System Settings

You can access the system configuration related to user preferences, such as ringtone, wallpaper, and font, using the System Settings API with the system setting keys.

The System Settings API provides 2 function types listed in the following table. Certain functions support both types, whereas others only support the getter function.

Table: System Settings API function types

The following example shows a typical use case. An application sees the name of the current wallpaper and you want to print out a message when the wallpaper changes:

void
_img_cb(system_settings_key_e key, void *user_data)
{
    dlog_print(DLOG_INFO, LOG_TAG, "THIS IS CALLED BY USER APPLICATION WHEN THE WALLPAPER CHANGES \n");
}

/* NOTIFIER 1 - Registering a callback function */
system_settings_set_changed_cb(SYSTEM_SETTINGS_KEY_WALLPAPER_HOME_SCREEN, _img_cb, NULL);
char * path;

/* GETTER */
system_settings_get_value_string(SYSTEM_SETTINGS_KEY_WALLPAPER_HOME_SCREEN, &path);
dlog_print(DLOG_INFO, LOG_TAG, "path of the current wallpaper is %s \n", path);

/* NOTIFIER 2 - Deregistering a callback function */
system_settings_unset_changed_cb(SYSTEM_SETTINGS_KEY_WALLPAPER_HOME_SCREEN);

Prerequisites

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

#include <system_settings.h>

Managing System Settings

To manage system settings, which provide access to system variables:

1. Define auxiliary structures:

   struct _ret_type_define {
       system_settings_key_e key;
       int returns;
   };
   
   typedef
   enum {
       _RET_BOOL = 0,
       _RET_INT,
       _RET_STRING
   } _SYSTEM_SETTINGS_TYPES;
   
   struct _ret_type_define
   _ret_type[] = {
       {
           SYSTEM_SETTINGS_KEY_INCOMING_CALL_RINGTONE, _RET_STRING
       },
       {
           SYSTEM_SETTINGS_KEY_WALLPAPER_HOME_SCREEN, _RET_STRING
       },
       {
           SYSTEM_SETTINGS_KEY_WALLPAPER_LOCK_SCREEN, _RET_STRING
       },
       {
           SYSTEM_SETTINGS_KEY_FONT_SIZE, _RET_INT
       },
       {
           SYSTEM_SETTINGS_KEY_FONT_TYPE, _RET_STRING
       },
       {
           SYSTEM_SETTINGS_KEY_MOTION_ACTIVATION, _RET_BOOL
       },
       {
           /* Others */
       }
   };
   
   static const char*
   _info_key[SYS_INFO_COUNT] = {
       "SYSTEM_SETTINGS_KEY_INCOMING_CALL_RINGTONE",
       "SYSTEM_SETTINGS_KEY_WALLPAPER_HOME_SCREEN",
       "SYSTEM_SETTINGS_KEY_WALLPAPER_LOCK_SCREEN",
       "SYSTEM_SETTINGS_KEY_FONT_SIZE",
       "SYSTEM_SETTINGS_KEY_FONT_TYPE",
       "SYSTEM_SETTINGS_KEY_MOTION_ACTIVATION",
       /* Others */
   };
   

2. Obtain the setting data.

   The available settings are defined in the system_settings_key_e enumerator (in mobile and wearable applications).

   Read the data using the following functions, according to the data type of the value you want to read:

   • system_settings_get_value_int()
   • system_settings_get_value_bool()
   • system_settings_get_value_double()
   • system_settings_get_value_string()

   #define SYS_INFO_COUNT 6
   
   int i;
   for (i = 0; i < SYS_INFO_COUNT; i++) {
       dlog_print(DLOG_ERROR, LOG_TAG, "%d- System_settings: %s: ", i, _info_key[_ret_type[i].key]);
   
       if (_ret_type[i].returns==_RET_BOOL) {
           system_settings_get_value_bool(_ret_type[i].key, &_bool_ret);
           dlog_print(DLOG_ERROR, LOG_TAG, "%d", _bool_ret);
       } else if (_ret_type[i].returns==_RET_INT) {
           system_settings_get_value_int(_ret_type[i].key, &_int_ret);
           dlog_print(DLOG_ERROR, LOG_TAG, "%d", _int_ret);
       } else if (_ret_type[i].returns==_RET_STRING) {
           system_settings_get_value_string(_ret_type[i].key, &_string_ret);
           dlog_print(DLOG_ERROR, LOG_TAG, "%s", _string_ret);
           free(_string_ret);
       } else if (_ret_type[i].returns==_RET_DOUBLE) {
           system_settings_get_value_double(_ret_type[i].key, &_double_ret);
           dlog_print(DLOG_ERROR, LOG_TAG, "%f", _double_ret);
       } else {
           dlog_print(DLOG_ERROR, LOG_TAG, "Undefined return type");
       }
   }
   

3. Monitor changes in the setting values.

   1. To monitor when a system setting value changes, set a callback using the system_settings_set_changed_cb() function with the appropriate key as the first parameter:

      for (i = 0; i < SYS_INFO_COUNT; i++)
          system_settings_set_changed_cb(_ret_type[i].key, _system_settings_changed_cb, 0);
      

   2. Define the callback to be invoked after each change.

      The system_settings_key_e key refers to the key that has changed.

      static void
      _system_settings_changed_cb(system_settings_key_e key, void *user_data)
      {
          dlog_print(DLOG_ERROR, LOG_TAG, "Runtime Info changed: %s", _info_key[key]);
      }
      

   3. When the callbacks are no longer needed, unset them:

      for (i = 0; i < SYS_INFO_COUNT; i++)
          system_settings_unset_changed_cb(_ret_type[i].key, _system_settings_changed_cb, 0);
      

System Setting Keys

The system_settings_key_e enumerator (in mobile and wearable applications) defines all enumerations that work as parameters for the System Settings API.

The following table lists the available system setting keys.

Table: System settings keys

Related Information

• Dependencies
  • Tizen 2.4 and Higher for Mobile
  • Tizen 2.3.1 and Higher for Wearable