sdk/fidl/fuchsia.input.interaction/notifier.fidl

// Copyright 2022 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.input.interaction;

/// The Notifier protocol offers a subscription interface through
/// which clients can watch for changes in the system's activity state.
@discoverable
protocol Notifier {
    /// Subscribe to changes in the system's state with a hanging-get FIDL
    /// pattern.
    ///
    /// The server will always respond immediately with the initial state,
    /// and after that whenever the system's state changes.
    WatchState() -> (resource struct {
        state State;
    });
};