fixed new participants not detected in syncs

fixes #20

src/core/renderer.typ

@@ -2,6 +2,7 @@
 
 #import "draw/note.typ": get-box as get-note-box, get-size as get-note-size
 #import "draw/participant.typ"
+#import "draw/sync.typ": in-sync-render
 #import "utils.typ": *
 #import "/src/consts.typ": *
 
@@ -15,22 +16,6 @@
   })
 }
 
-#let unwrap-syncs(elements) = {
-  let i = 0
-  while i < elements.len() {
-    let elmt = elements.at(i)
-    if elmt.type == "sync" {
-      elements = (
-        elements.slice(0, i + 1) +
-        elmt.elmts +
-        elements.slice(i + 1)
-      )
-    }
-    i += 1
-  }
-  return elements
-}
-
 #let seq-update-lifelines(participants, pars-i, seq) = {
   let participants = participants
   let com = if seq.comment == none {""} else {seq.comment}
@@ -308,7 +293,6 @@
 
 #let compute-columns-width(participants, elements, pars-i) = {
   elements = elements.filter(is-elmt)
-  elements = unwrap-syncs(elements)
 
   let cells
   (participants, elements, cells) = compute-max-lifeline-levels(participants, elements, pars-i)
@@ -334,7 +318,8 @@
     lifelines: participants.map(_ => (
       level: 0,
       lines: ()
-    ))
+    )),
+    in-sync: false
   )
   chronos-ctx.insert(
     "widths",
@@ -393,7 +378,13 @@
     if not is-elmt(elmt) {
       (elmt,)
     } else if "draw" in elmt and elmt.type != "par" {
-      (elmt.draw)(elmt)
+      get-ctx(ctx => {
+        if ctx.in-sync and elmt.type != "sync-end" {
+          in-sync-render(elmt)
+        } else {
+          (elmt.draw)(elmt)
+        }
+      })
     }
   }