lib: Major rewrite of the libfprint core and API

This is a rewrite of the core based on GObject and Gio. This commit
breaks the build in a lot of ways, but basic functionality will start
working again with the next commits.

libfprint/fpi-image-device.h

@@ -0,0 +1,118 @@
+/*
+ * FpImageDevice - An image based fingerprint reader device
+ * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#pragma once
+
+#include "fpi-device.h"
+#include "fp-image-device.h"
+
+/**
+ * FpImageDeviceState:
+ * @FP_IMAGE_DEVICE_STATE_INACTIVE: inactive
+ * @FP_IMAGE_DEVICE_STATE_AWAIT_FINGER_ON: waiting for the finger to be pressed or swiped
+ * @FP_IMAGE_DEVICE_STATE_CAPTURE: capturing an image
+ * @FP_IMAGE_DEVICE_STATE_AWAIT_FINGER_OFF: waiting for the finger to be removed
+ *
+ * The state of an imaging device while doing a capture. The state is
+ * passed through to the driver using the ::activate() or ::change_state() vfuncs.
+ *
+ * The driver needs to call fpi_image_device_report_finger_status() to move
+ * between the different states. Note that the capture state might be entered
+ * unconditionally if the device supports raw capturing.
+ */
+typedef enum {
+  FP_IMAGE_DEVICE_STATE_INACTIVE,
+  FP_IMAGE_DEVICE_STATE_AWAIT_FINGER_ON,
+  FP_IMAGE_DEVICE_STATE_CAPTURE,
+  FP_IMAGE_DEVICE_STATE_AWAIT_FINGER_OFF,
+} FpImageDeviceState;
+
+/**
+ * FpImageDeviceClass:
+ * @bz3_threshold: Threshold to consider bozorth3 score a match, default: 40
+ * @img_width: Width of the image, only provide if constant
+ * @img_height: Height of the image, only provide if constant
+ * @img_open: Open the device and do basic initialization
+ *   (use this instead of the #FpDeviceClass open vfunc)
+ * @img_close: Close the device
+ *   (use this instead of the #FpDeviceClass close vfunc)
+ * @activate: Start image capture and finger detection
+ * @deactivate: Stop image capture and finger detection
+ * @change_state: Notification about the current device state (i.e. waiting for
+ *   finger or image capture). Implementing this is optional, it can e.g. be
+ *   used to flash an LED when waiting for a finger.
+ *
+ * These are the main entry points for image based drivers. For all but the
+ * change_state vfunc, implementations *must* eventually call the corresponding
+ * function to finish the operation. It is also acceptable to call the generic
+ *
+ *
+ * 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).
+ *
+ * This API is solely intended for drivers. It is purely internal and neither
+ * API nor ABI stable.
+ */
+struct _FpImageDeviceClass
+{
+  FpDeviceClass parent_class;
+
+  gint          bz3_threshold;
+  gint          img_width;
+  gint          img_height;
+
+  void          (*img_open)     (FpImageDevice *dev);
+  void          (*img_close)    (FpImageDevice *dev);
+  void          (*activate)     (FpImageDevice *dev);
+  void          (*change_state) (FpImageDevice     *dev,
+                                 FpImageDeviceState state);
+  void          (*deactivate)   (FpImageDevice *dev);
+};
+
+void fpi_image_device_set_bz3_threshold (FpImageDevice *self,
+                                         gint           bz3_threshold);
+
+void fpi_image_device_session_error (FpImageDevice *self,
+                                     GError        *error);
+
+void fpi_image_device_open_complete (FpImageDevice *self,
+                                     GError        *error);
+void fpi_image_device_close_complete (FpImageDevice *self,
+                                      GError        *error);
+void fpi_image_device_activate_complete (FpImageDevice *self,
+                                         GError        *error);
+void fpi_image_device_deactivate_complete (FpImageDevice *self,
+                                           GError        *error);
+
+void fpi_image_device_report_finger_status (FpImageDevice *self,
+                                            gboolean       present);
+void fpi_image_device_image_captured (FpImageDevice *self,
+                                      FpImage       *image);
+void fpi_image_device_retry_scan (FpImageDevice *self,
+                                  FpDeviceRetry  retry);