grid (version 3.3.2)

grid.force: Force a grob into its components

Description

Some grobs only generate their content to draw at drawing time; this function replaces such grobs with their at-drawing-time content.

Usage

grid.force(x, ...)
# S3 method for default
grid.force(x, redraw = FALSE, ...)
# S3 method for gPath
grid.force(x, strict = FALSE, grep = FALSE, global = FALSE,
                           redraw = FALSE, ...) 
# S3 method for grob
grid.force(x, draw = FALSE, ...)
forceGrob(x)
grid.revert(x, ...)
# S3 method for gPath
grid.revert(x, strict = FALSE, grep = FALSE, global = FALSE,
                            redraw = FALSE, ...) 
# S3 method for grob
grid.revert(x, draw = FALSE, ...)

Arguments

x

For the default method, x should not be specified. Otherwise, x should be a grob or a gPath. If x is character, it is assumed to be a gPath.

strict

A boolean indicating whether the path must be matched exactly.

grep

Whether the path should be treated as a regular expression.

global

A boolean indicating whether the function should affect just the first match of the path, or whether all matches should be affected.

draw

logical value indicating whether a grob should be drawn after it is forced.

redraw

logical value indicating whether to redraw the grid scene after the forcing operation.

…

Further arguments for use by methods.

Warning

Forcing an explicit grob produces a result as if the grob were drawn in the current drawing context. It may not make sense to draw the result in a different drawing context.

Details

Some grobs wait until drawing time to generate what content will actually be drawn (an axis, as produced by grid.xaxis(), with an at or NULL is a good example because it has to see what viewport it is going to be drawn in before it can decide what tick marks to draw). The content of such grobs (e.g., the tick marks) are not usually visible to grid.ls() or accessible to grid.edit(). The grid.force() function replaces a grob with its at-drawing-time contents. For example, an axis will be replaced by a vanilla gTree with lines and text representing the axis tick marks that were actually drawn. This makes the tick marks visible to grid.ls() and accessible to grid.edit(). The forceGrob() function is the internal work horse for grid.force(), so will not normally be called directly by the user. It is exported so that methods can be written for custom grob classes if necessary. The grid.revert() function reverses the effect of grid.force(), replacing forced content with the original grob.

Examples

grid.newpage()
pushViewport(viewport(width=.5, height=.5))
# Draw xaxis
grid.xaxis(name="xax")
grid.ls()
# Force xaxis
grid.force()
grid.ls()
# Revert xaxis
grid.revert()
grid.ls()
# Draw and force yaxis
grid.force(yaxisGrob(), draw=TRUE)
grid.ls()
# Revert yaxis
grid.revert()
grid.ls()
# Force JUST xaxis
grid.force("xax")
grid.ls()
# Force ALL
grid.force()
grid.ls()
# Revert JUST xaxis
grid.revert("xax")
grid.ls()