Re: More than two y axises patch?

[Uwe R. <Uwe...@ti...>]

On Tuesday 15 September 2009 08:04, Paul Harris wrote:

> I can also forsee the need for multiple Y axes.  I agree you should try and
> not break the composite architecture...

No, the composite architecture is a design problem, that makes a lot of things 
more difficult as they need to be ( espacially the layout engine ). Breaking 
it is something I want to do since a long time, but as it has a major impact 
on Qwt and application code I won't do it soon.

> Perhaps all you need to do is index things like dimAxes like so
> dimAxes[QwtPlot::yLeft][INDEX]

That's more or less what the patch does. It works for many use cases, but it's 
not complete and doesn't handle the difficult aspects of the layout engine. 
That's ( and because I don't like the limitation ) why it is a patch only and 
won't make it into the official Qwt code.

I'm maintaining Qwt for quite a long time and for many years I never heard 
requests for more axis. I'm not sure what has changed - maybe because Qt is 
available on Windows and Qwt has become part of all major distributions, what 
increases the number of users. 

Of course I will implement this feature, but my steps ( without knowing the 
schedule myself ) are:

1) Complete Qwt 5.3 ( more types of plot items )
2) Drop Qt3 support
3) Making use of several Qt4 only features ( double based render code, OpenGL 
canvas, ... )
4) Breaking the composite architecture + more axes

Uwe