Qt for Python

@markleo said in For large Qt desktop projects, how is the database generally used in combination?:

Since large databases such as MySQL and PostgreSQL need to be installed on a PC

Those are typically installed on a server and clients access that server. It would be unusual to install such SQL servers on users machines.

Whether SQLite is sufficient or not really depends on your needs. It is, for example, not designed to be accessed in parallel by several applications at the same time. So, what are your requirements? Are your clients going to access same databases? If so, you should consider client/server architecture using MySQL/PostgreSQL.

@markleo Please post error messages as text. In this case the error message is not even completely visible.

@SGaist
Hey, bro.So how can i solve this problem in the win10?or how can i set tooltip backgroundColor in the win10?

@markleo said in Can Qt Creator create PyQt project?:

I use Qt Creator to create py project, there is only PySide for choosing.

As you might have noticed, there are two major Qt Python wrapper libraries: PySide and PyQt.
PySide is officially developed and maintained by TQtC, whereas PyQt is not.
Therefore there is no project template for PyQt available in QtCreator.

@markleo said in Is there any PyQt demos examples of architecture for modular design of large projects?:

Does PyQt have similar sample schemes that can be borrowed?

These are the official PySide Qt examples

https://doc.qt.io/qtforpython-6/examples/index.html

and here are some PyQt GitHub examples:

https://github.com/pyqt/examples

Something like the following ?

# code block import sys from PyQt6.QtWidgets import ( QApplication, QMainWindow, QWidget, QVBoxLayout, QPushButton, QStackedWidget, QLabel, QHBoxLayout, QGridLayout ) from PyQt6.QtCore import Qt from PyQt6.QtGui import QIcon, QFont, QFontDatabase class MainWindow(QMainWindow): def __init__(self): super().__init__() # Application Configuration self.resize(800, 600) self.setWindowIcon(QIcon("./Images/clown.ico")) self.setWindowTitle("Recalcitrant V1.0.0") # Create a central widget and main layout self.centralWidget = QWidget() self.setCentralWidget(self.centralWidget) mainLayout = QHBoxLayout(self.centralWidget) # Use QHBoxLayout for side-by-side self.sidebarFrame = self.createSidebarFrame() self.stacked_widget = QStackedWidget() # Create frames self.dashboardFrame = self.createDashboardFrame() self.frame2 = self.create_frame("This is Frame 2") self.frame3 = self.create_frame("This is Frame 3") # Add frames to the stacked widget self.stacked_widget.addWidget(self.dashboardFrame) self.stacked_widget.addWidget(self.frame2) self.stacked_widget.addWidget(self.frame3) # Add sidebar and stacked widget to the main layout mainLayout.addWidget(self.sidebarFrame) # Add sidebar first mainLayout.addWidget(self.stacked_widget) # Then the stacked widget mainLayout.setContentsMargins(0, 0, 0, 0) mainLayout.setSpacing(0) # Set the fixed width for the sidebar self.sidebarFrame.setFixedWidth(150) def createSidebarFrame(self): sidebarWidget = QWidget() sidebarWidget.setObjectName("sidebar") sidebar = QVBoxLayout() sidebar.setAlignment(Qt.AlignmentFlag.AlignTop) # Align sidebar to the top sidebarWidget.setStyleSheet(""" QWidget#sidebar { background-color: #22222E; border-radius: 10px; } QPushButton#button { background-color: #22222E; border: 2px solid #ffffff; border-radius: 10px; padding: 5px; } QPushButton#button:hover { background-color: #393A5A; } QLabel#sidebarLabels { text-align: center; color: white; } """) sidebarWidget.setLayout(sidebar) # Dashboard self.modulesText = QLabel("<div style='text-align: center;'>test</div>") self.modulesText.setObjectName("sidebarLabels") sidebar.addWidget(self.modulesText) self.test = QPushButton("DASHBOARD") self.test.setMaximumWidth(150) self.test.setMinimumWidth(100) self.test.setObjectName("button") self.test.clicked.connect(lambda: self.switch_frame("dashboard")) sidebar.addWidget(self.test) # test self.test = QLabel("<div style='text-align: center;'>test</div>") self.test.setObjectName("sidebarLabels") sidebar.addWidget(self.test) self.test = QPushButton("test") self.test.setMaximumWidth(150) self.test.setMinimumWidth(100) self.test.setObjectName("button") self.test.clicked.connect(lambda: self.switch_frame(1)) sidebar.addWidget(self.test) # test self.test = QLabel("<div style='text-align: center;'>test</div>") self.test.setObjectName("sidebarLabels") sidebar.addWidget(self.test) self.test = QPushButton("test") self.test.setMaximumWidth(150) self.test.setMinimumWidth(100) self.test.setObjectName("button") self.test.clicked.connect(lambda: self.switch_frame(2)) sidebar.addWidget(self.test) sidebar.setContentsMargins(0, 5, 0, 5) #sidebar.setSpacing(0) sidebarWidget.setContentsMargins(0, 5, 0, 5) return sidebarWidget # Return the sidebar widget, not the layout def createDashboardFrame(self): frame = QWidget() frame.setStyleSheet(""" QLabel#label { border: 2px solid #ffffff; border-radius: 10px; padding: 0px; } """) layout = QVBoxLayout() layout.setContentsMargins(0, 0, 0, 0) frame.setLayout(layout) hbox = QHBoxLayout() layout.addLayout(hbox) test = QLabel("<div style='text-align: center;'>test test</div>") test.setObjectName("label") hbox.addWidget(test) test = QLabel("<div style='text-align: center;'>test test</div>") test.setObjectName("label") hbox.addWidget(test) test = QLabel("<div style='text-align: center;'>test test test</div>") test.setObjectName("label") hbox.addWidget(test) vbox = QVBoxLayout() layout.addLayout(vbox) button = QPushButton("test") vbox.addWidget(button) button = QPushButton("test") vbox.addWidget(button) button = QPushButton("test") vbox.addWidget(button) return frame def create_frame(self, text): """Helper function to create a frame with a label.""" frame = QWidget() layout = QVBoxLayout() label = QLabel(text) layout.addWidget(label) frame.setLayout(layout) return frame def switch_frame(self, index): """Switch to the specified frame.""" if index == "dashboard": self.stacked_widget.setCurrentIndex(0) self.test.setStyleSheet("background-color: #393A5A;") self.test.setStyleSheet("") self.test.setStyleSheet("") elif index == 1: self.stacked_widget.setCurrentIndex(index) self.test.setStyleSheet("") self.test.setStyleSheet("background-color: #393A5A;") self.test.setStyleSheet("") elif index == 2: self.stacked_widget.setCurrentIndex(index) self.test.setStyleSheet("") self.test.setStyleSheet("") self.test.setStyleSheet("background-color: #393A5A;") if __name__ == "__main__": app = QApplication(sys.argv) window = MainWindow() window.show() sys.exit(app.exec())

Thank you @Axel-Spoerl and @JonB , works great and I understood all including lambda. Great help

@markleo said in Hi, how to use Qt Designer on macOS?:

I don't find a button called "Design"

Please look again: it is right there on the left side. It is greyed out because you do not have an ui file yet.

You're likely on Windows 11 and the new windows11 style has some issues.

@JimLomax said in Draw lines,arcs at design time then change color on an event at runtime:

There is no QGraphicsArcItem, the ellipse item can be told to create partial ellipses but I haven't found a way to make it create arcs - it creates pie pieces. 2. Using the QGraphicsPathItem sort of works but I haven't found a way to stop it adding a line to the start of the arc

I don't have anything to say about QML vs widgets as I only use the latter. But if you are still interested in how to draw an arc on a QGraphicsScene without the pie/line QT QGraphicsScene Drawing Arc shows how to do that.

You're welcome !

Since this is what you wanted, please mark the thread as solved using the "Topic Tool" button or the three dotted menu beside the answer you deem correct so that other forum users may know a solution has been found :-)

Making everything into custom widgets would be more work that sticking with that big class, but I'll definitely keep this in mind. Thank you both @jsulm and @JonB for help.

Hi,

It seems you have indeed found something. It's reproducible as well in C++.
You should open a ticket on the bug tracker with you reproducer (don't forget to check if something similar has already been reported).

Hi and thanks for your welcome.
Good question, I'm trying to create Qt bindings for Ada language.
Some attempts with C++ were failing due to some C++ subtleties.
But Python provides C API which I can used easily with Ada.
I provide some very first Qt bindings for Ada.
But class inheritance is still in Python.
I wanted to make them full Ada. I'm able to instantiate a class inherited from QRasterWindow (for instance) but a call to the method metric (for instance) provoques a seg fault.
(for simplicity I post the code in C)

@SGaist

Thanks

That works. If the parent has row() and column() values of -1, then that indicates the parent is the root node.

@Toastito said in How does PyQt5 handle system dark and light mode transitions?:

The downside is that PyQt5 will still send a palleteChanged signal/event when the system theme changes. Ideally, I would've been able to block it and implement my own.

I haven't tried, but would expect an event filter to be able to filter out PaletteChange events.

The QGuiApplication::paletteChanged signal doesn't appear to be connected to anything by default. QObject::disconnect() without a receiver would ensure that, for any existing objects at the time of the call. Note that disconnecting signals at random can have surprising results.

@jsulm Thank you. I will look into that!

Hi,

It seems you would need an item on top of your images that you would paint transparently and then use something like QPainterPath to create the shape for your selection. The QGraphicsPathItem might be enough for your needs.

Hope it helps