Slide with fletcher diagram and subsection generates different heading numbers

[Pamplemousse]

In a slide containing a fletcher diagram, I wanted to add a subsection title. However, the same subsection will take different heading number accross the slides.

The following source file:

// mwe.typ
#import "@preview/fletcher:0.5.1" as fletcher: edge, node
#import "@preview/touying:0.5.2": pause, slide, themes, touying-reducer
#import themes.metropolis: *

#show: metropolis-theme
#set heading(numbering: "1.1")

#let fletcher-diagram = touying-reducer.with(reduce: fletcher.diagram, cover: fletcher.hide)

= foo

#slide[
  == bar

  #fletcher-diagram(
    node-stroke: .1em,
    spacing: 3em,

    node((0, 1), `user`),
    pause,
    node((1, 1), `application`),
    edge((0, 1), (1, 1), `uses`, "->"),
  )
]

compiled with the following command:

typst watch --format png mwe.typ mwe{n}.png

then we get the following three slides:

I expected the heading for bar not to change as the rest of the diagram is revealed (the more pause are added, the more the heading gets incremented). Note that this example also highlights #84 which I separated because it doesn't seem related to fletcher.

[OrangeX4]

Duplicated with #38. We need to wait for frozen state to do this.

[OrangeX4]

And you can also consider:

#import "@preview/fletcher:0.5.1" as fletcher: edge, node
#import "@preview/touying:0.5.2": pause, slide, themes, touying-reducer
#import themes.metropolis: *

#show: metropolis-theme.with(
  header: utils.display-current-heading(level: 1),
  config-common(
    subslide-preamble: text(weight: "bold", utils.display-current-heading(level: 2)) + parbreak(),
  )
)
#set heading(numbering: "1.1")

#let fletcher-diagram = touying-reducer.with(reduce: fletcher.diagram, cover: fletcher.hide)

= foo

== bar

#fletcher-diagram(
  node-stroke: .1em,
  spacing: 3em,

  node((0, 1), `user`),
  pause,
  node((1, 1), `application`),
  edge((0, 1), (1, 1), `uses`, "->"),
)

I think it's a more elegant method.

[Pamplemousse]

I think it's a more elegant method.

But it breaks anything more complicated than the minimum example:

• Slides that have content (like a little introduction) before a subsection. You get

  == heading
  little intro
  == heading
  content

  instead of the expected

  little intro
  == heading
  content

• It doesn't handle multiple levels throughout the presentation, for example a slide with a diagram under a subsection, and another slide with a diagram under a subsubsection.