Re: [Discuss-gnuradio] new feature work: qtgui support in grc

[Josh Blum]

On 03/02/2011 04:11 PM, Alexandru Csete wrote:
> Hi Josh,
> 
> I had a few moments to try it out. It worked very well and I think it
> will be useful.
> 
> I got a little confused when I cloned the repository because it said
> there was no HEAD (or something like that) and the directory was
> empty, but I could still checkout to the wip/qtgui/grc branch. I hope
> I got the right thing.
> 

Ah, I dont have a master branch. Most people just git remote add my repo
to an existing gnuradio repo.

> You mention engineering notation for the widget. I believe for the
> text entry it is quite straightforward (xml attached - I just copied
> the code from the gr-qtgui example).
> 

Excellent, I will try to get this in the block as an option for
float/real numbers.

My goal is to have engineering notation for the text box in the qwt
slider. I think that involves making a custom qwt text/engine object. It
seems like something qwt should support or would not be hard to
implement. Not sure. http://pyqwt.sourceforge.net/doc5/reference.html

Thanks!
-Josh

> I will do more tests during the coming days.
> 
> Alex
> 
> 
> On Wed, Mar 2, 2011 at 2:52 AM, Josh Blum <address@hidden> wrote:
>> Hey list,
>>
>> I have been working on supporting PyQt widgets and the qtgui sinks in
>> the Gnuradio Companion. Get the code on my wip/qtgui/grc branch on
>> jblum.git http://gnuradio.org/cgit/jblum.git/log/?h=wip/qtgui/grc
>>
>> Available widgets:
>>  * qtgui plotter (dft, scope, etc)
>>  * tabbed panel
>>  * slider
>>  * combo box
>>  * radio buttons
>>  * text entry
>>  * label
>>
>> 1) The slider adds a new requirement of PyQwt (python Qwt bindings). Qwt
>> should already be installed for the qtgui sinks themselves.
>>
>> 2) The qtgui and wxgui widgets are distinctly separated. Previously, the
>> "variable slider" was a wx slider form. Now, there is a WX GUI Slider
>> and a QT GUI Slider. And the generate options now have a QT GUI option.
>> You cannot mix and match widgets from different graphics libraries.
>>
>> 3) No attempt was made to make the existence of different graphics
>> toolkits transparent to the user. That would have been a huge pain on my
>> part and I couldn't try new things. If this Qt thing catches on, I am
>> considering a migration script from wx->qt.
>>
>> 4) The Qt widgets in grc do not have a python wrapper/forms library like
>> they do in gnuradio. All the generated code uses the PyQt API directly.
>> This is in-part possible because Qwt supplies its own set of useful
>> wrappers around Qt widgets. Examples: http://qwt.sourceforge.net/sliders.png
>>
>> 5) Each widget block in grc has a gui hint parameter. This parameter is
>> a combination of the grid parameter and notebook parameter seen in the
>> wx widget blocks. It also allowed the implementation code to be a lot
>> more generic.
>>
>> Whats missing?
>> I feel that the widgets still need a bit of polishing. Engineering
>> notation would be nice. I'd like to see features in the wx scope sink
>> brought to the qtgui scope such as trigger modes and multiple channels.
>> I think the qt equivalent of the numbersink would be nice too (and that
>> could use some of those real fancy qwt widets):
>> http://read.pudn.com/downloads186/sourcecode/embed/872381/qwt/doc/images/dials2.png
>>
>> Why qtgui stuff?
>> The WX stuff in gnuradio is fairly polished in comparison; and when it
>> works, it works. But we have seen many issues with wx outside of the
>> linux+x86 world, not to mention opengl issues on the x86. I hope that
>> the qt stuff is a viable, cross platform option for live gnuradio
>> plotting and graphical applications.
>>
>> Please try it out. Feedback is welcome!
>> -Josh
>>
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