Create a grob with text inside. To extract the units describing
grob boundary location can be accessed with grobX and
grobY. The units describing width and height can be accessed with
grobWidth and grobHeight.
The justification of the text, `"left"`, `"right` and `"center"`.
See textGrob for more details.
txt_gp
An object of class gpar style to be applied to the
text. This will also be read from global options of "txt_gp". For
example, if one wants to set a font size for all the text inside box,
options(txt_gp = gpar(cex = 0.8)) will do the trick.
box_fn
Function to create box for the text. Parameters of `x=0.5`,
`y=0.5` and `box_gp` will be passed to this function and return a grob
object. This will also be read from global options of "box_gp".
box_gp
An object of class gpar style to be applied to the
box.