/usr/lib/python2.7/dist-packages/pyqtgraph/SignalProxy.py is in python-pyqtgraph 0.9.10-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 | # -*- coding: utf-8 -*-
from .Qt import QtCore
from .ptime import time
from . import ThreadsafeTimer
import weakref
__all__ = ['SignalProxy']
class SignalProxy(QtCore.QObject):
"""Object which collects rapid-fire signals and condenses them
into a single signal or a rate-limited stream of signals.
Used, for example, to prevent a SpinBox from generating multiple
signals when the mouse wheel is rolled over it.
Emits sigDelayed after input signals have stopped for a certain period of time.
"""
sigDelayed = QtCore.Signal(object)
def __init__(self, signal, delay=0.3, rateLimit=0, slot=None):
"""Initialization arguments:
signal - a bound Signal or pyqtSignal instance
delay - Time (in seconds) to wait for signals to stop before emitting (default 0.3s)
slot - Optional function to connect sigDelayed to.
rateLimit - (signals/sec) if greater than 0, this allows signals to stream out at a
steady rate while they are being received.
"""
QtCore.QObject.__init__(self)
signal.connect(self.signalReceived)
self.signal = signal
self.delay = delay
self.rateLimit = rateLimit
self.args = None
self.timer = ThreadsafeTimer.ThreadsafeTimer()
self.timer.timeout.connect(self.flush)
self.block = False
self.slot = weakref.ref(slot)
self.lastFlushTime = None
if slot is not None:
self.sigDelayed.connect(slot)
def setDelay(self, delay):
self.delay = delay
def signalReceived(self, *args):
"""Received signal. Cancel previous timer and store args to be forwarded later."""
if self.block:
return
self.args = args
if self.rateLimit == 0:
self.timer.stop()
self.timer.start((self.delay*1000)+1)
else:
now = time()
if self.lastFlushTime is None:
leakTime = 0
else:
lastFlush = self.lastFlushTime
leakTime = max(0, (lastFlush + (1.0 / self.rateLimit)) - now)
self.timer.stop()
self.timer.start((min(leakTime, self.delay)*1000)+1)
def flush(self):
"""If there is a signal queued up, send it now."""
if self.args is None or self.block:
return False
#self.emit(self.signal, *self.args)
self.sigDelayed.emit(self.args)
self.args = None
self.timer.stop()
self.lastFlushTime = time()
return True
def disconnect(self):
self.block = True
try:
self.signal.disconnect(self.signalReceived)
except:
pass
try:
self.sigDelayed.disconnect(self.slot())
except:
pass
#def proxyConnect(source, signal, slot, delay=0.3):
#"""Connect a signal to a slot with delay. Returns the SignalProxy
#object that was created. Be sure to store this object so it is not
#garbage-collected immediately."""
#sp = SignalProxy(source, signal, delay)
#if source is None:
#sp.connect(sp, QtCore.SIGNAL('signal'), slot)
#else:
#sp.connect(sp, signal, slot)
#return sp
if __name__ == '__main__':
from .Qt import QtGui
app = QtGui.QApplication([])
win = QtGui.QMainWindow()
spin = QtGui.QSpinBox()
win.setCentralWidget(spin)
win.show()
def fn(*args):
print("Raw signal:", args)
def fn2(*args):
print("Delayed signal:", args)
spin.valueChanged.connect(fn)
#proxy = proxyConnect(spin, QtCore.SIGNAL('valueChanged(int)'), fn)
proxy = SignalProxy(spin.valueChanged, delay=0.5, slot=fn2)
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