How do I make a resizable window and a resizable background image using PyQt?

Question

I was trying do make an application so I started building the main window, I took some time to figure out how to put a background image but in the end I got it, but when I clicked to maximize the window I noticed that the buttons were not in the center as they were before, and the background image also does not resize according to different sizes of the window. I want the background image and the buttons to adjust automatically. Please help this poor newbie T.T

Here's my code:

from PyQt4 import QtCore, QtGui
import sys

# Encoding Utf-8*
try:
    _from_utf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _from_utf8(s):
        return s
try:
    _encoding = QtGui.QApplication.UnicodeUTF8

    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

# Main Window


class Window (QtGui.QMainWindow):
    def __init__(self):
        super(Window, self).__init__()

        self.setGeometry(100, 100, 800, 600)
        self.setWindowTitle(_from_utf8("Virtual Library"))
        self.setStyleSheet("background-image: url(nwlib.jpg);")

        # ExitOption
        menu_action1 = QtGui.QAction("Exit", self)
        menu_action1.setShortcut("Ctrl+Q")
        menu_action1.setStatusTip('Exit The App')
        menu_action1.triggered.connect(self.close_application)

        self.statusBar()

        # MenuBar
        main_menu = self.menuBar()
        file_menu = main_menu.addMenu('Options')
        file_menu.addAction(menu_action1)

        self.home()

    def home(self):

        # NewLibrary btn
        new_lib_btn = QtGui.QPushButton("New Library", self)
        new_lib_btn.setGeometry(QtCore.QRect(310, 180, 141, 41))

        # AccessLibrary btn
        access_lib_btn = QtGui.QPushButton("Access Library", self)
        access_lib_btn.setGeometry(QtCore.QRect(310, 250, 141, 41))

        # FindNewBooks btn
        find_nbooks = QtGui.QPushButton("Find New Books", self)
        find_nbooks.setGeometry(QtCore.QRect(310, 320, 141, 41))

        self.show()

    def close_application(self):
        choice = QtGui.QMessageBox.question(self, 'Exit',
                                        "Close the application?",
                                        QtGui.QMessageBox.Yes | QtGui.QMessageBox.No)
        if choice == QtGui.QMessageBox.Yes:
            sys.exit()
        else:
            pass


def run():
    app = QtGui.QApplication(sys.argv)
    GUI = Window()
    sys.exit(app.exec_())


run()

Answer 1

You need some layout to place your widgets and you need set alignment also.I edited your code bit to get what you looking for. And I edited the close event also.

from PyQt4 import QtCore, QtGui import sys

# Encoding Utf-8*
try:
    _from_utf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _from_utf8(s):
        return s
try:
    _encoding = QtGui.QApplication.UnicodeUTF8

    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

# Main Window


class Window (QtGui.QMainWindow):
    def __init__(self):
        super(Window, self).__init__()

        self.setGeometry(100, 100, 800, 600)
        self.setWindowTitle(_from_utf8("Virtual Library"))
        self.setStyleSheet("background-image: url(nwlib.jpg);")

        # ExitOption
        menu_action1 = QtGui.QAction("Exit", self)
        menu_action1.setShortcut("Ctrl+Q")
        menu_action1.setStatusTip('Exit The App')
        menu_action1.triggered.connect(self.close_application)

        self.statusBar()

        # MenuBar
        main_menu = self.menuBar()
        file_menu = main_menu.addMenu('Options')
        file_menu.addAction(menu_action1)

        self.home()

    def home(self):

        # NewLibrary btn
        centralwidget = QtGui.QWidget(self)
        self.mainLayout = QtGui.QVBoxLayout(centralwidget)
        new_lib_btn = QtGui.QPushButton("New Library", self)
        new_lib_btn.setMinimumSize(141, 41)

        # AccessLibrary btn
        access_lib_btn = QtGui.QPushButton("Access Library", self)
        access_lib_btn.setMinimumSize(141, 41)

        # FindNewBooks btn
        find_nbooks = QtGui.QPushButton("Find New Books", self)
        find_nbooks.setMinimumSize(141, 41)

        self.mainLayout.addWidget(new_lib_btn)
        self.mainLayout.addWidget(access_lib_btn)
        self.mainLayout.addWidget(find_nbooks)

        self.mainLayout.setAlignment(QtCore.Qt.AlignCenter)

        self.setCentralWidget(centralwidget)

        self.show()

    def close_application(self):
        choice = QtGui.QMessageBox.question(self, 'Exit',
                                        "Close the application?",
                                        QtGui.QMessageBox.Yes | QtGui.QMessageBox.No)
        if choice == QtGui.QMessageBox.Yes:
            sys.exit()
        else:
            pass


def run():
    app = QtGui.QApplication(sys.argv)
    GUI = Window()
    sys.exit(app.exec_())


run()