App and the loop

vw::App owns the surfaces, the event sources and the loop. vw/vw.hpp includes the whole public API.

#include <vw/vw.hpp>

int main() {
  vw::App app;
  app.surface(build_bar)
     .surface(build_launcher)
     .on_event(vw::hyprland::event_fd(), vw::hyprland::drain_events);
  return app.run();
}

vw::App

Member	Meaning
`App()` / `App(build)`	an empty app, or one with a single surface
`surface(build)`	adds a surface built by `void(vw::Ui&)`; chainable
`on_event(fd, drain)`	rebuilds every surface when `fd` is readable and `drain()` returns true; negative fds are ignored
`run()`	runs until closed; returns `EXIT_SUCCESS`, or prints the error and returns `EXIT_FAILURE`
`build()`	builds the first surface once — check a scene without Wayland

When a surface rebuilds

Trigger	Which surfaces
input on a surface	that one at once, the rest before the loop sleeps
an event source fired	all of them
its `refresh_interval` elapsed (default 1 s)	only that one
a frame callback while animating	only that one
SIGHUP	all of them

SIGINT and SIGTERM end run() cleanly.

Lower level

vw::SceneSource is the interface the loop drives: build() returns a vw::Scene, event_sources() lists fds, and watch_directory()/affects(name) let a source rebuild on file edits (the Lua frontend uses this for hot reload). vw::run(source) runs one. Most programs never need it.

Host state

Functions in vw/host.hpp describe the surface being built:

Function	Returns
`vw::surface_size()`	the configured size of the layer surface being built, `{0, 0}` before the first configure
`vw::toplevel_size()`	the window’s configured size
`vw::lock_surface_context()`	width, height and output name of the lock surface being built
`vw::session_locked()`, `vw::session_authentication_failed()`	lock state
`vw::focus_grab_state()`	whether zwwm’s focus grab is available and active