Could a `stroke` argument be added to `element_geom` to control the outer line around filled points?

[davidhodge931]

Currently, it is controlled by borderwidth in element_geom, but often one might want a different size for this compared to the lines around polygons. Thanks for consideration!

[teunbrand]

You can already control the borderwidth of specific geoms like geom_point() separately from other geoms.

library(ggplot2)

df <- data.frame(x = 1:3, y = c(1, 3, 1))

ggplot(df, aes(x, y)) +
  geom_polygon(fill = "white", colour = "black") +
  geom_point(shape = 21, size = 5, fill = "white") +
  theme(
    geom = element_geom(borderwidth = 1),
    geom.point = element_geom(borderwidth = 5)
  )

^{Created on 2025-12-02 with reprex v2.1.1}

[davidhodge931]

Perhaps what I really mean is that is it's a bit confusing as because within the geom_point, you use the stroke argument to control this rather than the borderwidth argument

[davidhodge931]

library(ggplot2)

df <- data.frame(x = 1:3, y = c(1, 3, 1))

#this works
ggplot(df, aes(x, y)) +
  geom_point(shape = 21, size = 5, fill = "white", stroke = 3)

#this does not work
ggplot(df, aes(x, y)) +
  geom_point(shape = 21, size = 5, fill = "white", borderwidth = 3)

#so this is much more intuitive
ggplot(df, aes(x, y)) +
  geom_point(shape = 21, size = 5, fill = "white") +
  theme(geom = element_geom(stroke = 3))

#than this
ggplot(df, aes(x, y)) +
  geom_point(shape = 21, size = 5, fill = "white") +
  theme(geom.point = element_geom(borderwidth = 3))

[teunbrand]

Yes, but element_geom() has role-based rather than property-based arguments as I believe we indicated before.
Due to historical reasons, the stroke aesthetic is the linewidth aesthetic for geom_point().
I agree this can be confusing and we could think about superseding the stroke aesthetic.

[davidhodge931]

Consistencty would be great, if it can be made to work.

Want me to add a issue for whether the stroke aesthetic be superceded, and replaced with the linewidth aesthetic?

[davidhodge931]

Before I close, should this work?

ggplot(df, aes(x, y)) +
  geom_point(shape = 21, size = 5, fill = "white") +
  theme(geom = element_geom(borderwidth = 3))

[teunbrand]

should this work?

Yes the borderwidth setting should affect the point.

[davidhodge931]

Oh yep, my bad. That does work.

Still think it'd be nicer if you could do

set_theme(
  theme_grey() +
  theme(geom = element_geom(borderwidth = 0.25, stroke = 0.5))
)

Rather than...

set_theme(
  theme_grey() +
  theme(geom = element_geom(borderwidth = 0.25)) +
  theme(geom.point = element_geom(borderwidth = 0.5)
)

I'll close, but reopen if you want to do anything with this