PyQt5 QSpinBox - Accessing State Tip

Introduction

PyQt5 is a Python binding of the Qt toolkit. It is one of the most popular Python GUI frameworks. PyQt5 QSpinBox is a GUI widget that allows users to select an integer value from a range of values. It provides a simple and easy-to-use interface for users. In this tutorial, we will learn how to access the state of the QSpinBox and display a state tip to the user.

Prerequisites

To follow along with this tutorial, make sure you have the following installed:

• Python 3.x
• PyQt5

If you haven't installed PyQt5, you can install it using pip:

pip install pyqt5

PyQt5 QSpinBox

PyQt5 provides the QSpinBox class to create a spin box. A spin box is a widget where the user can select an integer value from a range of values. It has a value, a minimum value, a maximum value, a step value, and an editable property. By default, the spin box is not editable.

from PyQt5.QtWidgets import QApplication, QSpinBox, QWidget, QVBoxLayout

app = QApplication([])
window = QWidget()
layout = QVBoxLayout(window)
spin_box = QSpinBox()
spin_box.setRange(0, 100)
spin_box.setSingleStep(1)
layout.addWidget(spin_box)
window.show()
app.exec_()

The above code creates a spin box with a minimum value of 0 and a maximum value of 100. The spin box has a single step of 1. The spin box is added to the layout, which is added to the window.

Accessing the State

To access the state of the spin box, we can use the valueChanged() signal. This signal is emitted whenever the value of the spin box changes. We can connect this signal to a custom slot to handle the state change.

from PyQt5.QtWidgets import QApplication, QSpinBox, QWidget, QVBoxLayout
from PyQt5.QtCore import Qt

app = QApplication([])
window = QWidget()
layout = QVBoxLayout(window)
spin_box = QSpinBox()
spin_box.setRange(0, 100)
spin_box.setSingleStep(1)

def on_value_changed(value):
    if value > 50:
        spin_box.setStatusTip("Value is greater than 50")
    else:
        spin_box.setStatusTip("Value is less than or equal to 50")
        
spin_box.valueChanged.connect(on_value_changed)

layout.addWidget(spin_box)
window.show()
app.exec_()

In the above code, we define a custom slot called on_value_changed(). This slot is called whenever the value of the spin box changes. If the value is greater than 50, we set the status tip of the spin box to "Value is greater than 50". Otherwise, we set the status tip to "Value is less than or equal to 50". We connect the valueChanged() signal of the spin box to the on_value_changed() slot.

Conclusion

In this tutorial, we learned how to create a PyQt5 QSpinBox and how to access its state. We also learned how to display a status tip to the user based on the state of the spin box. The ability to access the state of the spin box can be useful to provide feedback to the user and to perform certain actions based on the state.