1.5 Signal Events

In Section 1.2 the Reactor component was described as being similar to a conventional event loop. This means that it is quite capable of processing external events such as GUI button presses or the receipt of an automatic data sensing event. In the context of the Reaction framework, this type of event is distinguished by referring to it as a signal event.

Objects which can receive signal events are referred to as signalable objects and implement the Signalable interface. A basic version of this interface is shown in Listing 1.5.

% latex2html id marker 133\begin{small}
\end{small}\caption{A Basic Signalable Interface Definition}

Multiple signalable objects may be attached to a single signal source, with the signal parameter data being passed to each signalable object in turn. The implementation of signalable objects and their relation to signal events is discussed in more detail in Chapter 4.