Signals & Slots | Qt Core | Qt 6.9.0
For instance, I created this simple qt program Qt signal and Slot program to show how to indirectly connect a built-in signal from one class to a slot on another class.
C++ Qt Signals and Slots
Most Qt widgets have slots available, to which you can connect any signal that emits the same type that it accepts. The widget documentation has the slots for each widget listed under "Public Slots".
New Signal Slot Syntax
When a you connect a signal to a slot, the signal and slot signatures are stored for later use. When a signal is emitted, all the slots previously connected to that signal are called using the method described above.