Media Key Events

Tizen enables you to manage media key events. The media key events are generated by the remote control buttons in a Bluetooth headset or Bluetooth earphone. The media_key_e enumerator (in mobile and wearable applications) defines the available key types.

The main features of the Media key API include:

  • Registering a callback

    You can register a callback for media key events using the media_key_reserve() function. The first parameter of the function defines the media_key_event_cb type callback, which you can implement to perform any actions you need.

  • Deregistering a callback

    You can deregister a callback for media key events using the media_key_release() function.

Prerequisites

To use the functions and data types of the Media key API (in mobile and wearable applications), include the <media_key.h> header file in your application:

#include <media_key.h>

Monitoring Media Key Events

To monitor media key events:

  1. Implement a callback to handle media key events.

    In the following example, the callback simply prints out the key from which the event originated and the state change that caused the event:

    void
event_cb(media_key_e key, media_key_event_e status, void* user_data)
{
    switch (key) {
    case MEDIA_KEY_PLAY:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_PLAY");
        break;
    case MEDIA_KEY_STOP:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_STOP");
        break;
    case MEDIA_KEY_PAUSE:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_PAUSE");
        break;
    case MEDIA_KEY_PREVIOUS:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_PREVIOUS");
        break;
    case MEDIA_KEY_NEXT:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_NEXT");
        break;
    case MEDIA_KEY_FASTFORWARD:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_FASTFORWARD");
        break;
    case MEDIA_KEY_REWIND:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_REWIND");
        break;
    case MEDIA_KEY_PLAYPAUSE:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_PLAYPAUSE");
        break;
    case MEDIA_KEY_UNKNOWN:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: MEDIA_KEY_UNKNOWN");
        break;
    default:
        dlog_print(DLOG_INFO, LOG_TAG, "Key: Unknown");
        break;
    }

    switch (status) {
    case MEDIA_KEY_STATUS_PRESSED:
        dlog_print(DLOG_INFO, LOG_TAG, "Event: MEDIA_KEY_STATUS_PRESSED");
        break;
    case MEDIA_KEY_STATUS_RELEASED:
        dlog_print(DLOG_INFO, LOG_TAG, "Event: MEDIA_KEY_STATUS_RELEASED");
        break;
    case MEDIA_KEY_STATUS_UNKNOWN:
        dlog_print(DLOG_INFO, LOG_TAG, "Event: MEDIA_KEY_STATUS_UNKNOWN");
        break;
    default:
        dlog_print(DLOG_INFO, LOG_TAG, "Event: Unknown");
        break;
    }
}

  2. Register the defined callback with the media_key_reserve() function:

    void
media_key_api_func()
{
    int r = 0;

    r = media_key_reserve(event_cb, NULL);

    if (r == MEDIA_KEY_ERROR_NONE)
        dlog_print(DLOG_INFO, LOG_TAG, "Reserve media key success.");
    else
        dlog_print(DLOG_ERROR, LOG_TAG, "Reserve media key failed.");

  3. When you no longer need to monitor the media key events, deregister the callback with the media_key_release() function:

        r = media_key_release();

    if (r == MEDIA_KEY_ERROR_NONE)
        dlog_print(DLOG_INFO, LOG_TAG, "Release media key success.");
    else if (r == MEDIA_KEY_ERROR_INVALID_PARAMETER)
        dlog_print(DLOG_ERROR, LOG_TAG, "Invalid parameter.");
    else if (r == MEDIA_KEY_ERROR_OPERATION_FAILED)
        dlog_print(DLOG_ERROR, LOG_TAG, "Operation failed.");
    else
        dlog_print(DLOG_ERROR, LOG_TAG, "Failed. Unknown reason.");
}
  • Dependencies
    • Tizen 2.4 and Higher for Mobile
    • Tizen 2.3.1 and Higher for Wearable
Edit this page