Explain why a node has its resolved size

Reports the resolved width and height of a named viewport (or grob) and what determined them — the layout track it was placed in, or the units of its own width/height. The layout companion to the visual render(scene, debug = TRUE) overlay; together they make coordinate debugging first-class rather than an exercise in archaeology.

Usage

why_size(scene, name)

Arguments

scene: A vl_scene() (or anything with an as_vellum_scene() method).
name: A node name (set via the name argument of a viewport/grob).

Value

A vellum_why_size record (a list with name, width_mm, height_mm, and determined_by), printed legibly.

Examples

s <- vl_scene(4, 3) |>
  push(vl_viewport(name = "panel", width = vl_unit(2, "in"), height = vl_unit(1, "in")))
why_size(s, "panel")
#> $name
#> [1] "panel"
#> 
#> $width_mm
#> [1] 50.8
#> 
#> $height_mm
#> [1] 25.4
#> 
#> $determined_by
#> [1] "placed by size: width = 2in, height = 1in"
#> 
#> attr(,"class")
#> [1] "vellum_why_size"