- Qt 6.8
- Qt Wayland Compositor
- QML Types
- QtWayland.Compositor.PresentationTime
- PresentationTime
- Qt Wayland Compositor | Commercial or GPLv3

# 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

- List of all members, including inherited members

## 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.