fpi-device: Add FpiDeviceFeature flags to FpDeviceClass

Allows drivers to define more fine grained features for devices, not
strictly depending on assumptions we can make depending on the
implemented vfuncs.

We keep this per class but could be in theory moved to each instance.

In any case, added an utility function to initialize it in the way we
can ensure that we've a consistent way for setting them across all the
devices.

libfprint/drivers/goodixmoc/goodix.c

@@ -1579,4 +1579,7 @@ fpi_device_goodixmoc_class_init (FpiDeviceGoodixMocClass *klass)
   dev_class->cancel = gx_fp_cancel;
   dev_class->verify   = gx_fp_verify_identify;
   dev_class->identify = gx_fp_verify_identify;
+
+  fpi_device_class_auto_initialize_features (dev_class);
+  dev_class->features |= FPI_DEVICE_FEATURE_DUPLICATES_CHECK;
 }

libfprint/drivers/synaptics/synaptics.c

@@ -1405,4 +1405,6 @@ fpi_device_synaptics_class_init (FpiDeviceSynapticsClass *klass)
   dev_class->delete = delete_print;
   dev_class->cancel = cancel;
   dev_class->list = list;
+
+  fpi_device_class_auto_initialize_features (dev_class);
 }

libfprint/drivers/upekts.c

@@ -1555,4 +1555,6 @@ fpi_device_upekts_class_init (FpiDeviceUpektsClass *klass)
   dev_class->verify = verify;
   dev_class->enroll = enroll;
   /* dev_class->cancel = cancel; */
+
+  fpi_device_class_auto_initialize_features (dev_class);
 }

libfprint/drivers/virtual-device-storage.c

@@ -244,4 +244,7 @@ fpi_device_virtual_device_storage_class_init (FpDeviceVirtualDeviceStorageClass
   dev_class->identify = dev_identify;
   dev_class->list = dev_list;
   dev_class->delete = dev_delete;
+
+  fpi_device_class_auto_initialize_features (dev_class);
+  dev_class->features |= FPI_DEVICE_FEATURE_DUPLICATES_CHECK;
 }

libfprint/drivers/virtual-device.c

@@ -776,4 +776,6 @@ fpi_device_virtual_device_class_init (FpDeviceVirtualDeviceClass *klass)
   dev_class->verify = dev_verify;
   dev_class->enroll = dev_enroll;
   dev_class->cancel = dev_cancel;
+
+  fpi_device_class_auto_initialize_features (dev_class);
 }

libfprint/fp-device.c

@@ -140,6 +140,8 @@ fp_device_constructed (GObject *object)
   FpDeviceClass *cls = FP_DEVICE_GET_CLASS (self);
   FpDevicePrivate *priv = fp_device_get_instance_private (self);
 
+  g_assert (cls->features != FPI_DEVICE_FEATURE_NONE);
+
   priv->type = cls->type;
   if (cls->nr_enroll_stages)
     priv->nr_enroll_stages = cls->nr_enroll_stages;
@@ -627,7 +629,7 @@ fp_device_supports_identify (FpDevice *device)
 
   g_return_val_if_fail (FP_IS_DEVICE (device), FALSE);
 
-  return cls->identify != NULL;
+  return cls->identify && !!(cls->features & FPI_DEVICE_FEATURE_IDENTIFY);
 }
 
 /**
@@ -645,7 +647,7 @@ fp_device_supports_capture (FpDevice *device)
 
   g_return_val_if_fail (FP_IS_DEVICE (device), FALSE);
 
-  return cls->capture != NULL;
+  return cls->capture && !!(cls->features & FPI_DEVICE_FEATURE_CAPTURE);
 }
 
 /**
@@ -664,7 +666,7 @@ fp_device_has_storage (FpDevice *device)
 
   g_return_val_if_fail (FP_IS_DEVICE (device), FALSE);
 
-  return cls->list != NULL;
+  return !!(cls->features & FPI_DEVICE_FEATURE_STORAGE);
 }
 
 /**
@@ -1254,6 +1256,7 @@ fp_device_delete_print (FpDevice           *device,
 {
   g_autoptr(GTask) task = NULL;
   FpDevicePrivate *priv = fp_device_get_instance_private (device);
+  FpDeviceClass *cls = FP_DEVICE_GET_CLASS (device);
 
   task = g_task_new (device, cancellable, callback, user_data);
   if (g_task_return_error_if_cancelled (task))
@@ -1274,7 +1277,7 @@ fp_device_delete_print (FpDevice           *device,
     }
 
   /* Succeed immediately if delete is not implemented. */
-  if (!FP_DEVICE_GET_CLASS (device)->delete)
+  if (!cls->delete || !(cls->features & FPI_DEVICE_FEATURE_STORAGE_DELETE))
     {
       g_task_return_boolean (task, TRUE);
       return;
@@ -1288,7 +1291,7 @@ fp_device_delete_print (FpDevice           *device,
                         g_object_ref (enrolled_print),
                         g_object_unref);
 
-  FP_DEVICE_GET_CLASS (device)->delete (device);
+  cls->delete (device);
 }
 
 /**

libfprint/fp-image-device.c

@@ -220,6 +220,8 @@ fp_image_device_class_init (FpImageDeviceClass *klass)
 
   fp_device_class->cancel = fp_image_device_cancel_action;
 
+  fpi_device_class_auto_initialize_features (fp_device_class);
+
   /* Default implementations */
   klass->activate = fp_image_device_default_activate;
   klass->deactivate = fp_image_device_default_deactivate;

libfprint/fpi-device.c

@@ -46,6 +46,40 @@ fp_device_get_instance_private (FpDevice *self)
                             g_type_class_get_instance_private_offset (dev_class));
 }
 
+/**
+ * fpi_device_class_auto_initialize_features:
+ *
+ * Initializes the #FpDeviceClass @features flags checking what device vfuncs
+ * are implemented.
+ * Drivers should call this at the end of the class initialization.
+ */
+void
+fpi_device_class_auto_initialize_features (FpDeviceClass *device_class)
+{
+  g_return_if_fail (FP_IS_DEVICE_CLASS (device_class));
+
+  if (device_class->capture)
+    device_class->features |= FPI_DEVICE_FEATURE_CAPTURE;
+
+  if (device_class->verify)
+    device_class->features |= FPI_DEVICE_FEATURE_VERIFY;
+
+  if (device_class->identify)
+    device_class->features |= FPI_DEVICE_FEATURE_IDENTIFY;
+
+  if (device_class->list)
+    {
+      device_class->features |= FPI_DEVICE_FEATURE_STORAGE;
+      device_class->features |= FPI_DEVICE_FEATURE_STORAGE_LIST;
+    }
+
+  if (device_class->delete)
+    {
+      device_class->features |= FPI_DEVICE_FEATURE_STORAGE;
+      device_class->features |= FPI_DEVICE_FEATURE_STORAGE_DELETE;
+    }
+}
+
 /**
  * fpi_device_retry_new:
  * @error: The #FpDeviceRetry error value describing the issue

libfprint/fpi-device.h

@@ -69,6 +69,30 @@ struct _FpIdEntry
   guint64 driver_data;
 };
 
+/**
+ * FpiDeviceFeature:
+ * @FPI_DEVICE_FEATURE_NONE: Device does not support any feature
+ * @FPI_DEVICE_FEATURE_CAPTURE: Supports image capture
+ * @FPI_DEVICE_FEATURE_IDENTIFY: Supports finger identification
+ * @FPI_DEVICE_FEATURE_VERIFY: Supports finger verification
+ * @FPI_DEVICE_FEATURE_STORAGE: Device has a persistent storage
+ * @FPI_DEVICE_FEATURE_STORAGE_LIST: Supports listing the storage templates
+ * @FPI_DEVICE_FEATURE_STORAGE_DELETE: Supports deleting stored templates
+ * @FPI_DEVICE_FEATURE_STORAGE_CLEAR: Supports clearing the whole storage
+ * @FPI_DEVICE_FEATURE_DUPLICATES_CHECK: Natively supports duplicates detection
+ */
+typedef enum /*< flags >*/ {
+  FPI_DEVICE_FEATURE_NONE = 0,
+  FPI_DEVICE_FEATURE_CAPTURE = 1 << 0,
+  FPI_DEVICE_FEATURE_IDENTIFY = 1 << 1,
+  FPI_DEVICE_FEATURE_VERIFY = 1 << 2,
+  FPI_DEVICE_FEATURE_STORAGE = 1 << 3,
+  FPI_DEVICE_FEATURE_STORAGE_LIST = 1 << 4,
+  FPI_DEVICE_FEATURE_STORAGE_DELETE = 1 << 5,
+  FPI_DEVICE_FEATURE_STORAGE_CLEAR = 1 << 6,
+  FPI_DEVICE_FEATURE_DUPLICATES_CHECK = 1 << 7,
+} FpiDeviceFeature;
+
 /**
  * FpDeviceClass:
  * @id: ID string for the driver. Should be a valid C identifier and should
@@ -76,6 +100,8 @@ struct _FpIdEntry
  * @full_name: Human readable description of the driver
  * @type: The type of driver
  * @id_table: The table of IDs to bind the driver to
+ * @features: The features the device supports, it can be initialized using
+ *   fpi_device_class_auto_initialize_features() on @class_init.
  * @nr_enroll_stages: The number of enroll stages supported devices need; use
  *   fpi_device_set_nr_enroll_stages() from @probe if this is dynamic.
  * @scan_type: The scan type of supported devices; use
@@ -133,6 +159,7 @@ struct _FpDeviceClass
   const gchar     *full_name;
   FpDeviceType     type;
   const FpIdEntry *id_table;
+  FpiDeviceFeature features;
 
   /* Defaults for device properties */
   gint       nr_enroll_stages;
@@ -153,6 +180,8 @@ struct _FpDeviceClass
   void (*cancel)   (FpDevice *device);
 };
 
+void fpi_device_class_auto_initialize_features (FpDeviceClass *device_class);
+
 /**
  * FpTimeoutFunc:
  * @device: The #FpDevice passed to fpi_device_add_timeout()