QWaylandPresentationTime Class

The QWaylandPresentationTime class is an extension to get timing for on-screen presentation. More...

Header: #include <QWaylandPresentationTime>
CMake: find_package(Qt6 REQUIRED COMPONENTS Waylandcompositor)
target_link_libraries(mytarget PRIVATE Qt6::Waylandcompositor)
qmake: QT += waylandcompositor
Since: Qt 6.3
Instantiated By: PresentationTime
Inherits: QWaylandCompositorExtensionTemplate

Public Functions

QWaylandPresentationTime(QWaylandCompositor *compositor)
QWaylandCompositor *compositor() const
void sendFeedback(QQuickWindow *window, quint64 sequence, quint64 tv_sec, quint32 tv_nsec)

Reimplemented Public Functions

virtual void initialize() override


void presented(quint64 sequence, quint64 tv_sec, quint32 tv_nsec, quint32 refresh_nsec)

Static Public Members

const struct wl_interface *interface()

Detailed Description

The QWaylandPresentationTime extension provides a way to track rendering timing for a surface. Client can request feedbacks associated with a surface, then compositor send events for the feedback with the time when the surface is presented on-screen.

QWaylandPresentationTime corresponds to the Wayland wp_presentation interface.

Member Function Documentation


Constructs an empty QWaylandPresentationTime object.

QWaylandPresentationTime::QWaylandPresentationTime(QWaylandCompositor *compositor)

Constructs a QWaylandPresentationTime object for compositor.

QWaylandCompositor *QWaylandPresentationTime::compositor() const

[override virtual] void QWaylandPresentationTime::initialize()

Reimplements: QWaylandCompositorExtension::initialize().

Initializes the extension.

[static] const struct wl_interface *QWaylandPresentationTime::interface()

Returns the Wayland interface for the QWaylandPresentationTime.

[signal] void QWaylandPresentationTime::presented(quint64 sequence, quint64 tv_sec, quint32 tv_nsec, quint32 refresh_nsec)

[invokable] void QWaylandPresentationTime::sendFeedback(QQuickWindow *window, quint64 sequence, quint64 tv_sec, quint32 tv_nsec)

Interface to notify that a frame is presented on screen using window. If your platform supports DRM events, page_flip_handler is the proper timing to send it. The sequence is the refresh counter. tv_sec and tv_nsec hold the seconds and nanoseconds parts of the presentation timestamp, respectively.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

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