I want the "Add" function to run when I input a number into "LE1" and press the "Enter" key on the keyboard. I also want the line edit to clear its text when I select it for editing.
from PyQt5 import QtWidgets, QtCore
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QLineEdit, QLabel, QGridLayout, QWidget, QDialog
class MyWindow(QtWidgets.QMainWindow):
def __init__(self):
super(MyWindow, self).__init__()
centralWidget = QWidget()
self.setCentralWidget(centralWidget)
self.Glayout = QGridLayout(centralWidget)
self.LE1 = QLineEdit('Input Number',self)
self.LE1.keyPressEvent(self.KPE)
Label1 = QLabel('+ 1 =',self)
self.LE2 = QLineEdit(self)
self.Glayout.addWidget(self.LE1)
self.Glayout.addWidget(Label1)
self.Glayout.addWidget(self.LE2)
def Add(self):
Num = float(self.LE1.text())
math = Num + 1
ans = str(math)
self.LE2.setText(ans)
def KPE(self):
if event.key() == Qt.Key_Enter:
self.Add()
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
window = MyWindow()
window.show()
sys.exit(app.exec_())
keyPressEvent is a method that if you override it that way you are losing the default behavior, besides it is unnecessary since QLineEdit has the returnPressed signal that notifies if Enter is pressed.
On the other hand, converting a string to floating can throw an exception so you should prevent that case, another better option is to use a widget that allows only numerical values with QSpinBox or QDoubleSpinBox, or at least restrict the values that are entered into the QLineEdit with a QValidator appropriate.
And finally do not use the word math as a variable name since that is the name of a library that could cause you problems in the future.
Considering the above, the solution is:
from PyQt5.QtWidgets import (
QApplication,
QGridLayout,
QLineEdit,
QLabel,
QMainWindow,
QWidget,
)
class MyWindow(QMainWindow):
def __init__(self, parent=None):
super(MyWindow, self).__init__(parent)
self.LE1 = QLineEdit("Input Number")
self.LE1.returnPressed.connect(self.add)
Label1 = QLabel("+ 1 =")
self.LE2 = QLineEdit()
centralWidget = QWidget()
self.setCentralWidget(centralWidget)
layout = QGridLayout(centralWidget)
layout.addWidget(self.LE1)
layout.addWidget(Label1)
layout.addWidget(self.LE2)
def add(self):
try:
num = float(self.LE1.text())
num += 1
self.LE2.setText(str(num))
except ValueError:
pass
if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
window = MyWindow()
window.show()
sys.exit(app.exec_())
Related
I use the following code to set a PySide6 app to the minimal possible size. This works fine when increasing the size of the widgets (set - to + in line 37), but not when decreasing it - in effect, the size of the windows does decrease, but it seems to be one step late.
I found a few workarounds, most notably in Qt Layout, resize to minimum after widget size changes, but none of what I tried seems to be working (and I have met other issues with app.processEvents(), which should be avoided anyway).
Edit: In the new code example below, I think the problem is the width of the QPushButton, which is calculated too late.
Interestingly, this width of the QPushButton is solved by the layout.setSizeConstraint(QLayout.SetFixedSize) workaround, but the window width is not.
app.processEvents() works for this example, but I see bad side effects on other signals when using it.
New code example:
from PySide6.QtCore import Qt
from PySide6.QtGui import QPixmap
from PySide6.QtWidgets import (QApplication, QLabel, QLayout, QMainWindow,
QPushButton, QVBoxLayout, QWidget)
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.i = 0
self.button = QPushButton("push me!")
self.button.clicked.connect(self.clicked)
self.label = QLabel()
layout = QVBoxLayout()
layout.addWidget(self.button)
layout.addWidget(self.label)
# https://stackoverflow.com/a/21458822/880783
# layout.setSizeConstraint(QLayout.SetFixedSize) # (ineffective)
widget = QWidget()
widget.setLayout(layout)
self.setCentralWidget(widget)
self.setWindowFlag(Qt.MSWindowsFixedSizeDialogHint)
self.clicked()
self.show()
def clicked(self):
npix = 500 - 50 * self.i
self.label.setPixmap(QPixmap(npix, npix))
# app.processEvents() # (effective, but discouraged)
self.adjustSize()
self.i += 1
app = QApplication()
win = Window()
app.exec()
Original code example:
import threading
import time
from PySide6.QtCore import Qt
from PySide6.QtGui import QPixmap
from PySide6.QtWidgets import (
QApplication,
QHBoxLayout,
QLabel,
QLayout,
QMainWindow,
QWidget,
)
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.label = QLabel()
layout = QHBoxLayout()
layout.addWidget(self.label)
# https://stackoverflow.com/a/21458822/880783
# layout.setSizeConstraint(QLayout.SetFixedSize) # (ineffective)
widget = QWidget()
widget.setLayout(layout)
self.setCentralWidget(widget)
self.setWindowFlag(Qt.MSWindowsFixedSizeDialogHint)
self.show()
def run(self):
for i in range(10):
npix = 500 - 50 * i
self.label.setPixmap(QPixmap(npix, npix))
# app.processEvents() # (ineffective)
self.adjustSize()
time.sleep(1)
app = QApplication()
threading.Thread(target=Window().run).start()
app.exec()
#musicamante has posted very helpful comments, which I now turn into an answer.
Basically, this code works great:
from PySide6.QtCore import QMetaObject, Qt, QTimer, Slot
from PySide6.QtGui import QPixmap
from PySide6.QtWidgets import (QApplication, QLabel, QMainWindow, QPushButton,
QVBoxLayout, QWidget)
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.i = 0
self.button = QPushButton("push me!")
self.button.clicked.connect(self.clicked)
self.label = QLabel()
layout = QVBoxLayout()
layout.addWidget(self.button)
layout.addWidget(self.label)
widget = QWidget()
widget.setLayout(layout)
self.setCentralWidget(widget)
self.setWindowFlag(Qt.MSWindowsFixedSizeDialogHint)
self.clicked()
self.show()
# #Slot()
# def adjustSize(self):
# super().adjustSize()
def clicked(self):
npix = 500 - 50 * self.i
self.label.setPixmap(QPixmap(npix, npix))
self.i += 1
# # As in https://stackoverflow.com/a/23954088/880783 - does not work
# QMetaObject.invokeMethod(self, "adjustSize")
# This works!
QTimer.singleShot(0, self.adjustSize)
app = QApplication()
win = Window()
app.exec()
As one can see, I have also tried the approach put forward https://stackoverflow.com/a/23954088/880783 - without success, however.
I'm trying to integrate QFontComboBox within Qmenu.
I try to make two things happen when selecting a particular font from the menu:
The Qmenu will close.
print the selected font.
from PyQt5.QtCore import QObject
from PyQt5.QtGui import QIcon, QFont, QCursor
from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QFontComboBox, QWidgetAction, QMenu, QPushButton
class Window(QWidget):
def __init__(self):
super().__init__()
self.setWindowTitle("Pyside2 FontCombo Box")
self.setGeometry(300,200,300,250)
self.setFontBox()
self.setIcon()
self.show()
def setIcon(self):
appIcon = QIcon("icon.png")
self.setWindowIcon(appIcon)
def setFontBox(self):
self.font_button = QPushButton(self)
self.font_button.setFixedWidth(300)
self.font_button.clicked.connect(lambda: self.setFontmenu())
vbox = QVBoxLayout()
vbox.addWidget(self.font_button)
self.setLayout(vbox)
def setFontmenu(self):
font_menu = QMenu()
font_submenu = QFontComboBox()
font_submenu.setCurrentFont(QFont("Arial"))
objectTest = QObject()
widget = QWidgetAction(objectTest)
widget.setDefaultWidget(font_submenu)
font_menu.addAction(widget)
font_menu.exec_(QCursor.pos())
menu = font_menu
menu.addSeparator()
font_submenu.showPopup()
font_submenu.setFocus()
font_submenu.currentFontChanged.connect(self._changed)
def _changed(self):
font = self.currentFont().family()
print(font)
return
myapp = QApplication(sys.argv)
window = Window()
myapp.exec_()
sys.exit()
How can I make sure that the do_something() function is called only when QListWidgetItem "Item 1" is clicked, but not QListWidgetItem "Item 2"?
In the implementation below, do_something() function is called each time I click on either of the items.
from PyQt5.QtWidgets import QApplication, QWidget, QListWidget, QHBoxLayout, QListWidgetItem
import sys
class Window(QWidget):
def __init__(self):
super().__init__()
self.list_widget = QListWidget()
self.layout = QHBoxLayout()
self.layout.addWidget(self.list_widget)
self.list_widget.insertItem(1, QListWidgetItem("Item 1"))
self.list_widget.insertItem(2, QListWidgetItem("Item 2"))
self.list_widget.itemClicked.connect(self.do_something)
self.setLayout(self.layout)
self.show()
def do_something(self):
print("It was clicked on item 1")
App = QApplication(sys.argv)
window = Window()
sys.exit(App.exec())
The solution is to obtain the row of the pressed item and verify that it is 0:
from PyQt5.QtCore import pyqtSlot
# ...
#pyqtSlot("QListWidgetItem*")
def do_something(self, item):
if self.list_widget.row(item) == 0:
print("It was clicked on item 1")
How do I print in multiple QLabel when I click the PushButton?, because it only works in Quantity I also want it in Item Name and Price. I tried putting multiple print_click(self) it wont work it say redefinition of unused 'print_clink'. Thanks in advance
My Code:
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QHBoxLayout, QPushButton, QLabel, QLineEdit
from PyQt5.QtCore import pyqtSlot`
class Window(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.ItemName = QLabel('Item Name:')
self.Item_Line = QLabel('')
self.Item_Name = QLineEdit('')
self.PriceName = QLabel('Price:')
self.Price_Line = QLabel('')
self.Price_Name = QLineEdit('')
self.QuantityName = QLabel('Quantity:')
self.Quantity_Line = QLabel('0')
self.Quantity_Name = QLineEdit()
self.Update_button = QPushButton("Update")
self.Update_button.clicked.connect(self.print_click)
self.Clear_button = QPushButton("Clear")
self.Clear_button.clicked.connect(self.clear_click)
hbox = QHBoxLayout(self)
hbox.addWidget(self.ItemName)
hbox.addWidget(self.Item_Name)
hbox.addWidget(self.PriceName)
hbox.addWidget(self.Price_Name)
hbox.addWidget(self.QuantityName)
hbox.addWidget(self.Quantity_Line)
hbox.addWidget(self.Quantity_Name)
hbox.addWidget(self.Update_button)
hbox.addWidget(self.Clear_button)
self.show()
self.Clear_button.clicked.connect(self.Item_Line.clear)
self.Clear_button.clicked.connect(self.Item_Name.clear)
self.Clear_button.clicked.connect(self.Price_Line.clear)
self.Clear_button.clicked.connect(self.Price_Name.clear)
self.Clear_button.clicked.connect(self.Quantity_Line.clear)
self.Clear_button.clicked.connect(self.Quantity_Name.clear)
#pyqtSlot()
def print_click(self):
self.Quantity_Line.setText(self.Quantity_Name.text())
def clear_click(self):
self.Quantity_Line(self.Quantity_Name.text(''))
return self.Quantity
if __name__ == "__main__":
app = QApplication(sys.argv)
win = Window()
sys.exit(app.exec_())
I'm not completely sure of the expected result but I guess there are some mistakes and redundancies in your code :
the Price_Line and Item_Line weren't added to the QHBoxLayout
the method print_click wasn't setting the text from Price_Name and Item_Name on the respective Price_Line and Item_Line.
the clear_click method wasn't really useful as you already connected the clear method of every other elements on that button.
The following code is adapted from yours, paying attention to the points mentioned above :
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QHBoxLayout, QPushButton, QLabel, QLineEdit
from PyQt5.QtCore import pyqtSlot
class Window(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.ItemName = QLabel('Item Name:')
self.Item_Line = QLabel('')
self.Item_Name = QLineEdit()
self.PriceName = QLabel('Price:')
self.Price_Line = QLabel('')
self.Price_Name = QLineEdit()
self.QuantityName = QLabel('Quantity:')
self.Quantity_Line = QLabel('0')
self.Quantity_Name = QLineEdit()
self.Update_button = QPushButton("Update")
self.Update_button.clicked.connect(self.print_click)
self.Clear_button = QPushButton("Clear")
hbox = QHBoxLayout(self)
hbox.addWidget(self.ItemName)
hbox.addWidget(self.Item_Line)
hbox.addWidget(self.Item_Name)
hbox.addWidget(self.PriceName)
hbox.addWidget(self.Price_Line)
hbox.addWidget(self.Price_Name)
hbox.addWidget(self.QuantityName)
hbox.addWidget(self.Quantity_Line)
hbox.addWidget(self.Quantity_Name)
hbox.addWidget(self.Update_button)
hbox.addWidget(self.Clear_button)
self.show()
self.Clear_button.clicked.connect(self.Item_Line.clear)
self.Clear_button.clicked.connect(self.Item_Name.clear)
self.Clear_button.clicked.connect(self.Price_Line.clear)
self.Clear_button.clicked.connect(self.Price_Name.clear)
self.Clear_button.clicked.connect(self.Quantity_Line.clear)
self.Clear_button.clicked.connect(self.Quantity_Name.clear)
def print_click(self):
self.Price_Line.setText(self.Price_Name.text())
self.Item_Line.setText(self.Item_Name.text())
self.Quantity_Line.setText(self.Quantity_Name.text())
if __name__ == "__main__":
app = QApplication(sys.argv)
win = Window()
sys.exit(app.exec_())
I am migrating some code from pyGObject to pyQT4 and I make use of set_progress_fraction as a means to indication the percentage of the MAXIMUM the inputted value is.
I am trying to find an equivalent in pyQT4 but I am failing.
QLineEdit does have a paint method so is the only real way to "paint" the LineEdit?
--edit--
example of the gtk equiv:
& snippit of my present pyGObject code
def on_entry_change(self,widget,*args):
try:
tmp = float(widget.get_text())
tmp = (tmp- widget.min_bin)/(widget.max_bin - widget.min_bin)
widget.set_progress_fraction(tmp)
except:
return
I think you want to connect the value in the QLineEdit to a method that modifies the progress bar. This might help:
from __future__ import division
import sys
from PyQt4.QtCore import (Qt, SIGNAL)
from PyQt4.QtGui import (QApplication, QDialog, QLineEdit,
QVBoxLayout, QProgressBar, QWidget, QLabel)
class Form(QWidget):
def __init__(self, parent=None):
super(Form, self).__init__(parent)
self.barA = QProgressBar()
self.maximum = 200
self.label1 = QLabel('Maximum = 200')
self.seqM = QLineEdit("num")
layoutO = QVBoxLayout() #set overal layout
layoutO.addWidget(self.label1)
layoutO.addWidget(self.barA)
layoutO.addWidget(self.seqM)
self.setLayout(layoutO)
self.connect(self.seqM, SIGNAL("returnPressed()"), self.updatebar)
def updatebar(self):
try:
currval = float(self.seqM.text())
except:
print 'enter float or integer only'
self.track = (currval/self.maximum)*100
self.barA.setValue(self.track)
app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()`