MessageFilter.h File Reference

Provides BMessageFilter class. More...

Classes
class	BMessageFilter
	Describes a message filter for BLooper and BHandler. More...

Typedefs
typedef filter_result(*	filter_hook) (BMessage *message, BHandler **target, BMessageFilter *filter)
	Prototype for a custom filter_hook for use in the BMessageFilter class.

Enumerations
enum	filter_result {   B_SKIP_MESSAGE ,   B_DISPATCH_MESSAGE }
enum	message_delivery {   B_ANY_DELIVERY ,   B_DROPPED_DELIVERY ,   B_PROGRAMMED_DELIVERY }
enum	message_source {   B_ANY_SOURCE ,   B_REMOTE_SOURCE ,   B_LOCAL_SOURCE }

Detailed Description

Provides BMessageFilter class.

Typedef Documentation

filter_hook

filter_result(* filter_hook)(BMessage *message, BHandler **target, BMessageFilter *filter)

Prototype for a custom filter_hook for use in the BMessageFilter class.

This hook can be used when you are constructing a new BMessageFilter object. It is a custom filter function you can use.

This hook should handle the following parameters:

Parameters

[in]	message	The message that needs to be verified.
[out]	target	If your filter hook is conscious about the available handlers, you can set a specific BHandler based on your filters requirements. You do not have to change this field, because there will always be a working default.
[in]	filter	A pointer to the filter from which this hook is called.

Returns

You should return B_SKIP_MESSAGE in case the message does not conform to the filter criteria, or B_DISPATCH_MESSAGE if the message passes these criteria.

See also

BMessageFilter(uint32, filter_hook)

BMessageFilter(message_delivery, message_source, filter_hook)

BMessageFilter(message_delivery, message_source, uint32, filter_hook)

Since

BeOS R3

Enumeration Type Documentation

filter_result

enum filter_result

Enumerator
B_SKIP_MESSAGE	The message does not pass the filter criteria and should not be handled. Since BeOS R3
B_DISPATCH_MESSAGE	The message passes the filter criteria and should be dispatched to a BHandler. Since BeOS R3

message_delivery

enum message_delivery

Enumerator
B_ANY_DELIVERY	Accept both delivery methods. Since BeOS R3
B_DROPPED_DELIVERY	Only accept messages that were dropped by the user in the GUI. Since BeOS R3
B_PROGRAMMED_DELIVERY	Only accept messages that were delivered using the BLooper::PostMessage() method. Since BeOS R3

message_source

enum message_source

Enumerator
B_ANY_SOURCE	Accept both local and remote messages. Since BeOS R3
B_REMOTE_SOURCE	Only accept messages from a remote source, so from other applications. Since BeOS R3
B_LOCAL_SOURCE	Only accept messages from your own local application. Since BeOS R3