How to align a QPushButton inside window? - python

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_())

Related

Have QScrollArea react on wheelEvent, also in space taken up by children?

Consider this example:
#!/usr/bin/env python
import sys,os
from PyQt5 import QtCore, QtWidgets, QtGui
from PyQt5.QtCore import Qt
class MainWindow(QtWidgets.QMainWindow):
class ScrollAreaWheel(QtWidgets.QScrollArea): # SO:9475772
def __init__(self, parent=None):
super(MainWindow.ScrollAreaWheel, self).__init__(parent)
self.parent = parent
def wheelEvent(self, event):
print("wheelEvent", event.angleDelta().y())
def __init__(self):
#~ self.do_init = QtCore.QEvent.registerEventType()
QtWidgets.QMainWindow.__init__(self)
self.setMinimumWidth(1000)
self.setMinimumHeight(400)
self.frame1 = QtWidgets.QFrame(self)
self.frame1.setFrameShape(QtWidgets.QFrame.StyledPanel)
self.frame1layout = QtWidgets.QGridLayout(self.frame1)
self.frame1layout.setSpacing(0);
self.frame1layout.setContentsMargins(0,0,0,0);
self.frame1widget = QtWidgets.QWidget()
self.frame1widget.setLayout(QtWidgets.QGridLayout())
self.frame1layout.addWidget(self.frame1widget)
self.frame1scroll = MainWindow.ScrollAreaWheel(self) #QtWidgets.QScrollArea()
self.frame1scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
self.frame1scroll.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
self.frame1widget.layout().addWidget(self.frame1scroll, 0, 0) #, Qt.AlignCenter)
#self.frame1scrolllayout = QtWidgets.QHBoxLayout(self.frame1scroll)
self.frame1scrolllayout = QtWidgets.QGridLayout(self.frame1scroll)
self.frame1scroll.setWidget(self.frame1scrolllayout.widget())
self.frame1scroll.setWidgetResizable(True)
self.frame1scroll.setAlignment(Qt.AlignCenter)
self.frame1label = QtWidgets.QLabel()
self.frame1scrolllayout.addWidget(self.frame1label, 0, 0, Qt.AlignCenter) ##
pixmap = QtGui.QPixmap(200, 100)
pixmap.fill(Qt.red)
self.frame1label.setPixmap(pixmap)
self.frame2 = QtWidgets.QFrame(self)
self.frame2.setFrameShape(QtWidgets.QFrame.StyledPanel)
self.frame2layout = QtWidgets.QHBoxLayout(self.frame2)
self.frame2layout.setSpacing(0);
self.frame2layout.setContentsMargins(0,0,0,0);
self.frame2scroll = QtWidgets.QScrollArea(self)
self.frame2scroll.setWidgetResizable(True)
self.frame2widget = QtWidgets.QWidget()
self.frame2widget.setLayout(QtWidgets.QGridLayout())
self.frame2scroll.setWidget(self.frame2widget)
self.frame2layout.addWidget(self.frame2scroll)
self.mainwid = QtWidgets.QWidget()
self.mainwid.setLayout(QtWidgets.QGridLayout())
self.setCentralWidget(self.mainwid)
self.splitter1 = QtWidgets.QSplitter(Qt.Horizontal)
self.splitter1.addWidget(self.frame1)
self.splitter1.addWidget(self.frame2)
self.splitter1.setSizes([600, 600]); # equal splitter at start
self.mainwid.layout().addWidget(self.splitter1)
self.mainwid.layout().update()
if __name__ == "__main__":
app = QtWidgets.QApplication([])
main = MainWindow()
main.show()
sys.exit(app.exec_())
It generates this (Ubuntu 18.04):
I want to use mousewheel only on the left QScrollArea, for which I've made a separate class. However, its wheelEvent fires only when I'm outside the red box, not when I hover over it. How can I make ScrollAreaWheel.wheelEvent fire even when mouse is over the child label (the red box)?
You are the QLabel placing on top of the QScrollArea instead of placing it inside, visually it is the same but at the level of events it is not.
from PyQt5 import QtCore, QtGui, QtWidgets
class ScrollAreaWheel(QtWidgets.QScrollArea):
def wheelEvent(self, event):
print("wheelEvent", event.angleDelta().y())
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setMinimumSize(1000, 400)
frame1 = QtWidgets.QFrame(frameShape=QtWidgets.QFrame.StyledPanel)
scrollarea1 = ScrollAreaWheel(widgetResizable=True)
scrollarea1.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
scrollarea1.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
widget1 = QtWidgets.QWidget()
scrollarea1.setWidget(widget1)
label_lay = QtWidgets.QGridLayout(widget1)
lay1 = QtWidgets.QVBoxLayout(frame1)
lay1.addWidget(scrollarea1)
pixmap = QtGui.QPixmap(200, 100)
pixmap.fill(QtCore.Qt.red)
label = QtWidgets.QLabel(pixmap=pixmap)
label_lay.addWidget(label, 0, 0, QtCore.Qt.AlignCenter)
#==============================
frame2 = QtWidgets.QFrame(frameShape=QtWidgets.QFrame.StyledPanel)
scrollarea2 = QtWidgets.QScrollArea(widgetResizable=True)
scrollarea2.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
scrollarea2.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
widget2 = QtWidgets.QWidget()
scrollarea2.setWidget(widget2)
splitter = QtWidgets.QSplitter(QtCore.Qt.Horizontal)
splitter.addWidget(frame1)
splitter.addWidget(frame2)
splitter.setSizes([600, 600])
self.setCentralWidget(splitter)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.resize(640, 480)
w.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.

mouseMoveEvent() while cursor is on button

I have to activate some function, when the cursor is moving. So, I used self.setMouseTracking(True) in MainWidget. But in this way mouseMoveEvent() works only when there is an empty form under cursor. I tried to create another widget over main, but it doesnt work at all.
class ClickButton(QPushButton):
def __init__(self, text, window):
...
def run(self):
...
class Window(QWidget):
def __init__(self):
super().__init__()
self.setGeometry(0, 0, 1000, 1000)
self.setMouseTracking(True)
self.clickers = [ClickButton('OK', self) for i in range(8)]
def mouseMoveEvent(self, ev):
for e in self.clickers:
e.run()
Whats to do?
If you want to detect the position of the mouse even when the mouse is on top of a child, a possible option is to use an event filter.
from PyQt5 import QtCore, QtGui, QtWidgets
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
w_ = QtWidgets.QWidget()
lay_w = QtWidgets.QHBoxLayout(w_)
for c in (QtWidgets.QPushButton(), QtWidgets.QLineEdit()):
lay_w.addWidget(c)
lay = QtWidgets.QVBoxLayout(self)
for w in (QtWidgets.QPushButton(), QtWidgets.QLineEdit(), QtWidgets.QTextEdit(), w_):
lay.addWidget(w)
for ws in self.findChildren(QtWidgets.QWidget) + [self]:
ws.setMouseTracking(True)
ws.installEventFilter(self)
def eventFilter(self, obj, event):
if event.type() == QtCore.QEvent.MouseMove:
p_respect_to_window = self.mapFromGlobal(obj.mapToGlobal(event.pos()))
print(p_respect_to_window)
return super(Widget, self).eventFilter(obj, event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
On the other hand if you only want to do it in only one type of custom widget it is better to overwrite the mouseMoveEvent method of the custom widget:
from PyQt5 import QtCore, QtGui, QtWidgets
class ClickButton(QtWidgets.QPushButton):
def __init__(self, text, parent=None):
super(ClickButton, self).__init__(text=text, parent=parent)
self.setMouseTracking(True)
def mouseMoveEvent(self, event):
self.run()
super(ClickButton, self).mouseMoveEvent(event)
def run(self):
print("call to run function in button{} and time: {}".format(self.text(),
QtCore.QDateTime.currentDateTime().toString()))
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
lay = QtWidgets.QVBoxLayout(self)
for i in range(10):
w = ClickButton(str(i), self)
lay.addWidget(w)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())

PyQt - Custom scrolling with QListWidget

I am trying to figure out a way to customize the scrollbars for QListWidget to have the scrollbars above and below the QListWidget instead of the normal vertical and horizontal scrollbars.
Please check out my example below if you don't understand what I mean.
In the example below I use QPushButtons with QTimers controlling the scrolling in place of the scrollbars but what I am looking for are scrollbars like the ones in QMenu when menu scrolling is enabled.
If that is not an option, I am wondering if there is a scrollbar signal or something that I could try to use to know when the scrollbars are normally activated? That way I can show/hide the buttons as needed. Thanks.
import sys
from PyQt5.QtCore import pyqtSignal, QTimer, Qt
from PyQt5.QtGui import QPainter
from PyQt5.QtWidgets import QWidget, QPushButton, QVBoxLayout, \
QApplication, QStyle, QListWidget, QStyleOptionButton, QListWidgetItem
class UpBtn(QPushButton):
mouseHover = pyqtSignal()
def __init__(self):
QPushButton.__init__(self)
self.setMouseTracking(True)
self.timer = QTimer()
def paintEvent(self, event):
painter = QPainter()
painter.begin(self)
opt = QStyleOptionButton()
self.initStyleOption(opt)
self.style().drawControl(QStyle.CE_ScrollBarSubLine, opt, painter, self)
painter.end()
def startScroll(self):
self.mouseHover.emit()
def enterEvent(self, event):
self.timer.timeout.connect(self.startScroll)
self.timer.start(120)
def leaveEvent(self, event):
self.timer.stop()
class DwnBtn(QPushButton):
mouseHover = pyqtSignal()
def __init__(self):
QPushButton.__init__(self)
self.setMouseTracking(True)
self.timer = QTimer()
def paintEvent(self, event):
painter = QPainter()
painter.begin(self)
opt = QStyleOptionButton()
self.initStyleOption(opt)
self.style().drawControl(QStyle.CE_ScrollBarAddLine, opt, painter, self)
painter.end()
def startScroll(self):
self.mouseHover.emit()
def enterEvent(self, event):
self.timer.timeout.connect(self.startScroll)
self.timer.start(120)
def leaveEvent(self, event):
self.timer.stop()
class Window(QWidget):
def __init__(self):
super(Window, self).__init__()
self.layout = QVBoxLayout()
self.layout.setContentsMargins(0, 0, 0, 0)
self.layout.setSpacing(0)
self.upBtn = UpBtn()
self.upBtn.setFixedWidth(230)
self.layout.addWidget(self.upBtn)
self.listWidget = QListWidget()
self.listWidget.setFixedWidth(230)
self.listWidget.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.listWidget.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.layout.addWidget(self.listWidget)
self.downBtn = DwnBtn()
self.downBtn.setFixedWidth(230)
self.layout.addWidget(self.downBtn)
self.setLayout(self.layout)
self.upBtn.clicked.connect(self.upBtnClicked)
self.upBtn.mouseHover.connect(self.upBtnClicked)
self.downBtn.clicked.connect(self.downBtnClicked)
self.downBtn.mouseHover.connect(self.downBtnClicked)
for i in range(100):
item = QListWidgetItem()
item.setText("list item " + str(i))
self.listWidget.addItem(item)
def upBtnClicked(self):
cur = self.listWidget.currentRow()
self.listWidget.setCurrentRow(cur - 1)
def downBtnClicked(self):
cur = self.listWidget.currentRow()
self.listWidget.setCurrentRow(cur + 1)
if __name__ == '__main__':
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
EDIT:
Here is an example image for what I am talking about. This is a scrollable QMenu.
EDIT:
Scrollable QMenu code.
Uncomment the commented parts to get a fixed size like in the image. Normally Qmenu scrolling only works when the menu items exceed the screen height. I am just looking for the top and bottom hover style scrolling but to be used in QListWidget.
import sys
from PyQt5.QtCore import QPoint, QEvent
from PyQt5.QtWidgets import QWidget, QPushButton, QVBoxLayout, \
QApplication, QAction, QMenu, QProxyStyle, QStyle
class MyMenu(QMenu):
def event(self, event):
if event.type() == QEvent.Show:
self.move(self.parent().mapToGlobal(QPoint(-108, 0)))
return super(MyMenu, self).event(event)
# class CustomStyle(QProxyStyle):
# def pixelMetric(self, QStyle_PixelMetric, option=None, widget=None):
# if QStyle_PixelMetric == QStyle.PM_MenuScrollerHeight:
# return 15
# if QStyle_PixelMetric == QStyle.PM_MenuDesktopFrameWidth:
# return 290
# else:
# return QProxyStyle.pixelMetric(self, QStyle_PixelMetric, option, widget)
class MainWindow(QWidget):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.layout = QVBoxLayout()
self.btn = QPushButton("Button")
self.btn.setFixedHeight(30)
self.btn.setFixedWidth(100)
self.myMenu = MyMenu("Menu", self.btn)
self.btn.setMenu(self.myMenu)
self.layout.addWidget(self.btn)
self.setLayout(self.layout)
menus = []
for _ in range(5):
myMenus = QMenu("Menu"+str(_+1), self.btn)
# myMenus.setFixedHeight(120)
myMenus.setStyleSheet("QMenu{menu-scrollable: 1; }")
menus.append(myMenus)
for i in menus:
self.btn.menu().addMenu(i)
for item in range(100):
action = QAction("item" + str(item), self)
i.addAction(action)
if __name__ == '__main__':
app = QApplication(sys.argv)
# app.setStyle(CustomStyle())
w = MainWindow()
w.show()
app.exec_()
The idea is to obtain the row of the upper and lower element that will decide whether the buttons are hidden or not, for that we use the method itemAt () that returns the item given the geometrical coordinates. On the other hand I have improved this calculation has to do every time they change the number of items in the QListView for that we use the signals of the internal model.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class Button(QtWidgets.QPushButton):
moveSignal = QtCore.pyqtSignal()
def __init__(self, *args, **kwargs):
super(Button, self).__init__(*args, **kwargs)
self.m_timer = QtCore.QTimer(self, interval=120)
self.m_timer.timeout.connect(self.moveSignal)
self.setMouseTracking(True)
self.setFixedHeight(20)
def mouseReleaseEvent(self, e):
super(Button, self).mousePressEvent(e)
self.setDown(True)
def enterEvent(self, e):
self.setDown(True)
self.m_timer.start()
super(Button, self).enterEvent(e)
def leaveEvent(self, e):
self.setDown(False)
self.m_timer.stop()
super(Button, self).leaveEvent(e)
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.setFixedWidth(230)
icon = self.style().standardIcon(QtWidgets.QStyle.SP_ArrowUp)
self.upBtn = Button(icon=icon)
self.upBtn.moveSignal.connect(self.moveUp)
icon = self.style().standardIcon(QtWidgets.QStyle.SP_ArrowDown)
self.downBtn = Button(icon=icon)
self.downBtn.moveSignal.connect(self.moveDown)
self.listWidget = QtWidgets.QListWidget()
self.listWidget.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.listWidget.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
layout = QtWidgets.QVBoxLayout(self)
layout.setContentsMargins(0, 0, 0, 0)
layout.setSpacing(0)
layout.addWidget(self.upBtn)
layout.addWidget(self.listWidget)
layout.addWidget(self.downBtn)
self.adjust_buttons()
self.create_connections()
def create_connections(self):
self.listWidget.currentItemChanged.connect(self.adjust_buttons)
model = self.listWidget.model()
model.rowsInserted.connect(self.adjust_buttons)
model.rowsRemoved.connect(self.adjust_buttons)
model.rowsMoved.connect(self.adjust_buttons)
model.modelReset.connect(self.adjust_buttons)
model.layoutChanged.connect(self.adjust_buttons)
#QtCore.pyqtSlot()
def adjust_buttons(self):
first = self.listWidget.itemAt(QtCore.QPoint())
r = self.listWidget.row(first)
self.upBtn.setVisible(r != 0 and r!= -1)
last = self.listWidget.itemAt(self.listWidget.viewport().rect().bottomRight())
r = self.listWidget.row(last)
self.downBtn.setVisible( r != (self.listWidget.count() -1) and r != -1)
#QtCore.pyqtSlot()
def moveUp(self):
ix = self.listWidget.moveCursor(QtWidgets.QAbstractItemView.MoveUp, QtCore.Qt.NoModifier)
self.listWidget.setCurrentIndex(ix)
#QtCore.pyqtSlot()
def moveDown(self):
ix = self.listWidget.moveCursor(QtWidgets.QAbstractItemView.MoveDown, QtCore.Qt.NoModifier)
self.listWidget.setCurrentIndex(ix)
#QtCore.pyqtSlot(str)
def add_item(self, text):
item = QtWidgets.QListWidgetItem(text)
self.listWidget.addItem(item)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
window = Window()
for i in range(100):
window.add_item("item {}".format(i))
window.show()
sys.exit(app.exec_())

How to define a mousePressEvent function for a QTextEdit widget without subclassing it?

class widget(QWidget):
...
self.edit=QTextEdit()
def mousePressEvent(self, event):
if event.button()==Qt.LeftButton:
print('test')
self.edit.mousePressEvent(event)
I have tried that but it does not work. It works for the parent widget. Is there anyway I can do it without subclassing the QTextEdit?
In this case you must use an eventFilter in addition to the classes that inherit from QAbstractScrollArea as QTextEdit you must use the viewport():
from PyQt5 import QtCore, QtWidgets
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
self.edit = QtWidgets.QTextEdit()
btn = QtWidgets.QPushButton()
le = QtWidgets.QLineEdit()
lay = QtWidgets.QVBoxLayout(self)
for w in (self.edit, btn, le):
lay.addWidget(w)
self.edit.viewport().installEventFilter(self)
def eventFilter(self, obj, event):
if obj is self.edit.viewport() and event.type() == QtCore.QEvent.MouseButtonPress:
if event.button() == QtCore.Qt.LeftButton:
print('test')
return super(Widget, self).eventFilter(obj, event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())

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