QSpinBox.valueChanged[str]
Phil Thompson
phil at riverbankcomputing.com
Tue Feb 2 15:43:36 GMT 2021
On 02/02/2021 15:11, Rodrigo de Salvo Braz wrote:
> Hi,
>
> I'm reading Martin Fitzpatrick's book on PyQt and came across this
> example
> which includes a signal indexed by the function str:
>
> widget = QSpinBox()
> widget.valueChanged[str].connect(self.value_changed_str)
>
> I have a few questions:
>
> Q1. Why not have a signal named textChanged instead? That would match
> Qt's
> reference <https://doc.qt.io/qt-5/qspinbox.html>. And I guess it would
> look
> more usual.
You can use that signal if you want to, but is was only added in Qt
v5.14.
> Q2. Can other functions or types be used as index too, or just str?
The index corresponds to the signature of the particular signal overload
you want to connect.
> Q2. How could I have figured how to use this from PyQt's reference or
> Qt's
> reference by myself (if I had not seen the example in the book)? PyQt's
> reference
> <https://www.riverbankcomputing.com/static/Docs/PyQt5/api/qtwidgets/qspinbox.html?highlight=qspinbox>
> indicates two signals, valueChanged(int) and valueChanged(str). Is
> there
> some kind of convention that would allow me to understand how to use
> valueChanged[str] from these documentation descriptions?
https://www.riverbankcomputing.com/static/Docs/PyQt5/signals_slots.html#connecting-disconnecting-and-emitting-signals
It would seem that Qt is moving away from having overloaded signals - a
good thing.
Phil
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