问将信息从模型发送到视图、MVC架构、PyQT5

EN

import sys
import time

from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget
from PyQt5.QtWidgets import QGridLayout, QLineEdit, QPushButton, QVBoxLayout, QProgressBar
from PyQt5.QtCore import Qt


class ExampleGUI(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('Sample Application')
        # Set some main window's properties
        self.setFixedSize(235, 235)
        # Set the central widget and the general layout
        self.generalLayout = QVBoxLayout()
        self._centralWidget = QWidget(self)
        self.setCentralWidget(self._centralWidget)
        self._centralWidget.setLayout(self.generalLayout)
        # Create the display and the buttons
        self._createDisplay()
        self._createButtons()

    def _createDisplay(self):
        """Create the display."""
        # Create the display widget
        self.display = QLineEdit()
        self.progress_bar = QProgressBar()
        # Set some display's properties
        self.display.setFixedHeight(35)
        self.display.setAlignment(Qt.AlignRight)
        self.display.setReadOnly(True)
        # Add the display to the general layout
        self.generalLayout.addWidget(self.display)
        self.generalLayout.addWidget(self.progress_bar)

    def _createButtons(self):
        """Create the buttons."""
        buttonsLayout = QGridLayout()
        self.button1 = QPushButton("Start")
        self.button1.setFixedSize(80, 40)
        self.button2 = QPushButton("Clear")
        self.button2.setFixedSize(80, 40)
        buttonsLayout.addWidget(self.button1)
        buttonsLayout.addWidget(self.button2)
        self.generalLayout.addLayout(buttonsLayout)

    def setDisplayText(self, text):
        """Set display's text."""
        self.display.setText(text)
        self.display.setFocus()

    def clearDisplay(self):
        """Clear the display."""
        self.setDisplayText("")


class Model:
    def __init__(self):
        self.counter = ''
        self.i = ''

    def countdown(self, counter):
        self.i = 0
        self.counter = counter
        while self.i < self.counter:
            self.i+=1
            time.sleep(1)
        return True


class Controller:
    def __init__(self, view, model):
        self._view = view
        self._model = model
        self._connect_settings_signals()

    def _set_message(self):
        self._view.progress_bar.setMaximum(10)
        reply = self._model.countdown(10)
        self._view.progress_bar.setValue(self._model.i)
        if reply:
            self._view.setDisplayText("Countdown complete!")

    def _clear_message(self):
        self._view.clearDisplay()

    def _connect_settings_signals(self):
        self._view.button1.clicked.connect(self._set_message)
        self._view.button2.clicked.connect(self._clear_message)


def main():
    """Main function."""
    # Create an instance of `QApplication`
    pycalc = QApplication(sys.argv)
    # Show the calculator's GUI
    view = ExampleGUI()
    view.show()
    model = Model()
    # Create instances of the model and the controller
    ctrl = Controller(view=view, model=model)
    # Execute calculator's main loop
    sys.exit(pycalc.exec_())


if __name__ == "__main__":
    main()