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PyQt5 Custom Widget Opens in Another Window

I started out with PyQt5 recently. I wanted to create a custom widget and then insert it into the main window of an application.
The custom Widget:
class ScoreCard(QtWidgets.QWidget):
def __init__(self, parent=None):
super(ScoreCard, self).__init__(parent=parent)
self.setWindowFlags(QtCore.Qt.CustomizeWindowHint)
self.pressing = False
self.init_ui()
self.show()
def init_ui(self):
# Layout in here
And this is the main Application:
from PyQt5.QtWidgets import *
from scorecard import ScoreCard
import sys
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.initUi()
self.show()
def initUi(self):
self.setGeometry(300,300,800,700)
window_layout = QVBoxLayout()
recent_playcard = ScoreCard()
window_layout.addWidget(recent_playcard)
self.setLayout(window_layout)
if __name__ == "__main__":
app = QApplication(sys.argv)
execute = MainWindow()
sys.exit(app.exec_())
Why is it that whenever I run the main Application, the custom widget appears in another window? I even tried removing the frame and setting the parent to none, but none of that changed this behavior. How do I fix this?

Looks like I mixed up QMainWindow and QDialog I should be using a central widget for the main application instead of setting a layout..

Is there a way to prevent the taskbar icon from being hidden when hide is called on the parent window?

I have a parent and child window. When you push the button from the parent class the child is shown and the parent is hidden. Is there anyway to keep the taskbar icon visible when doing this?
from PyQt5.QtCore import Qt, QDateTime
from PyQt5.QtWidgets import *
from PyQt5 import QtGui
class ParentWindow(QDialog):
def __init__(self):
super(ParentWindow, self).__init__()
self.cw = None
self.button = QPushButton('Go to child')
self.button.clicked.connect(self.child)
layout = QHBoxLayout()
layout.addWidget(self.button)
self.setLayout(layout)
self.show()
def child(self):
self.cw = ChildWindow(self)
self.hide()
def parent(self):
self.cw.close()
self.show()
class ChildWindow(QDialog):
def __init__(self, parent):
super(ChildWindow, self).__init__(parent)
self.button = QPushButton('Go to parent')
self.button.clicked.connect(self.parent().parent)
layout = QHBoxLayout()
layout.addWidget(self.button)
self.setLayout(layout)
self.show()
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = ParentWindow()
sys.exit(app.exec_())

The problem is that a child QDialog "shares" the same taskbar entry as its parent, and when the parent is hidden, so does the taskbar entry, no matter if a child is visible.
A possible solution is to not hide the parent, but minimize it. Keep in mind that this has only been tested as working on Windows, on Linux you can have unexpected behavior (depending on how the window manager relates to modal windows) and I don't know how it will work out on MacOs.
The idea is to use showMinimized() on the parent, then show the child, activate it to make it visible on top and, most importantly, use exec_() to ensure it has full control and make it behave as a dialog should.
Then we connect both the accepted and rejected signals of the dialog to restore the main window, and connect the clicked signal to accept.
class ParentWindow(QDialog):
def __init__(self):
super(ParentWindow, self).__init__()
self.cw = None
self.button = QPushButton('Go to child')
self.button.clicked.connect(self.child)
layout = QHBoxLayout()
layout.addWidget(self.button)
self.setLayout(layout)
self.show()
def child(self):
self.cw = ChildWindow(self)
self.showMinimized()
self.cw.show()
self.cw.activateWindow()
self.cw.exec_()
class ChildWindow(QDialog):
def __init__(self, parent):
super(ChildWindow, self).__init__(parent)
self.button = QPushButton('Go to parent')
self.button.clicked.connect(self.accept)
layout = QHBoxLayout()
layout.addWidget(self.button)
self.setLayout(layout)
self.accepted.connect(self.parent().showNormal)
self.rejected.connect(self.parent().showNormal)
PS: I ended up not using a custom function to call back the parent at all, but remember that you shouldn't overwrite function/property names like parent.

How can I edit the style of button with pyside2?

Now I use Pyside2 to create a UI, but the style of the button is very old, just like winxp. I want it to be newer, but I don't know how to do it, do anyone know how to do?
now ui
what I want
My code is just like that:
class MainWindow(QMainWindow):
def __init__(self, parent=None):
QMainWindow.__init__(self, parent)
self.open_directory_button = QPushButton("打开文件夹")
self.open_directory_button.clicked.connect(self.open_directory_button_clicked)
self.path_layout = QHBoxLayout()
self.path_layout.addWidget(self.path_edit)
self.path_layout.addWidget(self.open_directory_button)
self.main_layout = QVBoxLayout()
self.main_layout.addLayout(self.path_layout)
self.frame = QWidget(self)
self.frame.setLayout(self.main_layout)
self.setCentralWidget(self.frame)

As I see the style of the second image is the "fusion" so a possible solution is:
import sys
from PySide2 import QtWidgets
app = QtWidgets.QApplication(sys.argv)
app.setStyle("fusion") # <----
# ...

You need to use the setStyleSheet, see this:
open_directory_button = QtWidgets.QPushButton()
open_directory_button.setStyleSheet("QPushButton:pressed{image:url(C:\image.png); border:none} QPushButton:hover{image:url(C:\image_hover.png); border:none}")

QGraphicsGridLayout works in PySide but not PyQt4

I've been trying for hours to get QGraphicsGridLayout to work with PyQt4. I have PySide installed so I switched the imports to that for a quick check and it worked as expected! For the code below, when PySide is used, the paint method on the RectangleWidget is called as expected but when you use PyQt4 the paint method is never called.
I know that the RectangleWidget should override some more virtual methods for a proper implementation but I was stripping things out to try and get the minimal amount of code to narrow down the problem.
from PySide import QtGui, QtCore
# from PyQt4 import QtGui, QtCore
class RectangleWidget(QtGui.QGraphicsWidget):
def __init__(self, rect, parent=None):
super(RectangleWidget, self).__init__(parent)
self.rect = rect
def paint(self, painter, *args, **kwargs):
print('Paint Called')
painter.drawRect(self.rect)
class MainWindow(QtGui.QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.central_widget = QtGui.QWidget(self)
central_layout = QtGui.QHBoxLayout()
self.central_widget.setLayout(central_layout)
self.setCentralWidget(self.central_widget)
self.resize(500, 500)
self.view = QtGui.QGraphicsView()
self.scene = QtGui.QGraphicsScene()
self.view.setScene(self.scene)
panel = QtGui.QGraphicsWidget()
self.scene.addItem(panel)
layout = QtGui.QGraphicsGridLayout()
panel.setLayout(layout)
for i in range(4):
for j in range(4):
rectangle = RectangleWidget(QtCore.QRectF(0, 0, 50, 50))
layout.addItem(rectangle, i, j)
central_layout.addWidget(self.view)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
widget = MainWindow()
widget.show()
app.exec_()
Any help is appreciated! I would like to maintain compatibility with both PyQt4 and PySide so continuing using PySide only is not really an ideal solution. Thanks

The QGraphicsGridLayout takes ownership of the items added to it (see the docs for further details).
In your example, it would seem that all the RectangleWidget items are in danger of being garbage-collected once they go out of scope. So if you give them a parent:
rectangle = RectangleWidget(QtCore.QRectF(0, 0, 50, 50), panel)
all should be well.

Replace CentralWidget in MainWindow

I'm kinda new to PySide.I have a main window object which shows one widget at a time. I've been trying to change the central widget of the QMainWindow class in order to replace the visible Widget in the window when pressing a button. The problem is that the button pressed is in the Widget class, not in the main window class.
say...
class App(QtGui.QMainWindow):
def __init__(self):
super(App, self).__init__()
self.initUI()
def initUI(self):
self.statusBar().showMessage('Listo.') #Status Bar
self.login_screen = LoginScreen()
self.logged_in_screen = LoggedInScreen()
self.setCentralWidget(self.login_screen)
self.setGeometry(300, 300, 450, 600) #Window Size
self.setWindowTitle('PyTransactio - Client') #Window Title
self.setWindowIcon(QtGui.QIcon('icon.png')) #App Icon
self.show()
The pressed button is in the login_screen instance. The method called when the button is clicked is inside the LoginScreen class:
def login(self):
""" Send login data to the server in order to log in """
#Process
self.setParent(None)
Setting the parent widget to None removes the widget (login_screen) from the main window. What should I do in order to get another widget (e.g. logged_in_screen) as the central widget of the main window when the loginButton (inside the login_screen widget) is pressed?
Maybe the login method should be inside the main window class? If so, how can I connect the buttons pressed in login_screen with the main window's method?

You may use a QStackedWidget as central widget and add both the log-in screen and "logged-in" screen to it.
An example usage:
from PyQt4 import QtCore, QtGui
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.central_widget = QtGui.QStackedWidget()
self.setCentralWidget(self.central_widget)
login_widget = LoginWidget(self)
login_widget.button.clicked.connect(self.login)
self.central_widget.addWidget(login_widget)
def login(self):
logged_in_widget = LoggedWidget(self)
self.central_widget.addWidget(logged_in_widget)
self.central_widget.setCurrentWidget(logged_in_widget)
class LoginWidget(QtGui.QWidget):
def __init__(self, parent=None):
super(LoginWidget, self).__init__(parent)
layout = QtGui.QHBoxLayout()
self.button = QtGui.QPushButton('Login')
layout.addWidget(self.button)
self.setLayout(layout)
# you might want to do self.button.click.connect(self.parent().login) here
class LoggedWidget(QtGui.QWidget):
def __init__(self, parent=None):
super(LoggedWidget, self).__init__(parent)
layout = QtGui.QHBoxLayout()
self.label = QtGui.QLabel('logged in!')
layout.addWidget(self.label)
self.setLayout(layout)
if __name__ == '__main__':
app = QtGui.QApplication([])
window = MainWindow()
window.show()
app.exec_()
If you do not want to use this widget, then I think you'll have to call QMainWindow.setCentralWidget every time you change the central widget.
As to where the login method should be, it depends. Probably you could define a simple interface for your mainwindow to add/remove/show specific central widgets, and call it from the login method of LoginScreen. In this way the LoginScreen class does not have to know about implementation details such as if the central widget is actually a QStackedWidget or this thing is done in an other way.

You can use QMainWindow.setCentralWidget to do this (repeatedly):
#! /usr/bin/env python3
from PySide import QtGui
from PySide import QtCore
import sys
app = QtGui.QApplication(sys.argv)
mw = QtGui.QMainWindow()
w2 = QtGui.QWidget()
pb = QtGui.QPushButton('push me', w2)
l1 = QtGui.QLabel('orig')
l2 = QtGui.QLabel('changed')
mw.setCentralWidget(l1)
pb.clicked.connect(lambda: mw.setCentralWidget(l2))
mw.show()
w2.show()
sys.exit(app.exec_())