[PyQt] Can't neither setWindowFlags nor setFixedSize of a subwindow.

[JayCee]

Still can't get rid of the maximize button and fix the subwindow size... I simplified the code so it's easier to understand:

main.py

from PyQt5 import QtCore
from PyQt5.QtWidgets import QMainWindow, QApplication, QAction, QMdiArea, QDesktopWidget, QMdiSubWindow
import usuarios
import sys
 
 
class MainWin(QMainWindow):
    def __init__(self, parent=None):
        super(MainWin, self).__init__(parent)
        self.setupUI()
 
        self.setMinimumSize(1100, 600)
        area = self.frameGeometry()
        center = QDesktopWidget().availableGeometry().center()
        area.moveCenter(center)
        self.move(area.topLeft())
 
    def setupUI(self):
        self.setGeometry(0, 0, 1050, 600)
        self.mdi = QMdiArea()
        self.toolBarItem = self.addToolBar("File")
        self.myAction = QAction("Usuários", triggered=self.showFormUsers)
        self.toolBarItem.addAction(self.myAction)
        self.setCentralWidget(self.mdi)
 
    def showFormUsers(self):
        self.subWindow = usuarios.formUsers()
        self.mdi.addSubWindow(self.subWindow)
        self.subWindow.setWindowFlags(QtCore.Qt.WindowMinimizeButtonHint | QtCore.Qt.WindowCloseButtonHint)  # No effect. The maximize button still appears.
        self.subWindow.setFixedSize(480, 300) # No effect.  I can still resize the subwindow 
        self.subWindow.show()
 
 
if __name__ == '__main__':
    app = QApplication(sys.argv)
    win = MainWin()
    win.show()
    sys.exit(app.exec_())

usuarios.py

from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QMainWindow
 
 
class formUsers(QMainWindow):
 
    def __init__(self, parent=None):
 
        super(formUsers, self).__init__(parent)
 
        self.setWindowTitle("Usuários")
 
        # Input Fields ---------------------------------------------------------- >
 
        self.lineEdit_name = QtWidgets.QLineEdit(self, placeholderText="Name")
        self.lineEdit_name.setGeometry(QtCore.QRect(70, 80, 331, 20))
        self.lineEdit_name.setObjectName("lineEdit_name")
 
        self.lineEdit_login = QtWidgets.QLineEdit(self, placeholderText="Login")
        self.lineEdit_login.setGeometry(QtCore.QRect(70, 110, 113, 20))
        self.lineEdit_login.setObjectName("lineEdit_login")
 
        self.lineEdit_pwd = QtWidgets.QLineEdit(self, placeholderText="Password", echoMode=2)
        self.lineEdit_pwd.setGeometry(QtCore.QRect(70, 140, 113, 20))
        self.lineEdit_pwd.setObjectName("lineEdit_pwd")
 
        # Push Buttons ---------------------------------------------------------- >
 
        self.pushButton_first = QtWidgets.QPushButton(self)
        self.pushButton_first.setGeometry(QtCore.QRect(50, 210, 75, 23))
        self.pushButton_first.setObjectName("pushButton_first")
        self.pushButton_first.setText("<< First")
 
        self.pushButton_previous = QtWidgets.QPushButton(self)
        self.pushButton_previous.setGeometry(QtCore.QRect(140, 210, 75, 23))
        self.pushButton_previous.setObjectName("pushButton_previous")
        self.pushButton_previous.setText("< Previous")
 
        self.pushButton_next = QtWidgets.QPushButton(self)
        self.pushButton_next.setGeometry(QtCore.QRect(230, 210, 75, 23))
        self.pushButton_next.setObjectName("pushButton_next")
        self.pushButton_next.setText("Next >")
 
        self.pushButton_last = QtWidgets.QPushButton(self)
        self.pushButton_last.setGeometry(QtCore.QRect(330, 210, 75, 23))
        self.pushButton_last.setObjectName("pushButton_last")
        self.pushButton_last.setText("Last >>")