# Only needed for access to command line arguments
import sys

from PyQt5.QtCore import *
from PyQt5.QtWidgets import *


# 自定义窗口，继承 QMainWindow


class MainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)

        self.windowTitleChanged().connect(self.onWindowTitleChanged)

        self.windowTitleChanged().connect(lambda x: self.my_custom_fn())

        self.windowTitleChanged().connect(lambda x: self.my_custom_fn(x))

        self.windowTitleChanged().connect(lambda x: self.my_custom_fn(x, 25))

        self.setWindowTitle("My Awesome App")  # 标题

        label = QLabel("THIS IS AWESOME!!!")
        label.setAlignment(Qt.AlignCenter)

        self.setCentralWidget(label)

    def contextMenuEvent(self, event):
        print("Context menu event!")
        super(MainWindow, self).contextMenuEvent(event)

    def onWindowTitleChanged(self, s):
        print(s)

    def my_custom_fn(self, a="HELLO!", b=5):
        print(a, b)


if __name__ == '__main__':
    app = QApplication(sys.argv)

    window = MainWindow()
    window.show()  # 默认下 windows 是隐藏的
    # 开启事件循环
    app.exec_()