MediaBrowserService_8cpp

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title: src/Channel/MediaBrowser/MediaBrowserService.cpp summary: Media browser channel for browsing device music library.

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src/Channel/MediaBrowser/MediaBrowserService.cpp

Media browser channel for browsing device music library. More...

Namespaces

Name
aasdk
aasdk::channel
aasdk::channel::mediabrowser

Detailed Description

Media browser channel for browsing device music library.

MediaBrowserService enables the head unit to browse Android device media library (local files, streaming services like Spotify, cloud storage). Provides hierarchical navigation from root node through folders, playlists, artists, albums, and individual songs.

Message flow:

1. Head unit requests MEDIA_GET_NODE for current browsing point
2. Android responds with node tree (folders, files)
3. User selects item; head unit sends MEDIA_BROWSE_INPUT (select/navigate)
4. Android updates model; sends new MEDIA_*_NODE tree
5. Display refreshes with updated content

Node types:

• MEDIA_ROOT_NODE: Top-level library (all music)
• MEDIA_SOURCE_NODE: Music source (Spotify, local files, etc.)
• MEDIA_LIST_NODE: Folder, artist, or playlist
• MEDIA_SONG_NODE: Playable track (leaf node)

Scenario: Browsing Spotify on head unit

• T+0ms: User taps Music app on head unit
• T+5ms: MediaBrowserService sends MEDIA_GET_NODE
• T+50ms: Android responds with MEDIA_ROOT_NODE (Spotify, Local, etc.)
• T+50ms: Head unit displays options: "Spotify", "Local Files"
• T+100ms: User selects "Spotify"
• T+100ms: Head unit sends MEDIA_BROWSE_INPUT (navigate to Spotify)
• T+150ms: Android responds with MEDIA_SOURCE_NODE (Recently Played, Search, etc.)
• T+150ms: Display updated; user navigates playlists
• User continues browsing without re-establishing connection

Design: Stateful browsing session maintained by Android device; head unit sends incremental navigation commands; Android responds with updated tree.

This implementation can drive multiple LCD screens for advanced infotainment.

Source code

// This file is part of aasdk library project.
// Copyright (C) 2018 f1x.studio (Michal Szwaj)
// Copyright (C) 2024 CubeOne (Simon Dean - simon.dean@cubeone.co.uk)
// Copyright (C) 2026 OpenCarDev (Matthew Hilton - matthilton2005@gmail.com)
//
// aasdk is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// aasdk is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with aasdk. If not, see <http://www.gnu.org/licenses/>.

#include <aap_protobuf/service/mediabrowser/MediaBrowserMessageId.pb.h>
#include <aasdk/Channel/MediaBrowser/IMediaBrowserServiceEventHandler.hpp>
#include <aasdk/Channel/MediaBrowser/MediaBrowserService.hpp>
#include "aasdk/Common/Log.hpp"
#include <aasdk/Common/ModernLogger.hpp>

namespace aasdk::channel::mediabrowser {

  MediaBrowserService::MediaBrowserService(boost::asio::io_service::strand &strand,
                                           messenger::IMessenger::Pointer messenger)
      : Channel(strand, std::move(messenger), messenger::ChannelId::MEDIA_BROWSER) {

  }

  void MediaBrowserService::receive(IMediaBrowserServiceEventHandler::Pointer eventHandler) {

    AASDK_LOG_CHANNEL_MEDIA_BROWSER(debug, "receive()");
    auto receivePromise = messenger::ReceivePromise::defer(strand_);
    receivePromise->then(
        std::bind(&MediaBrowserService::messageHandler, this->shared_from_this(), std::placeholders::_1,
                  eventHandler),
        std::bind(&IMediaBrowserServiceEventHandler::onChannelError, eventHandler, std::placeholders::_1));

    messenger_->enqueueReceive(channelId_, std::move(receivePromise));
  }

  void MediaBrowserService::sendChannelOpenResponse(const aap_protobuf::service::control::message::ChannelOpenResponse &response,
                                                    SendPromise::Pointer promise) {
    AASDK_LOG_CHANNEL_MEDIA_BROWSER(debug, "sendChannelOpenResponse()");
    auto message(std::make_shared<messenger::Message>(channelId_, messenger::EncryptionType::ENCRYPTED,
                                                      messenger::MessageType::CONTROL));
    message->insertPayload(
        messenger::MessageId(
            aap_protobuf::service::control::message::ControlMessageType::MESSAGE_CHANNEL_OPEN_RESPONSE).getData());
    message->insertPayload(response);

    this->send(std::move(message), std::move(promise));
  }

  void MediaBrowserService::messageHandler(messenger::Message::Pointer message,
                                           IMediaBrowserServiceEventHandler::Pointer eventHandler) {
    AASDK_LOG_CHANNEL_MEDIA_BROWSER(debug, "messageHandler()");

    messenger::MessageId messageId(message->getPayload());
    common::DataConstBuffer payload(message->getPayload(), messageId.getSizeOf());

    switch (messageId.getId()) {
      case aap_protobuf::service::control::message::ControlMessageType::MESSAGE_CHANNEL_OPEN_REQUEST:
        this->handleChannelOpenRequest(payload, std::move(eventHandler));
      case aap_protobuf::service::mediabrowser::MediaBrowserMessageId::MEDIA_ROOT_NODE:
      case aap_protobuf::service::mediabrowser::MediaBrowserMessageId::MEDIA_SOURCE_NODE:
      case aap_protobuf::service::mediabrowser::MediaBrowserMessageId::MEDIA_LIST_NODE:
      case aap_protobuf::service::mediabrowser::MediaBrowserMessageId::MEDIA_SONG_NODE:
      case aap_protobuf::service::mediabrowser::MediaBrowserMessageId::MEDIA_GET_NODE:
      case aap_protobuf::service::mediabrowser::MediaBrowserMessageId::MEDIA_BROWSE_INPUT:
      default:
        AASDK_LOG(error) << "[MediaBrowserService] Message Id not Handled: " << messageId.getId();
        this->receive(std::move(eventHandler));
        break;
    }
  }

  void MediaBrowserService::handleChannelOpenRequest(const common::DataConstBuffer &payload,
                                                     IMediaBrowserServiceEventHandler::Pointer eventHandler) {
    AASDK_LOG_CHANNEL_MEDIA_BROWSER(debug, "handleChannelOpenRequest()");
    aap_protobuf::service::control::message::ChannelOpenRequest request;
    if (request.ParseFromArray(payload.cdata, payload.size)) {
      eventHandler->onChannelOpenRequest(request);
    } else {
      eventHandler->onChannelError(error::Error(error::ErrorCode::PARSE_PAYLOAD));
    }
  }
}

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Updated on 2026-03-15 at 09:02:41 +0000