QGestureRecognizer.registerRecognizer() crashes using PySide2
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@jeremy_k yes absolutely, I didn't pay attention to that method, because it still fails if I ignore otherwise, or everything from the beginning
def recognize(self, state: QGesture, watched, event: QEvent) -> QGestureRecognizer.Result: return QGestureRecognizer.Ignoreor in the example above:
def recognize(self, state: QGesture, watched, event: QEvent) -> QGestureRecognizer.Result: if event.type() == QEvent.TouchBegin: touch_event: QTouchEvent = event if len(touch_event.touchPoints()) == 1: state.press = touch_event.touchPoints()[0] state.pos = state.press return QGestureRecognizer.MayBeGesture elif event.type() == QEvent.TouchUpdate: touch_event: QTouchEvent = event state.last = state.pos state.pos = touch_event.touchPoints()[0] return QGestureRecognizer.TriggerGesture return QGestureRecognizer.IgnoreShouldn't that be sufficient?
@nutrx said in QGestureRecognizer.registerRecognizer() crashes using PySide2:
@jeremy_k yes absolutely, I didn't pay attention to that method, because it still fails if I ignore otherwise, or everything from the beginning
def recognize(self, state: QGesture, watched, event: QEvent) -> QGestureRecognizer.Result: return QGestureRecognizer.Ignore...
Shouldn't that be sufficient?
I'm not sure what you mean here. With the addition of the default Ignore, the application displays a window and doesn't do anything noteworthy in my environment. Are you still experiencing a crash?
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@nutrx said in QGestureRecognizer.registerRecognizer() crashes using PySide2:
@jeremy_k yes absolutely, I didn't pay attention to that method, because it still fails if I ignore otherwise, or everything from the beginning
def recognize(self, state: QGesture, watched, event: QEvent) -> QGestureRecognizer.Result: return QGestureRecognizer.Ignore...
Shouldn't that be sufficient?
I'm not sure what you mean here. With the addition of the default Ignore, the application displays a window and doesn't do anything noteworthy in my environment. Are you still experiencing a crash?
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@jeremy_k yes, exactly. I just tried to get it to run, so I could move on from there. But it still crashes the same as before. Sorry, I don't have PyQt set up rn
PanGestureRecognizer doesn't have an
__init__to callQGestureRecognizer.__init__. I vaguely recall reports of misbehavior using PyQt if a Qt object's constructor isn't invoked. This may have been limited to QObjects. It might not apply to PySide. Either way, it's an inexpensive experiment to run. QGestureRecognizer's C++ constructor is empty, but there may be some bookkeeping on the Python side. -
PanGestureRecognizer doesn't have an
__init__to callQGestureRecognizer.__init__. I vaguely recall reports of misbehavior using PyQt if a Qt object's constructor isn't invoked. This may have been limited to QObjects. It might not apply to PySide. Either way, it's an inexpensive experiment to run. QGestureRecognizer's C++ constructor is empty, but there may be some bookkeeping on the Python side.@jeremy_k you mean, I should try just calling QGestureRecognizer's
__init__inPanGestureRecognizer.__init__? I would've guessed that's ambiguous, or does instanciation lead to a direct call of the C++ parent constructor instead of the parent's__init__in Python? However, I just tried, still no luck :/ -
@jeremy_k you mean, I should try just calling QGestureRecognizer's
__init__inPanGestureRecognizer.__init__? I would've guessed that's ambiguous, or does instanciation lead to a direct call of the C++ parent constructor instead of the parent's__init__in Python? However, I just tried, still no luck :/class PanGestureRecognizer(QGestureRecognizer): def __init__(self): super().__init__()This doesn't seem to be necessary with pure python classes. The wording of object.__init__ led me to believe that it was, but a test suggests that the base class __init__ is called if no derived __init__ is defined.
Asking a question about code? http://eel.is/iso-c++/testcase/
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class PanGestureRecognizer(QGestureRecognizer): def __init__(self): super().__init__()This doesn't seem to be necessary with pure python classes. The wording of object.__init__ led me to believe that it was, but a test suggests that the base class __init__ is called if no derived __init__ is defined.
@jeremy_k
Well, in Python just like in, say, C++, if you do not define your own__init__()(constructor in C++) the language will always cause the base class's__init__()/constructor. If you do define your own, you must then explicitly call the base class__init__()/constructor, in either language.in Python.[EDIT As @jeremy_k pointed out below, I was wrong to say this applies in all C++ cases. Let's leave it as: in Python, if you define any derived
__init__()you must (should) explicitly call the base__init__()from there; but if you do not define a derived__init__()the base one will still be called.]I vaguely recall reports of misbehavior using PyQt if a Qt object's constructor isn't invoked
I don't know if somehow PySide2/PyQt requires you to explicitly define your own
__init__()and call the base, unless you have some reference for that? -
@jeremy_k
Well, in Python just like in, say, C++, if you do not define your own__init__()(constructor in C++) the language will always cause the base class's__init__()/constructor. If you do define your own, you must then explicitly call the base class__init__()/constructor, in either language.in Python.[EDIT As @jeremy_k pointed out below, I was wrong to say this applies in all C++ cases. Let's leave it as: in Python, if you define any derived
__init__()you must (should) explicitly call the base__init__()from there; but if you do not define a derived__init__()the base one will still be called.]I vaguely recall reports of misbehavior using PyQt if a Qt object's constructor isn't invoked
I don't know if somehow PySide2/PyQt requires you to explicitly define your own
__init__()and call the base, unless you have some reference for that?@JonB said in QGestureRecognizer.registerRecognizer() crashes using PySide2:
@jeremy_k
Well, in Python just like in, say, C++, if you do not define your own__init__()(constructor in C++) the language will always cause the base class's__init__()/constructor. If you do define your own, you must then explicitly call the base class__init__()/constructor, in either language.That's inaccurate for C++ base class default constructors. The compiler will insert a call to the base constructor if the programmer does not. Explicit invocation is only required if there are arguments to pass.
Asking a question about code? http://eel.is/iso-c++/testcase/
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@JonB said in QGestureRecognizer.registerRecognizer() crashes using PySide2:
@jeremy_k
Well, in Python just like in, say, C++, if you do not define your own__init__()(constructor in C++) the language will always cause the base class's__init__()/constructor. If you do define your own, you must then explicitly call the base class__init__()/constructor, in either language.That's inaccurate for C++ base class default constructors. The compiler will insert a call to the base constructor if the programmer does not. Explicit invocation is only required if there are arguments to pass.
@jeremy_k
You are quite correct, and thank you for pointing this out. Partly I was unconsciously thinking of constructors with parameters, and partly I make slips as I swap between C#/C++/Python/JavaScript! I will correct my previous post, so as not to mislead. -
You may have found a bug in the PySide2 implementation. Did you check if you have the same behaviour with PySide6 ?
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You may have found a bug in the PySide2 implementation. Did you check if you have the same behaviour with PySide6 ?
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Then you should go to the bug report system and see if there's already something there. If not, please consider opening a new issue providing your minimal runnable script that shows that behaviour.
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It's an issue on Python and it has likely not been used that much with that language. You can add a comment on the issue to remind the current assigned person that this is still not solved.
