У меня есть класс джойстика, написанный на python с gobject, он прекрасно работает, за исключением одной незначительной проблемы. Отскок кнопки, когда я запускаю приведенный ниже код, он подхватывает все нажатия кнопки несколько раз. Как я могу уменьшить это до одного сообщения за нажатие кнопки с разумной точностью?
'''
Copyright 2009 Jezra Lickter
This software is distributed AS IS. Use at your own risk.
If it borks your system, you have been forewarned.
This software is licensed under the LGPL Version 3
http://www.gnu.org/licenses/lgpl-3.0.txt
for documentation on Linux Joystick programming please see
http://www.mjmwired.net/kernel/Documentation/input/joystick-api.txt
'''
import gobject #needed for sending signals
import struct #needed for holding chunks of data
class Joystick(gobject.GObject):
'''The Joystick class is a GObject that sends signals that represent
Joystick events'''
EVENT_BUTTON = 0x01 #button pressed/released
EVENT_AXIS = 0x02 #axis moved
EVENT_INIT = 0x80 #button/axis initialized
#see http://docs.python.org/library/struct.html for the format determination
EVENT_FORMAT = "IhBB"
EVENT_SIZE = struct.calcsize(EVENT_FORMAT)
# we need a few signals to send data to the main
'''signals will return 4 variables as follows:
1. a string representing if the signal is from an axis or a button
2. an integer representation of a particular button/axis
3. an integer representing axis direction or button press/release
4. an integer representing the "init" of the button/axis
'''
__gsignals__ = {
'axis' :
(gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_INT,gobject.TYPE_INT,gobject.TYPE_INT)),
'button' :
(gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_INT,gobject.TYPE_INT,gobject.TYPE_INT))
}
def __init__(self,dev_num):
gobject.GObject.__init__(self)
#define the device
device = '/dev/input/js%s' % dev_num
#error check that this can be read
try:
#open the joystick device
self.device = open(device)
#keep an eye on the device, when there is data to read, execute the read function
gobject.io_add_watch(self.device,gobject.IO_IN,self.read_buttons)
except Exception,ex:
#raise an exception
raise Exception( ex )
def read_buttons(self, arg0='', arg1=''):
''' read the button and axis press event from the joystick device
and emit a signal containing the event data
'''
#read self.EVENT_SIZE bytes from the joystick
read_event = self.device.read(self.EVENT_SIZE)
#get the event structure values from the read event
time, value, type, number = struct.unpack(self.EVENT_FORMAT, read_event)
#get just the button/axis press event from the event type
event = type & ~self.EVENT_INIT
#get just the INIT event from the event type
init = type & ~event
if event == self.EVENT_AXIS:
signal = "axis"
elif event == self.EVENT_BUTTON:
signal = "button"
if signal:
print("%s %s %s %s" % (signal,number,value,init) )
self.emit(signal,number,value,init)
return True
if __name__ == "__main__":
try:
j = Joystick(0)
loop = gobject.MainLoop()
loop.run()
except Exception,e:
print(e)