R/layout_issues.R

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

#' Template for Layout Issues Note
#'
#' @note
#'
#' \strong{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:
#'
#' ```r
#' library(extrafont)
#' font_import()
#' loadfonts(device = 'all')
#' ```
#'
#' If you still see the warning while using RStudio, try changing the graphics backend.
#'
#' \strong{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:
#'
#' \preformatted{
#' 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"))
#'       )
#'     )
#'   )
#' )
#' }
#'
#' \strong{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`.
#'
#' @name layout_issue
NULL