Implement multiple content blocks per slide

book/src/slide.md

@@ -24,4 +24,21 @@ These are:
   see [here](./dynamic.html#internal-number-of-repetitions)
 - additional information used by the theme, see the [gallery](./theme-gallery/index.html)
   to find out which they are under your theme's "Extra keyword arguments" section
-  (typically, you can at least specify a slide title as `title`)
+  (typically, you can at least specify a slide title as `title`)
+
+## Slides with multiple content bodies
+In the vast majority of cases, you will call `#slide` the way described above
+with one content block.
+However, some [themes](./themes.html) (or some of their
+[variants](./themes.html#theme-variants-per-slide)) sometimes require or allow
+more than one such content.
+In that case, you will write:
+```typ
+#slide[
+  The first piece of content
+][
+  Even more content
+][
+  Who knows how much content we can come up with?
+]
+```

book/src/theme-gallery/Makefile

@@ -0,0 +1,11 @@
+all: default bipartite
+
+default:
+	pdftoppm ./default.pdf ./default -png
+	montage ./default-* -geometry +50+50 -background LightGray ./default.png
+	rm ./default-*
+
+bipartite:
+	pdftoppm ./bipartite.pdf ./bipartite -png
+	montage ./bipartite-* -geometry +50+50 -background LightGray ./bipartite.png
+	rm ./bipartite-*

book/src/theme-gallery/bipartite.typ

@@ -17,3 +17,9 @@
 #slide(theme-variant: "east", title: "On the right!")[
   #lorem(40)
 ]
+
+#slide(theme-variant: "center split")[
+  #lorem(40)
+][
+  #lorem(40)
+]

book/src/theme-gallery/index.md

@@ -8,6 +8,8 @@ Here you can find an overview over all themes shipped with this template.
 ---
 
 ## Default
+_[go to top](#theme-gallery)_
+
 If you do not specify a theme, the default one will be used.
 You can specify it explicitly by referring to `slides-default-theme`:
 ```typ
@@ -50,6 +52,8 @@ You can specify it explicitly by referring to `slides-default-theme`:
 ---
 
 ## Bipartite
+_[go to top](#theme-gallery)_
+
 This theme is inspired by
 [Modern Annual Report](https://slidesgo.com/theme/modern-annual-report).
 It features a dominant partition of space into a bright and a dark side.
@@ -66,6 +70,8 @@ It features a dominant partition of space into a bright and a dark side.
 ### Variants
 - `"east"`: same as default variant, but dark side on the right, text is right
   aligned
+- `"center split"`: bright left and dark right half of equal size, requires two
+  content bodies, one for each half (does not display a slide title)
 
 ### Extra keyword arguments
 - `title`: a title for that slide
@@ -91,6 +97,12 @@ It features a dominant partition of space into a bright and a dark side.
 #slide(theme-variant: "east", title: "On the right!")[
   #lorem(40)
 ]
+
+#slide(theme-variant: "center split")[
+  #lorem(40)
+][
+  #lorem(40)
+]
 ```
 ![bipartite theme screenshot](./bipartite.png)
 

book/src/themes.md

@@ -73,12 +73,15 @@ For example, you could define the title slide in the following way:
 
 On to the actual slides.
 Their appearance is defined by functions that accept some meta data, some
-content (the last argument to `#slide`, essentially) and return some richer
-content, somehow styling that slide.
+array of contents (the last argument(s) to `#slide`, essentially) and return
+some richer content, somehow styling that slide:
+```typ
+(dictionary, array of content) => content
+```
 You can define an arbitrary amount of such functions as values of the `variants`
 dictionary, but one of them must be stored under the key `"default"`.
 
-The meta data referred to above are a dictionary containing any extra keyword-
+The meta data referred to above are a dictionary containing any extra keyword
 arguments that the user has specified in their call to `#slide`.
 As a theme author, you should inform your users what kind of arguments you will
 respect.
@@ -101,6 +104,20 @@ then your styling function will be provided the following dictionary:
 ```
 especially not containing a `theme-variant` item!
 
+The `#slide` function accepts an arbitrary amount of positional arguments that
+are interpreted as content for the slide.
+The user of this template can provide them by simply juxtapositioning multiple
+content blocks after `#slide` or `#slide(...)`, see
+[this section](./slide.html#slides-with-multiple-content-bodies).
+Often, it will make sense to work with only a single piece of content,
+however.
+In any case, your variant function will always be provided an array of contents
+as the second argument, so you will usually have to extract that single entry
+you are interested in (using `.at(0)` or `.first()`).
+It might also make sense to `panic` with an informative error message if the user
+provided another number of content blocks than you expected.
+
+
 To make use of some of the functionality this template offers, you can access
 - the counter `logical-slide`, telling you the "page number" of a slide, but
   without counting up on dynamical slides that produce mulitple PDF pages;
@@ -113,17 +130,23 @@ Let us define two variants:
   (
     title-slide: align(center + horizon, data.title),
     variants: (
-      "default": (slide-info, body) => {
+      "default": (slide-info, bodies) => {
         text(.7em, [#slide-info.title (current section: #section.display())])
         v(1fr)
-        body
+        for body in bodies {
+          body
+          v(1em)
+        }
         v(1fr)
         text(.7em, [#h(1fr) #logical-slide.display()])
       },
-      "australia": (slide-info, body) => {
+      "australia": (slide-info, bodies) => {
+        if bodies.len() != 1 {
+          panic("australia variant expected exactly one body")
+        }
         text(.7em, [current section: #section.display()])
         v(1fr)
-        scale(y: -100%, body)
+        scale(y: -100%, bodies.first())
         v(1fr)
         text(.7em, [#h(1fr) #logical-slide.display()])
       },
@@ -139,6 +162,10 @@ The `"australia"` variant does not make use of the `slide-info` argument at all.
 That is completely fine, it must have this argument for formal reasons, anyway,
 though.
 
+Also, the `"default"` variant displays all the content blocks provided to `#slide`
+while the `"australia"` variant errors if more or less than one such block is
+given.
+
 And that's it already!
 Have fun creating your own theme and maybe consider opening a pull request
 at [the GitHub repository](https://github.com/andreasKroepelin/typst-slides)
@@ -150,14 +177,14 @@ be too limited for what you need.
 Sometimes, you might find yourself needing a very special purpose design _just_
 for a couple of slides.
 For that case, you can use the `override-theme` argument of the `#slide` function.
-It accepts a function of the form `(slide-info, body) => [slide content]`, just
+It accepts a function of the form `(slide-info, bodies) => [slide content]`, just
 as if you would define a theme variant (see details above).
 
 For example, you might write something like this:
 ```typ
-#let special-purpose-theme(slide-info, body) = align(horizon)[
+#let special-purpose-theme(slide-info, bodies) = align(horizon)[
   #rotate(45deg, heading(level: 2, slide-info.title))
-  #scale(x: -100%, body)
+  #scale(x: -100%, bodies.first())
 ]
 #slide(override-theme: special-purpose-theme, title: "This is rotated")[
   #lorem(40)

examples/override-theme.typ

@@ -15,9 +15,9 @@
   #lorem(40)
 ]
 
-#let special-purpose-theme(slide-info, body) = align(horizon)[
+#let special-purpose-theme(slide-info, bodies) = align(horizon)[
   #rotate(45deg, heading(level: 2, slide-info.title))
-  #scale(x: -100%, body)
+  #scale(x: -100%, bodies.first())
 ]
 #slide(override-theme: special-purpose-theme, title: "This is rotated")[
   #lorem(40)

slides.typ

@@ -178,8 +178,7 @@
     max-repetitions: 10,
     theme-variant: "default",
     override-theme: none,
-    ..kwargs,
-    body
+    ..args
 ) = {
     pagebreak(weak: true)
     logical-slide.step()
@@ -191,15 +190,16 @@
         if override-theme != none {
             slide-content = override-theme
         }
-        let slide-info = kwargs.named()
+        let slide-info = args.named()
+        let bodies = args.pos()
 
         for _ in range(max-repetitions) {
             locate( loc-inner => {
                 let curr-subslide = subslide.at(loc-inner).first()
                 if curr-subslide <= repetitions.at(loc-inner).first() {
                     if curr-subslide > 1 { pagebreak(weak: true) }
 
-                    slide-content(slide-info, body)
+                    slide-content(slide-info, bodies)
                 }
             })
             subslide.step()
@@ -240,7 +240,12 @@
         ]
     }
 
-    let default(slide-info, body) = {
+    let default(slide-info, bodies) = {
+        if bodies.len() != 1 {
+            panic("default variant of default theme only supports one body per slide")
+        }
+        let body = bodies.first()
+
         let decoration(position, body) = {
             let border = 1mm + color
             let strokes = (
@@ -283,7 +288,12 @@
         ]
     }
 
-    let wake-up(slide-info, body) = {
+    let wake-up(slide-info, bodies) = {
+        if bodies.len() != 1 {
+            panic("wake up variant of default theme only supports one body per slide")
+        }
+        let body = bodies.first()
+
         block(
             width: 100%, height: 100%, inset: 2em, breakable: false, outset: 0em,
             fill: color,

themes/bipartite.typ

@@ -34,7 +34,12 @@
     []
   }
 
-  let west(slide-info, body) = {
+  let west(slide-info, bodies) = {
+    if bodies.len() != 1 {
+      panic("default variant of bipartite theme only supports one body per slide")
+    }
+    let body = bodies.first()
+
     box(
       width: 30%, height: 100%, outset: 0em, inset: (x: 1em), baseline: 0em,
       stroke: none, fill: my-dark,
@@ -47,7 +52,12 @@
     )
   }
 
-  let east(slide-info, body) = {
+  let east(slide-info, bodies) = {
+    if bodies.len() != 1 {
+      panic("east variant of bipartite theme only supports one body per slide")
+    }
+    let body = bodies.first()
+
     box(
       width: 70%, height: 100%, outset: 0em, inset: (x: 1em), baseline: 0em,
       stroke: none, fill: my-bright,
@@ -60,8 +70,27 @@
     )
   }
 
+  let center-split(slide-info, bodies) = {
+    if bodies.len() != 2 {
+      panic("center split variant of bipartite theme only supports two bodies per slide")
+    }
+    let body-left = bodies.first()
+    let body-right = bodies.last()
+
+    box(
+      width: 50%, height: 100%, outset: 0em, inset: (x: 1em), baseline: 0em,
+      stroke: none, fill: my-bright,
+      align(right + horizon, text(fill: my-dark, body-left))
+    )
+    box(
+      width: 50%, height: 100%, outset: 0em, inset: (x: 1em), baseline: 0em,
+      stroke: none, fill: my-dark,
+      align(left + horizon, text(fill: my-bright, body-right))
+    )
+  }
+
   (
     title-slide: title-slide,
-    variants: ( "default": west, "east": east ),
+    variants: ( "default": west, "east": east, "center split": center-split ),
   )
 }