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 <olex...@gmail.com> 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.
>
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