PresentationTime QML Type

Provides tracking the timing when a frame is presented on screen. More...

Import Statement: import QtWayland.Compositor.PresentationTime
Since: Qt 6.3
Instantiates: QWaylandPresentationTime

Methods

  • void sendFeedback(Window window, int sequence, int sec, int nsec)

Detailed Description

The PresentationTime 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.

PresentationTime corresponds to the Wayland wp_presentation interface.

To provide the functionality of the presentationtime extension in a compositor, create an instance of the PresentationTime component and add it to the list of extensions supported by the compositor:

Then, call sendFeedback() when a surface is presented on screen. Usually, the timing can be obtained from drm page flip event.

 import QtWayland.Compositor.PresentationTime

 WaylandCompositor {
     PresentationTime {
         id: presentationTime
     }
 }

Method Documentation

void sendFeedback(Window window, int sequence, int sec, int 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. sec and nsec hold the seconds and nanoseconds parts of the presentation timestamp, respectively.