I think I found the solution. All credit goes to Mr. Harrison who made the Python tutorial website https://pythonprogramming.net. He helped me out. So here is what I did. Two major changes: 1. Structural change I previously had two classes: CustomGraph(TimedAnimation) and CustomFigCanvas(FigureCanvas). Now I got only one left, but he inherits from both TimedAnimation … Read more
Create a custom signal, and emit it from your reimplemented event handler: class MyWidget(QtGui.QWidget): keyPressed = QtCore.pyqtSignal(int) def keyPressEvent(self, event): super(MyWidget, self).keyPressEvent(event) self.keyPressed.emit(event.key()) … def on_key(key): # test for a specific key if key == QtCore.Qt.Key_Return: print(‘return key pressed’) else: print(‘key pressed: %i’ % key) self.widget.keyPressed.connect(on_key) (NB: calling the base-class implementation is required in order … Read more
As quark said, the functionality is not in Qt 4.5, but you can call the windows API directly from Qt. Its a little bit of work though. The new taskbar API is exposed through COM, so you can’t use ctypes.windll . You need to create a .tlb file to access the functions. Get the interface … Read more
This answer to this question is as found here: Python PySide (Internal c++ Object Already Deleted) Apparently, assigning one widget to QMainWindow using setCentralWidget and then assigning another widget with setCentralWidget will cause the underlying c++ QWidget to be deleted, even though I have an object that maintains reference to it. Note: QMainWindow takes ownership … Read more
It looks like all you need to do is check the keyboardModifiers in your button handler, and select a different action as appropriate. The various modifiers can be OR’d together in order to check for multi-key combinations: PyQt5: import sys from PyQt5 import QtCore, QtWidgets class Window(QtWidgets.QWidget): def __init__(self): super().__init__() self.button = QtWidgets.QPushButton(‘Test’) self.button.clicked.connect(self.handleButton) layout … Read more
This answer is thanks to Matthias BUSSONNIER from the ipython-users mailing list. When I close the window of the running demo application, I see this error: An exception has occurred, use %tb to see the full traceback. SystemExit: 0 Just don’t use sys.exit(0) as you are not exiting python, but still running IPython. Add it … Read more
Here is a very simple PyQt5 solution using QLockFile: from PyQt5 import QtCore, QtWidgets lockfile = QtCore.QLockFile(QtCore.QDir.tempPath() + ‘/my_app_name.lock’) if lockfile.tryLock(100): app = QtWidgets.QApplication([]) win = QtWidgets.QWidget() win.setGeometry(50, 50, 100, 100) win.show() app.exec() else: print(‘app is already running’) There were a couple of fairly straightforward C++ solutions given on the Qt Wiki which no longer … Read more
After a lot of research (and this one took quite time, so I add it here for future reference), this is the way I found to really clear and delete the widgets in a layout: for i in reversed(range(layout.count())): layout.itemAt(i).widget().setParent(None) What the documentation says about the QWidget is that: The new widget is deleted when … Read more
Don’t replace the widgets at runtime: promote the widgets in Qt Designer so that the line-edits are automatically replaced by your custom class when the GUI module is generated. Here’s how to promote a widget to use a custom class: In Qt Designer, select all the line-edits you want to replace, then right-click them and … Read more
you must call the QWebEnginePage::toHtml() inside the definition of the class. QWebEnginePage::toHtml() takes a pointer function or a lambda as a parameter, and this pointer function must in turn take a parameter of ‘str’ type (this is the parameter that contains the page’s html). Here is sample code below. import bs4 as bs import sys … Read more