nxt::ui::UIRuntime class
#include <nxtio/app.hpp>

Runtime state for the UI system. Owns scheduler, glyph table, compositor, and coordinates signals/events.

Constructors, destructors, conversion operators

UIRuntime()
Create runtime resources and discover the initial terminal size.
UIRuntime(const UIRuntime&) deleted
UIRuntime(UIRuntime&&) deleted
~UIRuntime()
Release runtime resources.

Public functions

void cleanup()
Clean up before exit - clears HUD region.
auto compositor() →  TerminalCompositor& noexcept
Direct access to compositor (for testing or advanced use).
auto damage_event() →  nxt::event& noexcept
Event signaled when damage occurs.
auto get_stop_token() const →  std::stop_token noexcept
Stop token tied to runtime shutdown.
auto glyphs() →  GlyphTable& noexcept
Access the glyph table.
auto has_terminal_surface() const →  bool noexcept
auto input_channel() →  nxt::queue<nxt::input::KeyEvent>& noexcept
Channel for keyboard input events.
auto input_loop() →  nxt::task
Coroutine that reads stdin and publishes decoded keyboard events.
auto next_input() →  nxt::task<std::optional<nxt::input::KeyEvent>>
auto operator=(const UIRuntime&) →  UIRuntime& deleted
auto operator=(UIRuntime&&) →  UIRuntime& deleted
void print(std::string_view text)
void println(std::string_view line)
template <typename Layout>
void render(const Layout& layout)
void request_shutdown()
Request shutdown.
auto resize_channel() →  nxt::queue<TermSize>& noexcept
Channel for resize notifications.
template <typename... Tasks>
auto run(Tasks && ... tasks) →  auto
Schedule tasks on the runtime scheduler and await all of them.
template <typename BuildUI>
auto run_render_loop(BuildUI build_ui, std::chrono::milliseconds frame_time = std::chrono::milliseconds{ 16}) →  nxt::task
auto scheduler() →  nxt::scheduler& noexcept
Access the scheduler.
auto scheduler_handle() →  std::unique_ptr<nxt::scheduler>& noexcept
Access the scheduler owner for libcoro networking APIs.
auto shutdown_after(nxt::task<> t) →  nxt::task
Run a task, then request shutdown when it completes.
auto shutdown_requested() const →  bool noexcept
Check if shutdown has been requested.
void signal_damage()
Signal that the view has been damaged and needs redraw.
auto signal_loop() →  nxt::task
template <class rep_type, class period_type>
auto sleep(std::chrono::duration<rep_type, period_type> duration) →  nxt::task
Sleep on the runtime scheduler.
auto terminal_height() const →  height_t noexcept
auto terminal_size() const →  TermSize noexcept
Current terminal dimensions.
auto terminal_width() const →  width_t noexcept

Function documentation

nxt::task<std::optional<nxt::input::KeyEvent>> nxt::ui::UIRuntime::next_input()

Wait for the next keyboard event. Returns nullopt if the channel shuts down.

void nxt::ui::UIRuntime::print(std::string_view text)

Write text to the scroll region cursor. HUD rendering preserves this cursor, so long-running streams can emit incremental text while the HUD keeps redrawing below.

void nxt::ui::UIRuntime::println(std::string_view line)

Print a line to the scroll region (only works when HUD height < terminal). In full-screen mode, this is a no-op.

template <typename Layout>
void nxt::ui::UIRuntime::render(const Layout& layout)

Render a layout to the screen. Computes HUD height from layout hint, sets up scroll region, renders.

template <typename BuildUI>
nxt::task nxt::ui::UIRuntime::run_render_loop(BuildUI build_ui, std::chrono::milliseconds frame_time = std::chrono::milliseconds{ 16})

Run a render loop until shutdown. BuildUI is called each frame to produce the layout. Waits for damage signal, but rate-limits to frame_time. Note: pass by value to avoid dangling references in coroutine.

nxt::task nxt::ui::UIRuntime::signal_loop()

Coroutine that handles signals from the pipe. Should be run as part of the main task group.