c/HandlerChain_Exercise.h File Reference

Declaration of the HandlerChain_Exercise() function as used in the HandlerChain Pattern. More...

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Macros
#define	__HANDLERCHAIN_EXERCISE_H__

Functions
void	HandlerChain_Exercise (void)
	Example of using the HandlerChain Pattern or Chain of Responsibility design pattern.

Detailed Description

Declaration of the HandlerChain_Exercise() function as used in the HandlerChain Pattern.

Definition in file c/HandlerChain_Exercise.h.

Macro Definition Documentation

__HANDLERCHAIN_EXERCISE_H__

#define __HANDLERCHAIN_EXERCISE_H__

Definition at line 9 of file c/HandlerChain_Exercise.h.

Function Documentation

HandlerChain_Exercise()

void HandlerChain_Exercise

(

void

)

Example of using the HandlerChain Pattern or Chain of Responsibility design pattern.

The Handler Chain pattern is used to support a dynamic list of handlers that are passed the same arguments. It is kind of the inverse of the Visitor pattern, where the Visitor pattern is a handler that is passed to all objects in a list and the Handler Chain pattern is an object passed to handlers in a list.

In this exercise, multiple rectangular regions represented by the MessageWindow structure are represented by window IDs. The IDs are kept in a list to which messages can be passed, using the HandlerChain_SendMessage() function. That function iterates through the list of window IDs and calls MessageWindow_ProcessMessage() for each ID with the desired message. MessageWindow_ProcessMessage() passes control to one of several handler functions based on the type of the message.

Definition at line 88 of file HandlerChain_Exercise.c.

References _HandleChain_DestroyWindows(), _HandlerChain_ConstructWindowChain(), _ShowHandlerChain(), ButtonDown, ButtonUp, HandlerChain_SendMessage(), and Message_Initialize().