| % File src/library/grid/man/current.viewport.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2013 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{Querying the Viewport Tree} |
| \alias{current.viewport} |
| \alias{current.parent} |
| \alias{current.vpTree} |
| \alias{current.vpPath} |
| \alias{current.transform} |
| \alias{current.rotation} |
| \title{Get the Current Grid Viewport (Tree)} |
| \description{ |
| \code{current.viewport()} |
| returns the viewport that Grid is going to draw into. |
| |
| \code{current.parent} returns the parent of the current viewport. |
| |
| \code{current.vpTree} returns the entire Grid viewport tree. |
| |
| \code{current.vpPath} returns the viewport path to the current viewport. |
| |
| \code{current.transform} returns the transformation |
| matrix for the current viewport. |
| |
| \code{current.rotation} returns the (total) rotation |
| for the current viewport. |
| } |
| \usage{ |
| current.viewport() |
| current.parent(n=1) |
| current.vpTree(all=TRUE) |
| current.vpPath() |
| current.transform() |
| } |
| \arguments{ |
| \item{n}{ The number of generations to go up.} |
| \item{all}{A logical value indicating whether the entire viewport |
| tree should be returned.} |
| } |
| \details{ |
| It is possible to get the grandparent of the current viewport |
| (or higher) using the \code{n} argument to \code{current.parent()}. |
| |
| The parent of the ROOT viewport is \code{NULL}. |
| It is an error to request the grandparent of the ROOT viewport. |
| |
| If \code{all} is \code{FALSE} then |
| \code{current.vpTree} only returns the subtree below |
| the current viewport. |
| } |
| \value{ |
| A Grid viewport object from \code{current.viewport} or |
| \code{current.vpTree}. |
| |
| \code{current.transform} returns a 4x4 transformation matrix. |
| |
| The viewport path returned by \code{current.vpPath} is \code{NULL} |
| if the current viewport is the \code{ROOT} viewport |
| } |
| \author{Paul Murrell} |
| \seealso{ |
| \code{\link{viewport}} |
| } |
| \examples{ |
| grid.newpage() |
| pushViewport(viewport(width=0.8, height=0.8, name="A")) |
| pushViewport(viewport(x=0.1, width=0.3, height=0.6, |
| just="left", name="B")) |
| upViewport(1) |
| pushViewport(viewport(x=0.5, width=0.4, height=0.8, |
| just="left", name="C")) |
| pushViewport(viewport(width=0.8, height=0.8, name="D")) |
| current.vpPath() |
| upViewport(1) |
| current.vpPath() |
| current.vpTree() |
| current.viewport() |
| current.vpTree(all=FALSE) |
| popViewport(0) |
| } |
| \keyword{dplot} |