Re: Matlab compatible legends for FLTK/Gnuplot backends?

[David Bateman]

Ben Abbott wrote:
> Implementing the legend the Matlab way with Gnuplot will get even messier, if 
> we need to handle the outerposition property in the manner Matlab does. I 
> recommend we continue to implement the legend for the Gnuplot backend using 
> Gnuplot's key.
>
> However, I see no need to keep the axes "key*" properties in place.
>
> A Matlab compatible legend has additional properties ...
>
>     'EdgeColor'
>     'Interpreter'
>     'Location'
>     'Orientation'
>     'String'
>     'TextColor'
>
> If we also include a list of handles for the objects listed in the legend, then 
> it will be possible to parse the information in the front end (i.e. properties) 
> and use Gnuplot's key to produce the desired legend.
>   
If we do this it means either one of two things has to be done that are 
quite ugly

1) In the gnuplot backend don't display the axes with a tag of "legend", 
but rather try and recover the information here to recreate the legend 
with gnuplot functions. This is ugly as essentially we are ignoring the 
text and line values in the legend axis and trying to re-associate these 
to the objects that they relate to.

2) Put a gnuplot dependency in the frontend legend function that 
prevents the legend axis being created in the first place. Its not good 
to make the frontend dependent on the backend as then switching 
dynamically between backends becomes problematic.

Another issue is that the I don't see how bug #30519 can be treated with 
the gnuplot legend functions. There might be a way though as I haven't 
investigated far.

D.