| % File src/library/grid/man/grid.DLapply.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2013 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{grid.DLapply} |
| \alias{grid.DLapply} |
| \title{ Modify the Grid Display List } |
| \description{ |
| Call a function on each element of the current display list. |
| } |
| \usage{ |
| grid.DLapply(FUN, ...) |
| } |
| \arguments{ |
| \item{FUN}{A function; the first argument to this function |
| is passed each element of the display list. |
| } |
| \item{\dots}{Further arguments to pass to \code{FUN} .} |
| } |
| \value{ |
| The side effect of these functions |
| is usually to modify the grid display list. |
| } |
| \details{ |
| This function is insanely dangerous (for the grid display list). |
| |
| Two token efforts are made to try to avoid ending up with complete |
| garbage on the display list: |
| |
| \enumerate{ |
| \item The display list is only replaced once all new elements have |
| been generated (so an error during generation does not result in a |
| half-finished display list). |
| \item All new elements must be either \code{NULL} or inherit from |
| the class of the element that they are replacing. |
| } |
| } |
| \seealso{ |
| \link{Grid}. |
| } |
| \examples{ |
| grid.newpage() |
| grid.rect(width=.4, height=.4, x=.25, y=.75, gp=gpar(fill="black"), name="r1") |
| grid.rect(width=.4, height=.4, x=.5, y=.5, gp=gpar(fill="grey"), name="r2") |
| grid.rect(width=.4, height=.4, x=.75, y=.25, gp=gpar(fill="white"), name="r3") |
| grid.DLapply(function(x) { if (is.grob(x)) x$gp <- gpar(); x }) |
| grid.refresh() |
| } |
| \keyword{dplot} |