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/*
* Copyright © 2012 Matt Pharoah (mr.exuberant@gmail.com)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef JOYSTICK_HH_
#define JOYSTICK_HH_
#include <thread>
#include <chrono>
#include <stdexcept>
#include <cstring>
#include <linux/joystick.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
using namespace std;
struct JSEvent {
unsigned int timestamp;
short value;
char type;
unsigned char button;
};
class Joystick {
private:
thread *driver;
char filename[15];
int device;
volatile bool alive;
volatile bool connected;
int DEB;
static void start(void (*listener)(const JSEvent&, void *), void (*onDisconnect)(void *), Joystick *me, void *userdata) {
JSEvent ev;
const struct timespec DECISECOND = { 0, 100000000 };
chrono::milliseconds deciSecond(100);
while (me->alive) {
while (!me->connected) {
if (!me->alive) return;
this_thread::sleep_for(deciSecond);
}
int status = 0;
fd_set dset;
while (status == 0 && me->device >= 0) {
FD_ZERO(&dset);
FD_SET(me->device, &dset);
status = pselect(me->device + 1, &dset, NULL, NULL, &DECISECOND, NULL);
if (!me->alive) return;
}
if (status > 0 && errno == 0 && me->device >= 0) {
if (read(me->device, (void *) &ev, sizeof(JSEvent)) == sizeof(JSEvent)) listener(ev, userdata);
} else if (onDisconnect != NULL) {
onDisconnect(userdata);
} else {
//default implementation of disconnect: wait a decisecond and try to reconnect
this_thread::sleep_for(deciSecond);
me->reconnect();
}
}
}
public:
static const char BUTTON_EVENT = 1;
static const char AXIS_EVENT = 2;
static const short PRESSED = 1;
static const short RELEASED = 0;
Joystick(unsigned char num, void (*listener)(const JSEvent&, void *), void (*onDisconnect)(void *) = NULL, void *userdata = NULL) {
if (num > 9) throw invalid_argument("Invalid joystick number. Valid range is [0,9]\n");
alive = true;
connected = true;
strcpy(filename, "/dev/input/js?");
filename[13] = (char) (48 + num);
device = open(filename, O_RDONLY);
driver = new thread(start, listener, onDisconnect, this, userdata);
}
/*
* NOTE: it is expected that reconnect() will be called from the same
* thread that onDisconnect() is called from (the joystick thread).
* Otherwise, errno will not be cleared since it is thread-specific
*/
void reconnect() {
close(device);
errno = 0;
device = open(filename, O_RDONLY);
connected = true;
}
inline unsigned char getPort() {
return ((unsigned char) filename[13] - 48);
}
~Joystick() {
alive = false;
driver->join();
delete driver;
close(device);
}
static void getNameAndButtons(unsigned char num, char *str, unsigned int string_size, unsigned char *buttons = NULL) {
if (num > 9) throw invalid_argument("Invalid joystick number. Valid range is [0,9]\n");
char fileName[15];
strcpy(fileName, "/dev/input/js?");
fileName[13] = (char) (48 + num);
int fd = open(fileName, O_RDONLY);
if (fd == -1) throw invalid_argument("Joystick not connected on this port.\n");
if (str != NULL) {
if (ioctl(fd, JSIOCGNAME(string_size), str) < 0) strcpy(str, "Unknown Device");
}
if (buttons != NULL) {
if (ioctl(fd, JSIOCGBUTTONS, buttons) < 0) *buttons = 8; //if the number of buttons can't be read for whatever reason, default to 8
}
close(fd);
}
};
#endif /* JOYSTICK_HH_ */
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