Develop Reference

Add dockable widgets in quadrants using PyQt

I'm creating a GUI using PyQt, to display 4 images in a window, positioned in this way:
Top left
Top right
Bottom left
Bottom right
I'd like to be able to undock them, but also to redock them back to any of the 4 available space.
My final goal is to set it up so that moving an undocked image where another one is already placed, would move that second image out of the way (docking it in another free quadrant or undocking it), or that placing it in the center would make it occupy all the 4 quadrants (undocking all the others).
I've tried achieving this with QDockWidget, but so far I'm not achieving good results.
My current code:
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("Window")
grid_layout = QGridLayout()
dock_window_1 = QMainWindow()
docked = QDockWidget("Dockable", self)
dock_window_1.addDockWidget(Qt.DockWidgetArea.TopDockWidgetArea, docked)
dockedWidget = QWidget(self)
docked.setWidget(dockedWidget)
dockedWidget.setLayout(QVBoxLayout())
dockedWidget.layout().addWidget(QPushButton("1"))
dock_window_2 = QMainWindow()
docked_2 = QDockWidget("Dockable_2", self)
dock_window_2.addDockWidget(Qt.DockWidgetArea.RightDockWidgetArea, docked_2)
dockedWidget_2 = QWidget(self)
docked.setWidget(dockedWidget_2)
dockedWidget_2.setLayout(QVBoxLayout())
dockedWidget_2.layout().addWidget(QPushButton("2"))
dock_window_3 = QMainWindow()
docked_3 = QDockWidget("Dockable_3", self)
dock_window_3.addDockWidget(Qt.DockWidgetArea.LeftDockWidgetArea, docked_3)
dockedWidget_3 = QWidget(self)
docked.setWidget(dockedWidget_3)
dockedWidget_3.setLayout(QVBoxLayout())
dockedWidget_3.layout().addWidget(QPushButton("3"))
dock_window_4 = QMainWindow()
docked_4 = QDockWidget("Dockable_4", self)
dock_window_4.addDockWidget(Qt.DockWidgetArea.BottomDockWidgetArea, docked_4)
dockedWidget_4 = QWidget(self)
docked.setWidget(dockedWidget_4)
dockedWidget_4.setLayout(QVBoxLayout())
dockedWidget_4.layout().addWidget(QPushButton("4"))
grid_layout.addWidget(dock_window_1, 0, 0)
grid_layout.addWidget(dock_window_2, 1, 0)
grid_layout.addWidget(dock_window_3, 0, 1)
grid_layout.addWidget(dock_window_4, 1, 1)
widget = QWidget()
widget.setLayout(grid_layout)
self.setCentralWidget(widget)
This kind of works, but I'm only able to redock a widget in its original place.
Can anyone help me getting on the right road here?
Thanks in advance!

Most of the behavior you are describing is actually already implemented by Qt using the QMainWindow and the QDockWidget.
The issue with your code is you are creating a unique QMainWindow for each of the QDockWidgets when the program only needs one QMainWindow. Additionally you are adding each of the QDockWidgets to the layout after you have already added them using the standard dockAreas surrounding the central widget.
If you eliminate the unneeded QMainWindows and instead assign each of the QDockWidgets to the your MainWindow, your desired functionality should work automatically.
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("Window")
grid_layout = QGridLayout()
docked = QDockWidget("Dockable", self)
docked.setAllowedAreas(Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea)
dockedWidget = QWidget(self)
docked.setWidget(dockedWidget)
dockedWidget.setLayout(QVBoxLayout())
dockedWidget.layout().addWidget(QPushButton("1"))
docked_2 = QDockWidget("Dockable_2", self)
docked_2.setAllowedAreas(Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea)
dockedWidget_2 = QWidget(self)
docked_2.setWidget(dockedWidget_2)
dockedWidget_2.setLayout(QVBoxLayout())
dockedWidget_2.layout().addWidget(QPushButton("2"))
docked_3 = QDockWidget("Dockable_3", self)
docked_3.setAllowedAreas(Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea)
dockedWidget_3 = QWidget(self)
docked_3.setWidget(dockedWidget_3)
dockedWidget_3.setLayout(QVBoxLayout())
dockedWidget_3.layout().addWidget(QPushButton("3"))
docked_4 = QDockWidget("Dockable_4", self)
docked_4.setAllowedAreas(Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea)
dockedWidget_4 = QWidget(self)
docked_4.setWidget(dockedWidget_4)
dockedWidget_4.setLayout(QVBoxLayout())
dockedWidget_4.layout().addWidget(QPushButton("4"))
self.addDockWidget(Qt.DockWidgetArea.LeftDockWidgetArea, docked)
self.addDockWidget(Qt.DockWidgetArea.RightDockWidgetArea, docked_2)
self.addDockWidget(Qt.DockWidgetArea.LeftDockWidgetArea, docked_3)
self.addDockWidget(Qt.DockWidgetArea.RightDockWidgetArea, docked_4)
widget = QWidget()
widget.setLayout(grid_layout)
self.setCentralWidget(widget)

How can I pass variables back and forth between two classes in PyQt5?

I am developing a GUI that imports and plots data (csv file). Data are initially imported in the TabWidget() class using getfile() and on_pushButtonLoad_clicked() and passed to the FirstTab() class, where MRChart() is plotted in the infrastructure() widget. To achieve this, I created the firstTab instance in TabWidget() (apologies if my terminology is incorrect here).
The end goal is to update the plot based on the numerical range selected on a rangeslider. Firstly, I want to pass the value of slider1 to FirstTab() and I should be able to manage from there. To do this, I have attempted to create the tabwidget instance in FirstTab(). However, I get the following: "RecursionError: maximum recursion depth exceeded". I presume this is due to each class having an instance of itself contained in the other.
Any help appreciated.
Code:
class TabWidget(QDialog):
def __init__(self, data):
super(TabWidget, self).__init__()
self.data = data
self.firstTab = FirstTab(self.data)
self.showMaximized()
# create Header
FilterLayout = QHBoxLayout()
FilterLayout.addWidget(self.createHeader1a(), 1)
FilterLayout.addWidget(self.createHeader2a(), 4)
# create Tab
tabwidget = QTabWidget()
tabwidget.addTab(self.firstTab, "Tab 1")
vbox = QVBoxLayout()
vbox.addLayout(FilterLayout)
vbox.addWidget(tabwidget)
self.setLayout(vbox)
def createHeader1a(self): #Import
HeaderBox = QGroupBox("Import Data")
inputfilebtn = QPushButton("Import")
inputfilebtn.clicked.connect(self.on_pushButtonLoad_clicked)
# importrow1
importrow1layout = QHBoxLayout()
importrow1layout.addWidget(inputfilebtn)
HeaderLayout = QVBoxLayout()
HeaderLayout.addLayout(importrow1layout)
HeaderBox.setLayout(HeaderLayout)
HeaderBox.setFlat(True)
return HeaderBox
def createHeader2a(self): #Filter
HeaderBox = QGroupBox("Filter Data")
rightlayout = QHBoxLayout()
# range slider bar to filter column data for plotting
label4 = QLabel(self)
label4.setText("Filter range:")
rightlayout.addWidget(label4)
self.slider1 = QLabeledRangeSlider(Qt.Horizontal)
self.slider1.setRange(5, 500)
self.slider1.setValue((150, 300))
rightlayout.addWidget(self.slider1)
HeaderBox.setLayout(rightlayout)
HeaderBox.setFlat(True) #
return HeaderBox
#import and return file
def getfile(self):
option = QFileDialog.Options()
fname = QFileDialog.getOpenFileName(self, 'Open file',
'c:\\', "CSV files (*.csv)", options=option)
return pd.read_csv(fname[0])
#QtCore.pyqtSlot()
def on_pushButtonLoad_clicked(self):
importedfile = self.getfile()
if importedfile is None:
return
self.firstTab.MRChart(importedfile)
global database
database = importedfile
def getslider1value(self):
return self.slider1.value
class FirstTab(QWidget):
def __init__(self, data):
super(FirstTab, self).__init__()
self.data = data
self.tabwidget = TabWidget(self.data)# issue here. Attempting to # access TabWidget class
# Grid layout of entire tab
layout = QGridLayout()
layout.addWidget(self.infrastructure(self.data), 3, 0)
layout.setRowStretch(4, 3)
layout.setColumnStretch(0, 1)
self.setLayout(layout)
def MRChart(self, importedfile): # pie chart
if self.radioButton1.isChecked():
fig = go.Pie(labels=importedfile[self.radioButton1.label])
elif self.radioButton2.isChecked():
fig = go.Pie(labels=importedfile[self.radioButton2.label])
layout = go.Layout(autosize=True, legend=dict(orientation="h", xanchor='center', x=0.5))
fig = go.Figure(data=fig, layout=layout)
fig.update_layout(margin=dict(t=0, b=0, l=0, r=0))
self.browser.setHtml(fig.to_html(include_plotlyjs='cdn'))
def infrastructure(self, importedfile):
groupBox = QGroupBox("Plot")
self.browser = QtWebEngineWidgets.QWebEngineView(self)
right = QVBoxLayout()
# Change/update plot (MRChart) depending on what Radio button is selected
self.radioButton1 = QRadioButton("Label 1")
self.radioButton1.label = "Column_label_1"
self.radioButton1.toggled.connect(lambda: self.MRChart(database))
right.addWidget(self.radioButton1)
self.radioButton2 = QRadioButton("Label 2")
self.radioButton2.setChecked(True)
self.radioButton2.label = "Column_label_2"
self.radioButton2.toggled.connect(lambda: self.MRChart(database))
right.addWidget(self.radioButton2)
middleright = QHBoxLayout()
middleright.addWidget(self.browser)
middleright.addLayout(right)
groupBox.setLayout(middleright)
groupBox.setFlat(True)
print(self.tabwidget.getslider1value())# attempting to print slider value here
return groupBox
if __name__ == "__main__":
app = QApplication(sys.argv)
tabwidget = TabWidget(data=None)
tabwidget.show()
app.exec()

The recursion error is clear: TabWidget tries to create FirstTab, but there you're trying to create another TabWidget, which will create a further FirstTab and so on.
If you want to keep reference between objects, you must pass references, not create new instances (see the note below).
Also, since FirstTab calls infrastructure in the __init__, at that point the slider in the parent widget has not been created yet.
You must move the creation of FirstTab after the slider is created, and pass the reference in the constructor.
class TabWidget(QDialog):
def __init__(self, data):
super(TabWidget, self).__init__()
self.data = data
self.showMaximized()
# create Header
FilterLayout = QHBoxLayout()
FilterLayout.addWidget(self.createHeader1a(), 1)
FilterLayout.addWidget(self.createHeader2a(), 4)
self.firstTab = FirstTab(self) # <- pass the reference of the parent
# ...
class FirstTab(QWidget):
def __init__(self, tabwidget):
super(FirstTab, self).__init__()
self.tabwidget = tabwidget
self.data = tabwidget.data
# ...
Note that this is the same problem you had in your previous question. I strongly suggest you to review the basics of classes and instances and OOP in general, as knowledge and comprehension of those aspects cannot be ignored.

Strange grafical artifacts while re-inserting widgets into gridlayout [duplicate]

I have a QVBox layout that houses a QVBox layout and a QHBox layout. I use the other QVBox layout to hold dynamically created GUI objects and the QHBox layout to hold the buttons that add/remove those objects. Everything works correctly if I position the QHBox on top of the QVBox, but when I try to position the QHBox beneath the QVBox the objects aren't removed correctly but stay there "lingering" on top of the QHBox. I'll upload pictures to demonstrate the problem. First picture is before taking action, second is after creating a new object and third is after deleting the object
Here is the code that creates and deletes the new objects
def addClient(self):
if (len(self.clients) < 5):
client = clientComponent(self)
self.clients.append(client)
index = len(self.clients)-1
self.vLayout3.addWidget(self.clients[index])
client.setIndex(index)
self.clients[index].startButton.clicked.connect(partial(self.threadcontrol, '2', client.getIndex()))
self.clients[index].stopButton.clicked.connect(partial(self.clientstop, '0', client.getIndex()))
def deleteClient(self):
if (len(self.clients) > 1):
self.vLayout3.removeWidget(self.clients.pop())
This is where I complete the layout
def initializeUi(self):
self.mainWidget = QWidget(self)
self.setCentralWidget(self.mainWidget)
self.mainLayout = QVBoxLayout(self.mainWidget)
self.hLayout1 = QHBoxLayout()
self.hLayout2 = QHBoxLayout()
self.vLayout1 = QVBoxLayout()
self.vLayout2 = QVBoxLayout()
self.vLayout3 = QVBoxLayout()
self.addServer()
self.addClient()
self.serverBox = QGroupBox('Server')
self.clientBox = QGroupBox('Client')
self.traffic1 = QLabel('0.0Mb/s', self)
self.traffic1.setAlignment(Qt.AlignRight)
self.traffic2 = QLabel('0.0Mb/s', self)
self.traffic2.setAlignment(Qt.AlignCenter)
self.traffic3 = QLabel('0.0Mb/s', self)
self.traffic3.setAlignment(Qt.AlignLeft)
self.newClientButton = QPushButton('+', self)
self.deleteClientButton = QPushButton('-', self)
self.hLayout1.addWidget(self.traffic1)
self.hLayout1.addWidget(self.traffic2)
self.hLayout1.addWidget(self.traffic3)
self.hLayout2.addWidget(self.newClientButton)
self.hLayout2.addWidget(self.deleteClientButton)
self.vLayout2.addLayout(self.vLayout3)
self.vLayout2.addLayout(self.hLayout2)
self.mainLayout.addWidget(self.plot)
self.mainLayout.addLayout(self.hLayout1)
self.serverBox.setLayout(self.vLayout1)
self.mainLayout.addWidget(self.serverBox)
self.clientBox.setLayout(self.vLayout2)
self.mainLayout.addWidget(self.clientBox)

This is happening because your main window remains the parent of the client widgets after you remove them from the layout. You will see similar behaviour if you assign a widget a parent widget without adding it to any layout.
Removing the parent should resolve the issue.
def deleteClient(self):
if (len(self.clients) > 1):
client = self.clients.pop()
self.vLayout3.removeWidget(client)
client.setParent(None)
You may also need to make a call to adjustSize to resize the window to fit the remaining widgets

When you delete a widget from layout it still remains in parent widget's
object tree, so it gets displayed outside of any layout.
To remove a widget from the object tree call widget.setParent(None).
widget.deleteLater() also works.
Here is my MCVE(Qt4, Py2.7):
from PyQt4.QtGui import (QApplication, QWidget, QPushButton,
QVBoxLayout, QHBoxLayout)
app=QApplication([])
self = QWidget()
main_layout = QVBoxLayout(self)
clients = []
l2 = QHBoxLayout()
main_layout.addLayout(l2)
b_add = QPushButton('add', self)
l2.addWidget(b_add)
def addClient():
b = QPushButton(str(len(clients)), self)
clients.append(b)
main_layout.addWidget(b)
b_add.clicked.connect(addClient)
b_rm = QPushButton('rm', self)
l2.addWidget(b_rm)
def deleteClient():
b = clients.pop()
main_layout.removeWidget(b)
# comment out two following lines to get the behavior you observe
b.setParent(None)
self.adjustSize()
b_rm.clicked.connect(deleteClient)
self.show()
app.exec_()
On my system I also have to call self.adjustSize() after deletion to resize the main window

Stop widgets from overlapping each other and add space between them

I am using QHBoxLayout for layout. The breakdown is: pic.1 is what happens, pic.2 is what I want - widgets don't overlap and there is a gap between them. For pic.2, I created a Gap widget to stick between the existing widgets. But this is a cumbersome solution which implies extra maintenance (especially when I have more than two widgets to care for). Moreover, since B overlaps A, I think the newly added gap widget overlaps A as well, maybe according the fraction of its size. I am not so sure about this.
I tried using self.layout.addSpacing(10), but that doesn't work. The red widget shifts by 10 pixels from where it was before, not from the border of the widget on the left.
Note, too, that the contained widgets will all have some minimum width specification.
So, how can I add the space between two widgets like in pic.2?
import sys
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
class Gap(QWidget):
def __init__(self, parent=None):
super().__init__(parent=parent)
self.setMinimumWidth(10)
self.setMinimumHeight(1)
class Line(QWidget):
def __init__(self, parent=None):
super().__init__(parent=parent)
# Set layout
self.layout = QHBoxLayout()
self.setLayout(self.layout)
# Set palette
self.palette1 = QPalette()
self.palette1.setColor(QPalette.Window, Qt.red)
self.palette2 = QPalette()
self.palette2.setColor(QPalette.Window, Qt.blue)
self.palettebg = QPalette()
self.palettebg.setColor(QPalette.Window, Qt.green)
self.setAutoFillBackground(True)
self.setPalette(self.palettebg)
# Set labels
self.label1 = QLabel(self)
self.label1.setText("A")
self.label1.setStyleSheet('font-size: 36pt;')
self.label1.adjustSize()
self.label1.setAutoFillBackground(True)
self.label1.setPalette(self.palette1)
self.label1.setMinimumSize(36, 36)
self.label2 = QLabel(self)
self.label2.setText("B")
self.label2.move(30, 0)
self.label2.setStyleSheet('font-size: 36pt;')
self.label2.adjustSize()
self.label2.setAutoFillBackground(True)
self.label2.setPalette(self.palette2)
self.label2.setMinimumSize(36, 36)
self.gap = Gap()
self.layout.addWidget(self.label1)
# self.layout.addWidget(self.gap)
# self.layout.addSpacing(10)
self.layout.addWidget(self.label2)
class App(QMainWindow):
def __init__(self):
super().__init__()
self.title = 'PyQt5'
self.left = 10
self.top = 10
self.width = 200
self.height = 54
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.line = Line(self)
self.line.resize(74, 54)
self.line.move(50, 50)
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
# CUSTOM
app.setFont(QFontDatabase().font("Monospace", "Regular", 14))
ex = App()
sys.exit(app.exec_())
EDIT clarification, as requested: (1) suppose the size of the parent widget is too small (and cannot be resized), (2) the parent widget has QHBoxLayout with widgets A and B added to it, (3) the parent widget being too small, QHBoxLayout aranges the child widgets A and B such that they overlap each other like in the first picture. (4) Such overlap is undesirable, instead the widgets just need to be placed one after another, with no overlap, and with gap between them, like in picture 2. I don't know how to do this with QHBoxLayout.
EDIT 2 Here is a visual explanation.
The green here is the parent widget - not resizable by assumption. Widget A is added:
Add widget B:
Now, widget B is on top of A. I don't want it. I want this instead:

The minimumSize of the child widgets does not influence the minimumSize of the parent widget, and the use of the layout does not influence the minimumSize of the widget either. The layouts set the minimumSizeHint and sizeHint using as information the minimumSize of the widgets that handle plus other features such as the size and sizing policy. So in the first instance you must set the minimumSize of the parent widget to be the minimumSizeHint of it.
On the other hand the layout has a spacing by default so it is advisable to set it to 0.
class Line(QWidget):
def __init__(self, parent=None):
super().__init__(parent=parent, autoFillBackground=True)
# Set palette
palette1 = QPalette()
palette1.setColor(QPalette.Window, Qt.red)
palette2 = QPalette()
palette2.setColor(QPalette.Window, Qt.blue)
palettebg = QPalette()
palettebg.setColor(QPalette.Window, Qt.green)
self.setPalette(palettebg)
# Set labels
self.label1 = QLabel(text="A", autoFillBackground=True)
self.label1.setStyleSheet('font-size: 36pt;')
self.label1.setPalette(palette1)
self.label1.setMinimumSize(36, 36)
self.label1.adjustSize()
self.label2 = QLabel(text="B", autoFillBackground=True)
self.label2.setStyleSheet('font-size: 36pt;')
self.label2.setPalette(palette2)
self.label2.setMinimumSize(36, 36)
self.label2.adjustSize()
# Set layout
layout = QHBoxLayout(self, spacing=0)
layout.addWidget(self.label1)
layout.addSpacing(10)
layout.addWidget(self.label2)
self.setMinimumSize(self.minimumSizeHint())
# or
# layout = QHBoxLayout(self, spacing=10)
# layout.addWidget(self.label1)
# layout.addWidget(self.label2)
# self.setMinimumSize(self.minimumSizeHint())
Update:
The maximum size of the layout that can be handled is the size of the parent widget, so in its case it will compress not respecting the spaces, a solution is to set a widget that is the content, and in that to establish the layout, so the layout will stretch to the content widget with freedom.
class Line(QWidget):
def __init__(self, parent=None):
super().__init__(parent=parent, autoFillBackground=True)
# Set palette
palette1 = QPalette()
palette1.setColor(QPalette.Window, Qt.red)
palette2 = QPalette()
palette2.setColor(QPalette.Window, Qt.blue)
palettebg = QPalette()
palettebg.setColor(QPalette.Window, Qt.green)
self.setPalette(palettebg)
# Set labels
self.label1 = QLabel(text="A", autoFillBackground=True)
self.label1.setStyleSheet('font-size: 36pt;')
self.label1.setPalette(palette1)
self.label1.setMinimumSize(36, 36)
self.label1.adjustSize()
self.label2 = QLabel(text="B", autoFillBackground=True)
self.label2.setStyleSheet('font-size: 36pt;')
self.label2.setPalette(palette2)
self.label2.setMinimumSize(36, 36)
self.label2.adjustSize()
content_widget = QWidget(self)
layout = QHBoxLayout(content_widget, spacing=10)
layout.addWidget(self.label1)
layout.addWidget(self.label2)
content_widget.setFixedSize(content_widget.minimumSizeHint())

PySide QtGui.QGraphicsWidget child-parent transform

I have a question about using QtGui.QGraphicsWidget. In a given example I will try to describe my problem. There are two QGraphicsWidget instances inside the QtGui.QtGraphicsScene, of which one is a parent (app_widget.main_widget - blue one when running), and other one is its child widget (app_widget.subwidget - red one when running). If you run the program, with a Plus key on your keyboard you can transform widgets circularly through the states.
# --coding: utf-8 --
# window.py
import sys
from PySide import QtGui, QtCore
class WidgetBase(QtGui.QGraphicsWidget):
def __init__(self, parent = None):
super(WidgetBase, self).__init__(parent)
def set_background(self, color_hex):
palette = QtGui.QPalette()
color = QtGui.QColor()
color.setRgba(color_hex)
palette.setColor(QtGui.QPalette.Background, color)
self.setPalette(palette)
self.setAutoFillBackground(True)
class AppWidget(WidgetBase):
def __init__(self):
super(AppWidget, self).__init__()
self.main_widget = WidgetBase(self)
self.subwidget = WidgetBase(self.main_widget)
class Window(QtGui.QMainWindow):
change_app_state = QtCore.Signal()
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
SCREEN_DIM = QtGui.QDesktopWidget().screenGeometry()
self.app_scene = QtGui.QGraphicsScene(0, 0, SCREEN_DIM.width(), SCREEN_DIM.height())
app_view = QtGui.QGraphicsView(self.app_scene)
app_view.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
app_view.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.setCentralWidget(app_view)
app_widget = AppWidget()
app_widget.main_widget.set_background(0x50449558)
app_widget.main_widget.resize(500, 500)
app_widget.subwidget.set_background(0x50ff3300)
app_widget.subwidget.resize(500 * 0.5, 500)
self.app_scene.addItem(app_widget)
self.machine = QtCore.QStateMachine()
state1 = QtCore.QState(self.machine)
state2 = QtCore.QState(self.machine)
state3 = QtCore.QState(self.machine)
state4 = QtCore.QState(self.machine)
state1.assignProperty(app_widget.main_widget, 'geometry', QtCore.QRectF(0, 0, 500, 500))
state2.assignProperty(app_widget.main_widget, 'scale', 0.5)
state3.assignProperty(app_widget.main_widget, 'scale', 1)
state4.assignProperty(app_widget.main_widget, 'geometry', QtCore.QRectF(0, 0, 1000, 500))
trans1 = state1.addTransition(self.change_app_state, state2)
trans2 = state2.addTransition(self.change_app_state, state3)
trans3 = state3.addTransition(self.change_app_state, state4)
trans4 = state4.addTransition(self.change_app_state, state1)
trans1.addAnimation(QtCore.QPropertyAnimation(app_widget.main_widget, 'scale', state1))
trans2.addAnimation(QtCore.QPropertyAnimation(app_widget.main_widget, 'scale', state2))
trans3.addAnimation(QtCore.QPropertyAnimation(app_widget.main_widget, 'geometry', state3))
trans4.addAnimation(QtCore.QPropertyAnimation(app_widget.main_widget, 'geometry', state4))
self.machine.setInitialState(state1)
self.machine.start()
def keyPressEvent(self, e):
if e.key() == QtCore.Qt.Key_Plus:
self.change_app_state.emit()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = Window()
window.showFullScreen()
sys.exit(app.exec_())
When scaling parent widget (changing 'scale' property - QtGui.QGraphicsWidget property inherited from QtGui.QGraphicsObject), a child widget also get scaled. But, when I change geometry of parent widget (changing 'geometry' property - QtGui.QGraphicsWidget property), child widget geometry remains unchanged.
I am running Python 2.7.6, PySide version 1.2.1 and QtCore version 4.8.6.
Why isn't a child widget always following parents transformations? Is there any way to scale only one axis of parent widget and get all children widgets to get scaled proportionally?

Answered on qt forum.
"It will only follow it's parent widget if you put it in a layout that you set on the said parent widget. Otherwise it's up to you to handle the positioning and size of the child widget."
Link on qt forum post:
https://forum.qt.io/topic/59958/pyside-qtgui-qgraphicswidget-child-parent-transformations