xref: /haiku/docs/user/app/MessageRunner.dox (revision db7ef1292a12e2bb248580fb7b22af8cd697979f)

/*
 * Copyright 2001-2015 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		John Scipione, jscipione@gmail.com
 *		Ingo Weinhold, bonefish@users.sf.net
 *
 * Corresponds to:
 *		headers/os/app/MessageRunner.h	hrev48689
 *		src/kits/app/MessageRunner.cpp	hrev48689
 */


/*!
	\file MessageRunner.h
	\ingroup app
	\ingroup libbe
	\brief Provides the BMessageRunner class.
*/


/*!
	\class BMessageRunner
	\ingroup app
	\ingroup libbe
	\brief Provides a mechanism for sending one or more messages
	       to a messenger at a specified interval and receive
	       reply messages.

	The application that creates the BMessageRunner can specify the message,
	the BMessenger to send the message to, how often to send the message,
	how many times to send the message, and the BMessenger to send reply
	messages from.

	The system roster handles dispatching the messages to the appropriate
	messengers at the specified time intervals. The target for any reply
	messages is \c be_app_messenger by default, or it can be specified in the
	constructor.

	After initializing a BMessageRunner, the initialization can and should be
	checked by calling InitCheck(). BMessageRunner will not take ownership of
	the message, you may freely change or delete the message after
	initialization.

	The BMessageRunner can be reconfigured (to change the interval or count)
	by calling SetInterval() and SetCount(). This is useful if you want to stop
	a BMessageRunner from sending messages early or if messages are set to
	be sent forever.

	\since BeOS R5
*/


/*!
	\fn BMessageRunner::BMessageRunner(BMessenger target,
		const BMessage* message, bigtime_t interval, int32 count)
	\brief Creates and initializes a new BMessageRunner and instructs the
	       system roster to send the specified \a message to the \a target
	       \a count times every \a interval microseconds, reply messages are
	       sent to \c be_app_messenger.

	\param target The target of the message(s).
	\param message The message to be sent to the target.
	\param interval Period of time before the first message is sent and
	       between messages (if more than one shall be sent) in microseconds.
	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.

	\since BeOS R5
*/


/*!
	\fn BMessageRunner::BMessageRunner(BMessenger target,
		const BMessage& message, bigtime_t interval, int32 count)
	\brief Creates and initializes a new BMessageRunner and instructs the
	       system roster to send the specified \a message to the \a target
	       \a count times every \a interval microseconds, reply messages are
	       sent to \c be_app_messenger.

	\param target Target of the message(s).
	\param message The message to be sent to the target.
	\param interval Period of time before the first message is sent and
	       between messages (if more than one shall be sent) in microseconds.
	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.

	\since Haiku R1
*/


/*!
	\fn BMessageRunner::BMessageRunner(BMessenger target,
		const BMessage* message, bigtime_t interval, int32 count,
		BMessenger replyTo)
	\brief Creates and initializes a new BMessageRunner and instructs the
	       system roster to send the specified \a message to the \a target
	       \a count times every \a interval microseconds.

	This constructor also allows you to specify the target for replies to
	the delivered messages.

	\param target Target of the message(s).
	\param message The message to be sent to the target.
	\param interval Period of time before the first message is sent and
	       between messages (if more than one shall be sent) in microseconds.
	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.
	\param replyTo Target replies to the delivered message(s) shall be sent to.

	\since BeOS R5
*/


/*!
	\fn BMessageRunner::BMessageRunner(BMessenger target,
		const BMessage& message, bigtime_t interval, int32 count,
		BMessenger replyTo)
	\brief Creates and initializes a new BMessageRunner and instructs the
	       system roster to send the specified \a message to the \a target
	       \a count times every \a interval microseconds.

	This constructor also allows you to specify the target for replies to
	the delivered messages.

	\param target Target of the message(s).
	\param message The message to be sent to the target.
	\param interval Period of time before the first message is sent and
	       between messages (if more than one shall be sent) in microseconds.
	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.
	\param replyTo Target replies to the delivered message(s) shall be sent to.

	\since Haiku R1
*/


/*!
	\fn BMessageRunner::~BMessageRunner()
	\brief Frees all resources associated with the object.

	\since BeOS R5
*/


/*!
	\fn status_t BMessageRunner::InitCheck() const
	\brief Returns the initialization status.

	\note As soon as the last message is sent, the message runner
	      becomes unusable. InitCheck() will still return \c B_OK, but
	      SetInterval(), SetCount() and GetInfo() will all fail.

	\return \c B_OK if the object was properly initialized or an error code
	        otherwise.

	\since BeOS R5
*/


/*!
	\fn status_t BMessageRunner::SetInterval(bigtime_t interval)
	\brief Sets the interval of time between messages.

	\param interval The new interval in microseconds.

	\return A status code, \c B_OK on success or an error code otherwise.
	\retval B_OK Everything went fine.
	\retval B_NO_INIT The message runner was not properly initialized.
	\retval B_BAD_VALUE \a interval was \c 0 or negative, or the message runner
	        had already sent all messages and became unusable.

	\since BeOS R5
*/


/*!
	\fn status_t BMessageRunner::SetCount(int32 count)
	\brief Sets the number of times message should be sent.

	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.

	\return A status code, \c B_OK on success or an error code otherwise.
	\retval B_OK Everything went fine.
	\retval B_NO_INIT The message runner was not properly initialized.
	\retval B_BAD_VALUE \a interval was \c 0 or negative, or the message runner
	        had already sent all messages and became unusable.

	\since BeOS R5
*/


/*!
	\fn status_t BMessageRunner::GetInfo(bigtime_t* interval,
		int32* count) const
	\brief Returns the time interval between two messages and the number of
	       times the message has still to be sent.

	Both parameters (\a interval and \a count) may be \c NULL.

	\param interval Pointer to a pre-allocated bigtime_t variable to be set
	       to the time interval. May be \c NULL.
	\param count Pointer to a pre-allocated int32 variable to be set
	       to the number of times the message has still to be sent.
	       May be \c NULL.

	\return A status code, \c B_OK on success or an error code otherwise.
	\retval B_OK Everything went fine.
	\retval B_BAD_VALUE \a interval was 0 or negative, or the message runner
	        had already sent all messages and became unusable.

	\since BeOS R5
*/


/*!
	\fn status_t BMessageRunner::StartSending(BMessenger target,
		const BMessage* message, bigtime_t interval, int32 count)
	\brief Creates and initializes a detached BMessageRunner and instructs the
	       system roster to send the specified \a message to the \a target
	       \a count times every \a interval microseconds, reply messages are
	       sent to \c be_app_messenger.

	You cannot alter the runner after the creation, and it will be deleted
	automatically the last message is sent.

	\param target Target of the message(s).
	\param message The message to be sent to the target.
	\param interval Period of time before the first message is sent and
		   between messages (if more than one shall be sent) in microseconds.
	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.

	\since Haiku R1
*/


/*!
	\fn status_t BMessageRunner::StartSending(BMessenger target,
		const BMessage* message, bigtime_t interval, int32 count,
		BMessenger replyTo)
	\brief Creates and initializes a detached BMessageRunner and instructs the
	       system roster to send the specified \a message to the \a target
	       \a count times every \a interval microseconds.

	You cannot alter the runner after the creation, and it will be deleted
	automatically once the last message is sent.

	\param target Target of the message(s).
	\param message The message to be sent to the target.
	\param interval Period of time before the first message is sent and
	       between messages (if more than one shall be sent) in microseconds.
	\param count Specifies how many times the message shall be sent.
	       A negative value indicates that the message will be sent
	       forever, or until the BMessageRunner is reconfigured or deleted.
	\param replyTo Target replies to the delivered message(s) shall be sent to.

	\since Haiku R1
*/