FpTimeoutFunc ()

void
(*FpTimeoutFunc) (FpDevice *device,
                  gpointer user_data);

The prototype of the callback function for fpi_device_add_timeout().

fpi_device_get_usb_device ()

GUsbDevice *
fpi_device_get_usb_device (FpDevice *device);

Get the GUsbDevice for this FpDevice. Only permissible to call if the FpDevice is of type FP_DEVICE_TYPE_USB.

fpi_device_get_udev_data ()

gpointer
fpi_device_get_udev_data (FpDevice *device,
                          FpiDeviceUdevSubtypeFlags subtype);

Get a subtype-specific hardware resource for this FpDevice. Only permissible to call if the FpDevice is of type FP_DEVICE_TYPE_UDEV.

fpi_device_get_virtual_env ()

const gchar *
fpi_device_get_virtual_env (FpDevice *device);

Get the value of the environment variable that caused the virtual FpDevice to be generated. Only permissible to call if the FpDevice is of type FP_DEVICE_TYPE_VIRTUAL.

fpi_device_get_current_action ()

FpiDeviceAction
fpi_device_get_current_action (FpDevice *device);

Get the currently ongoing action or FPI_DEVICE_ACTION_NONE if there is no operation at this time.

This is useful for drivers that might share code paths between different actions (e.g. verify and identify) and want to find out again later which action was started in the beginning.

fpi_device_retry_new ()

GError *
fpi_device_retry_new (FpDeviceRetry error);

Create a new retry error code for use with fpi_device_verify_complete() and similar calls.

fpi_device_error_new ()

GError *
fpi_device_error_new (FpDeviceError error);

Create a new error code for use with fpi_device_verify_complete() and similar calls.

fpi_device_retry_new_msg ()

GError *
fpi_device_retry_new_msg (FpDeviceRetry error,
                          const gchar *msg,
                          ...);

Create a new retry error code for use with fpi_device_verify_complete() and similar calls.

fpi_device_error_new_msg ()

GError *
fpi_device_error_new_msg (FpDeviceError error,
                          const gchar *msg,
                          ...);

Create a new error code for use with fpi_device_verify_complete() and similar calls.

fpi_device_get_driver_data ()

guint64
fpi_device_get_driver_data (FpDevice *device);

fpi_device_get_enroll_data ()

void
fpi_device_get_enroll_data (FpDevice *device,
                            FpPrint **print);

Get data for enrollment.

fpi_device_get_capture_data ()

void
fpi_device_get_capture_data (FpDevice *device,
                             gboolean *wait_for_finger);

Get data for capture.

fpi_device_get_verify_data ()

void
fpi_device_get_verify_data (FpDevice *device,
                            FpPrint **print);

Get data for verify.

fpi_device_get_identify_data ()

void
fpi_device_get_identify_data (FpDevice *device,
                              GPtrArray **prints);

Get prints gallery for identification.

The prints array is always non-NULL and may contain a list of FpPrint's that the device should match against.

Note that prints can be an empty array, in such case the device is expected to report the scanned print matching the one in its internal storage, if any.

fpi_device_get_delete_data ()

void
fpi_device_get_delete_data (FpDevice *device,
                            FpPrint **print);

Get data for delete.

fpi_device_get_cancellable ()

GCancellable *
fpi_device_get_cancellable (FpDevice *device);

Retrieve the GCancellable that may cancel the currently ongoing operation. This is primarily useful to pass directly to e.g. fpi_usb_transfer_submit() for cancellable transfers. In many cases the cancel vfunc may be more convenient to react to cancellation in some way.

fpi_device_action_is_cancelled ()

gboolean
fpi_device_action_is_cancelled (FpDevice *device);

Checks whether the current action has been cancelled by the user. This is equivalent to first getting the cancellable using fpi_device_get_cancellable() and then checking whether it has been cancelled (if it is non-NULL).

fpi_device_add_timeout ()

GSource *
fpi_device_add_timeout (FpDevice *device,
                        gint interval,
                        FpTimeoutFunc func,
                        gpointer user_data,
                        GDestroyNotify destroy_notify);

Register a timeout to run. Drivers should always make sure that timers are cancelled when appropriate.

fpi_device_set_nr_enroll_stages ()

void
fpi_device_set_nr_enroll_stages (FpDevice *device,
                                 gint enroll_stages);

Updates the reported number of enroll stages that the device needs. If all supported devices have the same number of stages, then the value can simply be set in the class.

fpi_device_set_scan_type ()

void
fpi_device_set_scan_type (FpDevice *device,
                          FpScanType scan_type);

Updates the the scan type of the device from the default. If all supported devices have the same scan type, then the value can simply be set in the class.

fpi_device_update_features ()

void
fpi_device_update_features (FpDevice *device,
                            FpDeviceFeature update,
                            FpDeviceFeature value);

Updates the feature flags for the device. This can be used to runtime detect features that are supported by the device.

fpi_device_critical_enter ()

void
fpi_device_critical_enter (FpDevice *device);

Enter a critical section in the driver code where no outside calls from libfprint should happen. Drivers can already assume that everything happens from the same thread, however, that still allows e.g. the cancel vfunc to be called at any point in time.

Using this kind of critical section, the driver can assume that libfprint will not forward any external requests to the driver for the time being. This is for example useful to prevent cancellation while the device is being set up. Or, said differently, using this feature means that the cancel handler is able to make more assumptions about the current state.

Please note that the driver is not shielded from all external changes. For example the cancellable as returned by fpi_device_get_cancellable() will still change immediately.

The driver may call this function multiple times, but must also ensure that fpi_device_critical_leave() is called an equal amount of times and that all critical sections are left before command completion.

fpi_device_critical_leave ()

void
fpi_device_critical_leave (FpDevice *device);

Leave a critical section started by fpi_device_critical_enter().

Once all critical sections have been left, libfprint will start flushing out the queued up requests. This is done from the mainloop and the driver is protected from reentrency issues.

fpi_device_remove ()

void
fpi_device_remove (FpDevice *device);

Called to signal to the FpDevice that it has been unplugged (physically removed from the system).

For USB devices, this API is called automatically by FpContext.

fpi_device_report_finger_status ()

gboolean
fpi_device_report_finger_status (FpDevice *device,
                                 FpFingerStatusFlags finger_status);

Report the finger status for the device . This can be used by UI to give a feedback

fpi_device_report_finger_status_changes ()

gboolean
fpi_device_report_finger_status_changes
                               (FpDevice *device,
                                FpFingerStatusFlags added_status,
                                FpFingerStatusFlags removed_status);

Report the finger status for the device adding the added_status flags and removing the removed_status flags.

This can be used by UI to give a feedback

fpi_device_action_error ()

void
fpi_device_action_error (FpDevice *device,
                         GError *error);

Finish an ongoing action with an error. This is the same as calling the corresponding complete function such as fpi_device_open_complete() with an error set. If possible, use the correct complete function as that results in improved error detection.

fpi_device_probe_complete ()

void
fpi_device_probe_complete (FpDevice *device,
                           const gchar *device_id,
                           const gchar *device_name,
                           GError *error);

Finish an ongoing probe operation. If error is NULL success is assumed.

fpi_device_open_complete ()

void
fpi_device_open_complete (FpDevice *device,
                          GError *error);

Finish an ongoing open operation. If error is NULL success is assumed.

fpi_device_close_complete ()

void
fpi_device_close_complete (FpDevice *device,
                           GError *error);

Finish an ongoing close operation. If error is NULL success is assumed.

fpi_device_enroll_complete ()

void
fpi_device_enroll_complete (FpDevice *device,
                            FpPrint *print,
                            GError *error);

Finish an ongoing enroll operation. The FpPrint can be stored by the caller for later verification.

fpi_device_verify_complete ()

void
fpi_device_verify_complete (FpDevice *device,
                            GError *error);

Finish an ongoing verify operation.

Note that error should only be set for actual errors. In the case of retry errors, report these using fpi_device_verify_report() and then call this function without any error argument.

If error is not set, we expect that a result (and print, in case) have been already reported via fpi_device_verify_report().

fpi_device_identify_complete ()

void
fpi_device_identify_complete (FpDevice *device,
                              GError *error);

Finish an ongoing identify operation.

Note that error should only be set for actual errors. In the case of retry errors, report these using fpi_device_identify_report() and then call this function without any error argument.

If error is not set, we expect that a match and / or a print have been already reported via fpi_device_identify_report()

fpi_device_capture_complete ()

void
fpi_device_capture_complete (FpDevice *device,
                             FpImage *image,
                             GError *error);

Finish an ongoing capture operation.

fpi_device_clear_storage_complete ()

void
fpi_device_clear_storage_complete (FpDevice *device,
                                   GError *error);

Finish an ongoing clear_storage operation.

fpi_device_delete_complete ()

void
fpi_device_delete_complete (FpDevice *device,
                            GError *error);

Finish an ongoing delete operation.

fpi_device_list_complete ()

void
fpi_device_list_complete (FpDevice *device,
                          GPtrArray *prints,
                          GError *error);

Finish an ongoing list operation.

Please note that the prints array will be free'ed using g_ptr_array_unref() and the elements are destroyed automatically. As such, you must use g_ptr_array_new_with_free_func() with g_object_unref() as free func to create the array.

fpi_device_suspend_complete ()

void
fpi_device_suspend_complete (FpDevice *device,
                             GError *error);

Finish a suspend request. Only return a NULL error if suspend has been correctly configured and the current action as returned by fpi_device_get_current_action() will continue to run after resume.

In all other cases an error must be returned. Should this happen, the current action will be cancelled before the error is forwarded to the application.

It is recommended to set error to FP_ERROR_NOT_IMPLEMENTED.

fpi_device_resume_complete ()

void
fpi_device_resume_complete (FpDevice *device,
                            GError *error);

Finish a resume request.

fpi_device_enroll_progress ()

void
fpi_device_enroll_progress (FpDevice *device,
                            gint completed_stages,
                            FpPrint *print,
                            GError *error);

Notify about the progress of the enroll operation. This is important for UI interaction. The passed error may be used if a scan needs to be retried, use fpi_device_retry_new().

fpi_device_verify_report ()

void
fpi_device_verify_report (FpDevice *device,
                          FpiMatchResult result,
                          FpPrint *print,
                          GError *error);

Report the result of a verify operation. Note that the passed error must be a retry error with the FP_DEVICE_RETRY domain. For all other error cases, the error should passed to fpi_device_verify_complete().

fpi_device_identify_report ()

void
fpi_device_identify_report (FpDevice *device,
                            FpPrint *match,
                            FpPrint *print,
                            GError *error);

Report the results of an identify operation.

In case of successful identification match is expected to be set to a FpPrint that matches one from the provided gallery, while print represents the scanned print and will be different.

If there are no errors, it's expected that the device always reports the recognized print even if there is no match with the provided gallery (that can be potentially empty). This is required for application logic further up in the stack, such as for enroll-duplicate checking. print needs to be sufficiently filled to do a comparison.

In case of error, both match and print are expected to be NULL. Note that the passed error must be a retry error from the FP_DEVICE_RETRY domain. For all other error cases, the error should passed to fpi_device_identify_complete().

fpi_device_class_auto_initialize_features ()

void
fpi_device_class_auto_initialize_features
                               (FpDeviceClass *device_class);

Initializes the FpDeviceClass features flags checking what device vfuncs are implemented. Drivers should call this at the end of the class initialization.

FpDeviceClass

typedef struct {
  /* Static information about the driver. */
  const gchar     *id;
  const gchar     *full_name;
  FpDeviceType     type;
  const FpIdEntry *id_table;
  FpDeviceFeature  features;

  /* Defaults for device properties */
  gint       nr_enroll_stages;
  FpScanType scan_type;

  /* Simple device temperature model constants */
  gint32 temp_hot_seconds;
  gint32 temp_cold_seconds;

  /* Callbacks */
  gint (*usb_discover) (GUsbDevice *usb_device);
  void (*probe)    (FpDevice *device);
  void (*open)     (FpDevice *device);
  void (*close)    (FpDevice *device);
  void (*enroll)   (FpDevice *device);
  void (*verify)   (FpDevice *device);
  void (*identify) (FpDevice *device);
  void (*capture)  (FpDevice *device);
  void (*list)     (FpDevice *device);
  void (*delete)   (FpDevice * device);
  void (*clear_storage)  (FpDevice * device);

  void (*cancel)   (FpDevice *device);
  void (*suspend)  (FpDevice *device);
  void (*resume)   (FpDevice *device);
} FpDeviceClass;

NOTE: If your driver is image based, then you should subclass FpImageDevice instead. FpImageDevice based drivers use a different way of interacting with libfprint.

These are the main entry points for drivers to implement. Drivers may not implement all of these entry points if they do not support the operation (or a default implementation is sufficient).

Drivers must eventually call the corresponding function to finish the operation. It is also acceptable to call the generic fpi_device_action_error() function but doing so is not recommended in most usecases.

Drivers must also handle cancellation properly for any long running operation (i.e. any operation that requires capturing). It is entirely fine to ignore cancellation requests for short operations (e.g. open/close).

Note that cancel , suspend and resume will not be called while the device is within a fpi_device_critical_enter()/fpi_device_critical_leave() block.

This API is solely intended for drivers. It is purely internal and neither API nor ABI stable.

enum FpiDeviceAction

Current active action of the device. A driver can retrieve the action.

struct FpIdEntry

struct FpIdEntry {
  union
  {
    struct
    {
      guint pid;
      guint vid;
    };
    const gchar *virtual_envvar;
    struct
    {
      FpiDeviceUdevSubtypeFlags udev_types;
      const gchar              *spi_acpi_id;
      struct
      {
        guint pid;
        guint vid;
      } hid_id;
    };
  };
  guint64 driver_data;
};

An entry in the table of supported hardware. For USB devices, the product ID and vendor ID should be provided. The optional driver_data field defaults to 0 and can be used as a simple flag for device quirks.

enum FpiDeviceUdevSubtypeFlags

Bitfield of required hardware resources for a udev-backed device.