added delay function

src/renderer.typ

@@ -322,6 +322,26 @@
     // Gap
     } else if elmt.type == "gap" {
       y -= elmt.size
+
+    // Delay
+    } else if elmt.type == "delay" {
+      let y0 = y
+      let y1 = y - elmt.size
+      for (i, line) in lifelines.enumerate() {
+        line.lines.push(("delay-start", y0))
+        line.lines.push(("delay-end", y1))
+        lifelines.at(i) = line
+      }
+      if elmt.name != none {
+        let x0 = x-pos.first()
+        let x1 = x-pos.last()
+        shapes += draw.content(
+          ((x0 + x1) / 2, (y0 + y1) / 2),
+          anchor: "center",
+          elmt.name
+        )
+      }
+      y = y1
     
     // Event
     } else if elmt.type == "evt" {
@@ -435,6 +455,28 @@
           if event == "destroy" {
             destructions.push((x + lvl * LIFELINE-W / 2, line.at(1)))
           }
+        } else if event == "delay-start" {
+          draw.line(
+            (x, last-y),
+            (x, line.at(1)),
+            stroke: (
+              dash: "dashed",
+              paint: gray.darken(40%),
+              thickness: .5pt
+            )
+          )
+          last-y = line.at(1)
+        } else if event == "delay-end" {
+          draw.line(
+            (x, last-y),
+            (x, line.at(1)),
+            stroke: (
+              dash: "loosely-dotted",
+              paint: gray.darken(40%),
+              thickness: .8pt
+            )
+          )
+          last-y = line.at(1)
         }
       }