KWayland::Server::BufferInterface Class Reference

#include <buffer_interface.h>

Inheritance diagram for KWayland::Server::BufferInterface:

Signals
void	aboutToBeDestroyed (KWayland::Server::BufferInterface *)
void	sizeChanged ()

Public Member Functions
QImage	data ()
bool	hasAlphaChannel () const
bool	isReferenced () const
LinuxDmabufBuffer *	linuxDmabufBuffer ()
void	ref ()
wl_resource *	resource () const
void	setSize (const QSize &size)
wl_shm_buffer *	shmBuffer ()
QSize	size () const
SurfaceInterface *	surface () const
void	unref ()
Public Member Functions inherited from QObject
	QObject (QObject *parent)
bool	blockSignals (bool block)
const QObjectList &	children () const
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const
void	deleteLater ()
void	destroyed (QObject *obj)
bool	disconnect (const char *signal, const QObject *receiver, const char *method) const
bool	disconnect (const QObject *receiver, const char *method) const
void	dumpObjectInfo ()
void	dumpObjectTree ()
QList< QByteArray >	dynamicPropertyNames () const
virtual bool	event (QEvent *e)
virtual bool	eventFilter (QObject *watched, QEvent *event)
T	findChild (const QString &name, QFlags< Qt::FindChildOption > options) const
QList< T >	findChildren (const QString &name, QFlags< Qt::FindChildOption > options) const
QList< T >	findChildren (const QRegExp &regExp, QFlags< Qt::FindChildOption > options) const
QList< T >	findChildren (const QRegularExpression &re, QFlags< Qt::FindChildOption > options) const
bool	inherits (const char *className) const
void	installEventFilter (QObject *filterObj)
bool	isWidgetType () const
bool	isWindowType () const
void	killTimer (int id)
virtual const QMetaObject *	metaObject () const
void	moveToThread (QThread *targetThread)
QString	objectName () const
void	objectNameChanged (const QString &objectName)
QObject *	parent () const
QVariant	property (const char *name) const
void	removeEventFilter (QObject *obj)
void	setObjectName (const QString &name)
void	setParent (QObject *parent)
bool	setProperty (const char *name, const QVariant &value)
bool	signalsBlocked () const
int	startTimer (int interval, Qt::TimerType timerType)
QThread *	thread () const

Static Public Member Functions
static BufferInterface *	get (wl_resource *r)
Static Public Member Functions inherited from QObject
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, const QObject *context, Functor functor, Qt::ConnectionType type)
bool	disconnect (const QMetaObject::Connection &connection)
bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method)
bool	disconnect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method)
bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method)
QString	tr (const char *sourceText, const char *disambiguation, int n)
QString	trUtf8 (const char *sourceText, const char *disambiguation, int n)

Additional Inherited Members
Properties inherited from QObject
	objectName
Protected Member Functions inherited from QObject
virtual void	childEvent (QChildEvent *event)
virtual void	connectNotify (const QMetaMethod &signal)
virtual void	customEvent (QEvent *event)
virtual void	disconnectNotify (const QMetaMethod &signal)
bool	isSignalConnected (const QMetaMethod &signal) const
int	receivers (const char *signal) const
QObject *	sender () const
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *event)

Detailed Description

Reference counted representation of a Wayland buffer on Server side.

This class encapsulates a rendering buffer which is normally attached to a SurfaceInterface. A client should not render to a Wayland buffer as long as the buffer gets used by the server. The server signals whether it's still used. This class provides a convenience access for this functionality by performing reference counting and deleting the BufferInterface instance automatically once it is no longer accessed.

The BufferInterface is referenced as long as it is attached to a SurfaceInterface. If one wants to keep access to the BufferInterface for a longer time ensure to call ref on first usage and unref again once access to it is no longer needed.

In Wayland the buffer is an abstract concept and a buffer might represent multiple different concrete buffer techniques. This class has direct support for shared memory buffers built and provides access to the native buffer for different (e.g. EGL/drm) buffers.

If the EGL display has been registered in the Display the BufferInterface can also provide some information about an EGL/drm buffer.

For shared memory buffers a direct conversion to a memory-mapped QImage possible using the data method. Please refer to the documentation for notes on the restrictions when using the shared memory-mapped QImages.

See also

Display

SurfaceInterace

Definition at line 65 of file buffer_interface.h.

Member Function Documentation

QImage KWayland::Server::BufferInterface::data

(

)

Creates a QImage for the shared memory buffer.

If the BufferInterface does not reference a shared memory buffer a null QImage is returned.

The QImage shares the memory with the buffer and this constraints how the returned QImage can be used and when this method can be invoked.

It is not safe to have two shared memory QImages for different BufferInterfaces at the same time. This method ensures that this does not happen and returns a null QImage if a different BufferInterface's data is still mapped to a QImage. Please note that this also applies to all implicitly data shared copies.

In case it is needed to keep a copy, a deep copy has to be performed by using QImage::copy.

As the underlying shared memory buffer is owned by a different client it is not safe to write to the returned QImage. The image is a read-only buffer. If there is need to modify the image, perform a deep copy.

Definition at line 280 of file buffer_interface.cpp.

bool KWayland::Server::BufferInterface::hasAlphaChannel

(

)

const

Returns whether the format of the BufferInterface has an alpha channel.

For shared memory buffers returns true for format WL_SHM_FORMAT_ARGB8888, for all other formats returns false.

For EGL buffers returns true for format EGL_TEXTURE_RGBA, for all other formats returns false.

If the format cannot be queried the default value (false) is returned.

Since

5.4

Definition at line 347 of file buffer_interface.cpp.

bool KWayland::Server::BufferInterface::isReferenced

(

)

const

Returns

whether the BufferInterface is currently referenced

See also

ref

unref

Definition at line 308 of file buffer_interface.cpp.

LinuxDmabufBuffer * KWayland::Server::BufferInterface::linuxDmabufBuffer

(

)

Returns a pointer to the LinuxDmabufBuffer when the buffer is a dmabuf buffer, and nullptr otherwise.

Definition at line 323 of file buffer_interface.cpp.

void KWayland::Server::BufferInterface::ref

(

)

Reference the BufferInterface.

As long as the reference counting has not reached 0 the BufferInterface is valid and blocked for usage by the client.

See also

unref

isReferenced

Definition at line 247 of file buffer_interface.cpp.

wl_resource * KWayland::Server::BufferInterface::resource

(

)

const

Returns

the native wl_resource wrapped by this BufferInterface.

Definition at line 328 of file buffer_interface.cpp.

void KWayland::Server::BufferInterface::setSize

(

const QSize &

size

)

Sets the size for non shared memory buffers.

See also

size

sizeChanged

Since

5.3

Definition at line 338 of file buffer_interface.cpp.

wl_shm_buffer * KWayland::Server::BufferInterface::shmBuffer

(

)

Returns

The native wl_shm_buffer if the BufferInterface represents a shared memory buffer, otherwise nullptr.

Definition at line 318 of file buffer_interface.cpp.

QSize KWayland::Server::BufferInterface::size

(

)

const

Returns the size of this BufferInterface.

Note: only for shared memory buffers (shmBuffer) the size can be derived, for other buffers it might be possible to derive the size if an EGL display is set on Display otherwise the user of the BufferInterface has to use setSize to provide the proper size.

See also

setSize

Display::setEglDisplay

Since

5.3

Definition at line 333 of file buffer_interface.cpp.

void KWayland::Server::BufferInterface::sizeChanged ( )

signal

Emitted when the size of the Buffer changes.

Since

5.3

SurfaceInterface * KWayland::Server::BufferInterface::surface

(

)

const

Returns

The SurfaceInterface this BufferInterface is attached to.

Definition at line 313 of file buffer_interface.cpp.

void KWayland::Server::BufferInterface::unref

(

)

Unreference the BufferInterface.

If the reference counting reached 0 the BufferInterface is released, so that the client can use it again. The instance of this BufferInterface will be automatically deleted.

See also

ref

isReferenced

Definition at line 252 of file buffer_interface.cpp.

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The documentation for this class was generated from the following files:

• buffer_interface.h
• buffer_interface.cpp