03:01 <cr1901_modern> rjo: So it turns out, a slider w/ two elements can be done in pure PyQt: https://github.com/mkilling/QxtSpanSlider.py. I'm guessing you would prefer a widget that was closer in style to a native widget compared to me drawing on a canvas/using QGraphics Framework.

03:03 <cr1901_modern> QGraphics Framework certainly gives me more flexibility in what I can do; it has classes to separate how graphic elements are stored, and what data is stored with them, from how to actually draw and update them.

03:07 <sb0> eew https://blogs.kde.org/2009/03/26/how-crash-almost-every-qtkde-application-and-how-fix-it-0

03:08 <sb0> i've avoided those "recursive event loop" functions in qt because they smelled bad, and indeed...

03:15 <cr1901_modern> Why would you EVER do a recursive event loop in a language that doesn't guarantee tail recursion (I didn't read the article; I assume it crashes due to stack overflow)?

03:17 <sb0> for blocking on modal dialogs

03:18 <sb0> a coroutine would be more appropriate, but c++ doesn't have them ...

03:20 <whitequark> sb0: huh? the problem is not in the event loop, it's in memory management

03:20 <whitequark> and I don't see how PyQt would be affected

03:24 <sb0> I know, but using a single stack for this is ugly, and encourages the memory management bug

03:26 <whitequark> I disagree about coroutines actually, the proper way to fix this is to bind a closure to the dialog's signal

03:27 <whitequark> (which I assume is trivial in PyQt. Or at least hope)

03:27 <whitequark> and you can finally do that in Qt 5 in C++, too.

03:28 <whitequark> this very modal dialog case is presented as an example, in fact: https://wiki.qt.io/New_Signal_Slot_Syntax#Asynchronous_made_easier.

03:28 <cr1901_modern> You mean by giving the dialog signal the environment on the event loop?

03:29 <whitequark> C++11 has closures

03:29 <sb0> yes, you can use a closure, but it breaks the flow of the program

03:30 <whitequark> it's definitely more annoying to write in Python due to the indentation

03:32 <cr1901_modern> I'm having trouble visualizing how a closure lets you prevent a recursive event loop. I *guess* it's because you move the blocking code of the modal dialog box out of the event loop itself, while still giving it access to all the variables it might possibly need from the event loop.

03:32 <sb0> hm, yes, c++ doesn't have the problem

03:33 <whitequark> the blocking is artificial, the exec() method just loops until the dialog's close signal fires

03:37 <sb0> and potentially your function can be called recursively, if the dialog's opening is triggered by anything else than the user touching the interface

09:53 <GitHub133> [artiq] sbourdeauducq pushed 1 new commit to master: http://git.io/vRMHq

09:53 <GitHub133> artiq/master 0da8955 Sebastien Bourdeauducq: gui: basic support for opening files outside repository

10:58 <GitHub151> [artiq] sbourdeauducq pushed 1 new commit to master: http://git.io/vRDmt

10:58 <GitHub151> artiq/master ed08352 Sebastien Bourdeauducq: gui: improve error handling

11:24 <GitHub66> [artiq] sbourdeauducq pushed 1 new commit to master: http://git.io/vRDGd

11:24 <GitHub66> artiq/master 7b25805 Sebastien Bourdeauducq: master: allow remote listing of directories

16:50 <rjo> cr1901_modern: sure. but don't be too much NIH here. implementing a widget from (low level) QGraphics up might be more work in the end (bugs, corner cases, implementation details, porting to other qt versions). but i am probably not the one to gitve authoritative advice here. just pointing out a few questions.

18:29 <cr1901_modern> rjo: I'm not sure what to do right now. sb0 said he potentially wants to remove the pyqtgraph dependency from the main GUI. If I do that, I will have to reimplement the axis, which yes, is a lot of code.

18:30 <cr1901_modern> Drawing tick marks, handling labeled ticks, and ealing with how to redraw the axis when it needs to be rescaled are just three things offhand that would need to be reimplemented.

18:30 <cr1901_modern> sb0: ping ^

18:30 <cr1901_modern> Oh wait, he's not here lol