Place Annotation at Center of Plot with ggplot2

Question

I\'d like to place an annotation at the center of a several ggplot objects.

I\'ve researched and found a few similar questions such as here: Relative positioning of

Answer 1

library(grid) # for textGrob

qplot(1,1) +
    annotation_custom(grid::textGrob("there"), 
                      xmin = -Inf, xmax = Inf, ymin = -Inf, ymax = Inf)