Как я могу отключить следующую кнопку PyQt5 QWizard, если условие не соблюдается?

Question

Мне нужно сделать GUI для сценария, запущенного на терминале, чтобы изменить вход в систему. Фон на Ubuntu, я решил использовать PyQt5 QWizard для этого, и на первой странице я должен отключить следующую кнопку, если используется дистрибутив не совместим. Я не могу найти способ отключить его, я искал везде, но не могу найти способ сделать это ..

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'wizard.ui'
#
# Created by: PyQt5 UI code generator 5.14.2
#
# WARNING! All changes made in this file will be lost!

import os
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QFileDialog


class Ui_Wizard(object):
    def setupUi(self, Wizard):
        Wizard.setObjectName("Wizard")
        Wizard.resize(470, 454)
        Wizard.setOptions(QtWidgets.QWizard.NoBackButtonOnLastPage|QtWidgets.QWizard.NoCancelButtonOnLastPage)
        self.page_1 = QtWidgets.QWizardPage()
        self.page_1.setEnabled(True)
        self.page_1.setObjectName("page_1")
        self.gridLayout_2 = QtWidgets.QGridLayout(self.page_1)
        self.gridLayout_2.setObjectName("gridLayout_2")
        self.label_2 = QtWidgets.QLabel(self.page_1)
        self.label_2.setAlignment(QtCore.Qt.AlignCenter)
        self.label_2.setObjectName("label_2")
        self.gridLayout_2.addWidget(self.label_2, 3, 0, 1, 1)
        spacerItem = QtWidgets.QSpacerItem(20, 40, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        self.gridLayout_2.addItem(spacerItem, 5, 0, 1, 1)
        spacerItem1 = QtWidgets.QSpacerItem(20, 40, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        self.gridLayout_2.addItem(spacerItem1, 1, 0, 1, 1)
        self.label_1 = QtWidgets.QLabel(self.page_1)
        self.label_1.setAlignment(QtCore.Qt.AlignCenter)
        self.label_1.setObjectName("label_1")
        self.gridLayout_2.addWidget(self.label_1, 2, 0, 1, 1)
        self.label_3 = QtWidgets.QLabel(self.page_1)
        self.label_3.setAlignment(QtCore.Qt.AlignCenter)
        self.label_3.setObjectName("label_3")
        self.gridLayout_2.addWidget(self.label_3, 4, 0, 1, 1)
        Wizard.addPage(self.page_1)
        self.page_2 = QtWidgets.QWizardPage()
        self.page_2.setObjectName("page_2")
        self.gridLayout = QtWidgets.QGridLayout(self.page_2)
        self.gridLayout.setObjectName("gridLayout")
        self.label_path = QtWidgets.QLabel(self.page_2)
        self.label_path.setObjectName("label_path")
        self.gridLayout.addWidget(self.label_path, 1, 0, 1, 1)
        spacerItem2 = QtWidgets.QSpacerItem(20, 90, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        self.gridLayout.addItem(spacerItem2, 0, 0, 1, 2)
        spacerItem3 = QtWidgets.QSpacerItem(20, 90, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        self.gridLayout.addItem(spacerItem3, 4, 0, 1, 2)
        self.edit_path = QtWidgets.QLineEdit(self.page_2)
        self.edit_path.setObjectName("edit_path")
        self.gridLayout.addWidget(self.edit_path, 3, 0, 1, 1)
        self.browse_path = QtWidgets.QPushButton(self.page_2)
        self.browse_path.setObjectName("browse_path")
        self.gridLayout.addWidget(self.browse_path, 3, 1, 1, 1)
        Wizard.addPage(self.page_2)
        self.page_3 = QtWidgets.QWizardPage()
        self.page_3.setAutoFillBackground(False)
        self.page_3.setObjectName("page_3")
        self.verticalLayout = QtWidgets.QVBoxLayout(self.page_3)
        self.verticalLayout.setObjectName("verticalLayout")
        spacerItem4 = QtWidgets.QSpacerItem(20, 40, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        self.verticalLayout.addItem(spacerItem4)
        self.label_4 = QtWidgets.QLabel(self.page_3)
        self.label_4.setAlignment(QtCore.Qt.AlignCenter)
        self.label_4.setObjectName("label_4")
        self.verticalLayout.addWidget(self.label_4)
        self.label_5 = QtWidgets.QLabel(self.page_3)
        self.label_5.setAlignment(QtCore.Qt.AlignCenter)
        self.label_5.setObjectName("label_5")
        self.verticalLayout.addWidget(self.label_5)
        self.label_6 = QtWidgets.QLabel(self.page_3)
        self.label_6.setAlignment(QtCore.Qt.AlignCenter)
        self.label_6.setTextInteractionFlags(QtCore.Qt.LinksAccessibleByMouse)
        self.label_6.setObjectName("label_6")
        self.verticalLayout.addWidget(self.label_6)
        spacerItem5 = QtWidgets.QSpacerItem(20, 40, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Expanding)
        self.verticalLayout.addItem(spacerItem5)
        Wizard.addPage(self.page_3)

        self.retranslateUi(Wizard)
        QtCore.QMetaObject.connectSlotsByName(Wizard)

    def retranslateUi(self, Wizard):
        _translate = QtCore.QCoreApplication.translate
        Wizard.setWindowTitle(_translate("Wizard", "Wizard"))
        self.page_1.setTitle(_translate("Wizard", "Change gdm Background wizard"))
        self.page_1.setSubTitle(_translate("Wizard", "Welcomet to the Change gdm Background wizard, and thank you for the download"))
        self.label_2.setText(_translate("Wizard", "Compatibility: Ubuntu 20.04"))
        self.label_1.setText(_translate("Wizard", "Use at your own risk"))
        value = self.check_distro()
        self.label_3.setText(_translate("Wizard", value))
        self.page_2.setSubTitle(_translate("Wizard", "Select the image to use as background"))
        self.label_path.setText(_translate("Wizard", "File Path"))
        self.browse_path.setText(_translate("Wizard", "..."))
        self.browse_path.clicked.connect(self.select_file)
        self.label_4.setText(_translate("Wizard", "Background set, restarting your device"))
        self.label_5.setText(_translate("Wizard", "Thank you for download"))
        self.label_6.setText(_translate("Wizard", "Credits to: ..."))

    # To check ubuntu version
    # script usable only if usinng ubuntu 20.04
    def check_distro(self):
        check = os.uname()
        if "Ubuntu" and "20.04" not in check[3]:
            value = "Not compatible with your Distro \n Please stop"
        else:
            value = "Compatible with your Distro \n Please go ahead"
            # next_btn = QtWidget.QtGui.QWizard.NextButton
            # next_btn.setEnabled(False)
        return value

    # To open FileDialog and select file
    # TODO: Add filtering file, to select only specific extension files.
    # example .jpg or photo format
    def select_file(self):
        title = "Explorer"
        qfd = QFileDialog()
        path = "$HOME"
        filter = "All Images(*.jpg | *.jpeg | *.png);;JPG Only(*.jpg);;JPEG Only(*.jpeg);;PNG Only(*.png)"
        filename = QFileDialog.getOpenFileName(qfd, title, path, filter)
        # filter_file(title)
        # filename = QFileDialog.getOpenFileName()
        self.edit_path.setText(filename[0])

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Wizard = QtWidgets.QWizard()
    ui = Ui_Wizard()
    ui.setupUi(Wizard)
    Wizard.show()
    sys.exit(app.exec_())

точно на первой странице, внутри метода "check_distro" i необходимо отключить кнопку Next внутри первого случая if

Answer 1

Вы должны переопределить метод isComplete, который возвращает, можете ли вы перейти к следующей странице.

С другой стороны, метод, который вы используете для проверки, является ли ваша ОС Ubuntu 20.04, неверен, поэтому он был переписан с использованием библиотеки distro (вы можете установить его с помощью python -m pip install distro или, если вы используете ubuntu или совместимую систему, вы можете установить его с помощью sudo apt-get python3-distro.

import distro
from PyQt5 import QtCore, QtGui, QtWidgets


class FirstPage(QtWidgets.QWizardPage):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setTitle("Change gdm Background wizard")
        self.setSubTitle(
            "Welcomet to the Change gdm Background wizard, and thank you for the download"
        )

        lay = QtWidgets.QVBoxLayout(self)

        self.message_label = QtWidgets.QLabel(alignment=QtCore.Qt.AlignCenter)

        lay.addStretch()
        lay.addWidget(self.message_label)
        lay.addStretch()

        message = "Use at your own risk\nCompatibility: Ubuntu 20.04\n%s" % (
            "Compatible with your Distro \n Please go ahead"
            if self.check_distro()
            else "Not compatible with your Distro \n Please stop"
        )
        self.message_label.setText(message)

    def check_distro(self):
        return distro.name() == "Ubuntu" and distro.version() == "20.04"

    def isComplete(self):
        return self.check_distro() and super().isComplete()


class SecondPage(QtWidgets.QWizardPage):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setSubTitle("Select the image to use as background")

        self.path_le = QtWidgets.QLineEdit()
        self.path_btn = QtWidgets.QPushButton("...")
        self.path_lbl = QtWidgets.QLabel()

        lay = QtWidgets.QGridLayout(self)
        lay.addWidget(QtWidgets.QLabel("File Path"))
        lay.addWidget(self.path_le, 1, 0)
        lay.addWidget(self.path_btn, 1, 1)
        lay.addWidget(self.path_lbl, 2, 0, 1, 2)

        self.path_btn.clicked.connect(self.handle_clicked)

    @QtCore.pyqtSlot()
    def handle_clicked(self):
        title = "Explorer"
        path = "$HOME"
        filter = "All Images(*.jpg | *.jpeg | *.png);;JPG Only(*.jpg);;JPEG Only(*.jpeg);;PNG Only(*.png)"
        filename, _ = QtWidgets.QFileDialog.getOpenFileName(None, title, path, filter)
        if filename:
            self.path_le.setText(filename)
            self.path_lbl.setPixmap(QtGui.QPixmap(filename))
            self.completeChanged.emit()

    def isComplete(self):
        return bool(self.path_le.text()) and super().isComplete()


class ThirdPage(QtWidgets.QWizardPage):
    def __init__(self, parent=None):
        super().__init__(parent)

        lay = QtWidgets.QVBoxLayout(self)

        self.message_label = QtWidgets.QLabel(alignment=QtCore.Qt.AlignCenter)

        lay.addStretch()
        lay.addWidget(self.message_label)
        lay.addStretch()
        self.message_label.setText(
            "Background set, restarting your device\nThank you for download\nCredits to: ..."
        )


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = QtWidgets.QWizard()
    w.setOptions(
        QtWidgets.QWizard.NoBackButtonOnLastPage
        | QtWidgets.QWizard.NoCancelButtonOnLastPage
    )
    w.addPage(FirstPage())
    w.addPage(SecondPage())
    w.addPage(ThirdPage())
    w.show()
    sys.exit(app.exec_())