Support saving objects from grDevices::recordPlot()

[ppoyk]

Add support for saving plot objects created by the recordPlot function from the base-R-bundled grDevices package. The dedicated function replayPlot is used in a new grid.draw method to display a recordedplot in a device.

This enables ggsave to be used more flexibly with base R code.

[teunbrand]

Hi there, thanks for the PR!
Just for clarification because there is no associated issue: what is the problem that this PR aims to solve?
From your description it seems you want ggsave() to work with base R plots, is that correct?
Can you give an example how this would be used?

[thomasp85]

Thanks for this contribution. However, it is not the objective of ggsave() to be used for anything other than saving ggplots and as such we are not going to merge it

[ppoyk]

That's unfortunate.

As ggsave is very user-friendly and intuitive function to use, it is ubiquitous for saving plots.
It would be handy to be able to save all major plot types (grid|base R) with just one function.

For posterity:
You can add the capability for ggsave() to save plot objects from recordPlot(). Globally define a new S3 method for grid.draw(), which is used internally by ggsave().

grid.draw.recordedplot <- function(x) { replayPlot(x) }

The class produced by recordPlot() is "recordedplot".