Have IJulia honor set_default_plot_format

[knuesel]

It would be nice if set_default_plot_format(:png) was working in IJulia. Not sure if this is a bug or feature request.

[Mattriks]

There's an example on Julia Discourse of one way to enable set_default_plot_format. I haven't tested that out on IJulia. Note IJulia creates it's own display, at the top of the display stack:

using Gadfly
import Base.Multimedia as mltm

# display stack:
mltm.display

3-element Vector{AbstractDisplay}:
 TextDisplay(Base.TTY(Base.Libc.WindowsRawSocket(0x0000000000000278) open, 0 bytes waiting))
 Gadfly.GadflyDisplay()
 IJulia.InlineDisplay()

as does VScode. Gadfly shouldn't override those displays by default e.g. see #1311. You may have to popdisplay() to get the discourse example working in IJulia.

[knuesel]

Thanks for the link, I couldn't figure out how to make set_default_plot_format do anything.

I was expecting something like in Plots.jl, where you can do plot(..., fmt=:png) to show a specific plot as PNG, or default(fmt=:png) to change the format of all plots. For the user this "just works" in IJulia without fiddling with displays.

It seems that Plots.jl does it by overloading IJulia.display_dict, see here and here. Maybe more a hack than a proper solution...

[Mattriks]

I can't tell from your posts if you have found (for a specific Gadfly plot):

p = plot(...)
draw(PNG(8inch, 8inch), p)

[knuesel]

Yes, in IJulia I'm currently using plot(...) |> PNG() which works fine but must be done for each plot. So it would be nice to have an easy way to change the default, and there's already set_default_plot_format which doesn't do much currently. But maybe the Plots.jl way is not the right way and the default should be set through IJulia rather than Gadfly...