# IQesdkEventCallBack

Source: [https://docs.qualcomm.com/doc/80-PK177-134/topic/java_iqesdk_event_callback.html](https://docs.qualcomm.com/doc/80-PK177-134/topic/java_iqesdk_event_callback.html)

Upon invocation of onEvent() by the QESDK framework to inform the application of
    service disconnects, the application may deinit() and init() again to re-acquire the
    service.

    IQesdkEventCallBack() {public void onEvent() {}}Copy to clipboard

## Parameters

| Parameter | Data type | Description |
| --- | --- | --- |
| opcode | int | The opcode of the subsystems listed in the other parameter that are<br>                disconnected. |
| subsys | int[] | The list of opcode: subsystems that are disconnected. |

If opcode is 0, the application should initialize all services again, since opcode 0 indicates
        that the QESDK framework restarted due to unexpected issues.

If opcode value is nonzero, the service corresponding to that opcode should initialize
        again.

| **Opcode** | **Service** |
| --- | --- |
| 11 | Modem |
| 19 | Performance |
| 17 | Sensor |
| 24 | Location |
| 0 | All services |

Note: 
          
- A given service end (de-init) on Java/Native, notifies Native/Java correspondingly, if the same service is being used.

    **For example:** If a service is initialized in both Java and Native and de-initializes the session for that
                service in Native, then it triggers the QESDK framework event callback to the application in
                Java. Vice-versa is also true.

Note: From Gen 3 release de-init will be required for all individual services.
- If an application needs to do some UI rendering inside a callback, it needs to switch to a UI thread first as all API callbacks are currently executed non-caller threads.
- Performing time-consuming operations within callbacks of an application is not recommended, due to potential negative impact on performance and real-time responsiveness.

**Parent Topic:** [QESDK Java callback interfaces](https://docs.qualcomm.com/doc/80-PK177-134/topic/qesdk_java_callback_interfaces.html)

Last Published: Nov 14, 2024

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