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  • Committer: Alejandro J. Cura
  • Date: 2012-03-30 00:37:10 UTC
  • Revision ID: alecu@canonical.com-20120330003710-18we5wlcbfpv2z4n
A Qt-based deferToThread

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ubuntu_sso/utils/windows.py
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"""Platform specific constants and functions (for Windows)."""
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PLATFORM_QSS = ":/windows.qss"
 
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from twisted.internet import defer
 
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from PyQt4.QtCore import QThread, QCoreApplication
 
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class DeferredThread(QThread):
 
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    """A thread that runs a given function."""
 
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    def __init__(self, f, *args, **kwargs):
 
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        """Initialize this thread."""
 
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        app = QCoreApplication.instance()
 
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        super(DeferredThread, self).__init__(app)
 
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        self.deferred = defer.Deferred()
 
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        self.f = f
 
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        self.args = args
 
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        self.kwargs = kwargs
 
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        self.succeeded = True
 
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        self.result = None
 
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        self.finished.connect(self.on_finished)
 
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    def run(self):
 
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        """This code runs inside the thread."""
 
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        try:
 
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            self.result = self.f(*self.args, **self.kwargs)
 
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        except Exception as e:
 
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            self.succeeded = False
 
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            self.result = e
 
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    def on_finished(self):
 
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        """The thread has completed."""
 
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        if self.succeeded:
 
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            self.deferred.callback(self.result)
 
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        else:
 
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            self.deferred.errback(self.result)
 
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def qtDeferToThread(f, *args, **kwargs):
 
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    """A Qt-based implementation of deferToThread."""
 
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    thread = DeferredThread(f, *args, **kwargs)
 
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    thread.start()
 
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    return thread.deferred