I have build a small application using PyQt and as far as I know QStackedWidget is used for making multipage applications. The issue is that it is opening multiple pages and also I'm unable to redirect to class Xyz using button in class Abc.
main.py
from PyQt4 import QtGui, QtCore
import sys
class Window(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.stacked_widget = QtGui.QStackedWidget()
layout = QtGui.QVBoxLayout()
layout.setContentsMargins(0,0,0,0)
layout.addWidget(self.stacked_widget)
widget = QtGui.QWidget()
widget.setLayout(layout)
self.setCentralWidget(widget)
widget_1 = Abc(self.stacked_widget)
widget_2 = Xyz(self.stacked_widget)
self.stacked_widget.addWidget(widget_1)
self.stacked_widget.addWidget(widget_2)
self.showMaximized()
class Abc(QtGui.QWidget):
def __init__(self, stacked_widget, parent=None):
super(Abc, self).__init__(parent)
self.stacked_widget = stacked_widget
self.frame = QtGui.QFrame()
self.frame_layout = QtGui.QVBoxLayout()
self.button = QtGui.QPushButton('Click me!')
self.button.clicked.connect(self.click)
self.frame_layout.addWidget(self.button)
self.frame.setLayout(self.frame_layout)
self.layout = QtGui.QVBoxLayout()
self.layout.addWidget(self.frame)
self.setLayout(self.layout)
self.showMaximized()
def click(self):
print("You clicked me!")
self.stacked_widget.setCurrentIndex(1)
class Xyz(QtGui.QWidget):
def __init__(self, parent=None):
super(Xyz, self).__init__(parent)
self.frame_layout = QtGui.QStackedLayout()
self.page1 = Page("Page 1", self.frame_layout)
self.page2 = Page("Page 2", self.frame_layout)
self.frame_layout.addWidget(self.page1)
self.frame_layout.addWidget(self.page2)
class Page(QtGui.QWidget):
def __init__(self, text, frame_layout, parent=None):
super(Page, self).__init__(parent)
print(self.width(), self.height())
self.frame_layout = frame_layout
self.frame = QtGui.QFrame()
self.frame_layout = QtGui.QVBoxLayout()
self.frame.setStyleSheet("background-color: rgb(191, 191, 191)")
self.label = QtGui.QLabel()
self.label.setText(text)
self.frame_layout.addWidget(self.label, alignment=QtCore.Qt.AlignCenter)
self.frame.setLayout(self.frame_layout)
self.layout = QtGui.QVBoxLayout()
self.layout.addWidget(self.frame)
self.layout.setContentsMargins(0,0,0,0)
self.setLayout(self.layout)
self.showMaximized()
print(self.width(), self.height())
if __name__ == "__main__":
app = QtGui.QApplication([])
window = Window()
window.show()
sys.exit(app.exec_())
The main problem is that you are not setting the QStackedLayout for the Xyz widget, the result is that all pages will actually appear as top level windows.
When a widget is added to a layout, it takes ownership of it; if the layout is already set to a widget, then the widget that was added to the layout becomes reparented to the other. The same happens if you set the layout afterwards.
Why does it show the first page as a separate window? And why doesn't it show the second?
When a new widget is created without a parent, it becomes a top level window; when a widget is added to a new stacked layout, Qt automatically tries to show it; you didn't set the layout to anything (which would reparent it as explained before), and the result is that the first page is shown as a standalone window.
Now, since the first "screen" is going to be shown only the first time, you can set that widget as the central widget, and then set a Xyz instance (which is actually a QStackedWidget subclass) as a new central widget.
Note that you don't need to use QWidget to add a QFrame if that's the only parent widget shown: you can just subclass QFrame.
This is a much simpler and cleaner version of your code:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.startPage = Abc()
self.setCentralWidget(self.startPage)
self.startPage.startRequest.connect(self.buildPages)
def buildPages(self):
self.pages = Xyz()
self.setCentralWidget(self.pages)
class Abc(QtGui.QFrame):
startRequest = QtCore.pyqtSignal()
def __init__(self, parent=None):
super(Abc, self).__init__(parent)
layout = QtGui.QVBoxLayout(self)
self.button = QtGui.QPushButton('Click me!')
self.button.clicked.connect(self.startRequest)
layout.addWidget(self.button)
class Xyz(QtGui.QStackedWidget):
def __init__(self, parent=None):
super(Xyz, self).__init__(parent)
self.page1 = Page("Page 1")
self.page2 = Page("Page 2")
self.addWidget(self.page1)
self.addWidget(self.page2)
self.page1.switchRequest.connect(lambda: self.setCurrentIndex(1))
self.page2.switchRequest.connect(lambda: self.setCurrentIndex(0))
class Page(QtGui.QFrame):
switchRequest = QtCore.pyqtSignal()
def __init__(self, text, parent=None):
super(Page, self).__init__(parent)
layout = QtGui.QVBoxLayout(self)
# set the background only for QFrame subclasses (which also includes
# QLabel), this prevents setting the background for other classes,
# such as the push button
self.setStyleSheet('''
QFrame {
background-color: rgb(191, 191, 191)
}
''')
# when adding a widget to a layout, the layout tries to automatically
# make it as big as possible (based on the widget's sizeHint); so you
# should not use the alignment argument for layout.addWidget(), but for
# the label instead
self.label = QtGui.QLabel(text, alignment=QtCore.Qt.AlignCenter)
layout.addWidget(self.label)
self.switchButton = QtGui.QPushButton('Switch')
layout.addWidget(self.switchButton)
self.switchButton.clicked.connect(self.switchRequest)
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
Related
I am trying to get input from a user in one tab then show it in the second tab. I could not find a question or an example about how to do that. This is an example of the code that I want to use, How can I show the data from Tab(1) Qlabel in QTextEdit box in Tab(2), I am a beginner in pyqt5 and not sure how this would work:
import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
class TabWidget(QDialog):
def __init__(self):
super().__init__()
self.setWindowTitle('Tab Widget Application')
tabwidget = QTabWidget()
tabwidget.addTab(FirstTab(), 'First Tab')
tabwidget.addTab(SecondTab(),'Second Tab')
vbox=QVBoxLayout()
vbox.addWidget(tabwidget)
self.setLayout(vbox)
class FirstTab(QWidget):
def __init__(self):
super().__init__()
self.nameLabel = QLabel(self)
self.nameLabel.setText('Name:')
self.line = QLineEdit(self)
self.line.move(80, 20)
self.line.resize(200, 32)
self.nameLabel.move(20, 20)
self.btn=QPushButton('switch',self)
self.btn.move(80, 50)
self.btn.clicked.connect(lambda: SecondTab.display(SecondTab(),self.nameLabel.text()))
class SecondTab(QWidget):
def __init__(self):
super().__init__()
self.layout = QVBoxLayout()
self.editor=QTextEdit()
self.layout.addWidget(self.editor)
self.setLayout(self.layout)
def display(self,text):
self.editor.setText(text)
if __name__ == '__main__':
app=QApplication(sys.argv)
tabwidget = TabWidget()
tabwidget.resize(500,500)
tabwidget.show()
app.exec()
In order to track changes amongst child widgets, you'll need a main "controller".
Your QTabWidget will suffice, as long as you implement it in the correct way:
class TabWidget(QDialog):
def __init__(self):
super().__init__()
self.setWindowTitle('Tab Widget Application')
# if the target widget of the layout is provided as an init argument, the
# layout will be automatically set to it
vbox = QVBoxLayout(self)
tabwidget = QTabWidget()
vbox.addWidget(tabwidget)
firstTab = FirstTab()
tabwidget.addTab(firstTab, 'First Tab')
secondTab = SecondTab()
tabwidget.addTab(secondTab,'Second Tab')
firstTab.line.textChanged.connect(secondTab.editor.setPlainText)
firstTab.btn.clicked.connect(lambda: tabwidget.setCurrentWidget(secondTab))
I am making a GUI with PyQt, and I am having issues with my MainWindow class. The window doesn't show widgets that I define in other classes, or it will show a small portion of the widgets in the top left corner, then cut off the rest of the widget.
Can someone please help me with this issue?
Here is some example code showing my issue.
import sys
from PyQt4 import QtGui, QtCore
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent=parent)
self.resize(300, 400)
self.centralWidget = QtGui.QWidget(self)
self.hbox = QtGui.QHBoxLayout(self.centralWidget)
self.setLayout(self.hbox)
names = ['button1', 'button2', 'button3']
testButtons = buttonFactory(names, parent=self)
self.hbox.addWidget(testButtons)
class buttonFactory(QtGui.QWidget):
def __init__(self, names, parent=None):
super(buttonFactory, self).__init__(parent=parent)
self.vbox = QtGui.QVBoxLayout()
self.setLayout(self.vbox)
for name in names:
btn = QtGui.QPushButton(name)
self.vbox.addWidget(btn)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
gui = MainWindow()
gui.show()
app.exec_()
A QMainWindow has a central widget that is a container in which you should add your widgets. It has its own layout. The layout of the QMainWindow is for toolbars and such. The centralWidget must be set with the setCentralWidget method. It isn't enough to just call it self.centralWidget
Use the following three lines instead.
self.setCentralWidget(QtGui.QWidget(self))
self.hbox = QtGui.QHBoxLayout()
self.centralWidget().setLayout(self.hbox)
I'm new to python and pyqt. I'm trying to open a new window after the first screen. My second window opens but without the options I specified, label and pushbutton.
from PyQt5 import QtWidgets
import sys
class secondwindow(QtWidgets.QMainWindow):
def __init__(self):
super(secondwindow, self).__init__()
self.label1 = QtWidgets.QLabel("Second Window");
self.button1 = QtWidgets.QPushButton("Click Me");
hbox = QtWidgets.QHBoxLayout()
hbox.addWidget(self.label1)
hbox.addWidget(self.button1)
self.setLayout(hbox)
class Window(QtWidgets.QWidget):
def btnclicked(self):
sender = self.sender()
if sender.text() == "OK":
self.secwin.show()
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.button1 = QtWidgets.QPushButton("OK");
vbox = QtWidgets.QVBoxLayout()
vbox.addWidget(self.button1)
self.setLayout(vbox)
self.button1.clicked.connect(self.btnclicked)
self.secwin = secondwindow()
self.show()
def main():
app = QtWidgets.QApplication(sys.argv)
main = Window()
main.show
sys.exit(app.exec())
if __name__ == '__main__':
main()
QMainWindow is a special widget because it has a defined structure, http://doc.qt.io/qt-5/qmainwindow.html#qt-main-window-framework:
As shown in the image there is already an area destined to place the widgets called Central Widget, in it you must place the widgets that you want to be displayed for it, you use setCentralWidget().
In your case the solution is:
class secondwindow(QtWidgets.QMainWindow):
def __init__(self):
super(secondwindow, self).__init__()
central_widget = QtWidgets.QWidget()
self.label1 = QtWidgets.QLabel("Second Window")
self.button1 = QtWidgets.QPushButton("Click Me")
hbox = QtWidgets.QHBoxLayout(central_widget)
hbox.addWidget(self.label1)
hbox.addWidget(self.button1)
self.setCentralWidget(central_widget)
I am creating an app using PyQt4. I have created two interfaces with Qt Designer. When a button is pushed I would like to switch between one layout and the other.
A sample of my code is:
from PyQt4 import QtGui, uic
form_class = uic.loadUiType("sample.ui")[0]
form_class2 = uic.loadUiType("sample2.ui")[0]
class SecondLayout(form_class2, QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
form_class2.setupUi(self)
class MainWindow(form_class, QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
self.btn.clicked.connect(self.open_new_window)
def open_new_window(self):
self.Window = SecondLayout()
# here I would like to switch the layout with a layout of self.Window
app = QtGui.QApplication(sys.argv)
myWindow = MainWindow(None)
myWindow.show()
app.exec_()
I have done a lot of searching and reading about QStackedLayout, but haven't been able to get it to work with layouts created in Qt Designer.
My Question is how would I be able to have one Main Window and switch its central widget but i'm not sure if that would work for the seperate menus. I have defined all the menus and widgets and status bars, etc. in Qt Designer as two different projects(both main windows) so I would like to have the main program in one of the main windows, then at some point create an instance of the second main window and switch the layout and all the widgets, menus, text edits, etc. I tried using setCentralWidget but hasn't worked for me.
Could someone please explain to me how to do this.
It sounds like you have two completely separate main windows. There is really no point in switching all the widgets, menus, toolbars, etc, because they will have no shared code. You might just as well simply hide one window, and then show the other one.
Here is a simple demo that shows one way to do that:
PyQt5
from PyQt5 import QtWidgets
class Window1(QtWidgets.QMainWindow):
def __init__(self, window2=None):
super(Window1, self).__init__()
self.setGeometry(500, 100, 100, 50)
self.button = QtWidgets.QPushButton('Go To Window 2', self)
self.button.clicked.connect(self.handleButton)
self.setCentralWidget(self.button)
self._window2 = window2
def handleButton(self):
self.hide()
if self._window2 is None:
self._window2 = Window2(self)
self._window2.show()
class Window2(QtWidgets.QMainWindow):
def __init__(self, window1=None):
super(Window2, self).__init__()
self.setGeometry(500, 100, 100, 50)
self.button = QtWidgets.QPushButton('Go To Window 1', self)
self.button.clicked.connect(self.handleButton)
self.setCentralWidget(self.button)
self._window1 = window1
def handleButton(self):
self.hide()
if self._window1 is None:
self._window1 = Window1(self)
self._window1.show()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Window1()
window.show()
sys.exit(app.exec_())
PyQt4
from PyQt4 import QtCore, QtGui
class Window1(QtGui.QMainWindow):
def __init__(self, window2=None):
super(Window1, self).__init__()
self.setGeometry(500, 100, 100, 50)
self.button = QtGui.QPushButton('Go To Window 2', self)
self.button.clicked.connect(self.handleButton)
self.setCentralWidget(self.button)
self._window2 = window2
def handleButton(self):
self.hide()
if self._window2 is None:
self._window2 = Window2(self)
self._window2.show()
class Window2(QtGui.QMainWindow):
def __init__(self, window1=None):
super(Window2, self).__init__()
self.setGeometry(500, 100, 100, 50)
self.button = QtGui.QPushButton('Go To Window 1', self)
self.button.clicked.connect(self.handleButton)
self.setCentralWidget(self.button)
self._window1 = window1
def handleButton(self):
self.hide()
if self._window1 is None:
self._window1 = Window1(self)
self._window1.show()
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window1()
window.show()
sys.exit(app.exec_())
I have a main Window derived form QMainWindow that may show different Widgets, depending on the task at hand.
I created a simplified example below:
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import sys
class MainWindow(QMainWindow):
def __init__(self, parent=None):
'''
Constructor
'''
QMainWindow.__init__(self, parent)
self.central_widget = QStackedWidget()
self.setCentralWidget(self.central_widget)
self.start_screen = Start(self)
self.second_screen = Second(self)
self.central_widget.addWidget(self.start_screen)
self.central_widget.addWidget(self.second_screen)
self.central_widget.setCurrentWidget(self.start_screen)
class Start(QWidget):
def __init__(self, parent=None):
super(Start, self).__init__(parent)
layout = QHBoxLayout()
button = QPushButton(text=QString('Push me!'))
layout.addWidget(button)
self.setLayout(layout)
self.connect(button, SIGNAL("clicked()"), self.change_widget)
def change_widget(self):
self.parent().setCurrentWidget(
self.parent().parent().second_screen)
class Second(QWidget):
def __init__(self, parent=None):
super(Second, self).__init__(parent)
layout = QHBoxLayout()
button = QPushButton(text=QString('Back to Start!'))
layout.addWidget(button)
self.setLayout(layout)
self.connect(button, SIGNAL("clicked()"), self.change_widget)
def change_widget(self):
self.parent().setCurrentWidget(
self.parent().parent().start_screen)
app = QApplication(sys.argv)
myWindow = MainWindow(None)
myWindow.show()
app.exec_()
This toggles between two different central widgets, nevertheless I found the handling with parent() functions tedious, and I'd like to know if there is a better method to organise the widgets.
The setCurrentWidget method will probably be always accessible with one parent() statement, but if for any reasons the hierarchy-depth changes, is there a better method to access the QMainWindow than parent().parent()? Or would I just re-create the Widget every time a button is clicked (I assume, if this would be a widget with data-Input possibilities, these data would be lost, which is annoying).
I appreciate any suggestions for improvement.
You should be using Signals. This allows any parent hierarchy and the child widgets don't have to have any knowledge of how they're being used or what order they're being displayed in. The main widget handles it all.
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import sys
class MainWindow(QMainWindow):
def __init__(self, parent=None):
'''
Constructor
'''
QMainWindow.__init__(self, parent)
self.central_widget = QStackedWidget()
self.setCentralWidget(self.central_widget)
self.start_screen = Start(self)
self.second_screen = Second(self)
self.central_widget.addWidget(self.start_screen)
self.central_widget.addWidget(self.second_screen)
self.central_widget.setCurrentWidget(self.start_screen)
self.start_screen.clicked.connect(lambda: self.central_widget.setCurrentWidget(self.second_screen))
self.second_screen.clicked.connect(lambda: self.central_widget.setCurrentWidget(self.start_screen))
class Start(QWidget):
clicked = pyqtSignal()
def __init__(self, parent=None):
super(Start, self).__init__(parent)
layout = QHBoxLayout()
button = QPushButton(text=QString('Push me!'))
layout.addWidget(button)
self.setLayout(layout)
button.clicked.connect(self.clicked.emit)
class Second(QWidget):
clicked = pyqtSignal()
def __init__(self, parent=None):
super(Second, self).__init__(parent)
layout = QHBoxLayout()
button = QPushButton(text=QString('Back to Start!'))
layout.addWidget(button)
self.setLayout(layout)
button.clicked.connect(self.clicked.emit)
app = QApplication(sys.argv)
myWindow = MainWindow(None)
myWindow.show()
app.exec_()