Runtime information: Receiving and Monitoring Runtime Information

This tutorial demonstrates how you can obtain runtime information, such as system preferences.

Warm-up

Become familiar with the Runtime information API basics by learning about:

• Getting Runtime Information

  Get runtime information.

• Monitoring Runtime Information Changes

  Register a callback function for a specific change in the runtime information.

Getting Runtime Information

To get runtime information, which consists of key, value pairs:

1. To use the runtime information-related features of the Runtime information API (in mobile and wearable applications), include the <runtime_info.h> header file in your application:

   #include <runtime_info.h>
   

2. Check whether Bluetooth is enabled.

   Use the RUNTIME_INFO_KEY_BLUETOOTH_ENABLED key to check whether Bluetooth is enabled. The type of the value is bool, and the runtime_info_get_value_bool() function is used for the information.

   #include <stdbool.h>
   #include <runtime_info.h>
   void func(void)
   {
      bool value;
      int ret;
   
      ret = runtime_info_get_value_bool(RUNTIME_INFO_KEY_BLUETOOTH_ENABLED, &value);
      if (ret != RUNTIME_INFO_ERROR_NONE)
      {
         // Error handling
         return;
      }
      dlog_print(DLOG_INFO, LOG_TAG, "Bluetooth: %s", value ? "Enabled" : "Disabled");
   }
   

3. Get the audio jack status.

   Use the RUNTIME_INFO_KEY_AUDIO_JACK_STATUS key to get the audio jack status. The type of the value is integer, and the runtime_info_get_value_int() function is used for the information.

   #include <runtime_info.h>
   
   void func(void)
   {
      int value;
      int ret;
   
      ret = runtime_info_get_value_int(RUNTIME_INFO_KEY_AUDIO_JACK_STATUS, &value);
      if (ret != RUNTIME_INFO_ERROR_NONE)
      {
         // Error handling
         return;
      }
   
      dlog_print(DLOG_INFO, LOG_TAG, "Audio jack status: %d", value);
      switch (value)
      {
      case RUNTIME_INFO_AUDIO_JACK_STATUS_UNCONNECTED:
         // Audio jack is not connected
         break;
      case RUNTIME_INFO_AUDIO_JACK_STATUS_CONNECTED_3WIRE:
         // 3-conductor wire is connected
         break;
      case RUNTIME_INFO_AUDIO_JACK_STATUS_CONNECTED_4WIRE:
         // 4-conductor wire is connected
         break;
      }
   }
   

Monitoring Runtime Information Changes

To monitor runtime information changes:

1. To use the runtime information-related features of the Runtime information API (in mobile and wearable applications), include the <runtime_info.h> header file in your application:

   #include <runtime_info.h>
   

2. Applications can be notified about changes in the runtime information. The runtime_info_set_changed_cb() and runtime_info_unset_changed_cb() functions are used to register a callback function.

   Use the RUNTIME_INFO_KEY_USB_CONNECTED key to monitor the connection state of the USB cable:

   #include <stdbool.h>
   #include <runtime_info.h>
   
   void usb_connection_changed(runtime_info_key_e key, void *user_data)
   {
      bool value;
      int ret;
   
      if (key != RUNTIME_INFO_KEY_USB_CONNECTED)
         return;
   
      ret = runtime_info_get_value_bool(key, &value);
      if (ret != RUNTIME_INFO_ERROR_NONE)
      {
         // Error handling
         return;
      }
   
      dlog_print(DLOG_INFO, LOG_TAG, "USB status: %s", value ? "Connected" : "Disconnected");
   }
   
   void func(void)
   {
      int ret;
      void *data;
   
      ret = runtime_info_set_changed_cb(RUNTIME_INFO_KEY_USB_CONNECTED, usb_connection_changed, data);
      if (ret != RUNTIME_INFO_ERROR_NONE)
      {
         // Error handling
         return;
      }
   
      ret = runtime_info_unset_changed_cb(RUNTIME_INFO_KEY_USB_CONNECTED);
      if (ret != RUNTIME_INFO_ERROR_NONE)
      {
         // Error handling
         return;
      }
   }