These generic functions are used to determine the size of grid grobs.
widthDetails(x)
heightDetails(x)
ascentDetails(x)
descentDetails(x)A grid grob.
A unit object.
These functions are called in the calculation of
"grobwidth" and "grobheight" units.
Methods should be written for classes derived from grob or gTree
where the size of the grob can be determined (see, for example
grid:::widthDetails.frame).
The ascent of a grob is the height of the grob by default and the descent of a grob is zero by default, except for text grobs where the label is a single character value or expression.