R: Search for grobs

grid.grep {grid}

R Documentation

Search for grobs

Description

Given a gPath, find all matching grobs on the display list or within a given grob.

Usage

grid.grep(path, x = NULL, grobs = TRUE, viewports = FALSE,
          strict = FALSE, grep = FALSE, global = FALSE,
          no.match = character())

Arguments

`path`	a gPath.
`x`	a grob or `NULL`. If `NULL`, the display list is searched.
`grobs`	A logical value indicating whether to search for grobs.
`viewports`	A logical value indicating whether to search for viewports.
`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.
`no.match`	The value to return if no matches are found.

Value

Either a gPath or, if global is TRUE a list of gPaths. If there are no matches, no.match is returned.

Examples

# A gTree, called "grandparent", with child gTree,
# called "parent", with childrenvp vpStack (vp2 within vp1)
# and child grob, called "child", with vp vpPath (down to vp2)
sampleGTree <- gTree(name="grandparent",
                     children=gList(gTree(name="parent",
                          children=gList(grob(name="child", vp="vp1::vp2")),
                          childrenvp=vpStack(viewport(name="vp1"),
                                             viewport(name="vp2")))))
# Searching for grobs
grid.grep("parent", sampleGTree)
grid.grep("parent", sampleGTree, strict=TRUE)
grid.grep("grandparent", sampleGTree, strict=TRUE)
grid.grep("grandparent::parent", sampleGTree)
grid.grep("parent::child", sampleGTree)
grid.grep("[a-z]", sampleGTree, grep=TRUE)
grid.grep("[a-z]", sampleGTree, grep=TRUE, global=TRUE)
# Searching for viewports
grid.grep("vp1", sampleGTree, viewports=TRUE)
grid.grep("vp2", sampleGTree, viewports=TRUE)
grid.grep("vp", sampleGTree, viewports=TRUE, grep=TRUE)
grid.grep("vp2", sampleGTree, viewports=TRUE, strict=TRUE)
grid.grep("vp1::vp2", sampleGTree, viewports=TRUE)
# Searching for both
grid.grep("[a-z]", sampleGTree, viewports=TRUE, grep=TRUE, global=TRUE)