python - Cómo aplicar PyQt QThread en esta pieza de código

pyqt5

Question

# -*- coding: utf-8 -*-
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.uic import loadUiType
import youtube_dl
import pafy
import urllib.request
import urllib.parse
from urllib.parse import *
import win32clipboard
import sys
import os
import humanize
import subprocess
import time
import shutil
import re
from pySmartDL import SmartDL
from os.path import splitext, basename
from os import path


Close = False
ShutDown = False
Sleep = False
Restart = False
Paused = False
Stopped = False
Start = True
Resume = True

if getattr(sys, ''frozen'', False):
    # frozen
    dir_ = os.path.dirname(sys.executable)
else:
    # unfrozen
    dir_ = os.path.dirname(os.path.realpath(__file__))
FORM_CLASS, _ = loadUiType(path.join(dir_, "main.ui"))


class MainApp(QMainWindow, FORM_CLASS):

    def __init__(self, parent=None):
        super(MainApp, self).__init__(parent)
        QMainWindow.__init__(self)
        self.setupUi(self)
        self.lineEdit.installEventFilter(self)
        self.lineEdit_3.installEventFilter(self)
        self.lineEdit_6.installEventFilter(self)
        self.Handle_Ui()
        self.Handle_Buttons()



    def closeEvent(self, evnt):
        if self._want_to_close:
            super(MainApp, self).closeEvent(evnt)
            sys.exit()

    def Handle_Ui(self):
        #self.lineEdit.setFocus()
        self.setFixedSize(861,441)


    def Handle_Buttons(self):
        self.pushButton_3.clicked.connect(self.open_file_loction)
        self.pushButton_2.clicked.connect(self.Start)
        self.pushButton_13.clicked.connect(self.Pause)
        self.pushButton_14.clicked.connect(self.Stop)
        self.pushButton.clicked.connect(self.Handle_Browse)
        self.pushButton_4.clicked.connect(self.Download_youtube_video)
        self.pushButton_10.clicked.connect(self.get_quality)
        self.pushButton_5.clicked.connect(self.Browse2)
        self.pushButton_6.clicked.connect(self.open_file_location2)
        self.pushButton_11.clicked.connect(self.Search_Qualities)
        self.pushButton_7.clicked.connect(self.Browse3)
        self.pushButton_9.clicked.connect(self.download_playlist)
        self.pushButton_8.clicked.connect(self.open_file_location3)
        self.pushButton_12.clicked.connect(self.open_video)
        self.comboBox_2.currentIndexChanged.connect(self.Action_Happened)
        self.comboBox_3.currentIndexChanged.connect(self.Action_Happened)
        self.comboBox_4.currentIndexChanged.connect(self.Action_Happened)

    def Start(self):
        global Start
        global Stopped
        global Paused
        Start = True
        Stopped = False
        Paused = False
        self.Download()

    def Pause(self):
        global Paused
        global Start
        global Resume
        if self.pushButton_13.text()=="Pause Downloading":
            Paused = True
            Start = False
            Stopped = False
            Resume = False
            self.pushButton_13.setText("Resume Downloading")
            QApplication.processEvents()
        elif self.pushButton_13.text()=="Resume Downloading":
            Start = True
            Paused = False
            Resume = True
            Stopped = False
            self.pushButton_13.setText("Pause Downloading")
            QApplication.processEvents()



    def Stop(self):
        global Stopped
        global Start
        Stopped = True
        Start = False
        Paused = False
        self.Download()


    def Download(self):
        directory = os.path.expanduser("~") + "/AppData/Local/Temp/pySmartDL"
        if not os.path.exists(directory):
            os.makedirs(directory)
        try:
            global Paused
            global Stopped
            global Start
            global XX
            url = self.lineEdit.text()
            save_location = self.lineEdit_2.text()
            obj = SmartDL(url, progress_bar=False)
            if Start == True:
                try:
                    obj.start(blocking=False)
                    while True:
                        self.progressBar.setValue(obj.get_progress()*100)
                        self.label_8.setText("Downloaded: " + str(obj.get_dl_size(human=True)))
                        self.label_38.setText("Speed: " + str(obj.get_speed(human=True)))
                        self.label_39.setText("Remaining Time: " + str(obj.get_eta(human=True)))
                        time.sleep(0.2)
                        QApplication.processEvents()
                        if Paused == True:
                            obj.pause()
                            QApplication.processEvents()
                        if Resume == True:
                                obj.unpause()
                                QApplication.processEvents()
                        if obj.isFinished():
                            break
                        if Stopped == True:
                            obj.stop()
                            self.progressBar.setValue(0)
                            break

                    if obj.isSuccessful():
                        #os.rename(obj.get_dest(), save_location)
                        shutil.move(obj.get_dest(), save_location)

                    if Close == True:
                        QApplication.quit()
                    elif ShutDown == True:
                        os.system(''shutdown -s'')
                    elif Sleep == True:
                        os.system("rundll32.exe powrprof.dll,SetSuspendState 0,1,0")
                    elif Restart == True:
                        subprocess.call(["shutdown", "/r"])
                    if Stopped == False:
                        QMessageBox.information(self, "Download Completed", "Your Download is Completed")
                except:
                    QMessageBox.warning(self, "Download Error", "Download Failed")
                    pass
        except Exception as e:
            pass



def main():
    app = QApplication(sys.argv)
    window = MainApp()
    window.show()
    app.exec_()

if __name__ == ''__main__'':
    main()

He estado buscando ayuda sobre cómo aplicar Qthread en el fragmento de código anterior para actualizar el Bar de progreso de forma dinámica sin ningún "problema de no respuesta"

He leído muchos temas y puedo entender el concepto principal de Qthread, pero aún no puedo obtener la idea de cómo aplicarlo a mi código, teniendo en cuenta que la función de descarga está conectada con un botón de descarga que no se ejecuta infinitamente.

¿Debo hacer una subclase Qthread o qué puedo hacer?

Si me puede ayudar con un ejemplo sobre cómo usarlo con el fragmento de código anterior, lo aplicaré en el código restante de mi aplicación Gui.

Gracias por adelantado.

Answer 1

Al implementar un QThread, la tarea que debe realizarse debe realizarse en el método run (), si desea actualizar la GUI, los datos proporcionados por el hilo no se deben hacer directamente sino a través de señales, ya que la GUI solo se debe actualizar en el principal hilo llamado por este el hilo GUI.

class DownloadThread(QThread):
    dataChanged = pyqtSignal(int, str, str, str)
    Started, Paused, Resume, Stopped = range(4)
    downloadError = pyqtSignal()
    downloadFinished = pyqtSignal()

    def __init__(self, parent=None):
        QThread.__init__(self, parent)
        self.state = DownloadThread.Stopped
        self.params = {"url": "", "save_location": ""}

    def setParams(self, params):
        self.params = params

    def setState(self, state):
        self.state = state

    def run(self):
        obj = SmartDL(self.params["url"], progress_bar=False)
        try:
            obj.start(blocking=False)
            while True:
                self.dataChanged.emit(obj.get_progress() * 100,
                                      str(obj.get_dl_size(human=True)),
                                      str(obj.get_speed(human=True)),
                                      str(obj.get_eta(human=True)))
                time.sleep(0.2)
                if self.state == DownloadThread.Paused:
                    obj.pause()
                if self.state == DownloadThread.Resume:
                    obj.unpause()
                    self.state = DownloadThread.Started
                if obj.isFinished():
                    break
                if self.state == DownloadThread.Stopped:
                    obj.stop()
                    self.progressBar.setValue(0)
                    break
            if obj.isSuccessful():
                # os.rename(obj.get_dest(), save_location)
                shutil.move(obj.get_dest(), self.params["save_location"])
                if self.state == DownloadThread.Started:
                    self.downloadFinished.emit()
        except:
            self.downloadError.emit()

Debe evitar el uso de variables globales, además de que puede reducir varias variables que están todas actualizadas a la vez por una sola variable, así que tuve que modificar el código de la GUI.

class MainApp(QMainWindow, FORM_CLASS):
    def __init__(self, parent=None):
        [...]
        self.Handle_Buttons()
        self.download = DownloadThread(self)
        self.download.dataChanged.connect(self.onDataChanged)
        self.download.downloadError.connect(self.errorDownload)
        self.download.downloadFinished.connect(self.successfulDownload)

    def closeEvent(self, evnt):
        [...]

    def Handle_Ui(self):
        # self.lineEdit.setFocus()
        self.setFixedSize(861, 441)

    def Handle_Buttons(self):
        [...]

    def onDataChanged(self, progress, downloaded, speed, remain):
        self.progressBar.setValue(progress)
        self.label_8.setText("Downloaded: " + downloaded)
        self.label_38.setText("Speed: " + speed)
        self.label_39.setText("Remaining Time: " + remain)

    def Start(self):
        directory = os.path.expanduser("~") + "/AppData/Local/Temp/pySmartDL"
        if not os.path.exists(directory):
            os.makedirs(directory)
        params = {"url": self.lineEdit.text(),
                  "save_location": self.lineEdit_2.text()}
        self.download.setParams(params)
        self.download.setState(DownloadThread.Started)
        self.download.start()

    def Pause(self):
        if self.pushButton_13.text() == "Pause Downloading":
            self.download.setState(DownloadThread.Paused)
            self.pushButton_13.setText("Resume Downloading")
        elif self.pushButton_13.text() == "Resume Downloading":
            self.download.setState(DownloadThread.Resume)
            self.pushButton_13.setText("Pause Downloading")

    def Stop(self):
        self.download.setState(DownloadThread.Stopped)
        self.progressBar.setValue(0)

    def errorDownload(self):
        QMessageBox.warning(self, "Download Error", "Download Failed")

    def successfulDownload(self):
        QMessageBox.information(self, "Download Completed", "Your Download is Completed")