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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi everyone,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have connected the signal selectionChanged so some code, which is executed after features are selected.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">myLayer.selectionChanged.connect(self.executeAfterSelection)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Then I have a method self. executeAfterSelection(self, featuresIds)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The SIGNAl/SLOT tandem works but now I realized every time when I call
<b>myLayer.selectionChanged.connect(self.executeAfterSelection)</b> It does not overwrite my previous call. It creates a second signa/slot tandem. During running the method executeAfterSelection is excuted twice, three times etc.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">How can I check if the SIGNAL selectionChanged is connected to the slot executeAfterSelection before I run myLayer.selectionChanged.connect(self.executeAfterSelection)?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I tried this:<o:p></o:p></p>
<p class="MsoNormal">receiversCount = QtCore.QObject.receivers(QtCore.SIGNAL(“selectionChanged()”)<o:p></o:p></p>
<p class="MsoNormal">receiversCount = QtCore.QObject.receivers(QtCore.SIGNAL(“selectionChanged”)<o:p></o:p></p>
<p class="MsoNormal">receiversCount = QtCore.QObject.receivers(QtCore.SIGNAL(“myLayer.selectionChanged()”)<o:p></o:p></p>
<p class="MsoNormal">receiversCount = QtCore.QObject.receivers(QtCore.SIGNAL(“myLayer.selectionChanged”)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Every time I get this error:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">QObject.receivers(SIGNAL()): first argument of unbound method must have type ‘QObject’).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Marian<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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