cannot add a colorbar to a WGLMakie 2d plot

[t-bltg]

MRE (also testing against #2428, errors out too), works in CairoMakie (untested GLMakie):

julia> using JSServe, Markdown, WGLMakie
julia> Page(exportable=true, offline=true)
julia> WGLMakie.activate!()
julia> fig, ax, plot = scatter(0:1)
julia> Colorbar(fig[1, 2]; label = "vertical cbar")
julia> display(fig)  # superfluous I guess

ERROR: TypeError: scene is undefined
Stacktrace:
  [1] error(s::String)
    @ Base ./error.jl:35
  [2] evaljs_value(session::Session, js::JSServe.JSCode; error_on_closed::Bool, time_out::Float64)
    @ JSServe ~/.julia/packages/JSServe/kIK9q/src/session.jl:238
  [3] evaljs_value
    @ ~/.julia/packages/JSServe/kIK9q/src/session.jl:206 [inlined]
  [4] insert!(td::WGLMakie.ThreeDisplay, scene::Scene, plot::Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ WGLMakie ~/.julia/packages/WGLMakie/L5URO/src/three_plot.jl:24
  [5] insert!(td::WGLMakie.Screen, scene::Scene, plot::Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ WGLMakie ~/.julia/packages/WGLMakie/L5URO/src/display.jl:173
  [6] push!(scene::Scene, plot::Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ Makie ~/.julia/packages/Makie/Ggejq/src/scenes.jl:409
  [7] plot!(scene::Scene, P::Type{Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}}}, attributes::Attributes, input::Tuple{Observable{Vector{GeometryBasics.HyperRectangle{2, Float32}}}}, args::Observable{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ Makie ~/.julia/packages/Makie/Ggejq/src/interfaces.jl:421
  [8] plot!(scene::Scene, P::Type{Poly}, attributes::Attributes, args::Observable{Vector{GeometryBasics.HyperRectangle{2, Float32}}}; kw_attributes::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Makie ~/.julia/packages/Makie/Ggejq/src/interfaces.jl:335
  [9] plot!
    @ ~/.julia/packages/Makie/Ggejq/src/interfaces.jl:302 [inlined]
 [10] #plot!#165
    @ ~/.julia/packages/Makie/Ggejq/src/interfaces.jl:286 [inlined]
 [11] poly!(::Scene, ::Vararg{Any}; attributes::Base.Pairs{Symbol, Any, Tuple{Symbol, Symbol, Symbol}, NamedTuple{(:color, :visible, :inspectable), Tuple{Observable{Vector{ColorTypes.RGBA{Float64}}}, Observable{Bool}, Bool}}})
    @ MakieCore ~/.julia/packages/MakieCore/JjXvr/src/recipes.jl:38
 [12] initialize_block!(cb::Colorbar)
    @ Makie ~/.julia/packages/Makie/Ggejq/src/makielayout/blocks/colorbar.jl:197
 [13] _block(::Type{Colorbar}, ::Figure; bbox::Nothing, kwargs::Base.Pairs{Symbol, String, Tuple{Symbol}, NamedTuple{(:label,), Tuple{String}}})
    @ Makie ~/.julia/packages/Makie/Ggejq/src/makielayout/blocks.jl:408
 [14] _block(::Type{Colorbar}, ::GridPosition; kwargs::Base.Pairs{Symbol, String, Tuple{Symbol}, NamedTuple{(:label,), Tuple{String}}})
    @ Makie ~/.julia/packages/Makie/Ggejq/src/makielayout/blocks.jl:294
 [15] #_#1077
    @ ~/.julia/packages/Makie/Ggejq/src/makielayout/blocks.jl:279 [inlined]
 [16] top-level scope
    @ REPL[9]:1

Encountered in #2478 and blocking.

[SimonDanisch]

How do you execute this? Looks like you're using Page without executing it in an environment that needs a page?

[t-bltg]

I just followed the mwe at https://docs.makie.org/stable/documentation/backends/wglmakie/#output (I don't know anything about this backend ... should I try something else ?), and opened http://localhost:9284/browser-display in my local browser (I think it's unrelated, but I'm using a ssh tunnel (port forwarding) since I'm working on a remote machine).

If I run the example without the colorbar line, the plot is displayed correctly in my browser.

(@v1.8) pkg> st Makie WGLMakie JSServe
Status `~.julia/environments/v1.8/Project.toml`
  [824d6782] JSServe v1.2.9
  [ee78f7c6] Makie v0.19.0
  [276b4fcb] WGLMakie v0.8.0

[SimonDanisch]

Yeah I think I found the problem...Inserting new scenes is buggy right now - only inserting new plots works correctly right now...
So you need to create all axes / legends / blocks, before displaying it.
While I'm working on a fix, you could also use that as a workaround for #2478
edit: Stepper(fig) displays the figure ;) So any block that creates new scenes needs to be created before that!

[jkrumbiegel]

The colorbars also don't need to be inserted live into the test figure. It's enough to have them there at all.

[t-bltg]

While I'm working on a fix, you could also use that as a workaround for #2478
edit: Stepper(fig) displays the figure ;) So any block that creates new scenes needs to be created before that!

Thanks Simon for the workaround and the explanation it seems to work locally. I'm pushing a fix in #2478.

The colorbars also don't need to be inserted live into the test figure. It's enough to have them there at all.

That could work, but IMO adding a colorbar with a label rotation to an existing plot should be tested for the label bounding boxes interaction (a standalone colorbar is a somewhat less common scenario).

[jkrumbiegel]

It's ok to add it, it's just not supposed to be added after displaying it for the first time I think.

[t-bltg]

Yeah, probably adding a semicolon after julia> fig, ax, plot = scatter(0:1); wouldn't have triggered display and would have worked.

[SimonDanisch]

Fixed by #2856

[SimonDanisch]

Actually, it seems it was fixed before that and should already be tagged