esp_bt_hidh_init() (IDFGH-5393)

[guo-max]

Is your feature request related to a problem? Please describe.

esp_err_t esp_bt_hidh_init(const esp_hidh_config_t *config)
{
    if (config == NULL) {
        ESP_LOGE(TAG, "Config is NULL");
        return ESP_FAIL;
    }
    esp_event_loop_args_t event_task_args = {
        .queue_size = 5,
        .task_name = "esp_bt_hidh_events",
        .task_priority = uxTaskPriorityGet(NULL),
        .task_stack_size = 2048,
        .task_core_id = tskNO_AFFINITY
    };
    esp_err_t ret = esp_event_loop_create(&event_task_args, &event_loop_handle);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "esp_event_loop_create failed!");
        return ret;
    }
    esp_event_handler_register_with(event_loop_handle, ESP_HIDH_EVENTS, ESP_EVENT_ANY_ID, config->callback, NULL);
    BTA_HhEnable(0, bta_hh_cb);
    return ESP_OK;
}

In the function

esp_err_t esp_bt_hidh_init(const esp_hidh_config_t *config)

there is a function call

 esp_event_handler_register_with(event_loop_handle, ESP_HIDH_EVENTS, ESP_EVENT_ANY_ID, config->callback, NULL);

And the last param "void* event_handler_arg" is given "NULL".

Because of this, the callback function is always has a "NULL" for the "void* event_handler_arg"

typedef void         (*esp_event_handler_t)(void* event_handler_arg,
                                        esp_event_base_t event_base,
                                        int32_t event_id,
                                        void* event_data); /**< function called when an event is posted to the queue */

Describe the solution you'd like

Can you add another member to the config like config->event_handler_arg and pass it to the function?

[boblane1]

Hi guo-max,

Your suggestion is reasonable, but adding config->event_handler_arg will cause the change of interface. Would you mind working around the problem by software?

Thanks!

[guo-max]

I need to use the callback function and the "void* event_handler_arg" argument. But the esp_bt_hidh_init function is always set it to NULL. I do not know how to work around this problem by software except make my own hidh_init function and not use the library.
Do you have a easier way to solve this problem?

[boblane1]

Hi guo-max,

I think there are two ways to solve this problem:

1. You can just change the esp_hidh_config_t structure and code on your local branch, the code is open source;
2. Replace event_handler_arg with a global variable in the callback function.

What about?

[Alvin1Zhang]

@guo-max Thanks for reporting. Would you please help share if any updates or details for this feature request? Thanks.

[Alvin1Zhang]

@guo-max Thanks for reporting. Would you please help share if any updates or details for this feature request? Thanks.

[Alvin1Zhang]

Thanks for reporting, this has been implemented in 5c95024, and will be part of IDF v4.4 release, you could update to the latest release/4.4 branch to have a try, feel free to reopen.