If a class is destroyed, it automatically disconnects all of its signals and slots.Every class can disconnect its slot or signal at any time when it is not interested in events anymore.If signals and slots are public properties, any class can connect to them whenever they want.Any signal can connect to as many slots and vice versa as you like.Any class can have as many slots and as many signals as you like.To use signals and slots, simply copy the files SignalSlot.h, Callback.h and PreProcessor.h to your project and #include 'SignalSlot.h'. Signals and slots are callbacks with enhanced features. This article is based on Part 1 ( Type-safe C++ Callbacks), but it is not necessary to read Part 1 before reading this article. New in version 3.0 (Oct 2007): support for callbacks to static functions and to functions in virtually derived classes the Combine function must not be static anymore.Tested on Visual Studio 6.0, 7.0, 7.1 and 8.0 (= Visual Studio 6, up to.Platform independent: running on Windows, Linux, Mac, etc.Some additional extra features are provided.The compiled code size is less than 1 KB, no extra libraries required.Signals are protected against reentrance.If a class is destroyed, all connected signals or slots are automatically disconnected.You can pass 0 to 5 arguments of any type to a signal and you can combine the multiple return values from the slots into one single return value given back to the caller (if the return type is not void).

You can connect as many signals to a slot and as many slots to a signal as you like.

A signal (event) fired anywhere in any class of your code can be received by slots (delegates) in any class of your code.

These classes add a highly comfortable signal / slot system to your projects.

Qt signal slot custom class