Develop Reference

How to align a QPushButton inside window?

I want to align a QPushButton to the bottom right corner, but without a fixed size, because if I use a fixed size and resize the window, it doen't look good anymore. Here's my code:
self.copy_btn = QtWidgets.QPushButton(self)
self.copy_btn.setText("Copy")
self.copy_btn.move(370, 350)
As you can see, I'm currenctly using .move(). I tried it with .setAlignment(QtCore.Qt.AlignRight), because it worked for the label, but it doesn't work for QPushButton.

There are several solutions depending on the context:
Using a QXBoxLayout
from PyQt5 import QtCore, QtWidgets
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.copy_btn = QtWidgets.QPushButton()
self.copy_btn.setText("Copy")
lay = QtWidgets.QVBoxLayout(self)
lay.setContentsMargins(0, 0, 0, 0)
lay.addStretch()
lay.addWidget(self.copy_btn, alignment=QtCore.Qt.AlignRight)
# or
# lay = QtWidgets.QHBoxLayout(self)
# lay.setContentsMargins(0, 0, 0, 0)
# lay.addStretch()
# lay.addWidget(self.copy_btn, alignment=QtCore.Qt.AlignBottom)
self.resize(640, 480)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
Using an eventFilter
from PyQt5 import QtCore, QtWidgets
class Resizer(QtCore.QObject):
def __init__(self, widget):
super().__init__(widget)
self._widget = widget
self.widget.installEventFilter(self)
if not self.widget.isWindow():
self.widget.window().installEventFilter(self)
#property
def widget(self):
return self._widget
def eventFilter(self, obj, event):
if obj is self.widget and not self.widget.isWindow():
if event.type() == QtCore.QEvent.ParentAboutToChange:
self.widget.window().removeEventFilter(self)
elif event.type() == QtCore.QEvent.ParentChange:
self.widget.window().installEventFilter(self)
if obj is self.widget.window() and event.type() == QtCore.QEvent.Resize:
geom = self.widget.geometry()
geom.moveBottomRight(QtCore.QPoint(event.size().width(), event.size().height()))
self.widget.setGeometry(geom)
return super().eventFilter(obj, event)
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.copy_btn = QtWidgets.QPushButton(self)
self.copy_btn.setText("Copy")
resizer = Resizer(self.copy_btn)
self.resize(640, 480)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())

how to set the background color for draw text?

I want to set the background for text, which means that I want to set the color of the rectangle contains the text. I have tested QPainter.setBackground, but it do not work. This is my code:
import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
class MyLabel(QLabel):
def __init__(self):
super(MyLabel, self).__init__()
self.setMinimumHeight(200)
self.setMinimumWidth(200)
def paintEvent(self, QPaintEvent):
super(MyLabel, self).paintEvent(QPaintEvent)
pos = QPoint(50, 50)
painter = QPainter(self)
brush = QBrush()
brush.setColor(QColor(255,0,0))
painter.setBackgroundMode(Qt.OpaqueMode)
painter.setBackground(brush)
painter.drawText(pos, 'hello,world')
class Window(QWidget):
def __init__(self):
super(Window, self).__init__()
layout = QHBoxLayout(self)
self.label = MyLabel()
layout.addWidget(self.label)
if __name__ == '__main__':
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
What I want is:
Thanks for any help.

It is not necessary to implement a personalized QLabel, it is enough to set the background color through Qt Style Sheet, also do not use a layout if you want to establish a certain position
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.label = QtWidgets.QLabel("hello,world", self)
self.label.adjustSize()
self.label.setStyleSheet(
"background-color: {};".format(QtGui.QColor(255, 0, 0).name())
)
self.label.move(QtCore.QPoint(50, 50))
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())

QListView Selected Index not updated when embedding a QWidget

I have embedded a QPushbutton in a Qwidget in a QListView:
QPushbutton >> QWidget >> QListView
list_widget = QWidget()
list_widget.layout(QHBoxLayout())
btn = QPushButton()
btn.pressed.connect(clicked)
list_widget.layout().addWidget(QPushButton())
list_view.setIndexWidget(self.list_model.index(row, 0), list_widget)
def clicked():
row = list_view.selectedIndexes()
The problem is now list_view.selectedIndexes() does not return the row of the pressed button, when pressed.
This seems to work only when the QPushbutton is embedded in the QListView directly: QPushbutton >> QListView.
Does anyone have an idea how to delegate the focus of the pushbutton to the QListView?

When you click on the button it is not transmitted to the QListView because the button consumes it and does not transmit it to other widgets so if you want to obtain the row it must be obtained indirectly, a possible solution is to use the geometry for it you must obtain the sender , in this case the button, and then for its topleft to global positions, then convert it to a local position with respect to the viewport of QListView, using that position with the method indexAt() you get the QModelIndex.
from PyQt5 import QtCore, QtGui, QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.list_model = QtGui.QStandardItemModel(200, 1)
self.list_view = QtWidgets.QListView()
self.list_view.setModel(self.list_model)
self.setCentralWidget(self.list_view)
for row in range(self.list_model.rowCount()):
list_widget = QtWidgets.QWidget()
hlay = QtWidgets.QHBoxLayout(list_widget)
btn = QtWidgets.QPushButton(str(row))
btn.pressed.connect(self.clicked)
hlay.addWidget(btn)
hlay.setContentsMargins(0, 0, 0, 0)
self.list_view.setIndexWidget(self.list_model.index(row, 0), list_widget)
#QtCore.pyqtSlot()
def clicked(self):
btn = self.sender()
gp = btn.mapToGlobal(QtCore.QPoint())
lp = self.list_view.viewport().mapFromGlobal(gp)
ix = self.list_view.indexAt(lp)
print("row", ix.row())
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
Another much simpler way is to pass the row as an argument using functools.partial():
from functools import partial
from PyQt5 import QtCore, QtGui, QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.list_model = QtGui.QStandardItemModel(200, 1)
self.list_view = QtWidgets.QListView()
self.list_view.setModel(self.list_model)
self.setCentralWidget(self.list_view)
for row in range(self.list_model.rowCount()):
list_widget = QtWidgets.QWidget()
hlay = QtWidgets.QHBoxLayout(list_widget)
btn = QtWidgets.QPushButton(str(row))
btn.pressed.connect(partial(self.clicked, row))
hlay.addWidget(btn)
hlay.setContentsMargins(0, 0, 0, 0)
self.list_view.setIndexWidget(self.list_model.index(row, 0), list_widget)
#QtCore.pyqtSlot(int)
def clicked(self, row):
print(row)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
Or using a lambda method:
from PyQt5 import QtCore, QtGui, QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.list_model = QtGui.QStandardItemModel(200, 1)
self.list_view = QtWidgets.QListView()
self.list_view.setModel(self.list_model)
self.setCentralWidget(self.list_view)
for row in range(self.list_model.rowCount()):
list_widget = QtWidgets.QWidget()
hlay = QtWidgets.QHBoxLayout(list_widget)
btn = QtWidgets.QPushButton(str(row))
btn.pressed.connect(lambda *args, row=row: self.clicked(row))
hlay.addWidget(btn)
hlay.setContentsMargins(0, 0, 0, 0)
self.list_view.setIndexWidget(self.list_model.index(row, 0), list_widget)
#QtCore.pyqtSlot(int)
def clicked(self, row):
print(row)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
In my case I prefer to use partials since you do not need to write a lot of logic and it's thread-safe.

pyqt5 Is there a limit to loading widgets using clicked.connect?

I'm using the QPushButton to load the UI. First -> Jumin -> Department -> next -> next I want to create the UI in order. The problem is that I can not load the third Department into the QMainwindow window. I do not know why
When you create a widget in QVBoxLayout, it changes the size of the widget according to the wallpaper like wxpython layout (wx.all). Can not change the position (move) and size (resize) by automatic centering?
import sys
from PyQt5.QtWidgets import *
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.center_widget = QWidget()
self.setCentralWidget(self.center_widget)
self.FirstUI()
def FirstUI(self):
self.btn1 = QPushButton('test1', self)
self.btn1.move(50, 50)
self.btn1.clicked.connect(self.btn1_click)
def JuminUI(self):
self.ju1 = QLineEdit('13')
self.btn2 = QPushButton('^^^^^^^^^^')
self.ju_text = QLabel('asd')
self.jumim_layout = QVBoxLayout()
self.jumim_layout.addWidget(self.ju_text)
self.jumim_layout.addWidget(self.ju1)
self.jumim_layout.addWidget(self.btn2)
self.centralWidget().setLayout(self.jumim_layout)
self.btn2.clicked.connect(self.btn2_click)
def DepartmentUI(self):
self.depart_layout = QVBoxLayout()
self.depart_layout.addWidget(QPushButton('sdfsdf'))
self.centralWidget().setLayout(self.depart_layout)
def btn1_click(self):
self.btn1.deleteLater()
self.JuminUI()
def btn2_click(self):
self.ju1.deleteLater()
self.btn2.deleteLater()
self.ju_text.deleteLater()
self.DepartmentUI()
if __name__ == "__main__":
app = QApplication(sys.argv)
fream = MainWindow()
fream.show()
app.exec_()

creating and removing widgets is almost always a bad idea, and your code falls into those bad ideas, it's always best to hide the widgets and for that you should use the QStackedWidget, what QStackedWidget does is just make a widget visible on all widgets that you have been assigned by changing the currentIndex.
import sys
from functools import partial
from PyQt5 import QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.center_widget = QtWidgets.QStackedWidget()
self.setCentralWidget(self.center_widget)
self.FirstUI()
self.JuminUI()
self.DepartmentUI()
def FirstUI(self):
widget = QtWidgets.QWidget()
self.btn1 = QtWidgets.QPushButton('test1', widget)
self.btn1.move(50, 50)
self.center_widget.addWidget(widget)
self.btn1.clicked.connect(partial(self.center_widget.setCurrentIndex, 1))
def JuminUI(self):
widget = QtWidgets.QWidget()
lay = QtWidgets.QVBoxLayout(widget)
self.ju1 = QtWidgets.QLineEdit('13')
self.btn2 = QtWidgets.QPushButton('^^^^^^^^^^')
self.ju_text = QtWidgets.QLabel('asd')
lay.addWidget(self.ju_text)
lay.addWidget(self.ju1)
lay.addWidget(self.btn2)
self.center_widget.addWidget(widget)
self.btn2.clicked.connect(partial(self.center_widget.setCurrentIndex, 2))
def DepartmentUI(self):
widget = QtWidgets.QWidget()
lay = QtWidgets.QVBoxLayout(widget)
lay.addWidget(QtWidgets.QPushButton('sdfsdf'))
self.center_widget.addWidget(widget)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
fream = MainWindow()
fream.show()
sys.exit(app.exec_())

PyQt: How to create a scrollable window

I think it should be much easier to create a scrollable window in PyQt.
I have a list of labels that goes out of the window and I would like to scroll down to view them. At the moment the code does not give me an error, but the window just doesn't appear:
class Example(QWidget):
def __init__(self):
super().__init__()
layout = QVBoxLayout()
lbl_arr = makeLabelArr()
for i in range(1,8):
qb = lbl_arr[i]
# qb.setFixedWidth(300)
layout.addWidget(qb)
layout.setAlignment(Qt.AlignTop)
scroll = QScrollArea()
scroll.setWidget(self)
scroll.setWidgetResizable(True)
scroll.setFixedHeight(400)
layout.addWidget(scroll)
self.setLayout(layout)
self.setGeometry(0, 0, 600, 220)
self.setWindowTitle('SnP watchlist')
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
#print(QDesktopWidget().availableGeometry())
ex = Example()
sys.exit(app.exec_())

Make the window itself a QScrollArea, like this:
class Window(QScrollArea):
def __init__(self):
super(Window, self).__init__()
widget = QWidget()
layout = QVBoxLayout(widget)
layout.setAlignment(Qt.AlignTop)
for index in range(100):
layout.addWidget(QLabel('Label %02d' % index))
self.setWidget(widget)
self.setWidgetResizable(True)

There is an example here: https://www.learnpyqt.com/tutorials/qscrollarea/
from PyQt5.QtWidgets import (QWidget, QSlider, QLineEdit, QLabel, QPushButton, QScrollArea,QApplication,
QHBoxLayout, QVBoxLayout, QMainWindow)
from PyQt5.QtCore import Qt, QSize
from PyQt5 import QtWidgets, uic
import sys
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.scroll = QScrollArea() # Scroll Area which contains the widgets, set as the centralWidget
self.widget = QWidget() # Widget that contains the collection of Vertical Box
self.vbox = QVBoxLayout() # The Vertical Box that contains the Horizontal Boxes of labels and buttons
for i in range(1,50):
object = QLabel("TextLabel: "+str(i))
self.vbox.addWidget(object)
self.widget.setLayout(self.vbox)
#Scroll Area Properties
self.scroll.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
self.scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.scroll.setWidgetResizable(True)
self.scroll.setWidget(self.widget)
self.setCentralWidget(self.scroll)
self.setGeometry(600, 100, 1000, 900)
self.setWindowTitle('Scroll Area Demonstration')
self.show()
return
def main():
app = QtWidgets.QApplication(sys.argv)
main = MainWindow()
sys.exit(app.exec_())
if __name__ == '__main__':
main()

You should set layout after adding the scroll bar widget.
class Example(QWidget):
def __init__(self):
super().__init__()
layout = QVBoxLayout()
lbl_arr = makeArrayOfLabelsHTML()
for i in range(1,8):
qb = lbl_arr[i]
layout.addWidget(qb)
layout.setAlignment(Qt.AlignTop)
scroll = QScrollArea()
scroll.setWidget(self)
scroll.setWidgetResizable(True)
scroll.setFixedHeight(400)
layout.addWidget(scroll)
# set layout after adding scroll bar
self.setLayout(layout)
self.setGeometry(0, 0, 600, 220)
self.setWindowTitle('SnP watchlist')
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
#print(QDesktopWidget().availableGeometry())
ex = Example()
sys.exit(app.exec_())