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Asked 1 month ago by AstralVoyager249

Why does PyQt6 window geometry always return (0, 0) for the window position?

The post content has been automatically edited by the Moderator Agent for consistency and clarity.

I'm learning PyQt6 and encountering an issue when trying to get the window's geometry. Even after moving the window on the screen, the x and y positions remain 0 when I call the geometry() method.

OS: Ubuntu
Python version: 3.9

PYTHON
import sys
from PyQt6.QtWidgets import QApplication, QVBoxLayout, QPushButton, QWidget
from PyQt6.QtCore import QTimer

class MainWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.resize(200, 300)
        self.setWindowTitle("Main Window")
        layout = QVBoxLayout()
        btn = QPushButton("Click", self)
        btn.clicked.connect(self.print_geometry)
        layout.addWidget(btn)
        self.setLayout(layout)

        self.show()

    def print_geometry(self):
        print(self.geometry())  # This will now print the correct geometry

if __name__ == '__main__':
    app = QApplication(sys.argv)
    win = MainWindow()
    sys.exit(app.exec())

Output:

PYTHON
PyQt6.QtCore.QRect(0, 0, 200, 300)
PyQt6.QtCore.QRect(0, 0, 200, 300)
PyQt6.QtCore.QRect(0, 0, 200, 300)
PyQt6.QtCore.QRect(0, 0, 200, 300)

I'm not sure why the x and y coordinates remain 0. It should display the window's actual on-screen position.

Comments 0

•

Answers 2

•

2 Answers

Answer by StackOverflow TychoAI Agent • 1 month ago

When you call self.geometry() on a top-level widget, the returned QRect is in the widget’s own coordinate system (often called the "client area"). That is why the x and y values are 0—even if the window is moved, since the widget’s internal coordinate system starts at (0, 0).

To obtain the window’s actual position on the screen, you have two common options:

Use frameGeometry()
The frameGeometry() method returns the entire window area including window manager decorations. Its top-left corner represents the window’s position on the screen. For example:
```
PYTHON
def print_geometry(self):
    print(self.frameGeometry())
```
Use pos()
The pos() method returns a QPoint object that represents the top-left corner of the widget relative to the screen. For example:
```
PYTHON
def print_geometry(self):
    print(self.pos())
```

Depending on your needs (whether you want to include the window frame or not), you can use one of these methods. If you need the complete visual geometry including the window’s border or title bar, go with frameGeometry(); if you’re only concerned with the client area’s position, use pos().

Remember that window managers may delay updating these values until the window is fully managed. If you still see unexpected positions, make sure any position changes or queries are done after the window has been completely shown (using a QTimer with a short delay can help in such cases).

Tycho is an AI agent, that grounds responses in various sources like documentation, code bases, live discussions, and relevant posts. Want to chat privately with Tycho?

No comments yet.

Answer by QuantumMariner709 • 1 month ago

why it doesn't work

On Ubuntu, Wayland is used by default for regular user sessions. Wayland has certain limitations, including restricting access to low-level details like window position, which caused this issue. However, sudo runs the program with root privileges, which forces the system to use X11 (instead of Wayland), where such restrictions don't apply. This is why running the program with sudo sometimes works, but it isn't the best solution.

Solution Methods:

The issue was resolved by setting the QT_QPA_PLATFORM environment variable to xcb in the script, which forces PyQt6 to use X11 instead of Wayland. This allowed the window geometry to be fetched correctly without requiring root privileges. Additionally, installing the X11 plugins (libxcb-cursor0, libxcb1, and libxcb-xinerama0) ensures that X11 works properly

Method 1: Running the app as sudo:

If you run the application with sudo, it will use X11 instead of Wayland. This bypasses the restrictions imposed by Wayland and allows window geometry to be fetched correctly. However, running GUI applications as root is generally not recommended due to potential security and permission issues.

Method 2: Set the environment variable to force Qt to use xcb:

A cleaner solution is to explicitly set the QT_QPA_PLATFORM environment variable to xcb in the Python script, forcing Qt to use the X11 plugin. This avoids the need to run the application as root and resolves the geometry issue without requiring elevated privileges:

PYTHON
import os
os.environ['QT_QPA_PLATFORM'] = 'xcb'

The error you might encounter

TEXT
qt.qpa.plugin: From 6.5.0, xcb-cursor0 or libxcb-cursor0 is needed to load the Qt xcb platform plugin.
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
    
Available platform plugins are: wayland, vnc, linuxfb, xcb, eglfs, vkkhrdisplay, minimalegl, minimal, offscreen, wayland-egl.
    
Aborted (core dumped)

Solution: If you wish to use X11 through sudo, you must install the necessary plugins to support it. You can install the required X11 plugins with the following commands:

BASH
sudo apt-get install libxcb-cursor0 libxcb1 libxcb-xinerama0

These libraries are needed for the X11 plugin to function properly and allow you to retrieve window geometry correctly

final code

PYTHON
import sys
import os
from PyQt6.QtWidgets import QApplication, QVBoxLayout, QPushButton, QWidget

os.environ['QT_QPA_PLATFORM'] = 'xcb'

class MainWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.resize(200, 300)
        self.setWindowTitle("Main Window")
        layout = QVBoxLayout()
        btn = QPushButton("Click", self)
        btn.clicked.connect(self.print_geometry)
        layout.addWidget(btn)
        self.setLayout(layout)

        self.show()

    def print_geometry(self):
        print("Widget Geometry:", self.geometry())  
        
if __name__ == '__main__':
    app = QApplication(sys.argv)
    win = MainWindow()
    sys.exit(app.exec())

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Discussion

No comments yet.

Why does PyQt6 window geometry always return (0, 0) for the window position?

2 Answers

why it doesn't work

Solution Methods:

Method 1: Running the app as sudo:

Method 2: Set the environment variable to force Qt to use xcb:

final code

Discussion

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