Learning Robotics using Python - Second Edition

Qt signals and slots

In Qt, GUI events are handled using the signals and slots features. A signal is emitted from the GUI when an event occurs. Qt widgets have many predefined signals, and users can add custom signals for GUI events. A slot is a function that is called in response to a particular signal. In this example, we are using the clicked() signal of PushButton and creating a custom slot for this signal.

We can write our own code inside this custom function. Let's see how we can create a button, connect a signal to a slot, and convert the entire GUI to Python. Here are the steps involved in creating the Hello World GUI application:

1. Drag and create a PushButton from Qt Designer to the empty Form.
2. Assign a slot for the button clicked ...