vbox behaves like hbox

[korsbo]

For some reason, vbox() has started outputting a row (not column) of widgets.

using Interact
sliders = fill(slider(1:10), 3)
display(vbox(sliders...))

This is now the same behaviour as hbox():

Combinations of hbox( vbox(), vbox() ) used to generate nice arrays of widgets, but now it just generates a long horizontal line.

I am guessing that this may be related to #197.

This is happening for me on a mac, using ipywidgets 7.0.1.

[JobJob]

Sad news.

The hbox, vbox code was cobbled together quickly and without a deep understanding of IPywidgets layout system, so it's a bit of a shambles.

If anyone wants to have a bash at cleaning it up, it would be great, and I'd try to help.

Having said that, this may just be some minor compatibility issue with IPywidgets 7 - I notice I'm getting errors in the javascript console.

Alternately, you could try https://github.com/JuliaGizmos/InteractNext.jl (follow the install instructions there), it uses obs(slider) instead of signal(slider), but otherwise the API is quite similar. It may work better.

We're really hoping to get WebIO/InteractNext to a proper release before the end of the year.

Unfortunately, it seems we've been a bit swamped with other stuff recently.

[korsbo]

I have found a hack for this problem.

in Interact/src/IJulia/setup.jl, replace

widget_class(::Box) = "Box"

with

widget_class(b::Box) = b.vert ? "VBox" : "Box"

This fixes the issue at hand, but a deeper problem remains.

The issue is that none of the attributes which Interact.jl are trying to pass to ipywigets FlexBox are actually registered by ipywidgets. I have not really been able to figure out precisely how Interact.jl deals with the python objects, but I think that I know where the problem lies.

Interact.jl creates an ipywidget Layout object. I can't spot any errors in its creation and this object should contain the output of

statedict(l::Layout) = begin
   state = Dict{Symbol, Any}(:display => "flex", :align_items => "stretch")
   l.box.vert && (state[:flex_flow] = "column")
   state
end

The resulting Layout python object is supposed to be passed to ipywidgets Box, as specified by

viewdict(b::Box) = begin
   Dict{Symbol, Any}(:layout => "IPY_MODEL_"*widget_comms[b.layout].id)
end

Hovewer, I do not think that this is done properly. If I replace this function with a dummy

viewdict(b::Box) = begin
   Dict{Symbol, Any}()
end

or

viewdict(b::Box) = begin
   Dict{Symbol, Any}(:layout=>"dummy")
end

it does not alter the behaviour at all.

In python one would write

import ipywidgets as widgets
from IPython.display import display

s = widgets.IntSlider(description="my slider")

my_layout_object = widgets.Layout(display="flex", align_items="stretch", flex_flow="column")
box = widgets.Box([s,s,s], layout=my_layout_object)
display(box)

and I believe that the point of failure for Interact.jl lies in the layout = my_layout_object assignment.
However, I do not know how to fix this, and the discovery of my hacky solution reduces my motivation to keep digging (especially if InteractNext.jl is supposed to take over soon).

[korsbo]

Fixed by #201, closing.