legend titles need more padding

[baptiste]

Not sure if it's a recent change (I'm using the dev version fresh from github), but with a large enough font the legend title collides with the legend and I can't find any setting to move it.

MRE

set.seed(123)
dummy <- data.frame(x=runif(10), y=runif(10), f = gl(2,5))
ggplot(dummy, aes(x,y, shape=f)) + 
  geom_point() +
  labs(shape="guide") +
  theme_grey(24)

With the default font size things are OK, albeit snug

With a larger font size (graphic aimed for slides), however,

I tried,

legend.margin = margin(100,100,100,100)
legend.spacing.y = unit(1,"cm")
legend.title = element_text(vjust = 2)

also played with guide_legend etc. to no avail.

[baptiste]

the relevant part seems to be in guide-legend.r

First, the text height is not accurately measured,

g <- ggplot2:::element_grob(
  element_text(angle = 0),
  label = "guide",
  hjust =  0.5,
  vjust =  0.5,
  expand_x = FALSE,
  expand_y = FALSE
)

grid.newpage()
grid.draw(g)
grid.rect(height=unit(ggplot2:::height_cm(g), "cm"),gp=gpar(fill=NA))

(it seems to be a limitation in grid, descenders aren't included for some reason). Not much to do about it. In passing height_cm should probably use grobHeight, not grobWidth.

And second there isn't any setting to change the margin, vgap is hard-coded to 0.3 lines

[baptiste]

oh, and I just had a quick look at guide-colorbar.r, it's the same problem, but the corresponding lines of code are slightly different, probably written by someone else.