Develop Reference

Detect Ctrl+S ion QTextedit?

So, I'm making a QTextEdit that edits a text file. I got the loading and saving working fine with buttons. But I got the habit of pressing Ctrl+S to save every time I paste something into the textedit because I used that in Notepad before. So I've been trying to implement it. But I can't wrap my head around how to detect and execute my save function. Lets call it savetext.
I've been going around trying to get keyPressEvent to work, but I just don't understand how it works. So I've been pretty helpless in trying to learn it.
My heavily simplified code looks like this:
class GUI(QProcess):
def init etc...
"Button creations and connect to save/load function"
self.textedit=QTextEdit()
def savetext(self):
code
def loadtext(self):
code
Now, how do I detect a key combination being detected in the QTextEdit, or anywhere in my program for that matter, and cause it to do savetext? In my case, Ctrl+S, though I'd just love a general explanation so I could apply it to any combo.

Use QShortcut and QKeySequence
from PyQt5.QtWidgets import QApplication, QTextEdit, QShortcut
from PyQt5.QtGui import QKeySequence
import sys
def slot():
print("Ctrl+S")
app = QApplication(sys.argv)
textedit=QTextEdit()
shortcut = QShortcut(QKeySequence("Ctrl+S"), textedit)
shortcut.activated.connect(slot)
textedit.show()
sys.exit(app.exec_())

You can probably use QShortcut, and right now it will activate only when textedit in focus. If you want to change the behavior please take a look here
Here is a example
import sys
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
layout = QtGui.QVBoxLayout(self)
self.edit = QtGui.QTextEdit()
layout.addWidget(self.edit)
self.button = QtGui.QPushButton('Test')
layout.addWidget(self.button)
foo = QtGui.QShortcut(QtGui.QKeySequence("Ctrl+S"), self.edit, self.saveCall, context=QtCore.Qt.WidgetShortcut)
def saveCall(self):
self.edit.append('Please save me')
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
win = Window()
win.show()
sys.exit(app.exec_())

Python3 and Qt Designer - Display an image in main window

I'm still new with python and Qt designer. I would like to develop an application where user need to press the 'pushbutton' in order to view the image(from local directory path) on GUI mainwindow.This will keep repeating until complete number of cycle.
Did tried using QLabel and QGraphiscView widget but doesn't work.(probably due to lack of knowledge). Could anyone help me to solve it?
Below is the code:
#!/usr/bin/env python
from __future__ import division
import sys
from PyQt4 import QtCore, QtGui, uic
gui_file = 'image.ui'
Ui_MainWindow, QtBaseClass = uic.loadUiType(gui_file)
class showImage(QtGui.QMainWindow,Ui_MainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
Ui_MainWindow.__init__(self)
self.setupUi(self)
self.get_image_button.clicked.connect(self.getImage)
def getImage(self):
image_path='c:/Users/mohd_faizal4/Desktop/Python/Image/image1.jpg' #path to image file
self.label_image.QPixmap(image_path)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
myWindow = showImage()
myWindow.show()
sys.exit()
app.exec_()
Really appreciate!

PyQt app crashes on exit (Python 3.4.3 / PyQt5 / Windows 10)

I realize this is a bit of a vague question, but I'm not sure how to make it more specific.
The skeleton for my code is below:
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
class FormWidget(QWidget):
def __init__(self, parent):
super(FormWidget, self).__init__(parent)
class MainWindow(QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
form = FormWidget(self)
self.setCentralWidget(form)
[do a bunch of stuff with form]
if __name__ == '__main__':
app = QApplication(sys.argv)
mainWindow = MainWindow()
mainWindow.show()
sys.exit(app.exec_())
Within the FormWidget class, there is a keyPressEvent() method that traps keyboard input, and on a specific key ('q'), calls this:
mainWindow.close()
Most of the time, that causes the app to exit, as desired. But occasionally (with no predictable pattern that I can discern), it causes a crash (dialog comes up that says 'python.exe has stopped working', with a 'Close program' button).
First question, I guess, is: Is this not the proper way to terminate a PyQt GUI app?
If it is, then second question is: Presumably, my code is misbehaving somewhere. But I'm not sure what sort of misbehavior to be looking for. What sort of mistake could I be making that would cause this?
Any thoughts appreciated.
/John

Access QT Designer Objects Programmatically

Disclaimer: New to both python and qt designer
QT Designer 4.8.7
Python 3.4
PyCharm 5.0.3
Question - How do I add controls to the main form or a scroll area widget on the main form (created in QT Designer) programmatically?
I have created a MainWindow in qt designer and added my widgets. The following is the entire test program in PyCharm:
import sys
from PyQt4 import QtGui, QtCore, uic
from PyQt4.QtGui import *
from PyQt4.QtCore import *
qtCreatorFile = "programLauncher.ui"
Ui_MainWindow, QtBaseClass = uic.loadUiType(qtCreatorFile)
class MyApp(QtGui.QMainWindow, Ui_MainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
Ui_MainWindow.__init__(self)
self.setupUi(self)
# Cannot resize or maximize
self.setFixedSize(1045, 770)
# Add button test
self.dateLabel = QtGui.QLabel("Test")
self.pushButton = QtGui.QPushButton('Test button')
# self.scrollArea_programs.addWidget()
grid = QtGui.QGridLayout()
# self.scrollArea_programs.addWidget(self.pushButton)
grid.addWidget(self.dateLabel,0,0)
grid.addWidget(self.pushButton,0,1)
self.setLayout(grid)
self.pushButton_exit.clicked.connect(self.closeEvent)
def closeEvent(self):
QtGui.QApplication.quit()
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
window = MyApp()
window.show()
sys.exit(app.exec_())
As you can see I tried to add controls to a grid but nothing shows up when the program runs - I have also tried to add a control to the scroll area. Can someone help me to just add 1 control to the scroll area at run time - so then I can know the proper way to do it or "a" proper way to do this.
Thanks in advance

Without having access to your programLauncher.ui and making minimal changes to your posted code, you can add your UI elements to the window like so:
from PyQt4 import QtGui
import sys
class MyApp(QtGui.QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
# Cannot resize or maximize
self.setFixedSize(1045, 770)
widget = QtGui.QWidget(self)
self.setCentralWidget(widget)
# Add button test
self.dateLabel = QtGui.QLabel("Test")
self.pushButton = QtGui.QPushButton('Test button')
grid = QtGui.QGridLayout()
grid.addWidget(self.dateLabel, 0, 0)
grid.addWidget(self.pushButton, 0, 1)
widget.setLayout(grid)
self.pushButton.clicked.connect(self.closeEvent)
def closeEvent(self, event):
QtGui.QApplication.quit()
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
window = MyApp()
window.show()
sys.exit(app.exec_())
This will get the controls on the screen, although the layout leaves a lot to be desired. You may have to make modifications to this based on what's in your .ui file. One thing that you'll want to note in this example is that the QMainWindow needs a central widget (widget in the example above). You then set the layout on that widget.

You can use the designer to create your .ui file
The you can load it in your .py using something like:
from PyQt4 import QtCore, QtGui, uic
class my_win(QtGui.QMainWindow):
def __init__(self):
self.ui = uic.loadUi('my_ui.ui',self)
then you can access all your widgets with something like
self.ui.actionQuit.triggered.connect(QtGui.qApp.quit)
or
self.ui.my_button.triggered.connect(self.do_someting)

Thanks to JCVanHamme (the programLauncher.ui hint) and also outside help I now learned most of what I need to know to access MainWindow at run time. So for anyone interested in this beginner tip:
Take a blank form in QT Designer
Add a control
Run pyuic4 batch file
Take a look at the generated .py file to learn EVERYTHING about how to add controls.
Don't let the power go to your head - cheers

How do I open sub window after I click on button on main screen in PyQt4

HI I am trying to make a simple converter.
I have used PyQt4 designed to make the Gui
I want to know how launch a new window after I click on the individual button.
This is the interface I have created using PyQt4 Designer.
Here is the Image link :
and I want to launch this windows when I click on currency button.
Here is the Image Link:
Here is my code for main.py
from PyQt4 import QtGui
from main_screen import mainscreen
def main():
import sys
qApp = QtGui.QApplication(sys.argv)
aw = mainscreen()
aw.show()
sys.exit(qApp.exec_())
if __name__ == '__main__':
main()
and code for mainscreen.py
from PyQt4 import QtCore, QtGui
from window_main import Ui_MainWindow
class mainscreen(QtGui.QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
super(mainscreen,self).__init__(parent)
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
How can I open new window after I click on currency button (object name for currency button is "currency_bt")
and do I have to write the code for currency in same window or I have to write in new window.
How do I do it.
I am new to Python Gui programming.

Each GUI form that you create in Qt Designer needs to be converted into a python module using pyuic. So, to start with, you need to do the same for currency.ui that you did for window_main.
Now you can import your currency window class into mainscreen.py, and connect a button to handler so you can display it.
The code would look something like this:
from PyQt4 import QtCore, QtGui
from window_main import Ui_MainWindow
from currency import Ui_CurrencyWindow
class CurrencyWindow(QtGui.QMainWindow, Ui_CurrencyWindow):
def __init__(self, parent=None):
super(CurrencyWindow, self).__init__(parent)
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
self.setupUi(self)
class MainScreen(QtGui.QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
super(MainScreen, self).__init__(parent)
self.setupUi(self)
self.currencyButton.clicked.connect(self.handleCurrencyButton)
def handleCurrencyButton(self):
window = CurrencyWindow(self)
window.show()
After looking at this example code, it will probably occur to you that you are going to end up importing a lot of modules, and have a lot of boiler-plate code to write for each one of them (which is not much fun).
So I would advise you to consider changing your GUI design, so that you have one main window containing a tabwidget, and then have a separate tab for each of your converters. This will not only make your application much easier to write, but it should also make it a lot nicer to use.

I'm making my bachelor thesis in PyQt4. First I also wanted to use the designer (generating code is nice), but afterall I was not using it during my work. Maybe it's a matter of taste.
But for your question (I did this without the QtDesigner):
Let's say we have a main window class:
import sys
from PyQt4 import QtCore, QtGui
class mainscreen(QtGui.QMainWindow):
def __init__(self, parent=None):
super(mainscreen,self).__init__(parent)
self.button = QtGui.QPushButton("push")
self.button.clicked.connect(self.pushed)
#pyqtSlot()
def pushed(self):
# in this section here you can create the new window and show it
qApp = QtGui.QApplication(sys.argv)
aw = mainscreen()
aw.show()
sys.exit(qApp.exec_())
There are some good tutorials (http://zetcode.com/gui/pyqt4/ helped me getting started).

Make two programs: main_win.py and second_win.py, then in main_win.py put this lines:
from os import system as sh //In the begin
def openewin(self): //In the class main_win
sh("python second_win.py")
Ready, just connect the push button to function openewin!