Here is my code for listing all sub-directories of a directory. I’m using it to understand QThread and signal and slots in pyside.
The problem is when I’m not using Qtcore.QApplication.processEvents() in scan() function of Main class, the code is not working. Is the event loop not already running?
import sys
import os
import time
from PySide import QtGui, QtCore
class Scanner(QtCore.QObject):
folderFound = QtCore.Signal(str)
done = QtCore.Signal()
def __init__(self, path):
super(Scanner, self).__init__()
self.path = path
@QtCore.Slot()
def scan(self):
for folder in os.listdir(self.path):
time.sleep(1)
self.folderFound.emit(folder)
class Main(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.resize(420,130)
self.setWindowTitle('Threads')
self.lyt = QtGui.QVBoxLayout()
self.setLayout(self.lyt)
self.topLyt = QtGui.QHBoxLayout()
self.lyt.addLayout(self.topLyt)
self.scanBtn = QtGui.QPushButton('Scan')
self.scanBtn.clicked.connect(self.scan)
self.clearBtn = QtGui.QPushButton('Clear')
self.topLyt.addWidget(self.scanBtn)
self.topLyt.addWidget(self.clearBtn)
self.folders = list()
self.show()
def scan(self):
self.th = QtCore.QThread()
scanner = Scanner(r"D:\\")
scanner.moveToThread(self.th)
scanner.folderFound.connect(self.addFolder)
scanner.done.connect(scanner.deleteLater)
scanner.done.connect(self.quit)
self.th.started.connect(scanner.scan)
self.th.start()
QtCore.QApplication.processEvents()
@QtCore.Slot()
def addFolder(self, folder):
lbl = QtGui.QLabel(folder)
self.folders.append(lbl)
self.lyt.addWidget(lbl)
@QtCore.Slot()
def quit(self):
self.th.quit()
self.th.wait()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
main = Main()
app.exec_()