Initial import

libinput_device_discovery.c

@@ -0,0 +1,169 @@
+/**
+ * @file libinput_device_discovery.c
+ *
+ */
+
+/*********************
+ *      INCLUDES
+ *********************/
+#include "libinput_device_discovery.h"
+#if USE_LIBINPUT || USE_BSD_LIBINPUT
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <libinput.h>
+
+#if USE_BSD_LIBINPUT
+#include <dev/evdev/input.h>
+#else
+#include <linux/input.h>
+#endif
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/**********************
+ *  STATIC PROTOTYPES
+ **********************/
+static int open_restricted(const char *path, int flags, void *user_data);
+static void close_restricted(int fd, void *user_data);
+static bool is_keyboard(struct libinput_device *device);
+static bool is_pointer_device(struct libinput_device *device);
+static bool is_touchscreen(struct libinput_device *device);
+
+/**********************
+ *  STATIC VARIABLES
+ **********************/
+static const struct libinput_interface interface = {
+  .open_restricted = open_restricted,
+  .close_restricted = close_restricted,
+};
+
+/**********************
+ *      MACROS
+ **********************/
+
+/**********************
+ *   GLOBAL FUNCTIONS
+ **********************/
+
+/**
+ * find connected keyboard devices
+ * @param match function returning true if device matches desired condition
+ * @param devices pre-allocated array to store device paths into
+ * @param count maximum number of devices
+ * @return number of devices discovered
+ */
+size_t libinput_discover(bool match(struct libinput_device *), char devices[][32], size_t count) {
+  struct libinput * context = libinput_path_create_context(&interface, NULL);
+
+  DIR *dir;
+  struct dirent *ent;
+  if (!(dir = opendir("/dev/input"))) {
+    perror("unable to open directory /dev/input:");
+    return 0;
+  }
+
+  int index = 0;
+  while (index < count && (ent = readdir(dir))) {
+    if (strncmp(ent->d_name, "event", strlen("event")) != 0) {
+      continue;
+    }
+
+    char path[32];
+    strcpy(path, "/dev/input/");
+    strcat(path, ent->d_name);
+
+    struct libinput_device * device = libinput_path_add_device(context, path);
+    if(!device) {
+      perror("unable to add device to libinput context:");
+      return false;
+    }
+
+    device = libinput_device_ref(device);
+    if(!device) {
+      perror("unable to reference device within libinput context:");
+      return false;
+    }
+
+    if (match(device)) {
+      strcpy(devices[index], path);
+      index++;
+    }
+
+    device = libinput_device_unref(device);
+    libinput_path_remove_device(device);
+  }
+
+  libinput_unref(context);
+  return index;
+}
+
+/**
+ * find connected keyboard devices
+ * @param devices pre-allocated array to store device paths into
+ * @param count maximum number of devices
+ * @return number of devices discovered
+ */
+size_t libinput_discover_keyboards(char devices[][32], size_t count) {
+  return libinput_discover(is_keyboard, devices, count);
+}
+
+/**
+ * find connected pointer devices
+ * @param devices pre-allocated array to store device paths into
+ * @param count maximum number of devices
+ * @return number of devices discovered
+ */
+size_t libinput_discover_pointer_devices(char devices[][32], size_t count) {
+  return libinput_discover(is_pointer_device, devices, count);
+}
+
+/**
+ * find connected touchscreen devices
+ * @param devices pre-allocated array to store device paths into
+ * @param count maximum number of devices
+ * @return number of devices discovered
+ */
+size_t libinput_discover_touchscreens(char devices[][32], size_t count) {
+  return libinput_discover(is_touchscreen, devices, count);
+}
+
+/**********************
+ *   STATIC FUNCTIONS
+ **********************/
+
+static int open_restricted(const char *path, int flags, void *user_data)
+{
+  int fd = open(path, flags);
+  return fd < 0 ? -errno : fd;
+}
+
+static void close_restricted(int fd, void *user_data)
+{
+  close(fd);
+}
+
+static bool is_keyboard(struct libinput_device * device) {
+  return libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_KEYBOARD)
+    && libinput_device_keyboard_has_key(device, KEY_A);
+}
+
+static bool is_pointer_device(struct libinput_device * device) {
+  return libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_POINTER);
+}
+
+static bool is_touchscreen(struct libinput_device * device) {
+  return libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_TOUCH);
+}
+
+#endif /* USE_LIBINPUT || USE_BSD_LIBINPUT */