[−][src]Trait wayland_protocols::presentation_time::client::wp_presentation::EventHandler
An interface for handling events.
Provided methods
fn clock_id(&mut self, object: WpPresentation, clk_id: u32)
clock ID for timestamps
This event tells the client in which clock domain the compositor interprets the timestamps used by the presentation extension. This clock is called the presentation clock.
The compositor sends this event when the client binds to the presentation interface. The presentation clock does not change during the lifetime of the client connection.
The clock identifier is platform dependent. On Linux/glibc, the identifier value is one of the clockid_t values accepted by clock_gettime(). clock_gettime() is defined by POSIX.1-2001.
Timestamps in this clock domain are expressed as tv_sec_hi, tv_sec_lo, tv_nsec triples, each component being an unsigned 32-bit value. Whole seconds are in tv_sec which is a 64-bit value combined from tv_sec_hi and tv_sec_lo, and the additional fractional part in tv_nsec as nanoseconds. Hence, for valid timestamps tv_nsec must be in [0, 999999999].
Note that clock_id applies only to the presentation clock, and implies nothing about e.g. the timestamps used in the Wayland core protocol input events.
Compositors should prefer a clock which does not jump and is not slewed e.g. by NTP. The absolute value of the clock is irrelevant. Precision of one millisecond or better is recommended. Clients must be able to query the current clock value directly, not by asking the compositor.