Produces graphical output from a graphical object.
An object of class "grob" or NULL.
A logical value to indicate whether the drawing
operation should be recorded on the Grid display list.
This is a generic function with methods for grob and gTree objects.
The grob and gTree methods automatically push any viewports in a
vp slot and automatically apply any gpar settings
in a gp slot. In addition, the gTree method pushes and
ups any viewports in a childrenvp slot and automatically
calls grid.draw for any grobs in a children slot.
The methods for grob and gTree call the generic hook functions
preDrawDetails, drawDetails, and postDrawDetails
to allow classes derived from grob or gTree to perform
additional viewport pushing/popping and produce additional
output beyond the default behaviour for grobs and gTrees.