focus.R

library(tibble)
tibble:::set_fansi_hooks()

x <- tibble(a = tibble(x = 1, y = 2), b = "long enough")

# Side effect: queries color information internally in pillar
x

## # A tibble: 1 × 2
##     a$x    $y b          
##   <dbl> <dbl> <chr>      
## 1     1     2 long enough

pillar::tbl_format_setup(x, width = 20)

## <pillar_tbl_format_setup>
## <tbl_format_header(setup)>
## # A tibble: 1 × 2
## <tbl_format_body(setup)>
##     a$x    $y b     
##   <dbl> <dbl> <chr> 
## 1     1     2 long …
## <tbl_format_footer(setup)>

pillar::tbl_format_setup(x, width = 20, focus = "b")

## <pillar_tbl_format_setup>
## <tbl_format_header(setup)>
## # A tibble: 1 × 2
## <tbl_format_body(setup)>
##     a$x b          
##   <dbl> <chr>      
## 1     1 long enough
## <tbl_format_footer(setup)>
## # … with 1 more
## #   variable:
## #   a$y <dbl>

pillar::tbl_format_setup(x[2:1], width = 20, focus = "a")

## <pillar_tbl_format_setup>
## <tbl_format_header(setup)>
## # A tibble: 1 × 2
## <tbl_format_body(setup)>
##   b        a$x    $y
##   <chr>  <dbl> <dbl>
## 1 long …     1     2
## <tbl_format_footer(setup)>