Python PyQt mouse tracking example

Python PyQt Event Handling: Exercise-7 with Solution

Write a Python program that creates a window using PyQt. The window will display the mouse coordinates, and update in real-time as you move the mouse cursor within the window.

From doc.qt.io:

QApplication Class: The QApplication class manages the GUI application's control flow and main settings.

QMainWindow Class: The QMainWindow class provides a main application window.

QLabel Class: The QLabel widget provides a text or image display.

Qt module: PyQt5 is a set of Python bindings for the Qt application framework. It allows us to use Qt, a popular C++ framework, to create graphical user interfaces (GUIs) in Python.

Sample Solution:

Python Code:

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel
from PyQt5.QtCore import Qt

class MouseTrackingApp(QMainWindow):
    def __init__(self):
        super().__init__()

        self.setWindowTitle("Mouse Tracking Example")
        self.setGeometry(100, 100, 400, 400)

        self.mouse_coordinates_label = QLabel(self)
        self.mouse_coordinates_label.setGeometry(10, 10, 150, 30)
        self.mouse_coordinates_label.setAlignment(Qt.AlignmentFlag.AlignLeft)

        # Track mouse movements in the main window
        self.setMouseTracking(True)

    def mouseMoveEvent(self, event):
        x = event.x()
        y = event.y()
        self.mouse_coordinates_label.setText(f"Mouse Coordinates: ({x}, {y})")

def main():
    app = QApplication(sys.argv)
    window = MouseTrackingApp()
    window.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    main()

Explanation:

In the exercise above -

• Import the necessary PyQt5 modules.
• Create a "MouseTrackingApp" class that inherits from "QMainWindow".
• Inside the "MouseTrackingApp" class, we set up a 'QLabel' (self.mouse_coordinates_label) to display the mouse coordinates. We position this label in the top-left corner of the window and align the text to the left.
• Enable mouse tracking for the main window using self.setMouseTracking(True). This allows the window to continuously receive mouse 'move' events.
• Override the mouseMoveEvent method to capture mouse movement. Inside this method, we extract the x and y coordinates from the event object and update the label text to display the current mouse coordinates.
• Finally, we create an instance of MouseTrackingApp and run the PyQt5 application.

Output:

Flowchart:

Python Code Editor:

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