grid.grob
Create Grid Graphical Objects, aka "Grob"s
Description
Creating grid graphical objects, short (“grob”s).
grob()
and gTree()
are the basic creators, grobTree()
and gList()
take several grobs to build a new one.
Usage
## Grob Creation: grob (..., name = NULL, gp = NULL, vp = NULL, cl = NULL) gTree(..., name = NULL, gp = NULL, vp = NULL, children = NULL, childrenvp = NULL, cl = NULL) grobTree(..., name = NULL, gp = NULL, vp = NULL, childrenvp = NULL, cl = NULL) gList(...) ## Grob Properties: childNames(gTree) is.grob(x)
Arguments
... | For |
name | a character identifier for the grob. Used to find the grob on the display list and/or as a child of another grob. |
children | a |
childrenvp | a |
gp | A |
vp | a |
cl | string giving the class attribute for the new class. |
gTree | a |
x | An R object. |
Details
These functions can be used to create a basic "grob"
, "gTree"
, or "gList"
object, or a new class derived from one of these.
A grid graphical object (“grob”) is a description of a graphical item. These basic classes provide default behaviour for validating, drawing, and modifying graphical objects. Both grob()
and gTree()
call the function validDetails
to check that the object returned is internally coherent.
A "gTree"
can have other grobs as children; when a gTree is drawn, it draws all of its children. Before drawing its children, a gTree pushes its childrenvp
slot and then navigates back up (calls upViewport
) so that the children can specify their location within the childrenvp
via a vpPath
.
Grob names need not be unique in general, but all children of a gTree must have different names. A grob name can be any string, though it is not advisable to use the gPath
separator (currently ::
) in grob names.
The function childNames
returns the names of the grobs which are children of a gTree.
All grid primitives (grid.lines
, grid.rect
, ...) and some higher-level grid components (e.g., grid.xaxis
and grid.yaxis
) are derived from these classes.
grobTree
is just a convenient wrapper for gTree
when the only components of the gTree are grobs (so all unnamed arguments become children of the gTree).
The grid.grob
function is defunct.
Value
An R object of class "grob"
, a graphical object.
Author(s)
Paul Murrell
See Also
grid.draw
, grid.edit
, grid.get
.
Copyright (©) 1999–2012 R Foundation for Statistical Computing.
Licensed under the GNU General Public License.