Some additional reflection on the topic: Personally I don't notice any delay when filtering events from Maya's main window (Maya 2019). IMHO I'm not sure this is as big of an issue as you may think it is. I need to test this more over time though. Because my intution tells me events are usually very light and their load stay the same regardless of the scene complexity, I'm really not sure why you would get noticable lag (even accounting for python overhead)
I haven't tried it yet but brave people might want to do event filtering inside their C++ plugin: https://around-the-corner.typepad.com/adn/2012/09/access-the-qt-event-loop-in-maya.html Since we can access Maya Qt core application from there as well. #include <QtCore/QCoreApplication> QCoreApplication *app = qApp; void QObject::installEventFilter (QObject *filterObj) Cheers 2018年5月28日月曜日 21時57分54秒 UTC+9 Marcus Ottosson: > > Yes, this is possible. > > from PySide import QtGui, QtCore > class MyEventHandler(QtCore.QObject): > def eventFilter(self, target, event): > if event.type() == event.KeyPress: > print("That's a keypress") > return super(MyEventHandler, self).eventFilter(target, event) > > handler = MyEventHandler() > > app = QtGui.QApplication.instance() > app.installEventFilter(handler)# app.removeEventFilter(handler) > > That would normally be fine, *however* if there is one object where you > never want a (Python) event filter, it would be the QApplication or Maya’s > MainWindow. Because what happens is that *every single event* in Maya > which was previously highly optimised C++ now has to pass through your > Python function. Which means that even if your function does nothing but > pass the event through, it still has a *significant* effect on > performance. For starters, you should notice that with this filter > installed, navigating in the viewport suddenly has a slight delay. As if > the click caused a minor lag before eventually allowing you to dolly the > camera. > > To put a picture in your head, here’s why. > > Information Super Highway > > --------------\ /---------------> > -------------- \ /----------------> > ---------------->-------------/-----------------> > -------------- / \-----------------> > --------------/ \----------------> > C++ Python C++ > > Instead, what you should consider, if you are able, is installing an event > filter *not* in QApplication or Maya’s main window, but in *your widget*. > > class MyWidget(QtGui.QDialog): > def __init__(self, parent=None): > super(MyWidget, self).__init__(parent) > > handler = MyEventHandler() > mywidget = MyWidget() > mywidget.installEventFilter(handler) > > But *most* preferably, would be to not use an event filter, and instead > override the event handler called only on keypress events > <http://doc.qt.io/qt-5/qwidget.html#keyPressEvent>. > > class MyWidget(QtGui.QDialog): > def __init__(self, parent=None): > super(MyWidget, self).__init__(parent) > > def keyPressEvent(self, event): > print("That's a press!") > return super(MyWidget, self).keyPressEvent(event) > > That way, there is zero overhead on any event handling, other than the one > you override. > > Hope it helps! > > > On 26 May 2018 at 07:27, Alexey Vasilyev <ole...@gmail.com <javascript:>> > wrote: > >> Hi. >> I'm new to Maya programming. >> I'm curious if it's possible to track keypress events in Maya main window >> using PySide or any other way? >> For example, when cube primitive is selected, I want to be able to >> increase or decrease its subdivisions using Left and Right arrows. When >> it's not selected, I want arrow keys to function in the default way. >> Thanks. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Python Programming for Autodesk Maya" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to python_inside_maya+unsubscr...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/python_inside_maya/c7024d27-4a67-448e-9e57-a873ff85dcbc%40googlegroups.com >> >> <https://groups.google.com/d/msgid/python_inside_maya/c7024d27-4a67-448e-9e57-a873ff85dcbc%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Python Programming for Autodesk Maya" group. To unsubscribe from this group and stop receiving emails from it, send an email to python_inside_maya+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/python_inside_maya/31a77359-f8e0-466d-8c68-ea826575cecb%40googlegroups.com.
