c52382c3b9
Pull request #907 addressed a specific case where a signal was emitted before a state update. If an application's slot then calls back into the instance, the instance was in an inconsistent state. This commit audits and fixes similar issues throughout the pyqtgraph library. This commit fixes several latent issues: * SignalProxy: flush -> sigDelayed -> signalReceived would have incorrectly resulted in timer.stop(). * ViewBox: resizeEvent -> sigStateChange -> background state * ViewBox: setRange -> sigStateChange -> autoranging not updated correctly * ViewBox: updateMatrix -> sigTransformChanged -> any _matrixNeedsUpdate = True -> ignored * Parameter: Child may have missed state tree messages on insert or received extra on remove * GraphicsView: updateMatrix -> sigDeviceRangeChanged/sigDeviceTransformChange -> before propagated to locked viewports.
119 lines
3.8 KiB
Python
119 lines
3.8 KiB
Python
# -*- coding: utf-8 -*-
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from .Qt import QtCore
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from .ptime import time
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from . import ThreadsafeTimer
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import weakref
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__all__ = ['SignalProxy']
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class SignalProxy(QtCore.QObject):
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"""Object which collects rapid-fire signals and condenses them
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into a single signal or a rate-limited stream of signals.
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Used, for example, to prevent a SpinBox from generating multiple
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signals when the mouse wheel is rolled over it.
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Emits sigDelayed after input signals have stopped for a certain period of time.
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"""
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sigDelayed = QtCore.Signal(object)
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def __init__(self, signal, delay=0.3, rateLimit=0, slot=None):
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"""Initialization arguments:
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signal - a bound Signal or pyqtSignal instance
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delay - Time (in seconds) to wait for signals to stop before emitting (default 0.3s)
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slot - Optional function to connect sigDelayed to.
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rateLimit - (signals/sec) if greater than 0, this allows signals to stream out at a
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steady rate while they are being received.
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"""
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QtCore.QObject.__init__(self)
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signal.connect(self.signalReceived)
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self.signal = signal
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self.delay = delay
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self.rateLimit = rateLimit
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self.args = None
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self.timer = ThreadsafeTimer.ThreadsafeTimer()
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self.timer.timeout.connect(self.flush)
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self.block = False
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self.slot = weakref.ref(slot)
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self.lastFlushTime = None
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if slot is not None:
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self.sigDelayed.connect(slot)
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def setDelay(self, delay):
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self.delay = delay
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def signalReceived(self, *args):
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"""Received signal. Cancel previous timer and store args to be forwarded later."""
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if self.block:
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return
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self.args = args
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if self.rateLimit == 0:
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self.timer.stop()
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self.timer.start((self.delay*1000)+1)
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else:
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now = time()
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if self.lastFlushTime is None:
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leakTime = 0
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else:
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lastFlush = self.lastFlushTime
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leakTime = max(0, (lastFlush + (1.0 / self.rateLimit)) - now)
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self.timer.stop()
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self.timer.start((min(leakTime, self.delay)*1000)+1)
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def flush(self):
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"""If there is a signal queued up, send it now."""
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if self.args is None or self.block:
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return False
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args, self.args = self.args, None
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self.timer.stop()
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self.lastFlushTime = time()
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#self.emit(self.signal, *self.args)
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self.sigDelayed.emit(args)
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return True
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def disconnect(self):
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self.block = True
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try:
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self.signal.disconnect(self.signalReceived)
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except:
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pass
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try:
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self.sigDelayed.disconnect(self.slot())
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except:
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pass
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#def proxyConnect(source, signal, slot, delay=0.3):
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#"""Connect a signal to a slot with delay. Returns the SignalProxy
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#object that was created. Be sure to store this object so it is not
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#garbage-collected immediately."""
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#sp = SignalProxy(source, signal, delay)
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#if source is None:
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#sp.connect(sp, QtCore.SIGNAL('signal'), slot)
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#else:
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#sp.connect(sp, signal, slot)
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#return sp
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if __name__ == '__main__':
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from .Qt import QtGui
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app = QtGui.QApplication([])
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win = QtGui.QMainWindow()
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spin = QtGui.QSpinBox()
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win.setCentralWidget(spin)
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win.show()
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def fn(*args):
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print("Raw signal:", args)
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def fn2(*args):
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print("Delayed signal:", args)
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spin.valueChanged.connect(fn)
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#proxy = proxyConnect(spin, QtCore.SIGNAL('valueChanged(int)'), fn)
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proxy = SignalProxy(spin.valueChanged, delay=0.5, slot=fn2)
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