Querying the Viewport Tree {grid} | R Documentation |
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.
current.viewport() current.parent(n=1) current.vpTree(all=TRUE) current.vpPath() current.transform()
n |
The number of generations to go up. |
all |
A logical value indicating whether the entire viewport tree should be returned. |
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.
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
Paul Murrell
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)