RStudio 1.4 support?

[cpsievert]

Just FYI, RStudio 1.4 comes with the capability of customizing the graphics backend. Perhaps showtext could leverage that new ability to render fonts in the RStudio graphics device?

[yixuan]

Thanks for sharing the news. This looks like an interesting update. I'll try the new RStudio when it is released.

[cpsievert]

Sounds good, thanks for considering. In case you didn't know, RStudio 1. 4 is currently available in the daily builds https://dailies.rstudio.com/

[yixuan]

Good to know that. I'll have a try when I get some time for this.

[yixuan]

Tracing back to rstudio/rstudio#2142, I accidentally found a workaround for the issue with RStudio 1.3 or earlier. Basically you just need to run the following code at the beginning of each R session:

trace(grDevices::png, exit = quote({
    showtext::showtext_begin()
}), print = FALSE)

And then run any showtext code in RStudio:

library(showtext)
font_add_google("Lobster", "lobster")
showtext_auto()

plot(1, pch = 16, cex = 3)
text(1, 1.1, "A fancy dot", family = "lobster", col = "steelblue", cex = 3)

Can you test if it works for you?

[cpsievert]

Nice, can confirm this works on RStudio Preview (1.3.952). I did notice, though, that exporting to pdf via the export dropdown doesn't appear to work

[yixuan]

Then you just need to add another tracer:

trace(grDevices::pdf, exit = quote({
    showtext::showtext_begin()
}), print = FALSE)

[cpsievert]

Interestingly it appears that if the RStudioGD is already open, this trace() workaround doesn't work, for example, if you first plot

plot(1)

then trace()

trace(grDevices::png, exit = quote({
    showtext::showtext_begin()
}), print = FALSE)

This no longer works

library(showtext)
font_add_google("Lobster", "lobster")
showtext_auto()

plot(1, pch = 16, cex = 3)
text(1, 1.1, "A fancy dot", family = "lobster", col = "steelblue", cex = 3)

[yixuan]

The thing is, RStudio will open a new PNG device after it plots, so the device might be already open before trace() is called. You can first create a fake plot to force RStudio open a new device:

plot(1)
trace(grDevices::png, exit = quote({
    showtext::showtext_begin()
}), print = FALSE)
# Force the new device to apply tracer
plot.new()

library(showtext)
font_add_google("Lobster", "lobster")
showtext_auto()

plot(1, pch = 16, cex = 3)
text(1, 1.1, "A fancy dot", family = "lobster", col = "steelblue", cex = 3)

[cpsievert]

Oh, I see, so RStudio must close and open a new device on every plot.new or grid.newpage? Is that your understanding of it?

[yixuan]

This is my guess, but may be wrong. RStudioGD seems to have some sophisticated operations at the backend. 🤔

Something that may be useful for checking is to set print = TRUE in trace():

trace(grDevices::png, exit = quote({
    cat("device opened\n")
}), print = TRUE)

plot(1)
plot(1)

In one of my sessions, the result is

> plot(1)
Tracing grDevices:::png("/tmp/RtmpmX3pAy/b64514f1d9c54eacb9e9152db63e5b4c.png",  .... on exit 
device opened
Tracing grDevices:::png("/tmp/RtmpmX3pAy/b64514f1d9c54eacb9e9152db63e5b4c.png",  .... on exit 
device opened
> plot(1)
Tracing grDevices:::png("/tmp/RtmpmX3pAy/72a6cf6868774d568d7abc6dececba9d.png",  .... on exit 
device opened

I check the last PNG file and it is 0 byte, so it should be used for future plots.

[yixuan]

As the new version is already on CRAN, I guess we can close this issue first.