Split code into multiple files

- added file for the uinput stuff that creates input events for a gesture
- added common.h that contains some common stuff used by multiple modules
- added int_array for dynamic int arrays with a length field

Author: Robin Müller

src/Makefile.am

@@ -1,2 +1,2 @@
 bin_PROGRAMS = touch_gestures
-touch_gestures_SOURCES = main.c
+touch_gestures_SOURCES = main.c int_array.c gestures_device.c

src/common.h

@@ -0,0 +1,13 @@
+#ifndef COMMON_H_
+#define COMMON_H_
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define die(str, args...) do { \
+        perror(str); \
+        exit(EXIT_FAILURE); \
+    } while(0)
+
+#endif // COMMON_H_

src/gestures_device.c

@@ -0,0 +1,89 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/input.h>
+#include <linux/uinput.h>
+
+#include "common.h"
+#include "gestures_device.h"
+
+int init_uinput(int_array keys) {
+  int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+  if(fd < 0) {
+      die("error: open");
+  }
+
+  ioctl(fd, UI_SET_EVBIT, EV_KEY);
+  ioctl(fd, UI_SET_EVBIT, EV_SYN);
+  ioctl(fd, UI_SET_EVBIT, EV_REL);
+  
+  ioctl(fd, UI_SET_RELBIT, REL_WHEEL);
+  
+  ioctl(fd, UI_SET_KEYBIT, BTN_LEFT);
+  ioctl(fd, UI_SET_KEYBIT, BTN_RIGHT);
+  ioctl(fd, UI_SET_KEYBIT, BTN_MIDDLE);
+
+  int i;
+  for (i = 0; i < keys.length; i++) {
+    ioctl(fd, UI_SET_KEYBIT, keys.data[i]);
+  }
+
+  struct uinput_user_dev uidev;
+
+  memset(&uidev, 0, sizeof(uidev));
+
+  snprintf(uidev.name, UINPUT_MAX_NAME_SIZE, "uinput-touch-gestures");
+  uidev.id.bustype = BUS_USB;
+  uidev.id.vendor  = 0x1;
+  uidev.id.product = 0x1;
+  uidev.id.version = 1;
+
+  if (write(fd, &uidev, sizeof(uidev)) < 0) {
+    die("error: write");
+  }
+  if (ioctl(fd, UI_DEV_CREATE) < 0) {
+    die("error: ioctl");
+  }
+  return fd;
+}
+
+int destroy_uinput(int fd) {
+  if (ioctl(fd, UI_DEV_DESTROY) < 0) {
+    die("error: ioctl");
+  }
+
+  close(fd);
+}
+
+void send_key(int fd, int key) {
+  struct input_event key_ev, syn_ev;
+
+  memset(&key_ev, 0, sizeof(struct input_event));
+  key_ev.type = EV_KEY;
+  key_ev.code = key;
+  // press the key
+  key_ev.value = 1;
+  if (write(fd, &key_ev, sizeof(struct input_event)) < 0) {
+    die("error: write");
+  }
+
+  memset(&syn_ev, 0, sizeof(struct input_event));
+  syn_ev.type = EV_SYN;
+  syn_ev.code = 0;
+  syn_ev.value = 0;
+  if (write(fd, &syn_ev, sizeof(struct input_event)) < 0) {
+    die("error: write");
+  }
+
+  // release the key
+  key_ev.value = 0;
+  if (write(fd, &key_ev, sizeof(struct input_event)) < 0) {
+    die("error: write");
+  }
+  if (write(fd, &syn_ev, sizeof(struct input_event)) < 0) {
+    die("error: write");
+  }
+}

src/gestures_device.h

@@ -0,0 +1,10 @@
+#ifndef GESTURES_DEVICE_H_
+#define GESTURES_DEVICE_H_
+
+#include "int_array.h"
+
+int init_uinput(int_array keys);
+int destroy_uinput(int fd);
+void send_key(int fd, int key);
+
+#endif // GESTURES_DEVICE_H_

src/int_array.c

@@ -0,0 +1,16 @@
+#include <stdlib.h>
+
+#include "int_array.h"
+
+int_array *new_int_array(size_t length) {
+  int_array *array;
+  /* we're allocating the size of basic t_int_array 
+     (which already contains space for one int)
+     and additional space for length-1 ints */
+  array = malloc(sizeof(int_array) + sizeof(int) * (length - 1));
+  if(!array) {
+    return 0;
+  }
+  array->length = length;
+  return array;
+}

src/int_array.h

@@ -0,0 +1,13 @@
+#ifndef INTEGER_ARRAY_H_
+#define INTEGER_ARRAY_H_
+
+#include <stddef.h>
+
+typedef struct t_int_array {
+  size_t length;
+  int data[1];
+} int_array;
+
+int_array * new_int_array(size_t length);
+
+#endif // INTEGER_ARRAY_H_