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| import os
import sys
from PySide6.QtCore import QObject, QThread, Slot, Signal, Qt
from PySide6.QtWidgets import (QApplication, QPushButton,
QLabel, QWidget, QVBoxLayout)
# 1. Create the worker class
class Worker(QObject):
finished = Signal()
progress = Signal(str)
error = Signal(str)
def __init__(self, parent=None):
super().__init__(parent)
# This is the method we want to execute.
# We are in a tight loop.
@Slot()
def process(self):
path = os.path.abspath('.').split(os.path.sep)[0] + os.path.sep
for root, _, _ in os.walk(path):
if QThread.currentThread().isInterruptionRequested():
return
self.progress.emit(os.path.basename(root))
class Window(QWidget):
def __init__(self):
super().__init__()
layout = QVBoxLayout()
self.setLayout(layout)
self.start_button = QPushButton('Start background thread')
self.start_button.clicked.connect(self.on_start_button_clicked)
self.cancel_button = QPushButton('Cancel')
self.cancel_button.clicked.connect(self.on_cancel_button_clicked)
self.cancel_button.setDisabled(True)
self.label = QLabel()
self.label.setAlignment(Qt.AlignmentFlag.AlignCenter)
layout.addWidget(self.start_button)
layout.addWidget(self.cancel_button)
layout.addWidget(self.label)
@Slot()
def on_start_button_clicked(self):
self.start_button.setDisabled(True)
self.cancel_button.setEnabled(True)
# 2. Create the thread
self.background_thread = QThread()
# 3. Create the worker and move it to the thread
self.worker = Worker()
self.worker.moveToThread(self.background_thread)
self.worker.finished.connect(self.on_finished)
# 4. Connect the appropriate signals to ensure
# both the worker and the thread are destroyed.
self.worker.error.connect(self.on_error)
self.background_thread.started.connect(self.worker.process)
self.worker.finished.connect(self.background_thread.quit)
self.worker.finished.connect(self.worker.deleteLater)
self.background_thread.finished.connect(self.background_thread.deleteLater)
self.worker.progress.connect(self.label.setText)
# 5. Start the thread.
self.background_thread.start()
# Stop the work by requesting interruption
@Slot()
def on_cancel_button_clicked(self):
self.start_button.setEnabled(True)
self.cancel_button.setDisabled(True)
if hasattr(self, 'background_thread'):
self.background_thread.requestInterruption()
self.background_thread.quit()
self.background_thread.wait()
@Slot()
def on_finished(self):
self.label.setText('Worker finished')
@Slot()
def on_error(self, message):
print(message)
# Make sure the thread is destroyed
# when the main window is closed.
def closeEvent(self, event):
try:
self.background_thread.requestInterruption()
self.background_thread.quit()
self.background_thread.wait()
except Exception as e:
print(e)
if __name__ == '__main__':
app = QApplication(sys.argv)
main_window = Window()
main_window.show()
sys.exit(app.exec())
|