A class that represents lightweight objects to signal the application of pipeline events. More...

#include <gstreamermm/message.h>

Inheritance diagram for Gst::Message:

[legend]

Public Member Functions
void	reference () const
	Increment the reference count for this object. More...

void	unreference () const
	Decrement the reference count for this object. More...

GstMessage*	gobj ()
	Provides access to the underlying C instance. More...

const GstMessage*	gobj () const
	Provides access to the underlying C instance. More...

GstMessage*	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...

	Message ()=delete

	Message (const Message&)=delete

Message&	operator= (const Message&)=delete

Gst::Structure	get_structure () const
	Access the structure of the message. More...

Glib::RefPtr< Gst::Message >	create_writable ()
	Checks if a message is writable. More...

guint32	get_seqnum () const
	Retrieve the sequence number of a message. More...

void	set_seqnum (guint32 seqnum)
	Set the sequence number of a message. More...

Glib::RefPtr< Gst::Message >	copy () const
	Creates a copy of the message. More...

MessageType	get_message_type () const
	Get the GstMessageType of message. More...

Gst::ClockTime	get_timestamp () const
	Get the timestamp of message. More...

Glib::RefPtr< Gst::Object >	get_source ()
	Get the object that posted the message. More...

Glib::RefPtr< const Gst::Object >	get_source () const

bool	has_name (const Glib::ustring& name) const
	Checks if message has the given name. More...

Public Member Functions inherited from Gst::MiniObject
void	reference () const
	Increment the reference count for this object. More...

void	unreference () const
	Decrement the reference count for this object. More...

GstMiniObject*	gobj ()
	Provides access to the underlying C instance. More...

const GstMiniObject*	gobj () const
	Provides access to the underlying C instance. More...

GstMiniObject*	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...

	MiniObject ()=delete

	MiniObject (const MiniObject&)=delete

MiniObject&	operator= (const MiniObject&)=delete

	~MiniObject ()

guint	get_flags () const

void	set_flags (const guint& value)

gint	get_refcount () const

gint	get_lockstate () const

bool	lock (LockFlags flags)
	Lock the mini-object with the specified access mode in flags. More...

void	unlock (LockFlags flags)
	Unlock the mini-object with the specified access mode in flags. More...

bool	is_writable () const
	If mini_object has the LOCKABLE flag set, check if the current EXCLUSIVE lock on object is the only one, this means that changes to the object will not be visible to any other object. More...

Glib::RefPtr< MiniObject >	create_writable ()
	Checks if a mini-object is writable. More...

void	set_qdata (GQuark quark, QuarkData* data)
	This sets an opaque, named pointer on a miniobject. More...

QuarkData*	get_qdata (GQuark quark) const
	This function gets back user data pointers stored via set_qdata(). More...

QuarkData*	steal_qdata (GQuark quark)
	This function gets back user data pointers stored via set_qdata() and removes the data from object without invoking its destroy() function (if any was set). More...

void	add_finalize_notifier (const SlotFinalizer& slot)
	Adds notifier when mini object is finalized. More...

void	remove_finalize_notifier ()
	Remove finalize notifier. More...

Protected Member Functions
void	operator delete (void*, std::size_t)

Protected Member Functions inherited from Gst::MiniObject
void	operator delete (void*, std::size_t)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gst::Message >	wrap (GstMessage* object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Related Functions inherited from Gst::MiniObject
Glib::RefPtr< Gst::MiniObject >	wrap (GstMiniObject* object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Additional Inherited Members
Public Types inherited from Gst::MiniObject
typedef sigc::slot< void >	SlotFinalizer

Detailed Description

A class that represents lightweight objects to signal the application of pipeline events.

Messages are implemented as a subclass of Gst::MiniObject with a generic Gst::Structure as the content. This allows for writing custom messages without requiring an API change while allowing a wide range of different types of messages.

Messages are posted by objects in the pipeline and are passed to the application using the Gst::Bus.

The basic use pattern of posting a message on a Gst::Bus is as follows:

bus->post(Gst::MessageEos::create(my_element));

Last reviewed on 2016-06-06 (1.8.0)

Constructor & Destructor Documentation

◆ Message() [1/2]

Gst::Message::Message ( )

delete

◆ Message() [2/2]

Gst::Message::Message ( const Message& )

delete

Member Function Documentation

◆ copy()

Glib::RefPtr<Gst::Message> Gst::Message::copy ( ) const

Creates a copy of the message.

Returns a copy of the message.

Returns: A new copy of msg.

MT safe.

◆ create_writable()

Glib::RefPtr<Gst::Message> Gst::Message::create_writable ( )

Checks if a message is writable.

If not, a writable copy is made and returned.

Returns: A Gst::Message (possibly the same pointer) that is writable.

◆ get_message_type()

MessageType Gst::Message::get_message_type ( ) const

Get the GstMessageType of message.

◆ get_seqnum()

guint32 Gst::Message::get_seqnum ( ) const

Retrieve the sequence number of a message.

Messages have ever-incrementing sequence numbers, which may also be set explicitly via gst_message_set_seqnum(). Sequence numbers are typically used to indicate that a message corresponds to some other set of messages or events, for example a SEGMENT_DONE message corresponding to a SEEK event. It is considered good practice to make this correspondence when possible, though it is not required.

Note that events and messages share the same sequence number incrementor; two events or messages will never have the same sequence number unless that correspondence was made explicitly.

Returns: The message's sequence number.

MT safe.

◆ get_source() [1/2]

Glib::RefPtr<Gst::Object> Gst::Message::get_source ( )

Get the object that posted the message.

◆ get_source() [2/2]

Glib::RefPtr<const Gst::Object> Gst::Message::get_source ( ) const

◆ get_structure()

Gst::Structure Gst::Message::get_structure ( ) const

Access the structure of the message.

Returns: The structure of the message. The structure is still owned by the message, which means that you should not free it and that the pointer becomes invalid when you free the message.

MT safe.

◆ get_timestamp()

Gst::ClockTime Gst::Message::get_timestamp ( ) const

Get the timestamp of message.

This is the timestamp when the message was created.

◆ gobj() [1/2]

GstMessage* Gst::Message::gobj ( )

Provides access to the underlying C instance.

◆ gobj() [2/2]

const GstMessage* Gst::Message::gobj ( ) const

Provides access to the underlying C instance.

◆ gobj_copy()

GstMessage* Gst::Message::gobj_copy ( ) const

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

◆ has_name()

bool Gst::Message::has_name ( const Glib::ustring & name ) const

Checks if message has the given name.

This function is usually used to check the name of a custom message.

Parameters

name	Name to check.

Returns: true if name matches the name of the message structure.

◆ operator delete()

void Gst::Message::operator delete	(	void *	,
		std::size_t
	)

protected

◆ operator=()

Message& Gst::Message::operator= ( const Message& )

delete

◆ reference()

void Gst::Message::reference ( ) const

Increment the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

◆ set_seqnum()

void Gst::Message::set_seqnum ( guint32 seqnum )

Set the sequence number of a message.

This function might be called by the creator of a message to indicate that the message relates to other messages or events. See gst_message_get_seqnum() for more information.

MT safe.

Parameters

seqnum A sequence number.

◆ unreference()

void Gst::Message::unreference ( ) const

Decrement the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gst::Message > wrap	(	GstMessage *	object,
		bool	take_copy = `false`
	)

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns: A C++ instance that wraps this C instance.

Public Member Functions

Protected Member Functions

Related Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Message() [1/2]

◆ Message() [2/2]

Member Function Documentation

◆ copy()

◆ create_writable()

◆ get_message_type()

◆ get_seqnum()

◆ get_source() [1/2]

◆ get_source() [2/2]

◆ get_structure()

◆ get_timestamp()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ has_name()

◆ operator delete()

◆ operator=()

◆ reference()

◆ set_seqnum()

◆ unreference()

Friends And Related Function Documentation

◆ wrap()