[PyKDE] Auto-connecting Slots
Patrick K. O'Brien
pobrien at orbtech.com
Sat Jan 28 00:00:52 GMT 2006
Andreas Pakulat wrote:
> On 27.01.06 22:46:29, Phil Thompson wrote:
>> On Friday 27 January 2006 8:10 pm, Patrick K. O'Brien wrote:
>>> Phil Thompson wrote:
>>>> Tonight's PyQt4 snapshot implements Torsten's suggestion for using a
>>>> decorator to control which signal/slot connections are made when pyuic4
>>>> The problem is best demonstrated by QSpinBox which emits
>>>> valueChanged(QString) and valueChanged(int). Defining an auto-connect
>>>> on_spinbox_valueChanged means that the method is connected to both
>>>> signals and so gets invoked twice. Until now the method had to look at
>>>> the type of the argument and just return if it was the one it didn't
>>>> The QtCore.signature() decorator takes a single argument which is, in
>>>> effect, the C++ signature of the method which tells the auto-connect code
>>>> which signal to connect. For example...
>>>> def on_spinbox_valueChanged(self, value):
>>>> # value will only ever be an integer.
>>> Any chance we could get an easier syntax, such as:
>>> def on_spinbox_valueChanged(self, value):
>> I want to keep it generic in case some other uses pop up.
>> At the very least your example would have to be @QtCore.qtsig("int")
> Now I know near to nothing about signatures thus I have to ask:
I think you mean decorators.
> The signature would always sit right in front of the function
> If yes than I guess the short version might be ok when it is documented
> good (not just a comment with some example, at least when the first
> version is released).
> If you can put the signature somewhere else (which I doubt currently),
No, you can't.
> then the longer version would IMHO be better as you can directly see
> which slot is meant.
Anything longer than necessary is redundant, imo.
> BTW: Will this also solve "issues" like the clicked()-signal from
> QAbstractButton? So I could do
> def on_mybutton_clicked(self):
> and I would get only the call when checked is None and not the 2nd?
While I think that particular form of the decorator is butt-ugly,
something like it should definitely be able to deal with all the
variations that Qt likes to support.
Patrick K. O'Brien
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