complex_layout: Complex Layout for a gridify object

In gridify: Enrich Figures and Tables with Custom Headers and Footers and More

Complex Layout for a gridify object

Description

This function creates a complex layout for a gridify object. The layout consists of six rows and three columns for headers, titles, notes and footnotes around the output.

Usage

complex_layout(
  margin = grid::unit(c(t = 0.1, r = 0.1, b = 0.1, l = 0.1), units = "npc"),
  global_gpar = grid::gpar(),
  background = grid::get.gpar()$fill,
  scales = c("fixed", "free")
)

Arguments

margin	A unit object specifying the margins around the output. Default is 10% of the output area on all sides.
global_gpar	A gpar object specifying the global graphical parameters. Must be the result of a call to grid::gpar().
background	A string specifying the background fill colour. Default grid::get.gpar()$fill for a white background.
scales	A string, either "free" or "fixed". By default, "fixed" ensures that text elements (titles, footers, etc.) retain a static height, preventing text overlap while maintaining a structured layout. However, this may result in different height proportions between the text elements and the output. The "free" option makes the row heights proportional, allowing them to scale dynamically based on the overall output size. This ensures that the text elements and the output maintain relative proportions.

Details

The layout consists of six rows for headers, titles, object (figure or table), notes, and footnotes. The object is placed in the fourth row.

• With "free" scales, the row heights are 5%, 5%, 5%, 70%, 5%, and 10% of the area, respectively.

• With "fixed" scales, the row heights are adjusted by the number of lines for all text elements around the object, with the remaining area occupied by the object. Note that reducing the output space will retain the space for all text elements, making the object appear smaller.

Value

A gridifyLayout object.

Note

The Font Issue Information:

Changes to the fontfamily may be ignored by some devices, but is supported by PostScript, PDF, X11, Windows, and Quartz. The fontfamily may be used to specify one of the Hershey Font families (e.g., HersheySerif, serif), and this specification will be honoured on all devices.

If you encounter this warning, you can register the fonts using the extrafont package:

library(extrafont)
font_import()
loadfonts(device = 'all')

If you still see the warning while using RStudio, try changing the graphics backend.

Negative Dimensions Issues:

grobs from the grid package and ggplot2 objects (when converted to grobs by gridify) may appear distorted in the output if there is insufficient space in the window, caused by negative dimensions. This should be resolved. However, if this is affecting your layout, please increase your window size or only use static heights/widths for custom layouts.

The negative dimensions are caused by the way grid handles null and npc heights/widths so if some dimensions are static, then the npc or null values may cause unexpected behaviour when the window size is too small. It was resolved by setting a minimum size of the object in the gridify object to 1 inch for each dimension.

The following example demonstrates this behaviour Try resizing your window:

library(grid)
library(ggplot2)
grid.newpage()
object <- ggplot2::ggplotGrob(ggplot(mtcars, aes(mpg, wt)) + geom_line())
grid::grid.draw(
  grid::grobTree(
    grid::grobTree(
      grid::editGrob(
        object,
        vp = grid::viewport(
          # height = grid::unit.pmax(grid::unit(1, "npc"), grid::unit(1, "inch")),
          # width = grid::unit.pmax(grid::unit(1, "npc"), grid::unit(1, "inch"))
        )
      ),
      vp = grid::viewport(
        layout.pos.row = 2,
        layout.pos.col = 1:3
      )
    ),
    vp = grid::viewport(
      layout = grid::grid.layout(
        nrow = 3,
        ncol = 3,
        heights = grid::unit(c(9, 1, 9), c("cm", "null", "cm"))
      )
    )
  )
)

gt Font Size Issue:

When specifying font sizes, the gt package interprets values as having the unit pixels (px), whilst the grid package, on which gridify is built, assumes points (pt). As a result, even if you set the font sizes in both gt and gridify (using grid::gpar()) to the same number, they may still appear different. To convert point size to pixel size, multiply the point size by 96 / 72.

Examples

complex_layout()

# (to use |> version 4.1.0 of R is required, for lower versions we recommend %>% from magrittr)
library(magrittr)

gridify(
  object = ggplot2::ggplot(data = mtcars, ggplot2::aes(x = mpg, y = wt)) +
    ggplot2::geom_line(),
  layout = complex_layout()
) %>%
  set_cell("header_left", "Left Header") %>%
  set_cell("header_middle", "Middle Header") %>%
  set_cell("header_right", "Right Header") %>%
  set_cell("title", "Title") %>%
  set_cell("subtitle", "Subtitle") %>%
  set_cell("note", "Note") %>%
  set_cell("footer_left", "Left Footer") %>%
  set_cell("footer_middle", "Middle Footer") %>%
  set_cell("footer_right", "Right Footer")

gridify(
  object = ggplot2::ggplot(data = mtcars, ggplot2::aes(x = mpg, y = wt)) +
    ggplot2::geom_line(),
  layout = complex_layout(margin = grid::unit(c(t = 0.2, r = 0.2, b = 0.2, l = 0.2), units = "npc"))
) %>%
  set_cell("header_left", "Left Header") %>%
  set_cell("header_right", "Right Header") %>%
  set_cell("title", "Title") %>%
  set_cell("note", "Note") %>%
  set_cell("footer_left", "Left Footer")

gridify(
  object = gt::gt(head(mtcars)),
  layout = complex_layout(
    margin = grid::unit(c(t = 0.2, r = 0.2, b = 0.2, l = 0.2), units = "npc"),
    global_gpar = grid::gpar(col = "blue", fontsize = 18)
  )
) %>%
  set_cell("header_left", "Left Header") %>%
  set_cell("header_right", "Right Header") %>%
  set_cell("title", "Title") %>%
  set_cell("note", "Note") %>%
  set_cell("footer_left", "Left Footer")

gridify documentation built on Feb. 5, 2026, 5:09 p.m.