pub fn frontmost_application() -> Option<ForegroundApp>Expand description
Return the currently frontmost application.
ForegroundApp::id is the identifier per-app profiles match on: the
bundle identifier on macOS (e.g. "com.microsoft.VSCode"), the WM_CLASS
class component under X11 / XWayland (e.g. "Code"), the xdg-shell
app_id under wlroots (e.g. "org.mozilla.firefox"), and the lower-cased
executable path on Windows. ForegroundApp::display_name is whatever the
platform can name it, falling back to the identifier.
None when no app is frontmost, when reading fails, or on an unsupported
platform — including a pure-Wayland session with no backend (see
linux::detect_frontmost_source). Costs one X11 round-trip on Linux and a
handful of objc_msgSends on macOS. Callers can use
watch_frontmost_application_changes to drive reads from native platform
events instead of polling.