How to trigger non-blocking long calculations in Makie?

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1

I want to do the following in Makie: press a button which triggers long computation that interactively updates the plot. I can’t seem to figure it out. Here is a MWE:

This example uses the bool observable running to track whether the long computation is triggered.

F = Figure(resolution=(600,600))
F[1,1] = inputgrid = GridLayout(tellwidth = false)
running = Observable(false)
b = Button(F, label = @lift(string($running)))
inputgrid[1,1] = b

on(b.clicks) do _
    running[] = true # this should change the button label from "false" to "true"
    sleep(1) # this is the long computation
    running[] = false # resetting the button label
end
F

When I press the button, the plot becomes non-responsive for a second and the label does not change. I am expecting the label to change immediately on button press to “true” and then change back to “false” after a second.

What am I doing wrong? Are notify calls incapable of working when called from withing an on call? How can I make the button turn to “true” on click and then on its own turn back to “false”?

This is on Julia 1.8.2 and GLMakie v0.7.3.

2

If sleeping happens on the main thread then no rendering can happen (rendering is done asynchronously but not on a different thread). You can use @async begin around the stuff in the on call and the whole thing will be interleaved with the rendering using coroutines, even if there’s still only one thread.

3 Likes
3

Thank you! Indeed, all I needed was to add @async

on(b.clicks) do _
    @async begin
        running[] = true
        sleep(1)
        running[] = false
    end
end