| Querying the Viewport Tree {grid} | R Documentation |
Get the Current Grid Viewport (Tree)
Description
current.viewport()
returns the viewport that Grid is going to draw into.
current.parent returns the parent of the current viewport.
current.vpTree returns the entire Grid viewport tree.
current.vpPath returns the viewport path to the current viewport.
current.transform returns the transformation
matrix for the current viewport.
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()
current.rotation()
Arguments
n |
The number of generations to go up. |
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 n argument to current.parent().
The parent of the ROOT viewport is NULL.
It is an error to request the grandparent of the ROOT viewport.
If all is FALSE then
current.vpTree only returns the subtree below
the current viewport.
Value
A Grid viewport object from current.viewport or
current.vpTree.
current.transform returns a 4x4 transformation matrix.
The viewport path returned by current.vpPath is NULL
if the current viewport is the ROOT viewport
Author(s)
Paul Murrell
See Also
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)