// Copyright 2019 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.ui.activity.control;

using fuchsia.ui.activity;

/// The Control protocol can be used to override the activity state of the
/// Activity Service (fuchsia.ui.activity).
///
/// State provided through this interface takes precedence over state which
/// is determined based on activity sent through the Tracker API.
///
/// Once a state has been assigned through this protocol, the Activity
/// Service will no longer determine state based on input to the
/// fuchsia.ui.activity.Tracker protocol, and instead will only report state
/// transitions occuring through the Control protocol.
// TODO(fxbug.dev/38334): Remove this transitional interface.
[Discoverable]
protocol Control {
    /// Sets the Activity Service's state to `state`.
    /// All listeners registered through the Provider protocol will immediately
    /// be notified of the new state.
    ///
    /// Typically, state transitions should occur minutes apart (e.g.
    /// transition from ACTIVE to IDLE after 15 minutes of inactivity).
    SetState(fuchsia.ui.activity.State state);
};