// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module media_session.mojom;

import "mojo/public/mojom/base/time.mojom";
import "services/media_session/public/mojom/media_session.mojom";

// Controls a MediaSession. This will automatically route commands to the
// correct session if the audio focus changes. If the media session is
// not controllable then the commands will be no-ops.
interface MediaController {
  // Suspend the media session.
  Suspend();

  // Resume the media session.
  Resume();

  // Stop the media session.
  Stop();

  // This will either suspend or resume the media session based on the
  // playback state.
  ToggleSuspendResume();

  // Adds an observer that will forward events from the active media session.
  // If the active session changes then observers do not need to be readded.
  // Adding the observer will update the observer with the latest state.
  AddObserver(MediaSessionObserver observer);

  // Skip to the previous track. If there is no previous track then this will be
  // a no-op.
  PreviousTrack();

  // Skip to the next track. If there is no next track then this will be a
  // no-op.
  NextTrack();

  // Seek the media session. If the media cannot seek then this will be a
  // no-op. The |seek_time| is the time delta that the media will seek by and
  // supports both positive and negative values. This value cannot be zero.
  // The |kDefaultSeekTimeSeconds| provides a default value for seeking by a
  // few seconds.
  Seek(mojo_base.mojom.TimeDelta seek_time);
};