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hotplug: Add ability to register device connection/disconnection callback (#299)
- initial API; - Windows backend implementation;
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Lines changed: 559 additions & 3 deletions

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‎hidapi/hidapi.h‎

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@@ -254,6 +254,112 @@ extern "C" {
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*/
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void HID_API_EXPORT HID_API_CALL hid_free_enumeration(struct hid_device_info *devs);
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/** @brief Callback handle.
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Callbacks handles are generated by hid_hotplug_register_callback()
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and can be used to deregister callbacks. Callback handles are unique
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and it is safe to call hid_hotplug_deregister_callback() on
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an already deregistered callback.
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@ingroup API
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*/
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typedef int hid_hotplug_callback_handle;
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/**
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Hotplug events
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@ingroup API
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*/
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typedef enum {
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/** A device has been plugged in and is ready to use */
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HID_API_HOTPLUG_EVENT_DEVICE_ARRIVED = (1 << 0),
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/** A device has left and is no longer available.
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It is the user's responsibility to call hid_close with a disconnected device.
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*/
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HID_API_HOTPLUG_EVENT_DEVICE_LEFT = (1 << 1)
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} hid_hotplug_event;
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/**
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Hotplug flags
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@ingroup API
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*/
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typedef enum {
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/** Arm the callback and fire it for all matching currently attached devices. */
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HID_API_HOTPLUG_ENUMERATE = (1 << 0)
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} hid_hotplug_flag;
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/** @brief Hotplug callback function type. When requesting hotplug event notifications,
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you pass a pointer to a callback function of this type.
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This callback may be called by an internal event thread and as such it is
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recommended the callback do minimal processing before returning.
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hidapi will call this function later, when a matching event had happened on
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a matching device.
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Note that when callbacks are called from hid_hotplug_register_callback()
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because of the \ref HID_API_HOTPLUG_ENUMERATE flag, the callback return
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value is ignored. In other words, you cannot cause a callback to be
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deregistered by returning 1 when it is called from hid_hotplug_register_callback().
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@ingroup API
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@param callback_handle The hid_hotplug_callback_handle callback handle.
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@param device The hid_device_info of device this event occurred on event that occurred.
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@param event Event that occurred.
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@param user_data User data provided when this callback was registered.
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(Optionally NULL).
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@returns bool
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Whether this callback is finished processing events.
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Returning non-zero value will cause this callback to be deregistered.
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*/
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typedef int (HID_API_CALL *hid_hotplug_callback_fn)(
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hid_hotplug_callback_handle callback_handle,
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struct hid_device_info *device,
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hid_hotplug_event event,
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void *user_data);
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/** @brief Register a HID hotplug callback function.
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If @p vendor_id is set to 0 then any vendor matches.
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If @p product_id is set to 0 then any product matches.
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If @p vendor_id and @p product_id are both set to 0, then all HID devices will be notified.
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@ingroup API
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@param vendor_id The Vendor ID (VID) of the types of device to notify about.
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@param product_id The Product ID (PID) of the types of device to notify about.
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@param events Bitwise or of hotplug events that will trigger this callback.
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See \ref hid_hotplug_event.
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@param flags Bitwise or of hotplug flags that affect registration.
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See \ref hid_hotplug_flag.
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@param callback The callback function that will be called on device connection/disconnection.
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See \ref hid_hotplug_callback_fn.
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@param user_data The user data you wanted to provide to your callback function.
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@param callback_handle Pointer to store the handle of the allocated callback
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(Optionally NULL).
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@returns
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This function returns 0 on success or -1 on error.
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*/
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int HID_API_EXPORT HID_API_CALL hid_hotplug_register_callback(unsigned short vendor_id, unsigned short product_id, int events, int flags, hid_hotplug_callback_fn callback, void *user_data, hid_hotplug_callback_handle *callback_handle);
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/** @brief Deregister a callback from a HID hotplug.
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This function is safe to call from within a hotplug callback.
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@ingroup API
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@param callback_handle The handle of the callback to deregister.
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@returns
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This function returns 0 on success or -1 on error.
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*/
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int HID_API_EXPORT HID_API_CALL hid_hotplug_deregister_callback(hid_hotplug_callback_handle callback_handle);
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/** @brief Open a HID device using a Vendor ID (VID), Product ID
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(PID) and optionally a serial number.
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‎hidtest/test.c‎

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Original file line numberDiff line numberDiff line change
@@ -109,6 +109,34 @@ void print_devices_with_descriptor(struct hid_device_info *cur_dev) {
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}
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}
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int device_callback(
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hid_hotplug_callback_handle callback_handle,
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struct hid_device_info* device,
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hid_hotplug_event event,
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void* user_data)
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{
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(void)user_data;
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if (event & HID_API_HOTPLUG_EVENT_DEVICE_ARRIVED)
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printf("Handle %d: New device is connected: %s.\n", callback_handle, device->path);
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else
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printf("Handle %d: Device was disconnected: %s.\n", callback_handle, device->path);
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printf("type: %04hx %04hx\n serial_number: %ls", device->vendor_id, device->product_id, device->serial_number);
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printf("\n");
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printf(" Manufacturer: %ls\n", device->manufacturer_string);
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printf(" Product: %ls\n", device->product_string);
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printf(" Release: %hx\n", device->release_number);
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printf(" Interface: %d\n", device->interface_number);
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printf(" Usage (page): 0x%hx (0x%hx)\n", device->usage, device->usage_page);
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printf("\n");
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//if (device->product_id == 0x0ce6)
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// return 1;
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return 0;
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}
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int main(int argc, char* argv[])
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{
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(void)argc;
@@ -120,6 +148,7 @@ int main(int argc, char* argv[])
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wchar_t wstr[MAX_STR];
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hid_device *handle;
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int i;
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hid_hotplug_callback_handle token1, token2;
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struct hid_device_info *devs;
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@@ -144,6 +173,17 @@ int main(int argc, char* argv[])
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print_devices_with_descriptor(devs);
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hid_free_enumeration(devs);
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hid_hotplug_register_callback(0, 0, HID_API_HOTPLUG_EVENT_DEVICE_ARRIVED | HID_API_HOTPLUG_EVENT_DEVICE_LEFT, HID_API_HOTPLUG_ENUMERATE, device_callback, NULL, &token1);
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hid_hotplug_register_callback(0x054c, 0x0ce6, HID_API_HOTPLUG_EVENT_DEVICE_ARRIVED | HID_API_HOTPLUG_EVENT_DEVICE_LEFT, HID_API_HOTPLUG_ENUMERATE, device_callback, NULL, &token2);
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while (1)
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{
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}
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hid_hotplug_deregister_callback(token2);
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hid_hotplug_deregister_callback(token1);
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// Set up the command buffer.
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memset(buf,0x00,sizeof(buf));
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buf[0] = 0x01;

‎libusb/hid.c‎

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Original file line numberDiff line numberDiff line change
@@ -863,6 +863,28 @@ void HID_API_EXPORT hid_free_enumeration(struct hid_device_info *devs)
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}
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}
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int HID_API_EXPORT HID_API_CALL hid_hotplug_register_callback(unsigned short vendor_id, unsigned short product_id, int events, int flags, hid_hotplug_callback_fn callback, void *user_data, hid_hotplug_callback_handle *callback_handle)
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{
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/* Stub */
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(void)vendor_id;
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(void)product_id;
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(void)events;
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(void)flags;
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(void)callback;
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(void)user_data;
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(void)callback_handle;
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return -1;
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}
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int HID_API_EXPORT HID_API_CALL hid_hotplug_deregister_callback(hid_hotplug_callback_handle callback_handle)
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{
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/* Stub */
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(void)callback_handle;
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return -1;
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}
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hid_device * hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
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{
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struct hid_device_info *devs, *cur_dev;

‎linux/hid.c‎

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Original file line numberDiff line numberDiff line change
@@ -942,6 +942,28 @@ void HID_API_EXPORT hid_free_enumeration(struct hid_device_info *devs)
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}
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}
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int HID_API_EXPORT HID_API_CALL hid_hotplug_register_callback(unsigned short vendor_id, unsigned short product_id, int events, int flags, hid_hotplug_callback_fn callback, void *user_data, hid_hotplug_callback_handle *callback_handle)
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{
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/* Stub */
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(void)vendor_id;
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(void)product_id;
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(void)events;
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(void)flags;
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(void)callback;
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(void)user_data;
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(void)callback_handle;
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return -1;
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}
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int HID_API_EXPORT HID_API_CALL hid_hotplug_deregister_callback(hid_hotplug_callback_handle callback_handle)
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{
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/* Stub */
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(void)callback_handle;
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return -1;
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}
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hid_device * hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
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{
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struct hid_device_info *devs, *cur_dev;

‎mac/hid.c‎

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Original file line numberDiff line numberDiff line change
@@ -726,6 +726,28 @@ void HID_API_EXPORT hid_free_enumeration(struct hid_device_info *devs)
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}
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}
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int HID_API_EXPORT HID_API_CALL hid_hotplug_register_callback(unsigned short vendor_id, unsigned short product_id, int events, int flags, hid_hotplug_callback_fn callback, void *user_data, hid_hotplug_callback_handle *callback_handle)
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{
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/* Stub */
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(void)vendor_id;
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(void)product_id;
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(void)events;
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(void)flags;
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(void)callback;
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(void)user_data;
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(void)callback_handle;
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return -1;
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}
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int HID_API_EXPORT HID_API_CALL hid_hotplug_deregister_callback(hid_hotplug_callback_handle callback_handle)
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{
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/* Stub */
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(void)callback_handle;
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return -1;
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}
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hid_device * HID_API_EXPORT hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
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{
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/* This function is identical to the Linux version. Platform independent. */

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