Worker(QRunnable):
    '''
    Worker thread

    Inherits from QRunnable to handler worker thread setup, signals and wrap-up.

    :param callback: The function callback to run on this worker thread. Supplied args and
                     kwargs will be passed through to the runner.
    :type callback: function
    :param args: Arguments to pass to the callback function
    :param kwargs: Keywords to pass to the callback function

    '''

    def __init__(self, fn, *args, **kwargs):
        super(Worker, self).__init__()

        # Store constructor arguments (re-used for processing)
        self.fn = fn
        self.args = args
        self.kwargs = kwargs
        self.signals = WorkerSignals()

        # Add the callback to our kwargs
        # self.kwargs['progress_callback'] = self.signals.progress

    @pyqtSlot()
    def run(self):
        '''
        Initialise the runner function with passed args, kwargs.
        '''
        try:  # 如果有错，就捕捉错误
            result = self.fn(*self.args, **self.kwargs)
        except Exception:  # 根据错误进行处理
            traceback.print_exc()
            exctype, value = sys.exc_info()[:2]

            self.signals.error.emit((exctype, value, traceback.format_exc()))
        else:  # 如果没有错误执行下面代码
            self.signals.finished.emit()  # Done
            self.signals.result.emit(result)  # Return the result of the processing
        finally:  # 不管有错无错，都要执行下面代码
            pass