Difficult-Rocket/libs/pyglet/app/xlib.py

89 lines
2.5 KiB
Python

import os
import select
import threading
from pyglet import app
from pyglet.app.base import PlatformEventLoop
class XlibSelectDevice:
def fileno(self):
"""Get the file handle for ``select()`` for this device.
:rtype: int
"""
raise NotImplementedError('abstract')
def select(self):
"""Perform event processing on the device.
Called when ``select()`` returns this device in its list of active
files.
"""
raise NotImplementedError('abstract')
def poll(self):
"""Check if the device has events ready to process.
:rtype: bool
:return: True if there are events to process, False otherwise.
"""
return False
class NotificationDevice(XlibSelectDevice):
def __init__(self):
self._sync_file_read, self._sync_file_write = os.pipe()
self._event = threading.Event()
def fileno(self):
return self._sync_file_read
def set(self):
self._event.set()
os.write(self._sync_file_write, b'1')
def select(self):
self._event.clear()
os.read(self._sync_file_read, 1)
app.platform_event_loop.dispatch_posted_events()
def poll(self):
return self._event.is_set()
class XlibEventLoop(PlatformEventLoop):
def __init__(self):
super(XlibEventLoop, self).__init__()
self._notification_device = NotificationDevice()
self.select_devices = set()
self.select_devices.add(self._notification_device)
def notify(self):
self._notification_device.set()
def step(self, timeout=None):
# Timeout is from EventLoop.idle(). Return after that timeout or directly
# after receiving a new event. None means: block for user input.
# Poll devices to check for already pending events (select.select is not enough)
pending_devices = []
for device in self.select_devices:
if device.poll():
pending_devices.append(device)
# If no devices were ready, wait until one gets ready
if not pending_devices:
pending_devices, _, _ = select.select(self.select_devices, (), (), timeout)
if not pending_devices:
# Notify caller that timeout expired without incoming events
return False
# Dispatch activity on matching devices
for device in pending_devices:
device.select()
# Notify caller that events were handled before timeout expired
return True